Colorectal cancer is the third most common cancer in terms of incidence rate in adults and the second most common cause of cancer-related death in Europe. Despite an increase in overall survival throughout the years, the prognosis of metastatic colorectal cancer remains poor. Until recently, its treatment was based on the use of standard chemotherapy combined with, anti-epidermal growth factor receptor (for RAS wild-type tumors) or anti-vascular endothelial growth factor, or immunotherapy for tumors with mismatch repair deficiency. Over the last years, precision medicine has become a challenge in oncology and there has been an increasing development of biomarker-driven therapies for metastatic colorectal cancer leading to better outcomes for specific molecular subgroups of patients. Human epidermal growth factor receptor 2 (HER2) amplification/overexpression has been identified in about 6 % of patients with RAS wild-type metastatic CRC and established as an important and drugable biomarker. Its prognostic and predictive implications are still debated but HER2 becoming a therapeutic target with promising results of anti-HER2 therapies for HER2-positive metastatic CRC. Multiple HER2-targeted regimens are now part of National Comprehensive Cancer Network and European Society for Medical Oncology guidelines with two recent Food and Drug Administration approvals for previously treated HER2-positive metastatic colorectal cancer for tucatinib (in combination with trastuzumab) and for trastuzumab-deruxtecan in patients with previously treated HER2-positive metastatic colorectal cancer. This review explores the prognostic and predictive value of HER2 as a biomarker in CRC, describing its molecular structure, the clinical characteristics of patients with HER2 alterations, diagnostic approaches and the most relevant clinical trials assessing its current and future role as a therapeutic target in metastatic colorectal cancer.

In recent years the treatment options for metastatic colorectal cancer have significantly improved. This progress has particularly benefited specific subgroups of patients identified by certain biomarkers, such as those with a microsatellite instability, patients with B‑Raf (BRAF) V600E mutation, Kirsten rat sarcoma (KRAS) G12C mutation or v‑erb-b2 erythroblastic leukemia viral oncogene homolog 2 (ERBB2) amplification. Additionally, targeted anti-epidermal growth factor (EGF) receptor therapy can be more effectively utilized through further patient selection. For patients who no longer respond to treatment, the new standard trifluridine/tipiracil in combination with bevacizumab has become established as the new third-line option. Furthermore, the selectively anti-angiogenic tyrosine kinase inhibitor fruquintinib has recently been approved as a last-line treatment. This article provides an overview of current standards and future developments in therapy.

Human epidermal growth factor receptor 2 (HER2; encoded by ERBB2) testing has been a cornerstone of patient selection for HER2-targeted therapies, principally in breast cancer but also in several other solid tumours. Since the introduction of HercepTest as the original companion diagnostic for trastuzumab, HER2 assessment methods have evolved substantially, incorporating various testing modalities, from western blots, immunohistochemistry and fluorescence in situ hybridization, to early chromogenic quantitative methods and, probably in the future, fully quantitative methods. The advent of highly effective HER2-targeted antibody-drug conjugates with clinical activity at low levels of HER2 expression, such as trastuzumab deruxtecan, has necessitated the re-evaluation of HER2 testing, particularly for HER2-low tumours. In this Review, we provide an in-depth overview of the evolution of HER2 testing, the current clinical guidelines for HER2 testing across various solid tumours, challenges associated with current testing methodologies and the emerging potential of quantitative techniques. We discuss the importance of accurately defining HER2-low expression for therapeutic decision-making and how newer diagnostic approaches, such as quantitative immunofluorescence and RNA-based assays, might address the limitations of traditional immunohistochemistry-based methods. As the use of HER2-targeted therapies continues to expand to a wider range of tumour types, ensuring the precision and accuracy of HER2 testing will be crucial for guiding treatment strategies and improving patient outcomes.

We have made steady gains in improving overall survival in patients with metastatic, unresectable, colon cancer in the last 5 to 10 years. The backbone of systemic treatment for most patients remains combination chemotherapy, but the field is becoming increasingly biomarker driven, with exciting new targeted therapies on the horizon. This review is organized in sections corresponding to currently relevant biomarkers in colon cancer and will summarize first-, second-, and third-line standard of care for metastatic, unresectable, colon cancer. The last section is intended to introduce the reader to promising agents and novel therapeutic strategies currently under investigation.

The FOxTROT trial has reported advantages of neoadjuvant chemotherapy (NAC) in locally advanced colon cancer (LACC). In this article, we present results of the embedded randomised phase II trial testing the addition of panitumumab to neoadjuvant FOLFOX compared with FOLFOX alone in RAS and BRAF-wild-type (wt) patients and with biomarker hyperselection.

Patients had operable, computed tomography-predicted stage T3-4, N0-2, M0 colon adenocarcinoma. KRAS-wt patients allocated to NAC could optionally be sub-randomised 1 : 1 to FOLFOX ± panitumumab during the preoperative phase. RAS/BRAF were tested by next-generation sequencing; and epiregulin (EREG)/amphiregulin (AREG) by RNAseq. The primary endpoint was time to recurrence (TTR) in RAS/BRAF-wt patients; secondary endpoints included safety, histological down-staging, disease-free survival (DFS), colon cancer-specific survival (CCSS), overall survival (OS) and impact of primary tumour location and EREG/AREG.

In total 269 KRAS-wt patients were enrolled into the embedded phase II trial. Extended RAS/BRAF data were available for 232 (83%) patients; 22/232 (9.5%) were RAS-mutant; 41/210 (20%) were BRAF-mutant. Median follow-up was 42 months. In 169 RAS/BRAF-wt patients, there was a trend towards reduced recurrences with FOLFOX plus panitumumab compared with FOLFOX (12% versus 21%, hazard ratio = 0.51, P = 0.09); significant improvements were seen for DFS, CCSS and OS. Within the hyperselected EREG/AREG-high group, there was significant reduction in recurrences with panitumumab. Panitumumab was not associated with increased pathological regression of the primary tumour (tumour regression grade 1-3 16% versus 22%, P = 0.27). FOLFOX plus panitumumab was associated with higher rates of grade 3 diarrhoea (8% versus 3%) and rash (22% versus 2%).

This exploratory analysis from a randomised phase II study shows a non-significant improvement in TTR from the addition of neoadjuvant panitumumab to perioperative FOLFOX in RAS/BRAF-wt LACC. Hyperselection with EREG/AREG status was associated with increased efficacy. A dedicated prospective trial within a biomarker-selected population is under development.

Although meta-analyses have demonstrated survival benefits associated with primary tumor resection in MBC, guidelines lack consensus on the survival benefit of postoperative radiation therapy (RT).

In this study, we included 1392 patients with de novo metastatic breast cancer (dnMBC) by integrating data from the SEER database (2010-2019) to systematically assess the efficacy of postoperative RT and develop a machine learning-driven prognostic tool. The primary endpoint was overall survival (OS).

Propensity score matching (PSM) results showed that postoperative RT significantly improved OS (HR = 0.573, 95 % CI = 0.475-0.693), but this survival gain showed great heterogeneity among different subgroups. It is found that patients with HR-/HER2-or HR+/HER2-subtypes gained significant OS benefit from (p < 0.001) postoperative RT, whereas patients with HER2+ subtype did not gain any survival benefit since the effect of targeted therapy overshadowed the postoperative RT. Further risk stratification by the random survival forest (RSF) model revealed that high-risk patients with T4/N3 stage, high tumor grade and poor response to chemotherapy had significantly prolonged OS after receiving RT (p < 0.001), while low-risk patients showed no additional benefit. The model had excellent predictive efficacy (training set C-index = 0.741, validation set C-index = 0.720) with key predictors including HER2 status, chemotherapy response and tumor grade. The research team developed an interactive web application (https://lee2287171854.shinyapps.io/RSFshiny/) based on this model, which can generate individualized survival risk scores in real-time to guide clinical decision-making.

This study is the first to propose a risk stratification strategy for postoperative RT in dnMBC, and innovatively integrates machine learning and clinical tools to provide a new paradigm for optimizing precision therapy.

ERBB2 overexpression/amplification in RAS/BRAF wild-type (WT) metastatic colorectal cancer (mCRC; human epidermal growth factor receptor 2 [HER2]-positive mCRC) appears to be associated with limited benefit from anti-EGFR antibodies and promising responses to dual-HER2 inhibition; however, comparative efficacy has not been investigated. We conducted a randomized phase II trial to evaluate efficacy and safety of dual-HER2 inhibition against standard-of-care anti-EGFR antibody-based therapy as second/third-line treatment in HER2-positive mCRC.

Patients with RAS/BRAF-WT mCRC after central confirmation of HER2 positivity (immunohistochemistry 3+ or 2+ and in situ hybridization amplified [HER2/CEP17 ratio >2.0]) were assigned (1:1) to either trastuzumab plus pertuzumab (TP; trastuzumab 6 mg/kg and pertuzumab 420 mg once every 3 weeks) or cetuximab plus irinotecan (CETIRI; cetuximab 500 mg/m2 and irinotecan 180 mg/m2 once every 2 weeks) until progression or unacceptable toxicity. Crossover to TP was allowed after progression on CETIRI. The primary end point was progression-free survival (PFS). Secondary end points included objective response rate (ORR), overall survival, safety, and HER2 gene copy number (GCN ≥20/<20) as a predictive factor.

Between October 2017 and March 2022, 54 participants were assigned to TP (n = 26) and CETIRI (n = 28). Median PFS did not vary significantly by treatment: 4.7 (95% CI, 1.9 to 7.6) and 3.7 (95% CI, 1.6 to 6.7) months in the TP and CETIRI groups, respectively. Efficacy of TP versus CETIRI differed significantly by HER2 GCN (median PFS, GCN ≥20 [9.9 v 2.9 months] and GCN <20 [3.0 v 4.2 months], respectively; P interaction = .003). On TP, ORR was 34.6% (57.1% with GCN ≥20 v 9.1% with GCN <20) with median GCN of 29.7 versus 13.2 for responders and nonresponders, respectively (P = .004). Grade ≥3 adverse events occurred in 23.1% and 46.1% of participants with TP and CETIRI, respectively.

TP appears to be a safe and effective cytotoxic chemotherapy-free option for patients with RAS/BRAF-WT, HER2-positive mCRC. Higher levels of HER2 amplification were associated with greater degree of clinical benefit from TP vis-à-vis CETIRI.

This study aimed to investigate the clinicomolecular profiles and the efficacy of human epidermal growth factor receptor 2 (HER2)-targeted therapy in HER2-amplified biliary tract cancer (BTC).

This study was an international collaboration that used combined data from the prospective SCRUM-Japan GOZILA and MONSTAR-SCREEN in Japan and retrospective reviews in the United States; patients with advanced BTC who had received systemic therapy were included. The clinicomolecular profiles were evaluated in an exploratory cohort, whereas the efficacy of HER2-targeted therapy was assessed in a biomarker-selected cohort.

Of the 439 patients in the exploratory cohort, 43 (10%) had HER2 amplification. The frequencies of coalterations were higher in patients with HER2 amplification versus patients without HER2 amplification including HER2 mutations (26% v 5%, P < .001), TP53 mutations (84% v 61%, P = .003), and BRAF amplification (9% v 2%, P = .030). There were no KRAS mutations identified in patients with HER2-amplified BTC. No significant difference in overall survival (OS) was observed between patients with and without HER2 amplification (median, 17.7 v 16.9 months; hazard ratio [HR], 0.95 [95% CI, 0.65 to 1.40]). Of the 60 patients with HER2-amplified BTC in the biomarker-selected cohort (43 from Japan and 17 from the United States), the OS was significantly longer in 29 patients who received HER2-targeted therapy than in those who did not receive HER2-targeted therapy (median, 24.3 v 12.1 months; HR, 0.39 [95% CI, 0.23 to 0.82]). Multivariate analysis identified HER2-targeted therapy as an independent prognostic factor for OS (HR, 0.29 [95% CI, 0.14 to 0.58]; P < .001).

HER2 amplification was found in 10% of advanced BTC and was not identified as an independent prognostic factor for OS. Patients with HER2-amplified BTC derive significant benefit from HER2-targeted therapy.

Limited treatment options exist for patients with locally advanced or metastatic biliary tract cancers (BTCs). Recently, several clinical trials provided preliminary evidence for human epidermal growth factor receptor 2 (HER2) as a new target for patients with HER2-expressing BTC. We conducted a systematic review and pooled analysis of the safety and efficacy of anti-HER2 agents in patients with advanced BTCs.

A comprehensive search of PubMed/MEDLINE and EMBASE was performed to identify phase I, II, or III clinical trials published between January 2019 and March 2024 that evaluated anti-HER2 therapy in locally advanced or metastatic BTC. Participant data included in the analysis were from trials evaluating the efficacy and safety of various anti-HER2 agents. The primary end points included objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS). The secondary end points included incidence of treatment-related adverse events (TRAEs), rate of treatment discontinuation, and death.

The analysis included 368 patients from eight publications diagnosed with advanced BTC. Patients were treated with several anti-HER2 agents including zanidatamab, pertuzumab plus trastuzumab, tucatinib plus trastuzumab, trastuzumab deruxtecan, trastuzumab plus chemotherapy, trastuzumab-pkrb plus chemotherapy, and neratinib. The pooled ORR and DCR were 34% (95% CI, 24 to 44) and 64% (95% CI, 51 to 77), respectively. The pooled weighted PFS and median overall survival were 4.8 and 9.4 months, respectively. The pooled duration of response for the reporting trials was 5.0 months. In the study cohort, 82.6% of patients experienced any adverse event and 32.1% experienced a grade 3-4 adverse event. Only 5.7% of the patients discontinued treatment secondary to TRAEs.

In patients with HER2-expressing BTCs, anti-HER2 therapies are viable options, particularly in the second-line setting.

HER2-targeting therapies are well-described in breast, gastric, and lung cancers, however accumulating data supports a role for HER2-targeted therapies in gynecologic cancers. Despite varied methodologies for HER2 testing, evidence supports that a substantial proportion of endometrial, ovarian, cervical, and vulvar cancers overexpress HER2. This underscores the rationale for HER2-targeted therapies in these malignancies, including the use of HER2-directed tyrosine kinase inhibitors, antibody-drug conjugates, and immune-stimulating antibody conjugates. Understanding mechanisms of resistance to HER2-targeted therapies will inform possible combinatorial strategies.

CGP provides genomic context for HER2 status beyond the information provided by IHC and FISH, including detection of ERBB2 mutations and co-alterations that may suggest sensitivity/resistance to HER2-directed therapies, and is therefore crucial for guiding treatment choice and understanding individual patient response.

ERBB2 pathway activation, through amplification or activating mutations, represents a new target for colon cancer (CC) treatment. Molecular methods were compared with the gold standard for assessing ERBB2 status, and the prognostic value of ERBB2 amplification, mutations, and expression was determined using data from 2 phase 3 trials involving nearly 3000 patients with stage III CC.

In the PETACC8 trial, immunohistochemistry and fluorescence in situ hybridization, DNA, and RNA analysis were performed on 1813, 1719, and 1733 samples, respectively. In the IDEA-France trial, DNA and RNA sequencing was performed on 1129 and 1263 samples. The breast cancer SCAN-B cohort (N = 3409) served as an external reference. A new molecular ERBB2-amplified status was defined using ERBB2 next-generation sequencing score, RNA sequencing expression, and clustering based on ERBB2 neighboring gene expression. Concordance between diagnostic techniques and the association between time to recurrence (TTR) and ERBB2-status were evaluated.

The prevalence of the molecular ERBB2-amplified group was 1.85% in PETACC8 and 1.5% in IDEA-France, with a concordance of 0.81 (95% CI, 0.70-0.92) with the gold standard immunohistochemistry and fluorescence in situ hybridization method in PETACC8. A nonlinear relationship was observed between TTR and ERBB2 expression, with extreme groups showing a less favorable prognosis (P < .0001) in both colon and breast cancers. Patients with molecular ERBB2-amplified status or mutations had the poorest prognosis, followed by low-expression and intermediate-expression groups (3-year TTR of 67.0%, 71.2%, and 77.9%, respectively). In multivariate analysis, the low-expression group had a significantly shorter TTR (hazard ratio, 1.28; 95% CI, 1.07-1.52).

The molecular definition of ERBB2 status could represent a cost-effective alternative in stage III CC. ERBB2 alterations and low RNA expression significantly reduced TTR, highlighting the complex role of ERBB2.

Multidisciplinary molecular tumor boards (MTB) are already well established in many comprehensive cancer centers and play an important role in the individual treatment planning for cancer patients. Comprehensive genomic profiling of tumor tissue based on next-generation sequencing is currently performed for diagnostic and mainly predictive testing. If somatic genomic variants are identified, which are suspected to be pathogenic germline variants (PGVs), MTB propose genetic counseling and germline DNA testing. Commonly used comprehensive genomic profiling approaches of tumor tissue do not include a matched germline DNA control. Therefore, the detection of PGVs could be only predicted based on the content of tumor cells (CTC) in selected tumor area (%) and variant allele frequency score (%). For conclusion, the role of a medical geneticist is essential in these cases. The overall prevalence of PGVs in patients with pancreatic ductal adenocarcinoma (PDAC) and colorectal cancer (CRC) is approximately 10%. In this single-center study, we present 37 patients with PDAC and 48 patients with CRC who were presented at MTB and tested using the large combined DNA/RNA sequencing panel. Content of tumor cells and variant allele frequency scores were evaluated in all tested patients. In case of suspicion of PGV and no previous genetic testing based on the standard guidelines, genetic counseling was recommended regardless of age, sex, and family history. In the PDAC subgroup, five patients were recommended by MTB for genetic counseling based on suspicious genetic findings. Based on a medical geneticist's decision, germline DNA sequencing was performed in four of these cases, and all of them tested positive for PGV in the following genes: ATM, ATM, BRCA1, and BRCA2. In the CRC subgroup, no PGV was confirmed in the two patients genetically tested based on the MTB recommendations. Furthermore, we present data from our center's registry of patients with PDAC and CRC who underwent genetic counseling and germline DNA testing based on the standard screening criteria. Our data confirm that comprehensive genomic profiling of tumor tissue can identify patients with hereditary forms of PDAC, who could remain unidentified by standard screening for hereditary forms of cancer.

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related deaths worldwide. Despite treatment advancements in the last decades, CRC remains heterogeneous with significant clinical and genetic diversity. Human epidermal growth factor receptor 2 (HER2) proto-oncogene plays a critical role, as its amplification or overexpression leading to abnormal cell proliferation and tumorigenesis. HER2 overexpression or amplification is identified in 2-4% of metastatic CRCs (mCRC) patients, representing a potential therapeutic target. It is also associated with resistance against epidermal growth factor receptor (EGFR)-targeted therapies like cetuximab and panitumumab, for treatment of RAS wild-type mCRC. Although HER2-positive mCRC is rare, assessing HER2 levels is important. Furthermore, anti-HER2 therapies exhibited non-toxic profile and high efficacy in chemorefractory cases. This review delves into modern management of anti-HER2 therapies in CRC with a particular focus on recent advances and current knowledge about the prognostic and predictive value of HER2.

Fruquintinib is a highly selective, oral inhibitor of all 3 VEGF receptors. The global, randomized, double-blind phase 3 FRESCO-2 trial (NCT04322539) met its primary endpoint demonstrating significantly improved overall survival in patients with refractory metastatic colorectal cancer (mCRC) who received fruquintinib plus best supportive care (BSC) versus placebo plus BSC. Here we report detailed safety data from FRESCO-2 including an analysis of treatment-related adverse events of special interest (AESIs).

Patients with mCRC eligible for FRESCO-2 had received all standard chemotherapies and prior anti-VEGF and anti-EGFR therapies if indicated, and displayed progression on, or intolerance to, TAS-102 and/or regorafenib. Prespecified AESIs based on VEGFR tyrosine kinase inhibitor drug classes were evaluated.

Incidences of treatment-related AESIs were 64.9% with fruquintinib + BSC versus 23.0% with placebo + BSC. The most frequent all-grade treatment-related AESIs for fruquintinib were hypertension (28.9%; grade ≥3 10.7%), palmar-plantar erythrodysesthesia syndrome/hand-foot skin reaction (PPE 18.6%; grade ≥3 6.1%), and hypothyroidism (15.6%; grade ≥3 0.4%). Dose reductions due to treatment-related AESIs were reported in 10.3% of patients who received fruquintinib + BSC versus 0.4% with placebo + BSC. The most common treatment-related AESIs resulting in dose reduction for fruquintinib were PPE syndrome (5.0%), hypertension (2.9%), and proteinuria (1.3%). Overall, 5.9% versus 0.9% had treatment-related AESIs resulting in study drug discontinuation.

Fruquintinib + BSC demonstrated a predictable and manageable safety profile in pretreated patients with mCRC and is a novel oral treatment option that prolongs survival and enriches the continuum of care in this population.

The growing importance of HER2 expression as a biomarker across multiple cancers is largely driven by advances in HER2-directed antibody-drug conjugates. The recent approval of trastuzumab deruxtecan (T-DXd) as a tumor-agnostic therapy has revolutionized treatment strategies for HER2-overexpressed tumors beyond breast, gastric, and colorectal cancers (CRC). This mini-review explores the evolving role of assessing HER2 overexpression in pan-solid tumors, following the recent approval of T-DXd as a tumor-agnostic therapy. It examines how HER2 scoring criteria for pan-tumor indications rely on immunohistochemistry (IHC) assessment, which may be prone to subjective interpretation and interobserver variability, and how these criteria differ from those used in breast, gastric, and CRC tumors. We also address the potential for NGS approaches to identify ERBB2 copy number gain (CNG) and the utility of artificial intelligence (AI) algorithms to enhance the consistency and accuracy of HER2 score interpretation for T-DXd treatment eligibility in solid tumors.

Human epidermal growth factor receptor 2 (HER2, also known as ERBB2) signaling promotes cell growth and differentiation, and is overexpressed in several tumor types, including breast, gastric and colorectal cancer. HER2-targeted therapies have shown clinical activity against these tumor types, resulting in regulatory approvals. However, the efficacy of HER2 therapies in tumors with HER2 mutations has not been widely investigated. SGNTUC-019 is an open-label, phase 2 basket study evaluating tucatinib, a HER2-targeted tyrosine kinase inhibitor, in combination with trastuzumab in patients with HER2-altered solid tumors. The study included a cohort of 31 heavily pretreated female patients with HER2-mutated metastatic breast cancer who were also HER2 negative per local testing. Hormone receptor (HR)-positive patients also received fulvestrant. The overall response rate (primary endpoint) was 41.9% (90% confidence interval (CI): 26.9-58.2). Secondary endpoints of duration of response and progression-free survival were 12.6 months (90% CI: 4.7 to not estimable) and 9.5 months (90% CI: 5.4-13.8), respectively. No new safety signals were detected. Responses were observed across various HER2 mutations, including mutations in the tyrosine kinase and extracellular domains. The chemotherapy-free regimen of tucatinib and trastuzumab showed clinically meaningful antitumor activity with durable responses and favorable tolerability in heavily pretreated patients with HER2 mutations. These data support further investigation of HER2-targeted therapies in this patient population. ClinicalTrials.gov registration: NCT04579380 .

Biliary tract cancers (BTCs) are a wide class of malignancies with dismal prognosis. The therapeutic scenario of metastatic BTCs has profoundly changed during recent years. The combination of cisplatin-gemcitabine plus immunotherapy is currently the gold standard in the first line. The more extensive comprehension of the mechanisms at the basis of BTCs and the identification of several molecular alterations has led to the introduction of target-directed therapies in the second line and beyond that have expanded the therapeutic armamentarium alongside the standard FOLFOX regimen, and for the near future, the results of some trials with targeted therapies in first line are expected. HER2 represents a promising therapeutic target detected in BTCs, being overexpressed in approximately 15-20% of cases, with a strong predilection for gallbladder carcinoma and extrahepatic cholangiocarcinoma, although a small proportion of HER2 overexpression can be detected even in intrahepatic cholangiocarcinoma. The efficacy and safety of different HER2 inhibitors have been investigated in several studies in the second line and beyond with encouraging results. This comprehensive review is intended to provide a summary of existing evidence and future perspectives on HER2 altered BTCs.

Cholangiocarcinoma is an aggressive bile duct malignancy with heterogeneous genomic features. Although most patients receive standard-of-care chemotherapy/immunotherapy, genomic changes that can be targeted with established or emerging therapeutics are common. Accordingly, precision medicine strategies are transforming the next-line treatment for patient subsets. Hotspot IDH1 mutations and activating fibroblast growth factor receptor 2 fusions occur frequently, and small-molecule inhibitors against these alterations are US Food and Drug Administration approved. Translational and basic science studies have elucidated the mechanisms of response and resistance in cholangiocarcinoma, providing insights into these targets that extend to other cancers. Additional US Food and Drug Administration-approved and National Comprehensive Cancer Network guideline-recommended treatments for recurrent genomic changes include BRAF inhibition (BRAF-V600E) and trastumazab deruxtecan (human epidermal growth factor receptor 2 amplification). Furthermore, ongoing clinical trials show promising results with KRAS inhibition (KRAS-codon 12 mutations), PRTM5 inhibition, alone or with methylthioadenosine inhibition (5-methylthioadenosine phosphorylase deletion), and murine double minute 2 inhibition (murine double minute 2 amplification). Despite these advances, the rate, depth, and duration of response to each treatment need improvement. Moreover, many patients do not have currently targetable genotypes. This review examines the clinical efficacy and mechanisms of resistance associated with these treatments, as well as insights into the molecular and biological effects of pathway activation and inhibition, based on study of patient samples and preclinical models. It also explores strategies to overcome resistance and possible precision medicine approaches for additional patient subsets.

In this editorial, we reviewed the article by Fadlallah et al that was recently published in the World Journal of Clinical Oncology. The article provided a comprehensive and in-depth view of the management and treatment of colorectal cancer (CRC), one of the leading causes of cancer-related morbidity and mortality worldwide. The article analyzed the therapeutic modalities and their sequencing, focusing on total neoadjuvant therapy for locally advanced rectal cancer. It highlighted the role of immunotherapy in tumors with high microsatellite instability or deficient mismatch repair, addressing recent advances that have improved prognosis and therapeutic response in localized and metastatic CRC. Innovations in surgical techniques, advanced radiotherapy, and systemic agents targeting specific mutational profiles are also discussed, reflecting on how they revolutionized clinical management. Circulating tumor DNA has emerged as a promising tool for detecting minimal residual disease, prognosis, and therapeutic monitoring, solidifying its role in precision oncology. This review emphasized the importance of technological and therapeutic advancements in improving clinical outcomes and personalizing CRC treatment.

Human epidermal growth factor receptor 2 (HER-2) amplification has been identified in approximately 3% of patients with metastatic colorectal cancer (mCRC). Owing to the lack of established anti-ERBB2 therapeutic approaches, mCRC patients with Her-2 amplification rarely receive targeted treatments. Moreover, conventional chemotherapy regimens are not ideal for these patients, leaving options in the advanced stage limited to best supportive care or participation in clinical drug trials.

This report presents a case of a patient with Her-2-amplified refractory mCRC treated with a salvage regimen combining Disitamab Vedotin and Pyrotinib, resulting in a partial response and progression-free survival for 6 months, which is still ongoing.

This case study suggests that the anti-Her-2 regimen involving Disitamab Vedotin and Pyrotinib may offer a potential salvage treatment option for patients with Her-2-amplified mCRC patients. However, further validation in larger cohorts is necessary in future studies.

Background: While advances in therapies have improved metastatic cancer survival rates, elderly patients with colorectal cancer often experience delayed diagnoses, receive less frequent systemic therapies, and show inferior survival outcomes compared to younger groups. Patients over the age of 80 years old face greater treatment risks due to frailty and comorbidities. In this article, we examine characteristics, treatment and outcomes in older adults with metastatic colorectal cancer. Methods: The medical records of all patients aged 80 years and above and comparable patients aged 65-75 years old, who were diagnosed with stage 4 colorectal cancer at a cancer center over a six-year period, were retrospectively reviewed. Results: Patients in the 80 years old and older group more frequently had right-sided primary colon cancer (71.5%), compared to younger patients aged 65-75 years old (34.1%, p = 0.006). Patients in the younger cohort more commonly presented with stage 4 disease at initial diagnosis (59.5%) compared to older patients (22.2%). Elevated carcinoembryonic antigen (CEA) levels were more commonly identified in younger metastatic patients (76.3% vs. 46.4%, p = 0.013). Patients in the younger age group were more likely to have received previous neoadjuvant and adjuvant chemotherapy prior to metastatic progression (p = 0.02, and p = 0.01); however, a significant difference in palliative chemotherapy was not identified between the age groups of metastatic patients. The adverse effects of chemotherapy treatment were similar between the age groups. Conclusions: The active treatment of metastatic colorectal cancer in patients aged 80 and above is feasible when tailored according to the patients' performance status, comorbidities, and life expectancy. Understanding metastatic disease presentations in elderly patients can improve treatment outcomes in this challenging-to-treat group.

Breast cancer is a major health challenge for women worldwide, and human epidermal growth factor receptor 2 (HER-2)-positive breast cancers have a relatively high incidence and are highly aggressive. Targeted therapeutic agents, represented by trastuzumab, have been effective in improving the survival rate of HER-2-positive breast cancer patients. However, in clinical applications, this type of targeted drugs exhibits varying degrees of cardiotoxicity, and the mechanism of their cardiotoxicity is currently unclear. In this paper, we classify them into three categories: monoclonal antibodies (mAbs), small-molecule tyrosine kinase inhibitors (TKIs), and antibody-drug conjugate (ADCs). We list the evidence of cardiotoxicity for various drugs based on current clinical trials and summarize their corresponding epidemiological profiles. We also discuss the regulation of cardiotoxicity from three perspectives: clinical biomarkers of cardiotoxicity, permissive cardiotoxicity, and the current status of cardiotoxicity regulation.

The molecular characterization of early-stage (1-3) colorectal cancer (CRC) remains incomplete, as opposed to metastatic disease, where comprehensive genomic profiling (CGP) is routinely performed. This study aimed to characterize the genomics of stages 1-3 versus IV CRC, and the genomics of patients recurring within 1 year of diagnosis.

Patients from a de-identified CRC clinico-genomic database who received Foundation Medicine testing (FoundationOne/FoundationOne CDx) during routine clinical care at approximately 280 US cancer clinics between March 2014 and June 2023 were included. Genomic alterations (GA) were compared by Fisher's exact test.

A total of 4702 patients were included; 1902 with stages 1-3 and 2800 with stage 4 disease. Among patients with stages 1-3 disease, 546 recurred within 1 year. Patients staged 1-3 had higher prevalence of microsatellite instability (MSI-H, 11.4% vs 4.5%, P < .001), tumor mutational burden (TMB) ≥ 10 Mut/Mb (14.6% vs 6.8%, P < .001), GA in RNF43 (11.2% vs 5.7%, P < .001), MSH6 (3.9% vs 1.7%, P < .001), MLH1 (2.3% vs 0.7%, P < .001), and MSH2 (1.5% vs 0.6%, P < .01) compared to those with stage 4 disease. Patients who recurred within 1 year had higher prevalence of MSI-H (13.2% vs 4.4%, P < .001), TMB ≥ 10 Mut/Mb (16.2% vs 6.9%, P < .001), BRAF V600E (17.2% vs 7.9%, P < .003), GA in RNF43 (13.7% vs 5.3%, P < .001), MSH6 (4.2% vs 1.6%, P = .035), and BRCA1/2 (6.2% vs 3.0%, P = .030). On recurrence, more patients received targeted therapy when CGP was performed before versus after first-line therapy (43% vs 19%, P < .001).

Early-stage CRC patients can have distinct genomic profiles and CGP in this population can help expand access to targeted therapies.

Patients diagnosed with metastatic colorectal cancer (mCRC) have a poor prognosis with survival ranging 2-3 years. The prevalence of human epidermal growth factor receptor 2 (HER2) amplification is approximately 3-4% in mCRC and increases up to 8% in patients with KRAS/NRAS/BRAF wild-type (WT) CRC tumors. Tucatinib is a highly selective HER2-directed tyrosine kinase inhibitor that, in combination with trastuzumab, has demonstrated clinically meaningful activity in patients with chemotherapy-refractory, HER2-positive (HER2+), RAS WT mCRC in the MOUNTAINEER trial. The MOUNTAINEER-03 phase III trial is designed to investigate the efficacy and safety of first-line tucatinib in combination with trastuzumab and modified FOLFOX6 (mFOLFOX6) versus standard of care (mFOLFOX6 plus bevacizumab or cetuximab) in patients with untreated HER2+, RAS WT locally advanced unresectable or mCRC. MOUNTAINEER-03 will include two arms of approximately 400 patients randomized 1:1 to either treatment arm. The primary endpoint is progression-free survival per RECIST v1.1 by blinded independent central review (BICR). Key secondary endpoints are overall survival and confirmed objective response rate (according to RECIST v1.1 per BICR). Safety assessments will include surveillance and recording of adverse events, physical examination findings, vital signs, cardiac assessments, Eastern Cooperative Oncology Group performance status, concomitant medications, and laboratory tests.Clinical trial registration: NCT05253651 (ClinicalTrials.gov).

Targeted therapy, the milestone in the development of human medicine, originated in 2004 when the FDA approved the first targeted agent bevacizumab for colorectal cancer treatment. This new development has resulted from drug developers moving beyond traditional chemotherapy, and several trials have popped up in the last two decades with an unprecedented speed. Specifically, EGF/EGFR, VEGF/VEGFR, HGF/c-MET, and Claudin 18.2 therapeutic targets have been developed in recent years. Some targets previously thought to be undruggable are now being newly explored, such as the RAS site. However, the efficacy of targeted therapy is extremely variable, especially with the emergence of new drugs and the innovative use of traditional targets for other tumors in recent years. Accordingly, this review provides an overview of the major signaling pathway mechanisms and recent advances in targeted therapy for gastrointestinal cancers, as well as future perspectives.

Cancers of the digestive system are major contributors to global cancer-associated morbidity and mortality, accounting for 35% of annual cases of cancer deaths. The etiologies, molecular features, and therapeutic management of these cancer entities are highly heterogeneous and complex. Over the last decade, genomic and functional studies have provided unprecedented insights into the biology of digestive cancers, identifying genetic drivers of tumor progression and key interaction points of tumor cells with the immune system. This knowledge is continuously translated into novel treatment concepts and targets, which are dynamically reshaping the therapeutic landscape of these tumors. In this review, we provide a concise overview of the etiology and molecular pathology of the six most common cancers of the digestive system, including esophageal, gastric, biliary tract, pancreatic, hepatocellular, and colorectal cancers. We comprehensively describe the current stage-dependent pharmacological management of these malignancies, including chemo-, targeted, and immunotherapy. For each cancer entity, we provide an overview of recent therapeutic advancements and research progress. Finally, we describe how novel insights into tumor heterogeneity and immune evasion deepen our understanding of therapy resistance and provide an outlook on innovative therapeutic strategies that will shape the future management of digestive cancers, including CAR-T cell therapy, novel antibody-drug conjugates and targeted therapies.

Colorectal cancer (CRC) is widely recognized as the third most prevalent malignancy globally and the second leading cause of cancer-related mortality. Traditional treatment modalities for CRC, including surgery, chemotherapy, and radiotherapy, can be utilized either individually or in combination. However, these treatments frequently result in significant side effects due to their non-specificity and cytotoxicity affecting all cells. Moreover, a considerable number of patients face relapses following these treatments. Consequently, it is imperative to explore more efficacious treatment interventions for CRC patients. Immunotherapy, an emerging frontier in oncology, represents a novel therapeutic approach that leverages the body's immune system to target cancer cells. The principal advantage of immunotherapy is its capacity to selectively target cancer cells while minimizing damage to healthy cells. Its recent adoption as a neoadjuvant therapy presents significant potential to transform the treatment landscape for both primary resectable and metastatic CRC. This review endeavors to offer a comprehensive overview of current strategies in CRC immunotherapy, critically analyze existing literature, underscore anticipated outcomes from ongoing clinical trials, and deliberate on the challenges and impediments encountered within the field of immunotherapy.

This review provides a comprehensive overview of the evolving role of minimal residual disease (MRD) for patients with Colon Cancer (CC). Currently, the standard of care for patients with non-metastatic CC is adjuvant chemotherapy (ACT) for all patients with stage III and high-risk stage II CC following surgical intervention. Despite a 5-20% improvement in long-term survival outcomes, this approach also results in a significant proportion of patients receiving ACT without any therapeutic benefit and being unnecessarily exposed to the risks of secondary side effects. This underscores an unmet clinical need for more precise stratification to distinguish patients who necessitate ACT from those who can be treated with surgery alone. By employing liquid biopsy, it is possible to discern MRD enabling the categorization of patients as MRD-positive or MRD-negative, potentially revolutionizing the management of ACT. This review aimed to examine the heterogeneity of methodologies currently available for MRD detection, encompassing the state-of-the-art technologies, their respective advantages, limitations, and the technological challenges and multi-omic approaches that can be utilized to enhance assay performance. Furthermore, a discussion was held regarding the clinical trials that employ an MRD assay focusing on the heterogeneity of the assays used. These differences in methodology, target selection, and performance risk producing inconsistent results that may not solely reflect biological/clinical differences but may be the consequence of the preferential use of particular products in studies conducted in different countries. Standardization and harmonization of MRD assays will be crucial to ensure the liquid revolution delivers reliable and clinically actionable outcomes for patients.

Colorectal cancer (CRC) represents a major public health challenge globally, particularly in the Gulf Cooperation Council (GCC) countries, where it is identified as the second most prevalent form of cancer. Despite advancements in management strategies, tailored guidelines specific to the Gulf region are lacking. This paper presents consensus recommendations developed by a panel of experts from the GCC countries to address this gap. The guidelines cover epidemiology, screening, biomarkers, and treatment strategies for metastatic CRC. Treatment guidelines emphasize tailored approaches based on tumor characteristics, including sidedness and molecular profiles. Furthermore, the importance of maintenance therapy and emerging biomarkers are discussed. These guidelines aim to improve CRC management and outcomes in the Gulf region.

Human epidermal growth factor receptor 2 (HER2)-targeted therapies have shown promise in treating HER2-amplified metastatic colorectal cancer (mCRC). Identifying optimal biomarkers for treatment decisions remains challenging. This study explores the potential of artificial intelligence (AI) in predicting treatment responses to trastuzumab plus pertuzumab (TP) in patients with HER2-amplified mCRC from the phase II TRIUMPH trial.

AI-powered HER2 quantification continuous score (QCS) and tumor microenvironment (TME) analysis were applied to the prescreening cohort (n = 143) and the TRIUMPH cohort (n = 30). AI analyzers determined the proportions of tumor cells (TCs) with HER2 staining intensity and the densities of various cells in TME, examining their associations with clinical outcomes of TP.

The AI-powered HER2 QCS for HER2 immunohistochemistry (IHC) achieved an accuracy of 86.7% against pathologist evaluations, with a 100% accuracy for HER2 IHC 3+ patients. Patients with ≥50% of TCs showing HER2 3+ staining intensity (AI-H3-high) exhibited significantly prolonged progression-free survival (PFS; median PFS, 4.4 v 1.4 months; hazard ratio [HR], 0.12 [95% CI, 0.04 to 0.38]) and overall survival (OS; median OS, 16.5 v 4.1 months; HR, 0.13 [95% CI, 0.05 to 0.38]) compared with the AI-H3-low (<50% group). Stratification among patients with AI-H3-high included TME-high (all lymphocyte, fibroblast, and macrophage densities in the cancer stroma above the median) and TME-low (anything below the median), showing a median PFS of 1.3 and 5.6 months for TME-high and TME-low respectively, with an HR of 0.04 (95% CI, 0.01 to 0.19) for AI-H3-high with TME-low compared with AI-H3-low.

AI-powered HER2 QCS and TME analysis demonstrated potential in enhancing treatment response predictions in patients with HER2-amplified mCRC undergoing TP therapy.

Approximately 75% of colorectal cancers (CRCs) harbour an identifiable driver mutation, 5% of which are heritable. These drivers have recognised implications for prognosis and therapy selection. In addition, potential germline mutations require investigations to inform testing of relatives, as well as surveillance for other malignancies. With increasing numbers of targeted drugs being approved, judicious testing is required to ensure sufficient tumour sample is available for testing and at the right point in the cancer pathway. Liquid biopsy with circulating tumour DNA (ctDNA) in the blood presents an exciting adjunct to tumour tissue testing for molecular drivers, as well as escalation and de-escalation of therapy. Here, we review the most frequent molecular alterations in CRC, how genomic testing should be integrated into the treatment pathway for CRC, and sources of further education.

Colorectal cancer (CRC) continues to be a global health concern, necessitating further research into its complex biology and innovative treatment approaches. The etiology, pathogenesis, diagnosis, and treatment of colorectal cancer are summarized in this thorough review along with recent developments. The multifactorial nature of colorectal cancer is examined, including genetic predispositions, environmental factors, and lifestyle decisions. The focus is on deciphering the complex interactions between signaling pathways such as Wnt/β-catenin, MAPK, TGF-β as well as PI3K/AKT that participate in the onset, growth, and metastasis of CRC. There is a discussion of various diagnostic modalities that span from traditional colonoscopy to sophisticated molecular techniques like liquid biopsy and radiomics, emphasizing their functions in early identification, prognostication, and treatment stratification. The potential of artificial intelligence as well as machine learning algorithms in improving accuracy as well as efficiency in colorectal cancer diagnosis and management is also explored. Regarding therapy, the review provides a thorough overview of well-known treatments like radiation, chemotherapy, and surgery as well as delves into the newly-emerging areas of targeted therapies as well as immunotherapies. Immune checkpoint inhibitors as well as other molecularly targeted treatments, such as anti-epidermal growth factor receptor (anti-EGFR) as well as anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibodies, show promise in improving the prognosis of colorectal cancer patients, in particular, those suffering from metastatic disease. This review focuses on giving readers a thorough understanding of colorectal cancer by considering its complexities, the present status of treatment, and potential future paths for therapeutic interventions. Through unraveling the intricate web of this disease, we can develop a more tailored and effective approach to treating CRC.

Approximately 20% of patients living with colorectal cancer (CRC) have activating mutations in their tumors in the PIK3CA oncogene. Two or more activating mutations (multi-hit) for the PIK3CA allele increase PI3K⍺ signaling compared to single-point mutations, resulting in exceptional response to PI3K⍺ inhibition. We aimed to identify the prevalence of PIK3CA multi-hit mutations in metastatic CRC to identify patients who may benefit from PI3K inhibitors.

The Foundation Medicine database (Boston, MA, USA) was analyzed for patients with CRC who underwent genomic profiling on tumor DNA isolated during routine clinical care from 2013 to 2021. Molecular and clinical variables were abstracted for patients with PIK3CA mutations.

We identified 49 051 patients with CRC who underwent Foundation Medicine testing. 710/41154 (1.7%) patients had multi-hit PIK3CA mutations, of which 53% were male (n = 448) with a median age of 60. Microsatellite status was available for 697 patients with multi-hit PIK3CA and 17.6% (123/697) were microsatellite instability-high. Clinically relevant mutations in KRAS and BRAFV600E were seen in 459/710 (64.7%) and 65/710 (9.1%), respectively. The 4 most common PIK3CA variants were H1047R (9.8%), E545K (9.2%), E542K (9.0%), and R88Q (7.1%). The most common variant pair was E542K-E545K (4.7%).

Multi-hit mutations in PIK3CA are seen in 1.7% of advanced CRC, a meaningful prevalence given the high burden of CRC worldwide, and may represent a subset of patients that have enhanced sensitivity to PI3K inhibition. Future investigation regarding the clinical utility of PI3K inhibitors is warranted in multi-hit PIK3CA CRC.

There is ongoing discussion around the optimal course of treatment for metastatic colorectal cancer (mCRC) following the second line. Trifluridine/tipiracil (T) and regorafenib (R) have been the mainstay of therapy in this situation, as they both increased overall survival (OS) in comparison to a placebo. Despite the paucity of evidence, therapy rechallenge is also recognized as an option for practical use. In the third-line scenario of mCRC, we planned to investigate the survival outcomes using (T) and (R), both with and without prior rechallenge treatment.

Between 2012 and 2023, we examined the medical records of 1156 patients with refractory mCRC who were enrolled in the multicenter retrospective ReTrITA study. We then separated the patients into two cohorts based on the rechallenge therapy that was given before regorafenib and/or trifluridine/tipiracil at 17 Italian centres.

A total of 981 patients underwent T and/or R therapy, while 175 patients had therapy rechallenge before T and/or R. The median overall survival (mOS) for patients treated with T/R and R/T sequences in the rechallenge therapy cohort was 14.5 months and 17.6 months, respectively (p = 0.1955). A statistically significant survival benefit was observed in patients who received monotheraphy with R (mOS: 6 months) compared to the T group (mOS: 4.2 months) (p = 0.0332). In the same cohort, a median progression-free survival (mPFS) benefit was demonstrated in favour of the R/T group (11.3 months) vs. 9 months of the reverse sequence (p = 0.4004). In the no-rechallenge cohort, the mOS was statistically longer in the R/T sequence than in the T/R sequence (16.2 months vs. 12.3 months, respectively; p = 0.0014). In terms of the mPFS, we saw the same significant result for the adoption of R/T treatment (11.5 months vs. 8.4 months, respectively; p < 0.0001). The two monotherapy groups did not reveal any significant differences.