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.

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.

Adding monoclonal antibodies to chemotherapy drastically changed the landscape of advanced colorectal cancer. The prediction of benefit from anti-EGFR therapies is mainly based on the absence of mutations in RAS and BRAF genes, the primary tumor sidedness and microsatellite MSS/MSI status. Molecular hyperselection may optimize the outcome of patients receiving anti-EGFR while detecting additional resistance alterations, both in chemo-naïve and in chemo-refractory settings.

Our review focuses on negative molecular hyperselection, both on tissue samples and ctDNA, and the impact of this further patient selection on response rate and survival outcomes. We searched electronic database, selecting relevant English-language publications from 2017 to 2024.

Negative hyperselection beyond RAS and BRAF in advanced colorectal cancer appears to be a powerful tool for predicting outcomes to anti-EGFR therapy and spare patients from unnecessary treatment. This improvement appears in both naïve and pre-treated patients. However, data come mainly from retrospective studies. Therefore, to validate and integrate these findings in the clinical practice, prospective studies should be conducted. It will be interesting to elucidate the role of ctDNA in this setting and the choice of molecular techniques, considering costs and accessibility, to guarantee its implementation in the clinic.

The optimal strategy for patients with colorectal liver metastases (CRLM) is unclear. The Precision1 prospective, observational trial assessed whether pre-operative functional imaging and whole genome sequencing (WGS), could enhance individualized decision-making.

Patients with CRLM considered for hepatectomy were recruited. In addition to standard staging, patients underwent a quantitative multiparametric MRI (mpMRI) scan, to assess liver function. Use of mpMRI to aid surgical decision-making, was prospectively recorded, as were short-term clinical outcomes in patients who underwent hepatectomy. In the first 45 patients, WGS was performed on blood and liver tumour samples collected per-operatively.

95 mpMRI scans were performed in 84 patients, who underwent 87 resections. The mpMRI scan affected surgical decision-making in 41 % (39/95) of scans, with 11 undergoing dual-vein embolization, 16 undergoing more conservative parenchymal-sparing surgery, 11 having more extensive surgery, and one patient following a low calorie diet pre-operatively. There were significant (Clavien-Dindo grades 3/4) complications in 5 % of patients, no Grade C post-hepatectomy liver failure, and zero 90-day mortality. WGS suggested additional therapeutic options and prognostic factors for 22 of 35 (63 %) evaluable patients.

Precision1 shows mpMRI can aid surgical decision-making, and optimise clinical outcomes. WGS provides additional information, to further enhance personalised decision-making.

NSUN2, a major methyltransferase that catalyzes m5C methylation in eukaryotes, is known to be implicated in the development of multiple cancers. However, its role in colorectal cancer (CRC) and the related molecular mechanisms have yet to be sufficiently determined. Here, we conducted an analysis of public database (722 CRC patients) and two distinct cohorts from our centre (1559 CRC patients), which revealed that NSUN2 is upregulated in CRC and correlates with unfavourable prognosis. Our analyses also showed that NSUN2 promotes the proliferation and metastasis capabilities of CRC cells. Intriguingly, NSUN2 was found to promote CRC via an m5C-independent mechanism, which has not been previously reported. Overexpression of both wild-type and m5C enzymatic-dead mutant NSUN2 upregulated and activated the ErbB-STAT3 signalling pathway. We also found that both wild-type and the m5C enzymatic-dead mutant NSUN2 closely interacted with CUL4B. Silencing of CUL4B effectively inhibited the m5C-independent function of NSUN2. Moreover, overexpression of NSUN2 enhanced the sensitivity of CRC cells to lapatinib. Taken together, our findings revealed a novel m5C-independent mechanism for NSUN2 in the malignancy and lapatinib sensitivity of CRC via activation of the CUL4B/ErbB-STAT3 pathway, which provides a potential therapeutic strategy for patients with CRC. HIGHLIGHTS: NSUN2 is upregulated in CRC and associated with poor prognosis of CRC patients. NSUN2 promotes CRC malignancy independently of its m5C-enzymatic activity, a mechanism that has not been previously reported. The non-m5C carcinogenic roles of NSUN2 may be mediated through interactions with CUL4B, thereby activating the ErbB-STAT3 signalling pathway. NSUN2-mediated upregulation of ErbB-STAT3 pathway enhances the sensitivity of CRC to lapatinib treatment.

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.

This review article aims to address the challenges associated with targeted therapy for the treatment of metastatic colorectal cancer (mCRC). We will first provide an overview of approved targeted therapies for treating mCRC, which include antiangiogenic therapy, as well as inhibitors of EGFR, BRAFV600E, HER2 inhibitors, and immune checkpoints. Second, we discuss the different mechanisms of primary resistance, including tumor heterogeneity, both as inter-patient and intra-patient heterogeneity, and mechanisms of secondary resistance which include: driver oncogene alterations, downstream or parallel bypass signaling, presence of co-dominant driver oncogenes, tumor lineage plasticity, and epithelial to mesenchymal transition. Resistance mechanisms towards the different drug classes targeting mCRC are discussed in detail. Strategies to overcome resistance primarily involve combination of therapies, although this approach is typically linked to increased drug toxicity, manifesting as on and off-target effects. Moreover, the cost and accessibility of targeted therapies pose significant challenges for diverse populations. Addressing these challenges necessitates further research efforts aimed at optimizing the use of targeted therapy in mCRC. Integration of genomic biomarkers, such as sequencing and liquid biopsy, into routine clinical practice holds promise in enhancing treatment outcomes. In conclusion, this comprehensive review underscores the complex challenges encountered in targeted therapy for mCRC.

Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide. In cases of metastatic CRC (mCRC) that are resistant to conventional chemotherapy-based treatments, the efficacy of available therapeutic options is typically low. CRC exhibiting overexpression or amplification of the human epidermal growth factor receptor 2 (HER2) gene has shown responsiveness to HER2-targeted therapies.

We present the case of a 69-year-old woman diagnosed with mCRC with an NRAS p.G12V mutation and microsatellite stability, identified through tumor sequencing, along with HER2 overexpression detected by immunohistochemistry. She exhibited an excellent response to disitamab vedotin-containing therapy. To our knowledge, this is the first reported case of mCRC with HER2 overexpression and an NRAS p.G12V mutation achieving a remarkable clinical response to anti-HER2 therapy.

Disitamab vedotin demonstrates promising anti-tumor effects in HER2-overexpressing mCRC, offering patients an additional treatment option.

Human epidermal growth factor receptor 2 (HER2) is an anti-cancer drug target for colon cancer. Among patients with colorectal malignancy (colorectal cancer, CRC), those with HER2 mutations have a poor overall prognosis and a significantly increased drug resistance. In recent years, anti-HER2 therapeutic drugs have developed rapidly. According to several clinical studies and case reports, anti-HER2 therapy, as an emerging anti-cancer approach, plays a crucial role in the treatment of HER2-positive CRC patients. Here, we present a case of HER2-positive descending colon cancer with peritoneal metastasis. The patient is a 26-year-old male, diagnosed with malignant tumor of the descending colon with peritoneal metastasis in April 2020. After multiple treatment modalities, the disease progressed. After chemotherapy with Trastuzumab Deruxtecan (T-DXd/DS-8201), the metastatic foci significantly shrank, and after surgical resection, a tumor-free state (NED) was achieved. Up to now, the patient's survival period has reached 56 months.

Over the past 20 years, the treatment landscape of HER2-amplified tumors has considerably evolved. Until now, no approved targeted therapies were available for patients with HER2-amplified metastatic colorectal cancer (mCRC). Tucatinib, a highly selective tyrosine kinase inhibitor, demonstrated significant efficacy in combination with trastuzumab in patients with refractory mCRC, leading to its approval by the Food and Drug Administration (FDA).

This review dives into the efficacy of tucatinib-based regimens in gastrointestinal malignancies, with a focus on the pivotal MOUNTAINEER trial, which led to the FDA approval of tucatinib plus trastuzumab in chemo-refractory HER2-amplified mCRC. Additionally, ongoing trials are exploring tucatinib in earlier treatment lines and across other gastrointestinal cancers, including biliary tract, gastric, and pancreatic malignancies. The mechanistic basis of dual HER2 inhibition and its implications for clinical practice are discussed.

The future of tucatinib-based therapeutic strategies in GI malignancies depends on their integration into different treatment lines. Addressing acquired resistance using liquid biopsy-guided strategies and other TKIs like lapatinib will be paramount to improve outcomes.

Colorectal cancer most commonly metastasizes to the liver. While various treatment strategies have been developed, surgical management of these patients has vital implications on the prognosis and survival of this group of patients. There remains a need for a consensus guideline regarding the surgical evaluation and management of patients with colorectal liver metastases (CRLM).

This review article is a consensus guideline established by the members of the AHPBA Professional Standards Committee, as an amalgamation of existent literature and a guide to surgeons managing this complex disease.

These guidelines reports the benefits and shortcomings of various diagnostic modalities including imaging and next-generation sequencing in the management of patients with CRLM. While surgery has established survival benefits in patients with resectable disease, this report notes the importance of treatment sequencing with non-surgical modalities as well as between colon and liver resection. Finally, the guidelines address the various treatment modalities for patients with unresectable disease, that may have significant impact on survival.

CRLM is a complex diagnosis which warrants multidisciplinary approach with early surgical involvement in both assessment and management of the disease, to optimize patient outcomes and survival.

Colorectal cancer (CRC) is ranked as the second leading cause of cancer-related deaths globally, necessitating urgent advancements in therapeutic approaches. The emergence of groundbreaking therapies, including chimeric antigen receptor-T (CAR-T) cell therapies, oncolytic viruses, and immune checkpoint inhibitors, marks a transformative era in oncology. These innovative modalities, tailored to individual genetic and molecular profiles, hold the promise of significantly enhancing patient outcomes. This comprehensive review explores the latest clinical trials and advancements, encompassing targeted molecular therapies, immunomodulatory agents, and cell-based therapies. By evaluating the strengths, limitations, and potential synergies of these approaches, this research aims to reshape the treatment landscape and improve clinical outcomes for CRC patients, offering new found hope for those who have exhausted conventional options. The culmination of this work is anticipated to pave the way for transformative clinical trials, ushering in a new era of personalized and effective CRC therapy.

The 2024 updates of the Chinese Society of Clinical Oncology (CSCO) Clinical Guidelines for the diagnosis and treatment of colorectal cancer emphasize standardizing cancer treatment in China, highlighting the latest advancements in evidence-based medicine, healthcare resource access, and precision medicine in oncology. These updates address disparities in epidemiological trends, clinicopathological characteristics, tumor biology, treatment approaches, and drug selection for colorectal cancer patients across diverse regions and backgrounds. Key revisions include adjustments to evidence levels for intensive treatment strategies, updates to regimens for deficient mismatch repair (dMMR)/ microsatellite instability-high (MSI-H) patients, proficient mismatch repair (pMMR)/ microsatellite stability (MSS) patients who have failed standard therapies, and rectal cancer patients with low recurrence risk. Additionally, recommendations for digital rectal examination and DNA polymerase epsilon (POLE)/ DNA polymerase delta 1 (POLD1) gene mutation testing have been strengthened. The 2024 CSCO Guidelines are based on both Chinese and international clinical research, as well as expert consensus, ensuring their relevance and applicability in clinical practice, while maintaining a commitment to scientific rigor, impartiality, and timely updates.

The optimal treatment for metastatic colorectal cancer (mCRC) beyond second line is still questioned. Besides the standard of care agents (regorafenib, REG, or trifluridine/tipiracil, FTD/TPI), chemotherapy rechallenge or reintroduction (CTr/r) are commonly considered in clinical practice, despite weak supporting evidence. The prognostic performance of CTr/r, REG and FTD/TPI in this setting are herein evaluated.

PROSERpYNa is a multicenter, observational, retrospective study, in which patients with refractory mCRC, progressing after at least 2 lines of CT, treated with CTr/r, REG or FTD/TPI, are considered eligible and were enrolled in 2 independent data sets (exploratory and validation). Primary endpoint was overall survival (OS); secondary endpoints were investigator-assessed progression-free survival (PFS), objective response rate (RR) and safety. A propensity score adjustment was accomplished for survival analyses.

Data referring to patients treated between Jan-10 and Jan-19 from 3 Italian institutions were gathered (341 and 181 treatments for exploratory and validation data sets respectively). In the exploratory cohort, median OS (18.5 vs. 6.5 months), PFS (6.1 vs. 3.5 months) and RR (28.6% vs. 1.4%) were significantly longer for CTr/r compared to REG/FTD/TPI. Survival benefits were retained at the propensity score analysis, adjusted for independent prognostic factors identified at multivariate analysis. Moreover, these results were confirmed within the validation cohort analyses.

Although the retrospective fashion, CTr/r proved to be a valuable option in this setting in a real-world context, providing superior outcomes compared to standard of care agents at the price of a moderate toxicity.

Lapatinib, an FDA-approved tyrosine kinase inhibitor, treats HER2+ advanced/metastatic breast cancer. This study comprehensively analyzed its adverse reaction profile using FDA Adverse Event Reporting System (FAERS) to guide clinical use.

Adverse event (AE) reports for lapatinib from the second quarter of 2007 to the second quarter of 2024 in FAERS were analyzed using Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Multi-item Gamma Poisson Shrinkage (MGPS) and Bayesian Confidence Propagation Neural Network (BCPNN) to identify AE signals.

Among 8300 AE reports, females (91.47%) and ages 40-59.9 (33.71%) were predominant. 20 system organ classifications (SOCs) were affected, with gastrointestinal disorders (ROR = 3.46) and skin disorders (ROR = 2.47) most significant. Based on the PT level, a total of 111 PTs were analyzed that met the four algorithms, including typical AEs such as diarrhea (n = 3410), vomiting (n = 856), and rash (n = 856), as well as some rare AEs that were not prompted by the drug inserts, such as neutropenia (n = 252), pericardial effusion (n = 43), lymphedema (n = 20). The majority of lapatinib-associated AEs had onset within 30 days (51%).

Lapatinib has a generally favorable safety profile, but gastrointestinal toxicity and dermatotoxicity require close monitoring to prevent serious AEs.

Colorectal cancer (CRC) is a major cause of cancer-related mortality worldwide, with a significant impact on public health. Current treatment options include surgery, chemotherapy, radiotherapy, molecular-targeted therapy, and immunotherapy. Despite advancements in these therapeutic modalities, resistance remains a significant challenge, often leading to treatment failure, poor progression-free survival, and cancer recurrence. Mechanisms of resistance in CRC are multifaceted, involving genetic mutations, epigenetic alterations, tumor heterogeneity, and the tumor microenvironment. Understanding these mechanisms at the molecular level is crucial for identifying novel therapeutic targets and developing strategies to overcome resistance. This review provides an overview of the diverse mechanisms driving drug resistance in sporadic CRC and discusses strategies currently under investigation to counteract this resistance. Several promising strategies are being explored, including targeting drug transport, key signaling pathways, DNA damage response, cell death pathways, epigenetic modifications, cancer stem cells, and the tumor microenvironment. The integration of emerging therapeutic approaches that target resistance mechanisms aims to enhance the efficacy of current CRC treatments and improve patient outcomes.

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.

Methylthioadenosine phosphorylase (MTAP) is an essential metabolic enzyme in the purine and methionine salvage pathway. In cancer, MTAP gene copy number loss (MTAP loss) confers a selective dependency on the related protein arginine methyltransferase 5. The impact of MTAP alterations in gastrointestinal (GI) cancers remains unknown although hypothetically druggable. Here, we aim to investigate the prevalence, clinicopathological features and prognosis of MTAP loss GI cancers.

Cases with MTAP alterations were retrieved from The Cancer Genome Atlas (TCGA) and a real-world cohort of GI cancers profiled by next-generation sequencing. If MTAP alterations other than loss were found, immunohistochemistry was performed. Finally, we set a case-control study to assess MTAP loss prognostic impact.

Findings across the TCGA dataset (N=1363 patients) and our cohort (N=508) were consistent. Gene loss was the most common MTAP alteration (9.4%), mostly co-occurring with CDKN2A/B loss (97.7%). Biliopancreatic and gastro-oesophageal cancers had the highest prevalence of MTAP loss (20.5% and 12.7%, respectively), being mostly microsatellite stable (99.2%). In colorectal cancer, MTAP loss was rare (1.1%), while most MTAP alterations were mutations (5/7, 71.4%); among the latter, only MTAP-CDKN2B truncation led to protein loss, thus potentially actionable. MTAP loss did not confer worse prognosis.

MTAP alterations are found in 5%-10% of GI cancers, most frequently biliopancreatic and gastro-oesophageal. MTAP loss is the most common alteration, identified almost exclusively in MSS, CDKN2A/B loss, upper-GI cancers. Other MTAP alterations were found in colorectal cancer, but unlikely to cause protein loss and drug susceptibility.

Tendomodulin (TNMD) is pivotal in various malignancies, including colorectal cancer (CRC). However, its comprehensive impact across cancers, particularly its immunomodulatory function in CRC, remains underexplored. This study explored the role of TNMD in CRC by focusing on its immunomodulatory functions through comprehensive molecular and clinical analyses.

Multiple bioinformatics databases and analytical tools were utilized for the TNMD in pan-cancer analysis. To validate the role of TNMD in CRC, we performed experiments, including immunofluorescence (IF), immunohistochemistry (IHC), real-time quantitative reverse transcription PCR (qPCR), western blotting, and cell migration assays.

TNMD expression and gene mutation vary across cancers and offer high diagnostic value. Survival analysis found that TNMD is associated with prognosis in multiple cancers. Notably, in patients with high microsatellite instability (MSI-H) CRC, TNMD expression correlated positively with various immune cells, particularly natural killer (NK) cells, whereas it was inversely correlated with regulatory T cells (Tregs). Crucially, in patients with microsatellite stability (MSS) CRC, high TNMD expression was associated with better immunotherapy outcomes, indicating its potential as a biomarker for patient stratification and tailored treatment approaches. Furthermore, single-cell sequencing data revealed stronger interactions between TNMD-positive tumor cells and fibroblasts or macrophages in the tumor microenvironment. Finally, TNMD was overexpressed in CRC tumor tissues and cell lines, thereby promoting invasion and metastasis.

Our findings reveal a critical immunomodulatory role of TNMD in CRC, particularly in influencing tumor-immune interactions. Beyond its potential diagnostic and prognostic biomarker, TNMD promotes CRC metastasis and invasion, thus emerging as a promising therapeutic target. These findings highlight TNMD's significance in CRC and potentially other malignancies.

Human epidermal growth factor receptor-2 (HER2) expression is an important biomarker for the management of RAS wild-type metastatic colorectal carcinoma (CRC). Immunohistochemistry (IHC) with reflex in situ hybridization (ISH) is accepted as a standard method of assessment, yet there are currently the following 2 sets of criteria used to interpret results: the HER2 Amplification for Colorectal Cancer Enhanced Stratification (HERACLES) criteria and the MyPathway criteria. The HER2 Amplification for Colorectal Cancer Enhanced Stratification criteria require ISH confirmation when IHC staining is 3+ in 10% to 49% of cells, whereas the MyPathway criteria mirror those for gastric HER2 assessment and do not recommend ISH confirmation in the previously referenced scenario. We aimed to assess the prevalence of HER2 3+ heterogeneity and its association with ERBB2 copy number amplification to evaluate the necessity of ISH testing when IHC staining is 3+ in <50% of cells. Next-generation sequencing of DNA (592-gene panel or whole exome sequencing) was performed for 13,208 CRC tumors submitted to Caris Life Sciences. HER2 (4B5) expression was tested using IHC. A subset of tumors was tested for ERBB2 amplification via chromogenic ISH and/or via next-generation sequencing (copy number amplification). χ2 tests or Fisher exact tests were applied where appropriate, with P values adjusted for multiple comparisons (P < .05). Of 13,208 CRCs with HER2 IHC, 87.4% (11,541/13,208) were negative for HER2 expression (≤3+ intensity and <10% tumor-cell staining) and 11.2% (1473/13,208) demonstrated at least low HER2 expression (1 to 2+ and ≥10%). Only 1.5% (194/13,208) of all tested tumors were either positive or heterogeneously positive for HER2 overexpression (3+ and ≥10%). Of these, 14% (28/194) had heterogenous HER2 overexpression (3+ staining of 10%-49% of cells). Among 22 HER2-positive/heterogenous cases with successful ISH testing, 100% (22/22) demonstrated amplification via ISH. Because the classification of tumors as HER2-positive/heterogenous using IHC correlated very closely with ISH positivity, our results suggest that ISH is likely unnecessary for CRCs with 3+ HER2 overexpression in 10% to 49% of neoplastic cells.

Introduction  Colorectal carcinoma (CRC) is the second leading cause of cancer-related mortality worldwide. Within this context, a subset of CRCs shows overexpression of the human epidermal growth factor receptor 2 (HER2/neu), a characteristic also seen in other malignancies like breast and gastric cancers. The success of targeting the HER2 pathway in these cancers has prompted investigations into the potential use of similar interventions in CRC. Aims This research aims to assess HER2/neu expression in CRCs and its correlation with the CRC stage and histopathology, as well as to evaluate the demographic characteristics of CRC patients. Materials and methods  This prospective observational study was conducted on a cohort of 40 CRC patients, using histopathology and immunohistochemistry (IHC) sections from the Department of Pathology. Clinical and demographic data were collected over a 24-month period, and routine tissue processing and IHC staining were performed on colectomy tissues. Immunostaining with the HER2/neu marker was conducted for detailed analysis. Data were analyzed using IBM SPSS Statistics for Windows, Version 27.0 (Released 2020; IBM Corp., Armonk, NY, United States). Results  Among the 40 CRC cases studied, six cases (15%) exhibited robust membranous positivity, while eight cases (20%) showed moderate focal membranous positivity. Twenty-six cases (65%), however, demonstrated no HER2/neu staining positivity. A significant correlation was found between the histological grade of the tumor and HER2/neu expression (p = 0.0001). Additionally, HER2/neu expression was significantly correlated with lymphovascular invasion (p < 0.0001) and lymph node status (p < 0.047). Conclusion  This study found a strong correlation between the tumor's stage, grade, lymph node status, and lymphovascular invasion and HER2/neu expression. Therefore, HER2/neu can be a predictive and therapeutic marker in colorectal cancers. This underscores the potential importance of incorporating these parameters in the clinical evaluation and targeted treatment strategies for CRC patients.

Claudin 18.2 (CLDN18.2) immunohistochemical (IHC) expression can be used to select patients with gastric/gastroesophageal junction adenocarcinomas for zolbetuximab (IMAB362) therapy, zolbetuximab (IMAB362) being a monoclonal antibody targeting CLDN18.2. The aim of this study was to correlate IHC expression of CLDN18.2 with clinicopathologic and molecular features in a large series of digestive tract cancers. IHC for CLDN18.2 was performed on tissue microarrays from 1404 adenocarcinomas including 155 gastric/gastroesophageal, 74 pancreatic ductal, and 1175 colorectal (576 in the initial test cohort; 599 in the subsequent validation cohort), and correlated with HER2 and mismatch repair (MMR) status. Cases were scored as CLDN18.2 positive or negative, with positivity defined as moderate-to-strong membranous staining in ≥75% of tumor cells. CLDN18.2 expression was correlated with clinicopathologic and molecular features for all colorectal adenocarcinomas. CLDN18.2 was positive in 39% (61/155) of gastric/gastroesophageal adenocarcinomas, 38% (28/74) of pancreatic ductal adenocarcinomas, and 3.4% (40/1175) of colorectal adenocarcinomas (P < .001). For gastric/gastroesophageal and pancreatic ductal adenocarcinoma, there was no correlation between CLDN18.2 expression and either HER2 or MMR status. In contrast, CLDN18.2-positive colorectal adenocarcinomas had distinct clinicopathologic and molecular features. CLDN18.2-positive colorectal adenocarcinomas were more frequently proximally located and were more often MMR deficient and BRAF V600E positive (all with P < .05). Quantitative pathologic analysis using the digital pathology biomarker QuantCRC (Aiforia) demonstrated marked differences in histologic features between CLDN18.2-positive and CLDN18.2-negative colorectal adenocarcinomas, with CLDN18.2-positive tumors having an increased tumor:stroma ratio and %mucin but decreased %immature stroma in both the test and validation cohorts (all with P < .05). In conclusion, CLDN18.2-positive colorectal adenocarcinomas are frequently MMR deficient and BRAF V600E mutated, and demonstrate distinct histologic features. Future studies addressing the efficacy of zolbetuximab therapy in this subset of colorectal cancers are needed.

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) 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.

Over the past few years, several novel systemic treatments have emerged for patients with treatment-refractory metastatic colorectal cancer, thus making selection of the most effective later-line therapy a challenge for medical oncologists. Over the past decade, regorafenib and trifluridine-tipiracil were the only available drugs and often provided limited clinical benefit compared to best supportive care. Results from subsequent practice-changing trials opened several novel therapeutic avenues, both for unselected patients (such as trifluridine-tipiracil plus bevacizumab or fruquintinib) and for subgroups defined by the presence of actionable alterations in their tumours (such as HER2-targeted therapies or KRASG12C inhibitors) or with no acquired mechanisms of resistance to the previously received targeted agents in circulating tumour DNA (such as retreatment with anti-EGFR antibodies). In this Review, we provide a comprehensive overview of advances in the field over the past few years and offer a practical perspective on translation of the most relevant results into the daily management of patients with metastatic colorectal cancer using an evidence-based algorithm. Finally, we discuss some of the most appealing ongoing areas of research and highlight approaches with the potential to further expand the therapeutic armamentarium.

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.

This study suggests that rechallenge therapy may improve survival rates in the third-line treatment of mCRC, particularly if it is administered before sequential R/T treatment. This could allow for the extension of mCRC treatment choices until prospective studies are finished or randomised trials are performed.

DESTINY-CRC01 (NCT03384940) was a multicentre, open-label, phase 2 study that investigated the safety and efficacy of trastuzumab deruxtecan (T-DXd) in patients with human epidermal growth factor receptor 2 (HER2)-expressing metastatic colorectal cancer (CRC). The present exploratory biomarker analysis aims to investigate relationships between biomarkers and clinical outcomes in patients with HER2-positive (immunohistochemistry [IHC] 3+ or IHC 2+ and in situ hybridization [ISH] positive) Cohort A (N = 53) of DESTINY-CRC01. Higher levels of HER2 biomarkers in baseline tissue and liquid biopsies, including HER2 status (IHC/ISH), HER2/CEP17 ratio, HER2 ISH signals, HER2 H-score, plasma HER2 (ERBB2) amplification status, HER2 adjusted plasma copy number, and HER2 extracellular domain correlate with antitumor activity (indicated by objective response rate, progression-free survival, and overall survival) of T-DXd. Baseline circulating tumor DNA (ctDNA) analysis suggests antitumor activity of T-DXd in patients who had baseline activating RAS, PIK3CA, or HER2 mutations detected in ctDNA.

Colorectal cancer (CRC) remains a significant global health burden, necessitating a thorough understanding of prognostic and predictive factors to enhance patient outcomes. This systematic review aims to comprehensively evaluate prognostic and predictive determinants in CRC, encompassing both traditional and emerging biomarkers. A systematic search of major electronic databases was conducted to identify relevant studies published from 1995 up to 2024. Eligible articles were critically appraised, and data extraction was performed according to predefined criteria. The prognostic determinants examined included clinicopathological features such as tumor stage, grade, and lymph node involvement, as well as molecular biomarkers including RAS, BRAF, and MSI status. Predictive determinants encompassed biomarkers influencing response to targeted therapies and immunotherapy, such as HER2 and Immunoscore. The review also explores novel prognostic and predictive markers, including tumor microenvironment characteristics and liquid biopsy-based biomarkers. Synthesizing evidence from diverse studies, this review provides insights into the prognostic and predictive landscape of CRC, highlighting the potential clinical implications of identified determinants. Understanding the multifaceted nature of prognostic and predictive factors in CRC is imperative for the advancement of personalized treatment strategies and improvement of patient outcomes.

Metastatic colorectal cancer is a leading cause of cancer-related death across the world. The treatment paradigm has shifted away from systemic chemotherapy alone to include targeted therapy and immunotherapy. The past two decades have been characterized by increased investigation into molecular profiling of colorectal cancer. These molecular profiles help physicians to better understand colorectal cancer biology among patients with metastatic disease. Additionally, improved data on genetic pathways allow for specific therapies to be targeted at the underlying molecular profile. Investigation of the EGFR, VEGF, HER2, and other pathways, as well as deficient mismatch repair, has led to the development of multiple targeted therapies that are now utilized in the National Comprehensive Cancer Network guidelines for colon and rectal cancer. While these new therapies have contributed to improved survival for metastatic colorectal cancer, long-term survival remains poor. Additional investigation to understand resistance to targeted therapy and development of new targeted therapy is necessary. New therapies are under development and are being tested in the preclinical and clinical settings. The aim of this review is to provide a comprehensive evaluation of molecular profiling, currently available therapies, and ongoing obstacles in the field of colorectal cancer.

Uveal melanoma (UM) is the most common malignant intraocular tumor with the trait of distant metastases. Currently, the standard clinical therapy results in suboptimal outcomes due to ineffective inhibition of tumor metastasis. Thus, developing novel therapeutic modalities for UM remains a critical priority. Herein, we have developed an injectable nanocomposite hydrogel (HA-DOX/LAP gel) through integrating hyaluronic acid-based drug-loaded nanoparticles into an alginate-dopamine gel, delivering the chemotherapeutic drugs, lapatinib and doxorubicin for combinational treatment of UM. HA-DOX/LAP gel is fabricated in situ by a simple injection of the mixed precursor solution into tumor sites and maintains in vivo for more than 21 days. The entrapped drug-loaded nanoparticles can gradually release from HA-DOX/LAP gel, enhancing tumor targeting and penetration, and synchronously releasing lapatinib and doxorubicin into the acidic intracellular environment to synergistically destroy UM cells. In vivo anti-tumor studies conducted in MuM-2B tumor models demonstrated that HA-DOX/LAP gel significantly impedes tumor growth, diminishes postoperative recurrence, and prolongs overall survivals of UM tumor-bearing mice through only single injection. Remarkably, the escaped drug-loaded nanoparticles effectively reduce the risk of tumor metastases. Our findings provide new insights for the development of multifunctional nanocomposite-incorporating combination therapy against UM by targeting tumor recurrence and metastases.

This narrative review explores the efficacy and applicability of anti-EGFR therapy as the first-line treatment for patients with RAS wild-type (WT) left-sided metastatic colorectal cancer (mCRC). It critically examines current guidelines, along with recent evidence in the literature, to assess whether it should be universally applied.

Recent evidences highlight the variability of the response to anti-EGFR therapies due to molecular diversity and several clinical factors, such as RAS mutational status and primary tumor location. Anti-EGFR plus chemotherapy is the standard first-line treatment for most patients with MSS, RAS-WT, left-sided mCRC. Whether this combination is the best treatment for these patients remains an open question. This review delves into the role of EGFR inhibition in mCRC, focusing on clinical factors and the knowledge of biology, molecular targets, and biomarkers. It underscores the crucial role of a personalized approach, empowering healthcare providers and equipping them with the confidence to make informed decisions.