Considering past research in Europe and the USA, the conditions for medical insurance coverage of BRCA1/2 genetic testing (GT) in Japan have been established as follows: 1. Breast cancer onset at 45 years or younger age; 2. Triple-negative breast cancer (TNBC) onset at 60 years or younger age; 3. Onset of two or more primary breast cancers; 4. Family history of breast cancer, ovarian cancer, or pancreatic cancer up to the third degree; 5. Male breast cancer, 6. Ovarian, fallopian, or peritoneal cancers. However, data to determine the importance and extent of each factor in the current conditions are insufficient. Consequently, this study aimed to assess the validity of insurance coverage conditions in Japan, elucidate the relationship between these conditions, and explore the possibility of proposing new indicators.

A total of 5987 breast cancer patients were enrolled from 92 centers participating in the HBOC consortium and the JOHBOC registry project. Of these, 5904 patients were analyzed after excluding 48 male breast cancer patients due to insufficient numbers for analysis and 35 patients whose age at breast cancer onset was unknown or unregistered. We compared 1,091 cases in which pathogenic variants (PVs) (BRCA1(B1s): 543, BRCA2(B2s): 548) were detected with 4580 cases in which no variants (non-Vs) were detected. Variants of uncertain significance (VUS: 233 cases) were not classified as either PVs or non-Vs for subsequent analysis. We investigated the validity of each condition under which an HBOC diagnosis could be considered for medical insurance coverage.

Regardless of the insurance coverage conditions, the detection rate of pathogenic variants (DRPV) of all analyzed cases was 19.2%. The DRPV under the insurance coverage conditions for GT-'Age of breast cancer onset ≤ 45 years,' 'TNBC onset at ≤ 60 years,' ' ≥ 2 primary breast cancers,' 'Patients with breast cancer concurrent with ovarian cancer,' and ' ≥ 1 family history of breast or ovarian cancer up to the third degree'-was 25.4%, 31.6%, 24.6%, 48.8%, and 25.6%, respectively. Those within the insurance coverage group showed a pathogenic variant detection rate of 21.1%, compared to only 5.6% outside of the coverage. Our analysis indicates that medical insurance coverage conditions effectively identify candidates for GT. Furthermore, when examining the number of conditions met and the positivity rate, the positivity rate was 11.2%, with only one condition met. This rate increases exponentially as more conditions are met, underscoring the importance of multiple matching conditions. Additionally, those with comorbid ovarian cancer or a family history of ovarian cancer are more likely to have a pathogenic variant. Additionally, we reevaluated cases who did not meet the medical insurance conditions. TNBC occurrence was significantly associated with B1s, even when restricted to onset age ≥ 61 years. Familial history of prostate cancer also significantly associated with B2s.

This study determined that the Japanese medical insurance coverage conditions effectively identified candidates eligible for GT. Consequently, it is imperative to disseminate information to all patients with breast cancer covered by insurance, emphasizing the opportunity for GT, particularly if they have ovarian cancer complications or a family history of ovarian cancer.

The targeted delivery of therapeutics to internal organs to, for example, promote healing or apoptosis holds promise in the treatment of numerous diseases1-4. Currently, the prevailing delivery modality relies on the circulation; however, this modality has substantial efficiency, safety and/or controllability limitations5-9. Here we report a battery-free, chipless, soft nanofluidic intracellular delivery (NanoFLUID) patch that provides enhanced and customized delivery of payloads in targeted internal organs. The chipless architecture and the flexible nature of thin functional layers facilitate integration with internal organs. The nanopore-microchannel-microelectrode structure enables safe, efficient and precise electroperforation of the cell membrane, which in turn accelerates intracellular payload transport by approximately 105 times compared with conventional diffusion methods while operating under relatively low-amplitude pulses (20 V). Through evaluations of the NanoFLUID patch in multiple in vivo scenarios, including treatment of breast tumours and acute injury in the liver and modelling tumour development, we validated its efficiency, safety and controllability for organ-targeted delivery. NanoFLUID-mediated in vivo transfection of a gene library also enabled efficient screening of essential drivers of breast cancer metastasis in the lung and liver. Through this approach, DUS2 was identified as a lung-specific metastasis driver. Thus, NanoFLUID represents an innovative bioelectronic platform for the targeted delivery of payloads to internal organs to treat various diseases and to uncover new insights in biology.

Genomic loss-of-heterozygosity (gLOH) consists in the loss of chromosomal regions and is associated with homologous recombination repair (HRR) system deficiency. We explored the role of gLOH and HRR-related gene alterations in metastatic colorectal cancer (mCRC).

FoundationOne CDx assay was used to determine the percentage of gLOH and the presence of alterations in 27 HRR-related genes in archival chemo-naïve tumor tissues of patients with mCRC treated with first-line oxaliplatin- or irinotecan-based doublets and triplet ± anti-PD-L1.

Overall, 243 samples were analyzed. None of the nine deficient mismatch repair/microsatellite instability high tumors were gLOH-high, while 16 (7%) of 234 proficient mismatch repair/microsatellite stable (pMMR/MSS) tumors were gLOH-high. In the pMMR/MSS population, six (3%) and 18 (8%) had at least a biallelic or monoallelic HRR-related gene alteration, respectively. Among patients receiving FOLFOXIRI alone (n = 68) or with an anti-PD-L1 (N = 90), higher benefit from the addition of the immune checkpoint inhibitor (ICI) was observed in the gLOH-high subgroup (n = 12), in terms of both progression-free survival (PFS; Pint = .02) and overall survival (OS; Pint = .03). No differences in PFS or OS were reported between patients treated with first-line oxaliplatin- (n = 40) versus irinotecan-based doublets (n = 25) or with the triplet FOLFOXIRI (n = 68) versus doublets (n = 65), according to the gLOH status. Among patients not receiving an anti-PD-L1, longer PFS was observed in the gLOH-low group (n = 138) versus the gLOH-high (n = 6) group (5.1 v 12.1 months; hazard ratio, 8.73 [95% CI, 3.64 to 20.9]; P < .001), and this was confirmed in the multivariate analysis (P < .001). No prognostic impact of monoallelic or biallelic HRR-related gene alterations was shown.

In pMMR/MSS mCRC, gLOH-high was associated with worse prognosis and higher benefit from the addition of anti-PD-L1 agents to chemotherapy. If confirmed in larger series, these results may inform the design of clinical trials.

BRCA1 is one of the causative genes for hereditary breast and ovarian cancer syndrome with a high risk of early-onset breast cancer. Whereas olaparib (OLA), an inhibitor of poly-ADP-ribose polymerase, has been applied as adjuvant therapy to those cancer patients, its effect on ovarian reproductive function remains unelucidated. Recently, a rat model (MUT; Brca1(L63X/+) mutation) mimicking a human BRCA1 pathogenic variant has been established. Using this model, we evaluated the effects of OLA on ovarian reproductive function in comparison with the wild-type (WT) rats. MUT showed a significantly reduced number of primordial follicles and subfertility in accordance with aging. Oxidative stress was significantly elevated in the young MUT granulosa cells (GCs) accompanied by increased mTOR but decreased PTEN signals. OLA administration in MUT further decreased primordial follicles, with gene set enrichment analysis, indicating upregulated DNA repair pathways. Furthermore, a combination of OLA and cyclophosphamide (CPA) induced empty primordial follicles, recognized as CPA-induced severe ovarian toxicity. Whereas OLA + CPA caused greater reduction in primordial follicles both in MUT and WT in comparison with CPA alone, MUT ovaries were more susceptible to oxidative stress, potentially depleting primordial follicles via activation of GCs and inducing oocyte death due to accumulated DNA damage by OLA treatment. Our findings in this preclinical model underscore the importance of evaluating ovarian reserve prior to chemotherapy by performing reproductive consultation with female patients with BRCA1 pathogenic variants.

To describe the effectiveness and safety of olaparib off-label indications in patients with impaired homologous recombination genes and solid tumors different than those authorized.

A single-center, observational and retrospective study including patients treated with olaparib for off-label use. The main variables were patient characteristics, prior therapies, response to therapy, progression-free survival, overall survival and adverse events.

A total of 6 patients were included. All patients had metastases and received 3 or more lines of prior treatment. The primary tumor locations and mutations were partner and localizer of BRCA2 (PALB2) intrahepatic cholangiocarcinoma, ataxia telangiectasia mutated (ATM) non-small cell lung adenocarcinoma, somatic breast cancer gene (sBRCA2) colorectal cancer, germinal breast cancer gene 2 (gBRCA2) breast neuroendocrine tumor, gBRCA2 ampullary cancer and gBRCA2 pancreatic neuroendocrine tumor. At the end of the study, one patient was still receiving olaparib showing more than 25 months of sustained stable disease response. No novel toxicities were observed besides those included in the product information.

There is limited published evidence on the use of olaparib in patients harboring pathogenic variants other than breast cancer genes, like PALB2 and ATM and conditions different than those authorized such as digestive tract, neuroendocrine and lung tumors. Further research is to assess the efficacy of olaparib in these patients.

Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPis) have emerged as critical agents for cancer therapy. By inhibiting the catalytic activity of PARP enzymes and trapping them in the DNA, PARPis disrupt DNA repair, ultimately leading to cell death, particularly in cancer cells with homologous recombination repair deficiencies, such as those harboring BRCA mutations. This review delves into the mechanisms of action of PARPis in anticancer treatments, including the inhibition of DNA repair, synthetic lethality, and replication stress. Furthermore, the clinical applications of PARPis in various cancers and their adverse effects as well as their combinations with other therapies and the mechanisms underlying resistance are summarized. This review provides comprehensive insights into the role and mechanisms of PARP and PARPis in DNA repair, with a particular focus on the potential of PARPi-based therapies in precision medicine for cancer treatment.

Tumor diseases represent a significant global health challenge, impacting both humans and companion animals, notably dogs. The parallels observed in the pathophysiology of cancer between humans and dogs underscore the importance of advancing comparative oncology and translational research methodologies. Furthermore, dogs serve as valuable models for human cancer research due to shared environments, genetics, and treatment responses. In particular, breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2), which are critical in human cancer, also influence the development and progression of canine tumors. The role of BRCA1 and BRCA2 in canine cancers remains underexplored, but its potential significance as therapeutic targets is strongly considered. This systematic review aims to broaden the discussion of BRCA1 and BRCA2 beyond mammary tumors, exploring their implications in various canine cancers. By emphasizing the shared genetic underpinnings between species and advocating for a comparative approach, the review indicates the potential of BRCA genes as targets for innovative cancer therapies in dogs, contributing to advances in human and veterinary oncology.

Triple-negative breast cancer (TNBC) is traditionally treated with systemic chemotherapy, often resulting in significant off-target toxicity. In this study, we assess the efficacy of intraductal chemotherapeutic delivery, aimed at reducing systemic side effects. Using an in situ TNBC model, created by intraductal injection of 4T1-luc cells, we identified day 3 post-tumor implantation as an optimal early intervention point. Echocardiographic analysis confirmed that intraductal administration of eribulin (ERI) or doxorubicin (DOX) did not cause cardiac dysfunction or apoptosis. Our results demonstrate that intraductal delivery of ERI and DOX significantly enhances anti-tumor and anti-metastatic effects. Mechanistically, ERI followed by DOX increased intratumoral perfusion, improved drug concentration, reversed epithelial-mesenchymal transition, and inhibited tumor cell invasion and metastasis. Additionally, this approach triggered immunogenic cell death and activated a systemic anti-tumor immune response. These findings underscore the potential of intraductal chemotherapy as a safe, highly effective approach, offering a preclinical foundation for minimally invasive TNBC therapies.

Cancer is a complex disease driven by multiple genetic changes, including mutations in oncogenes, tumor suppressor genes, DNA repair genes, and genes involved in cancer metabolism. Synthetic lethality (SL) is a promising approach in cancer research and treatment, where the simultaneous dysfunction of specific genes or pathways causes cell death. By targeting vulnerabilities created by these dysfunctions, SL therapies selectively kill cancer cells while sparing normal cells. SL therapies, such as PARP inhibitors, WEE1 inhibitors, ATR and ATM inhibitors, and DNA-PK inhibitors, offer a distinct approach to cancer treatment compared to conventional targeted therapies. Instead of directly inhibiting specific molecules or pathways, SL therapies exploit genetic or molecular vulnerabilities in cancer cells to induce selective cell death, offering benefits such as targeted therapy, enhanced treatment efficacy, and minimized harm to healthy tissues. SL therapies can be personalized based on each patient's unique genetic profile and combined with other treatment modalities to potentially achieve synergistic effects. They also broaden the effectiveness of treatment across different cancer types, potentially overcoming drug resistance and improving patient outcomes. This review offers an overview of the current understanding of SL mechanisms, advancements, and challenges, as well as the preclinical and clinical development of SL. It also discusses new directions and opportunities for utilizing SL in targeted therapy for anticancer treatment.

Breast cancer is the second most commonly diagnosed cancer in women and the fifth leading cause of cancer-related deaths worldwide. It is a highly heterogeneous disease, consisting of multiple subtypes that vary significantly in clinical characteristics and survival outcomes. Triple-negative breast cancer (TNBC) is a particularly aggressive and challenging subtype of breast cancer. Several immunotherapeutic approaches have been tested in patients with TNBC to improve disease outcomes, including the administration of dendritic cell (DC)-based vaccines. DCs are a heterogeneous cell population that play a crucial role in bridging the innate and adaptive immune systems. Therefore, DCs have been increasingly used in cancer vaccines due to their ability to prime and boost antigen specific T-cell immune responses. This review aims to provide a comprehensive overview of TNBC, including potential targets and pharmacological strategies, as well as an overview of DCs and their relevance in TNBC. In addition, we review ongoing clinical trials and shed light on the evolving landscape of DC-based immunotherapy for TNBC.

Breast cancer (BC) survivors are at increased risk for cardiovascular disease (CVD) and require their primary care physicians to manage their long-term general medical care, including cardiovascular (CV) health. Yet, evidence exists that some primary care physicians possess insufficient knowledge about survivorship care. With the goal of bridging these knowledge gaps, a PubMed review was conducted from July 7, 2020, through October 2, 2020, with an updated PubMed review from January 3, 2024, through April 28, 2024, focusing on CV health considerations in the primary care of BC survivors. Search terms included variations of "breast cancer survivors" and "cardiovascular." In total, 152 publications were included. Breasts cancer survivors may have increased CVD risk because some anticancer therapies are cardiotoxic and risk factors for BC often also increase the risk for CVD. Multiple risk factors overlap for BC and CVD such as older age, Western diet, early menarche, physical inactivity, high body mass index, and smoking. In this review, results are summarized from studies that report the presence of CV risk factors and CVD in BC survivors. Also described are the CV effects of BC therapies (chemotherapy, hormonal agents, targeted therapies, and radiotherapy) and the type of CV evaluation (cardiac imaging and measurement of biomarkers) that these patients may need. Primary care physicians have an important role in managing the CV health of BC survivors from preventing, assessing, and managing CV risk factors to referring patients to appropriate specialists when needed.

The discovery of effective breast cancer therapy is both urgent and daunting, beset by a myriad of challenges that range from the disease's inherent heterogeneity to its complex molecular underpinnings. Drug resistance, the intricacies of the tumor microenvironment, and patient-specific variables further complicate this landscape. The stakes are even higher when dealing with subtypes like triple-negative breast cancer, which eludes targeted hormonal therapies due to its lack of estrogen, progesterone, and HER2 receptors. Strategies to overcome such challenges include combinations of drugs and identifying new drug targets. Developing new drugs based on such targets could be a better solution than relying on costly immunotherapy or combinational therapies. In this review, we have endeavored to comprehensively examine the proven therapeutic drug targets associated with breast cancer and elucidate their respective molecular mechanisms and current clinical status. This study aims to facilitate researchers in conducting a comparative analysis of different targets to select single and multi-targeted drug discovery approaches for breast cancer.

Aggressive breast cancers often fail or acquire resistance to radiotherapy. To develop new strategies to improve the outcome of aggressive breast cancer patients, we studied how PARP inhibition radiosensitizes breast cancer models to proton therapy, which is a radiotherapy modality that generates more DNA damage in the tumor than standard radiotherapy using photons. Two human BRCA1-mutated breast cancer cell lines and their isogenic BRCA1-recovered pairs were treated with a PARP inhibitor and irradiated with photons or protons. Protons (9.9 and 3.85 keV/µm) induced higher cell kill independent of BRCA1 status. PARP inhibition amplified the cell kill effect to both photons and protons (9.9 and 3.85 keV/µm) independent of BRCA1 status. Numbers of γH2AX foci, micronuclei, and cGAS-positive micronuclei were significantly higher in BRCA1-mutated cells. Cell cycle distribution and stress-induced senescence were not affected by PARP inhibition in our cell lines. In vivo, the combination of protons (3.99 keV/µm) and PARP inhibition induced the greatest tumor growth delay and the highest survival. We found that PARP inhibition increases radiosensitization independent of BRCA1 status for both protons and photons. The combination of protons and PARP inhibition was the most effective in decreasing clonogenic cell survival, increasing DNA damage, and delaying tumor growth.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with a poor prognosis. This research aims to find real hub genes for prognostic biomarkers of TNBC therapy. The GEO datasets GSE27447 and GSE233242 were analyzed using R package limma to explore DEGs. The PPI was generated using the STRING database. Cytoscape software plug-ins were used to screen the hub genes. Using the DAVID database, GO functional enrichment and KEGG pathway enrichment analysis were performed. Different online expression databases were employed to investigate the functions of real hub genes in tumor driving, diagnosis, and prognosis in TNBC patients with various clinicopathologic characteristics. A total of one hundred DEGs were identified between both datasets. The seven hub genes were identified after the topological parameter analysis of the PPI network. The KEGG pathway and GO analysis suggest that four genes (PSMB1, PSMC1, PSMF1, and PSMD8) are highly enriched in proteasome and were finally considered as real hub genes. Additionally, the expression analysis demonstrated that hub genes were notably up-regulated in TNBC patients compared to controls. Furthermore, correlational analyses revealed the positive and negative correlations among the expression of the real hub genes and various ancillary data, including tumor purity, promoter methylation status, overall survival (OS), genetic alterations, infiltration of CD8+ T and CD4+ immune cells, and a few more, across TNBC samples. Finally, our analysis identified a couple of significant chemotherapeutic drugs, miRNAs and transcription factors (TFS) with intriguing curative potential. In conclusion, we identified four real hub genes as novel biomarkers to overcome heterogenetic-particular challenges in diagnosis, prognosis, and therapy for TNBC patients.

DNA repair dysregulation is a key driver of cancer development. Understanding the molecular mechanisms underlying DNA repair dysregulation in cancer cells is crucial for cancer development and therapies. Here, we report that enhancer of zeste homolog 2 (EZH2) directly methylates poly(adenosine diphosphate-ribose) polymerase-1 (PARP-1), an essential enzyme involved in DNA repair, and regulates its activity. Functionally, EZH2-catalyzed methylation represses PARP1 catalytic activity, down-regulates the recruitment of x-ray repair cross-complementing group-1 to DNA lesions and its associated DNA damage repair; on the other hand, it protects the cells from nicotinamide adenine dinucleotide overconsumption upon DNA damage formation. Meanwhile, EZH2-mediated methylation regulates PARP1 transcriptional and oncogenic activity, at least in part, through impairing PARP1-E2F1 interaction and E2F1 transcription factor activity. EZH2 and PARP1 inhibitors synergistically suppress prostate cancer growth. Collectively, our findings uncover an insight of EZH2 functions in fine-tuning PARP1 activity during DNA damage repair and cancer progression, which provides a rationale for combinational targeting EZH2 and PARP1 in cancer.

The use of circulating tumour DNA (ctDNA) to profile mutational signatures represents a non-invasive opportunity for understanding cancer mutational processes. Here we present MisMatchFinder, a liquid biopsy approach for mutational signature detection using low-coverage whole-genome sequencing of ctDNA. Through analysis of 375 plasma samples across 9 cancers, we demonstrate that MisMatchFinder accurately infers single-base and doublet-base substitutions, as well as insertions and deletions to enhance the detection of ctDNA and clinically relevant mutational signatures.

Invasive Lobular Carcinoma (ILC) presents a distinct subtype of breast cancer, representing 10-15% of cases, with unique clinical and molecular features. Characterized by a non-cohesive, single-file invasion pattern, ILC is typically estrogen receptor (ER)- and progesterone receptor (PR)-positive but human epidermal growth factor receptor 2 (HER2)-negative. Despite favorable prognostic features, its highly metastatic nature and predilection for atypical sites contribute to lower long-term survival compared to invasive breast carcinoma of no special type (NST). ILC's genetic landscape includes mutations in various genes (CDH1, BRCA2, ATM, etc.) and signaling pathways that impact treatment responses, especially in endocrine treatment. Furthermore, the diverse ILC subtypes complicate its management. Current challenges in chemotherapy, along with the targeted therapies, are also discussed. The present article aims to comprehensively review the recent literature, focusing on the pathological and molecular aspects of ILC, including associated genetic mutations influencing disease progression and drug resistance.

We tested whether the PARP inhibitor, Olaparib, can effectively enhance radiosensitivity while inhibiting OSCC growth and metastasis in vitro and in vivo. Patient samples were used for survival validation.

The present study investigated the effect of Olaparib and ionizing radiation (IR) on clonogenic, migratory, and invasive ability in human IR-sensitive (OML1) and IR-resistant (OML1-R) OSCC cell lines. We next explored the underlying mechanism with ELISA and a Western blotting assay. Two in vivo mouse models were established to investigate the efficacy of Olaparib combined with radiotherapy (RT) on local tumor growth and lung metastasis. IL-17 A expression was confirmed in tissue specimens of OSCC patients by immunohistochemistry.

We found that Olaparib, in combination with IR, substantially inhibited cell growth, migration, and invasion in vitro. Mechanistically, the Olaparib treatment significantly reduced the secretion of IL-17 A in irradiated OSCC cells by attenuating NF-κB and p38 activity. Consistently, Olaparib enhanced the radiosensitivity and, with RT, synergistically reduced both tumor growth and lung metastasis in mice. In addition, OSCC patients with high IL-17 A expression were substantially associated with an increased risk of lymph node involvement and worse survival.

This study has highlighted that Olaparib displays radiosensitizing and antimetastatic effects by inhibiting the IL-17 A-dependent signal. Remarkably, Olaparib could provide a remarkable anticancer efficacy to improve treatment response in OSCC patients with recurrent/metastatic disease after RT.

Breast cancer (BC) is a highly heterogeneous disease, and the presence of germline breast cancer gene mutation (gBRCAm) is associated with a poor prognosis. Triple-negative breast cancer (TNBC) is a BC subtype, characterized by the absence of hormone and growth factor receptor expression, making therapeutic decisions difficult. Defects in the DNA damage response pathway due to mutation in breast cancer genes (BRCA 1/2) lead to homologous recombination deficiency (HRD). However, in HRD conditions, poly (adenosine diphosphate-ribose) polymerase (PARP) proteins repair DNA damage and lead to tumor cell survival. Biological understanding of HRD leads to the development of PARP inhibitors (PARPi), which trap PARP proteins and cause genomic instability and tumor cell lysis. HRD assessment can be an important biomarker in identifying gBRCAm patients with BC who could benefit from PARPi therapy. HRD can be identified by homologous recombination repair (HRR) gene-based assays, genomic-scarring assays and mutational signatures, transcription and protein expression profiles, and functional assays. However, gold standard methodologies that are robust and reliable to assess HRD are not available currently. Hence, there is a pressing need to develop accurate biomarkers identifying HRD tumors to guide targeted therapies such as PARPi in patients with BC. HRD assessment has shown fruitful outcomes in chemotherapy studies and preliminary evidence on PARPi intervention as monotherapy and combination therapy in HRD-stratified patients. Furthermore, ongoing trials are exploring the potential of PARPi in BC and clinically complex TNBC settings, where HRD testing is used as an adjunct to stratify patients based on BRCA mutations.

The modern oncology drug development landscape has shifted away from traditional cytotoxic chemotherapies. Following their initial approvals, many oncology drugs have been approved in subsequent indications either as monotherapy or in combination to benefit a broader patient population. To date, dose selection strategies for subsequent indications have not been systematically reviewed. This review examines how approved dosing regimens were selected in subsequent indications for FDA-approved oncology drugs.

The Drugs@FDA database was used to identify FDA-approved new molecular entities (NMEs) between 2010 and 2023. NMEs with more than 1 approved indication were included in the analysis. In total, the dosing regimens for 67 novel oncology drugs that obtained FDA approvals for multiple indications were evaluated.

Overall, in subsequent indications, 72% of NMEs used the same or clinically equivalent alternative dosing regimens to those approved in the initial indications. Amongst the 28% of NMEs that used different dosing regimens, safety/tolerability was the leading cause of a dosing regimen changes in both monotherapy and combination therapy settings. Other factors leading to changes in dosing regimens include differences in tumor biology, disease burden, pharmacokinetics, and overall benefit-risk profiles obtained from dose-finding studies.

Our analysis highlighted the importance of selecting a safe, tolerable, and yet efficacious dosing regimen for the initial indication as a suboptimal initially approved regimen could lead to dosing regimen changes in later indications. Preclinical and clinical data could be leveraged to understand the pharmacology, pharmacokinetic, and pharmacodynamic differences between indications and thus support dose selection in subsequent indications.

Homologous recombination deficiency (HRD) represents an impairment in the homologous recombination repair (HRR) pathway, crucial for repairing DNA double-strand breaks and contributing to genomic instability in cancer. The HRD score may be a more reliable biomarker than HRR-related gene mutations for identifying patients sensitive to poly(ADP-ribose) polymerase inhibitors. Despite its relevance in various cancers, the HRD score remains underexplored in esophageal squamous cell carcinoma (ESCC). We retrospectively analyzed HRD scores in 96 ESCC patients, examining correlations with clinical characteristics and survival outcomes, and validated our findings using the TCGA dataset. Genomic sequencing utilized a custom superHRD next-generation sequencing panel, and HRD scores were calculated from 54,000 single-nucleotide polymorphisms using Kruskal-Wallis rank-sum tests and two cut-off points for analysis. Higher HRD scores correlated with advanced tumor stages, recurrence, and mutations in TP53 and ABCB1, while APC mutations were linked to lower HRD scores. Patients with high HRD scores had significantly shorter disease-free survival (p = 0.013) and a trend toward shorter overall survival (OS) (p = 0.005), particularly those not receiving adjuvant therapy. Conversely, HRD-high patients undergoing adjuvant therapy showed a trend toward longer OS (p = 0.015). Multivariate analysis identified HRD as an independent prognostic factor (hazard ratio = 2.814 for recurrence, p = 0.015). Validation with the TCGA dataset supported these findings. This study highlights the associations between HRD scores, clinical characteristics, and genomic mutations in ESCC, suggesting HRD as a potential prognostic biomarker. HRD assessment may aid in patient stratification and personalized treatment strategies, warranting further investigation to validate the therapeutic implications of HRD scores in ESCC.

Breast cancer is the most common cancer among women worldwide, and its incidence rate is still increasing, especially among younger women. Nationally, it constitutes one-fifth of all cancer cases and almost 40% of all female cancers. With a median age of 51 years, breast cancer is diagnosed at least a decade earlier, and at more advanced stages compared to Western societies. Hereditary cancers account for 10% or more of all cancer burden worldwide. With expanded indications, increased number of genes tested, and significant decline in cost of testing, such proportion will probably increase. Individuals with pathogenic variants of BRCA1 and BRCA2 are at higher risk of breast, ovarian, pancreatic and many other cancers. Over the past two decades, several highly penetrant cancer-susceptibility genes were identified across almost all tumor sites, thus increasing the need for comprehensive cancer genetic programs that address the testing process, counselling patients and at-risk family members, and then deal with all testing results and its consequences. In addition to its important role in preventing more cancers in index patients themselves and among their close relatives, identification of pathogenic or likely pathogenic variants, mostly in BRCA1 or BRCA2, may inform therapeutic decisions in common cancers including breast, ovarian, prostate and pancreatic cancers. In this manuscript, we describe the experience of a comprehensive cancer center, in a resource-limited country in establishing a comprehensive clinical cancer genetics program that can serve as an example for others who share similar demographic and financial restrains.

The synthetic lethal effect observed with the use of PARP inhibitors (PARPi) with tumors characterized by the loss of key players in the homologous recombination (HR) pathway, commonly referred to as "BRCAness", is maintaining high interest in oncology. While BRCAness is a well-established feature in breast, ovarian, prostate, and pancreatic carcinomas, our recent findings indicate that up to 15% of colorectal cancers (CRC) also harbor defects in the HR pathway, presenting promising opportunities for innovative therapeutic strategies in CRC patients. We developed a new tool called HRDirect, which builds upon the HRDetect algorithm and is able to predict HR deficiency (HRD) from reference-free tumor samples. We validated HRDirect using matched breast cancer and CRC patient samples. Subsequently, we assessed its efficacy in predicting response to the PARP inhibitor olaparib by comparing it with two other commercial assays: AmoyDx HRD by Amoy Diagnostics and the TruSight Oncology 500 HRD (TSO500-HRD) panel by Illumina NGS technology. While all three approaches successfully identified the most PARPi-sensitive CRC models, HRDirect demonstrated superior precision in distinguishing resistant models compared to AmoyDX and TSO500-HRD, which exhibited overlapping scores between sensitive and resistant cells. Furthermore, we propose integrating HRDirect scoring with ATM and RAD51C immunohistochemical analysis as part of our "composite biomarker approach" to enhance the identification of HRD tumors, with an immediate translational and clinical impact for CRC personalized treatment.

Accurate detection of homologous recombination deficiency (HRD) in cancer patients is paramount in clinical applications, as HRD confers sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors. With the advances in genome sequencing technology, mutational profiling on a genome-wide scale has become readily accessible, and our knowledge of the genomic consequences of HRD has been greatly expanded and refined. Here, we review the recent advances in HRD detection methods. We examine the copy number and structural alterations that often accompany the genome instability that results from HRD, describe the advantages of mutational signature-based methods that do not rely on specific gene mutations, and review some of the existing algorithms used for HRD detection. We also discuss the choice of sequencing platforms (panel, exome, or whole-genome) and catalog the HRD detection assays used in key PARP inhibitor trials.

In recent years, the influence of specific biomarkers in the diagnosis and prognosis of solid organ malignancies has been increasingly prominent. The relevance of the use of predictive biomarkers, which predict cancer response to specific forms of treatment provided, is playing a more significant role than ever before, as it affects diagnosis and initiation of treatment, monitoring for efficacy and side effects of treatment, and adjustment in treatment regimen in the long term. In the current review, we explored the use of predictive biomarkers in the treatment of solid organ malignancies, including common cancers such as colorectal cancer, breast cancer, lung cancer, prostate cancer, and cancers associated with high mortalities, such as pancreatic cancer, liver cancer, kidney cancer and cancers of the central nervous system. We additionally analyzed the goals and types of personalized treatment using predictive biomarkers, and the management of various types of solid organ malignancies using predictive biomarkers and their relative efficacies so far in the clinical settings.

DNA damage response (DDR) deficiency has been one of the emerging targets in treating breast cancer in recent years. On the one hand, DDR coordinates cell cycle and signal transduction, whose dysfunction may lead to cell apoptosis, genomic instability, and tumor development. Conversely, DDR deficiency is an intrinsic feature of tumors that underlies their response to treatments that inflict DNA damage. In this review, we systematically explore various mechanisms of DDR, the rationale and research advances in DDR-targeted drugs in breast cancer, and discuss the challenges in its clinical applications. Notably, poly (ADP-ribose) polymerase (PARP) inhibitors have demonstrated favorable efficacy and safety in breast cancer with high homogenous recombination deficiency (HRD) status in a series of clinical trials. Moreover, several studies on novel DDR-related molecules are actively exploring to target tumors that become resistant to PARP inhibition. Before further clinical application of new regimens or drugs, novel and standardized biomarkers are needed to develop for accurately characterizing the benefit population and predicting efficacy. Despite the promising efficacy of DDR-related treatments, challenges of off-target toxicity and drug resistance need to be addressed. Strategies to overcome drug resistance await further exploration on DDR mechanisms, and combined targeted drugs or immunotherapy will hopefully provide more precise or combined strategies and expand potential responsive populations.

Circadian rhythms, the endogenous biological clocks that govern physiological processes, have emerged as pivotal regulators in the development and progression of breast cancer. This comprehensive review delves into the intricate interplay between circadian disruption and breast tumorigenesis from multifaceted perspectives, encompassing biological rhythms, circadian gene regulation, tumor microenvironment dynamics, and genetic polymorphisms.

Epidemiological evidence underscores the profound impact of external factors, such as night shift work, jet lag, dietary patterns, and exercise routines, on breast cancer risk and progression through the perturbation of circadian homeostasis. The review elucidates the distinct roles of key circadian genes, including CLOCK, BMAL1, PER, and CRY, in breast cancer biology, highlighting their therapeutic potential as molecular targets. Additionally, it investigates how circadian rhythm dysregulation shapes the tumor microenvironment, fostering epithelial-mesenchymal transition, chronic inflammation, and immunosuppression, thereby promoting tumor progression and metastasis. Furthermore, the review sheds light on the association between circadian gene polymorphisms and breast cancer susceptibility, paving the way for personalized risk assessment and tailored treatment strategies.

Importantly, it explores innovative therapeutic modalities that harness circadian rhythms, including chronotherapy, melatonin administration, and traditional Chinese medicine interventions. Overall, this comprehensive review emphasizes the critical role of circadian rhythms in the pathogenesis of breast cancer and highlights the promising prospects for the development of circadian rhythm-based interventions to enhance treatment efficacy and improve patient outcomes.

Around 25% of patients with advanced prostate cancer harbor alterations in the homologous recombination/DNA damage repair (HRR) pathway. Inhibiting poly (ADP-ribose) polymerase (PARP) in these patients leads to synthetic lethality, making PARP inhibitors (PARPi), including talazoparib, a promising treatment for metastatic castration-resistant prostate cancer (mCRPC) and potentially for metastatic hormone-sensitive prostate cancer (mHSPC).

This article examines the mechanism of action, chemical properties, pharmacokinetics, pharmacodynamics, and clinical safety and efficacy data of different PARPis, including talazoparib in prostate cancer. It reviews the TALAPRO-1 and TALAPRO-2 clinical trials and the ongoing TALAPRO-3 trial.

Despite recent therapeutic advancements, mCRPC remains a lethal disease. Androgen receptor pathway inhibitors (ARPIs) are approved for patients with mCRPC and mHSPC, yet most patients first receive these agents in the castration-resistant setting. Real-world data indicate that around half of patients with mCRPC do not receive subsequent lines of therapy, underscoring the efficacy of upfront combination therapies. The combinations of ARPI plus PARPi are indicated for patients with mCRPC harboring HRR mutations, though identifying these patients is challenging due to limited genomic testing. Further research and improved access to genomic testing are essential to optimize treatment strategies.

Navigating the complex landscape of breast cancer treatment involves distinct strategies for luminal and triple-negative subtypes. While neoadjuvant chemotherapy historically dominates the approach for aggressive triple-negative tumors, recent evidence highlights the transformative impact of immunotherapy, alongside chemotherapy, in reshaping treatment paradigms. In luminal cancers, endocrine therapy, notably aromatase inhibitors, demonstrates promising outcomes in postmenopausal patients with low-grade luminal A tumors. However, integrating targeted therapies like CDK4/6 inhibitors in neoadjuvant setting remains inconclusive. Identifying predictive factors for treatment response, especially in luminal tumors, poses a challenge, emphasizing the necessity for ongoing research. A multidisciplinary approach, tailored to individual patient profiles, is crucial for maximizing efficacy while minimizing toxicity. As we strive to optimize breast cancer management, a comprehensive understanding of the distinct characteristics and treatment implications of luminal and triple-negative subtypes, including the transformative role of immunotherapy, is essential for informed decision-making and personalized care.

The Chromodomain helicase DNA-binding protein 1-like (CHD1L) is a nucleosome remodeling enzyme, which plays a key role in chromatin relaxation during the DNA damage response. Genome editing has shown that deletion of CHD1L sensitizes cells to PARPi, but the effect of its pharmacological inhibition has not been defined. Triple-negative breast cancer SUM149PT, HCC1937, and MDA-MB-231 cells were used to assess the mechanism of action of the CHD1Li OTI-611. Cytotoxicity as a single agent or in combination with standard-of-care treatments was assessed in tumor organoids. Immunofluorescence was used to assess the translocation of PAR and AIF to the cytoplasm or the nucleus and to study markers of DNA damage or apoptosis. Trapping of PARP1/2 or CHD1L onto chromatin was also assessed by in situ subcellular fractionation and immunofluorescence and validated by Western blot. We show that the inhibition of CHD1L's ATPase activity by OTI-611 is cytotoxic to triple-negative breast cancer tumor organoids and synergizes with PARPi and chemotherapy independently of the BRCA mutation status. The inhibition of the remodeling function blocks the phosphorylation of H2AX, traps CHD1L on chromatin, and leaves PAR chains on PARP1/2 open for hydrolysis. PAR hydrolysis traps PARP1/2 at DNA damage sites and mediates PAR translocation to the cytoplasm, release of AIF from the mitochondria, and induction of PARthanatos. The targeted inhibition of CHD1L's oncogenic function by OTI-611 signifies an innovative therapeutic strategy for breast cancer and other cancers. This approach capitalizes on CHD1L-mediated DNA repair and cell survival vulnerabilities, thereby creating synergy with standard-of-care therapies.

Resistance to poly (ADP-ribose) polymerase inhibitors (PARPi) limits the therapeutic efficacy of PARP inhibition in treating breast cancer susceptibility gene 1 (BRCA1)-deficient cancers. Here we reveal that BRCA1 has a dual role in regulating ferroptosis. BRCA1 promotes the transcription of voltage-dependent anion channel 3 (VDAC3) and glutathione peroxidase 4 (GPX4); consequently, BRCA1 deficiency promotes cellular resistance to erastin-induced ferroptosis but sensitizes cancer cells to ferroptosis induced by GPX4 inhibitors (GPX4i). In addition, nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy and defective GPX4 induction unleash potent ferroptosis in BRCA1-deficient cancer cells upon PARPi and GPX4i co-treatment. Finally, we show that xenograft tumors derived from patients with BRCA1-mutant breast cancer with PARPi resistance exhibit decreased GPX4 expression and high sensitivity to PARP and GPX4 co-inhibition. Our results show that BRCA1 deficiency induces a ferroptosis vulnerability to PARP and GPX4 co-inhibition and inform a therapeutic strategy for overcoming PARPi resistance in BRCA1-deficient cancers. Significance: BRCA1 deficiency promotes resistance to erastin-induced ferroptosis via blocking VDAC3 yet renders cancer cells vulnerable to GPX4i-induced ferroptosis via inhibiting GPX4. NCOA4 induction and defective GPX4 further synergizes GPX4i with PARPi to induce ferroptosis in BRCA1-deficient cancers and targeting GPX4 mitigates PARPi resistance in those cancers. See related commentary by Alborzinia and Friedmann Angeli, p. 1372.

PARP inhibitors (PARPi) hold substantial promise in treating glioblastoma (GBM). However, the adverse effects have restricted their broad application. Through unbiased transcriptomic and proteomic sequencing, it is discovered that the BET inhibitor (BETi) Birabresib profoundly alters the processes of DNA replication and cell cycle progression in GBM cells, beyond the previously reported impact of BET inhibition on homologous recombination repair. Through in vitro experiments using established GBM cell lines and patient-derived primary GBM cells, as well as in vivo orthotopic transplantation tumor experiments in zebrafish and nude mice, it is demonstrated that the concurrent administration of PARPi and BETi can synergistically inhibit GBM. Intriguingly, it is observed that DNA damage lingers after discontinuation of PARPi monotherapy, implying that sequential administration of PARPi followed by BETi can maintain antitumor efficacy while reducing toxicity. In GBM cells with elevated baseline replication stress, the sequential regimen exhibits comparable efficacy to concurrent treatment, protecting normal glial cells with lower baseline replication stress from DNA toxicity and subsequent death. This study provides compelling preclinical evidence supporting the development of innovative drug administration strategies focusing on PARPi for GBM therapy.