The role of homologous recombination deficiency testing in ovarian cancer and its clinical implications: do we need it?

Robust Assessment of Homologous Recombination Deficiency Genomic Instability by OncoScan Microarrays

Genomic instability scars are markers for detecting homologous recombination deficiency (HRD) status in patients with ovarian cancer and predicting the response to poly (ADP-ribose) polymerase inhibitor treatment. Currently, only a few reliable and validated assays are available, with the Myriad myChoice CDx being the most commonly used commercial assay for genomic instability scar score determination. Given the need for a more straightforward, accessible, and reliable method for detecting genomic instability scars methods, in this work, we describe the feasibility of using the microarray OncoScan copy number variant assay and open-source software packages to quantify genomic instability scores, and the development of an open-access online platform for genomic instability score calculation. The laboratory-developed test accurately classified homologous recombination-proficient and recombination-deficient samples based on genomic instability scores derived from the OncoScan copy number variant assay. Internally evaluated genomic instability scores demonstrated a 92% overall agreement and a higher sample success rate compared with externally analyzed genomic instability scar scores. The availability of HRD determination has doubled the number of patients eligible for poly (ADP-ribose) polymerase therapy. The assay can be conveniently performed on individual samples, and the open-access online platform facilitates HRD determination without the need for specialized bioinformatics support.

Unraveling the complexity of HRD assessment in ovarian cancer by combining genomic and functional approaches: translational analyses of MITO16-MaNGO-OV-2 trial

BACKGROUND

Ovarian cancer (OvC) constitutes significant management challenges primarily due to its late-stage diagnosis and the development of resistance to chemotherapy. The standard treatment regimen typically includes carboplatin and paclitaxel, with the addition of poly (ADP-ribose) polymerase inhibitors for patients with high-grade serous ovarian cancer (HGSOC) harboring BRCA1/2 mutations. However, the variability in treatment responses suggests the need to investigate factors beyond BRCA1/2 mutations, such as DNA repair mechanisms and epigenetic alterations. Notably, homologous recombination repair deficiency (HRD) is observed in an additional 20% of HGSOC cases, indicating a broader spectrum of DNA repair defects. Existing commercial HRD assays have certain limitations, prompting a global effort to develop new genomic and functional tests through academic research.

MATERIALS AND METHODS

This study investigates, in the 187 high-grade serous and endometrioid tumors from the MITO16/MaNGO-OV-2 trial, academic HRD genomic tests in conjunction with a RAD51 immunofluorescence assay to assess functional activation of HRD. Additionally, the study incorporates analysis of microRNA-506 (miR-506) expression as a putative epigenetic effector.

RESULTS

The RAD51 test identified HRD in 73% of the samples and genomic HRD testing in 57%, with HRD identified in 45% of samples by both tests. The significant discrepancy between the two assays emphasizes the need to refine tumor classification for HRD. A three-group genomic classification unveiled superior progression-free survival (PFS) in high- and mild-HRD tumors compared with negative-HRD tumors. High concordance between RAD51 and genomic testing in high-HRD tumors suggests a subset of 'super-HRD' tumors exhibiting superior PFS. High expression of miR-506 may be used to further refine HRD status.

CONCLUSIONS

The study underscores the complexities of HRD assessment and advocates for a combined genomic and functional approach to enhance predictive accuracy in OvC treatment responses.

A Narrative Review of the Clinical, Humanistic, and Economic Value of Pembrolizumab-Based Immunotherapy for the Treatment of Breast and Gynecologic Cancers

Breast and gynecologic cancers are common across the world and are associated with substantial societal and economic burden. Pembrolizumab was among the first immune checkpoint inhibitors targeting programmed cell death protein 1 to be approved for the treatment of patients with triple-negative breast cancer, cervical cancer, and endometrial cancer. Recent clinical trials have established pembrolizumab regimens as a standard of care treatment for these tumor types. Clinical data are further supported by patient-reported outcome, cost-effectiveness, and real-world evidence. Pembrolizumab monotherapy and combination regimens do not negatively influence health-related quality of life and are cost-effective relative to comparators. Ongoing phase 3 studies with pembrolizumab will expand the current understanding of its use in breast and gynecologic cancers. Several of these studies are in patients with early-stage disease with the hope of curing patients. The main objective of this review is to summarize the clinical, humanistic, and economic value of pembrolizumab in these settings and to describe the future challenges for patients, caregivers, clinicians, and payers.

Pan-Cancer Analysis of Homologous Recombination Deficiency in Cell Lines

SIGNIFICANCE

HRD is common in cancer and can be exploited therapeutically, as it sensitizes cells to DNA-damaging agents. Here, we scored more than 1,300 cancer cell lines for HRD using two different bioinformatic approaches, thereby enabling large-scale analyses that provide insights into the etiology and features of HRD.

BRCA loss of function including BRCA1 DNA-methylation, but not BRCA-unrelated homologous recombination deficiency, is associated with platinum hypersensitivity in high-grade ovarian cancer

BACKGROUND

In high-grade ovarian cancer (HGOC), determination of homologous recombination deficiency (HRD) status is commonly used in routine practice to predict response to platinum-based therapy or poly (ADP-ribose) polymerase inhibitors (PARPi). Here we tested the hypothesis that BRCA loss of function (LOF) due to epigenetic or genetic aberrations is a better predictor for the clinical outcome than HRD. One hundred thirty-one HGOC tissues were tested for BRCA DNA-methylation, BRCA mutations, HRD and BRCA1 mRNA expression, followed by a comprehensive survival analysis.

RESULTS

BRCA1-methylation was detected in 11% of the tumors, exclusively in BRCA1-wild-type (wt) HGOCs. BRCA1-methylated tumors (BRCA1-meth) had HRD-scores similar to those of BRCA-mutated (mut) tumors, and higher compared to unmethylated-BRCA-wt tumors (BRCA-wt-unmeth; P < 0.001). Platinum-refractory or -resistant HGOCs at first recurrence were all BRCA-unmeth cancers. Only one of the BRCA-mut cancers had a platinum-resistant recurrence. Thus, 99% of relapses in cancers with epigenetic or genetic BRCA-alterations were platinum-sensitive. Multivariate analysis confirmed BRCA-LOF as an independent predictor of progression-free survival (PFS) and overall survival (OS), whereas HRD-status had no predictive value for PFS and OS. Patients with BRCA-wt-unmeth cancers had the worst outcome compared to patients with cancers harboring epigenetic or genetic BRCA-alterations (PFS: P = 0.007; OS: P = 0.022). Most importantly, the BRCA-wt-unmeth subfraction of HRD-positive HGOCs exhibited the same poor survival as the entire HRD-negative cohort.

CONCLUSION

In HGOC BRCA mutational status together with BRCA1-methylation exhibit the best predictive power for favorable clinical outcome and thus high sensitivity to platinum-based therapy, whereas BRCA-unrelated HRD positivity was not associated with improved platinum sensitivity.

Drug resistance biomarkers in ovarian cancer: a bibliometric study from 2017 to 2022

Background

Late diagnosis and patient relapse, mainly due to chemoresistance, are the key reasons for the high mortality rate of ovarian cancer patients. Hence, the search for biomarkers of high predictive value within the phenomenon of chemoresistance is vital. This study performs a bibliometric analysis of the scientific literature concerning biomarkers of drug resistance in ovarian cancer, considering the period from 2017 to 2022.

Methods

The terms "drug resistance biomarker" and "ovarian cancer" were linked by the Boolean operator "AND". The search was done in PubMed, selecting documents published over the last 5 years (2017-2022), which were analyzed with the open-source tool Bibliometrix developed in the R package. The language of the publications was restricted to English. Several types of papers such as case reports, clinical trials, comparative studies, and original articles were considered.

Results

A total of 335 scientific articles were analyzed. The United States and China were the leading contributors and established the largest number of scientific collaborations. The Huazhong University of Science and Technology and the University of Texas MD Anderson Cancer Center were the most influential institutions. The Journal of Ovarian Research, International Journal of Molecular Science, and Scientific Reports are among the most relevant journals. The study identified high-profile, relevant thematic niches and important descriptors that indicate topics of interest, including studies on women, cell lines, solid tumors, and gene expression regulation. As well as studies involving middle-aged and adult participants, and those focusing on prognosis evaluation. Descriptors such as "drug resistance," "neoplasm," "genetics," "biomarker," "gene expression profile," and "drug therapy" would indicate new research trends. In addition, we propose that BCL-2, CHRF, SNAIL, miR-363, iASPP, ALDH1, Fzd7, and EZH2 are potential biomarkers of drug resistance.

Conclusions

This paper contributes to the global analysis of the scientific investigation related to drug resistance biomarkers in ovarian cancer to facilitate further studies and collaborative networks, which may lead to future improvements in therapy for this lethal disease.

Dual Targeting of CX3CR1 and PARP in Models of High-Grade Serous Ovarian Carcinoma

BACKGROUND/OBJECTIVES

Clinical use of poly(ADP-ribose) polymerase inhibitors (PARPis) against metastatic high-grade serous ovarian carcinoma (HGSOC) is limited to cases with deficient a homologous recombination (HR). Our objective was to determine whether the impairment of the fractalkine receptor (CX3CR1) could sensitize HR-proficient cases to PARPis.

METHODS

The efficacy of a dual drug combination, including AZD8797, an inhibitor of CX3CR1, and several PARPis was examined using cell lines and xenograft models.

RESULTS

The effectiveness of PARPis and AZD8797 drug combinations ranged from additive to strongly synergistic. Olaparib was synergistic with AZD8797 in OVCAR-4, Caov-3, and OHSAHO. Niraparib and AZD8797 produced synergy in OVCAR-4 and ES2. Rucaparib and AZD8797 were strongly synergistic in Caov-3 and OVSAHO. Veliparib was strongly synergistic with AZD8797 in OVCAR-4 and Caov-3. Notably, a combination of veliparib and AZD8797 produced a strong synergistic effect in a xenograft model.

CONCLUSIONS

While the exact mechanisms determining the nature of the PARPis and AZD8797 interaction remain to be uncovered, our data indicate that, in a subset of models, selected PARPis strongly synergize with the inhibition of CX3CR1, suggesting a potential therapeutic opportunity.

Emerging strategies to overcome PARP inhibitors' resistance in ovarian cancer

The utilization of PARP inhibitors (PARPis) has significantly improved the prognosis for ovarian cancer patients. However, as the use of PARPis increases, the issue of PARPi resistance has become more prominent. Prolonged usage of PARPis can lead to the development of resistance in ovarian cancer, often mediated by mechanisms such as homologous recombination (HR) recovery, ultimately resulting in cancer relapse. Overcoming PARPi resistance in ovarian cancer is a pressing concern, aiming to enhance the clinical benefits of PARPi treatment and delay disease recurrence. Here, we summarize the mechanisms underlying PARPi resistance, methods for analyzing resistance, and strategies for overcoming it. Our goal is to inspire the development of more cost-effective and convenient methods for analyzing resistance mechanisms, as well as safer and more effective strategies to overcome resistance. These advancements can contribute to developing personalized approaches for treating ovarian cancer.

Deep Learning Artificial Intelligence Predicts Homologous Recombination Deficiency and Platinum Response From Histologic Slides

PURPOSE

Cancers with homologous recombination deficiency (HRD) can benefit from platinum salts and poly(ADP-ribose) polymerase inhibitors. Standard diagnostic tests for detecting HRD require molecular profiling, which is not universally available.

METHODS

We trained DeepHRD, a deep learning platform for predicting HRD from hematoxylin and eosin (H&E)-stained histopathological slides, using primary breast (n = 1,008) and ovarian (n = 459) cancers from The Cancer Genome Atlas (TCGA). DeepHRD was compared with four standard HRD molecular tests using breast (n = 349) and ovarian (n = 141) cancers from multiple independent data sets, including platinum-treated clinical cohorts with RECIST progression-free survival (PFS), complete response (CR), and overall survival (OS) endpoints.

RESULTS

DeepHRD predicted HRD from held-out H&E-stained breast cancer slides in TCGA with an AUC of 0.81 (95% CI, 0.77 to 0.85). This performance was confirmed in two independent primary breast cancer cohorts (AUC, 0.76 [95% CI, 0.71 to 0.82]). In an external platinum-treated metastatic breast cancer cohort, samples predicted as HRD had higher complete CR (AUC, 0.76 [95% CI, 0.54 to 0.93]) with 3.7-fold increase in median PFS (14.4 v 3.9 months; P = .0019) and hazard ratio (HR) of 0.45 (P = .0047). There were no significant differences in nonplatinum treatment outcome by predicted HRD status in three breast cancer cohorts, including CR (AUC, 0.39) and PFS (HR, 0.98, P = .95) in taxane-treated metastatic breast cancer. Through transfer learning to high-grade serous ovarian cancer, DeepHRD-predicted HRD samples had better OS after first-line (HR, 0.46; P = .030) and neoadjuvant (HR, 0.49; P = .015) platinum therapy in two cohorts.

CONCLUSION

DeepHRD can predict HRD in breast and ovarian cancers directly from routine H&E slides across multiple external cohorts, slide scanners, and tissue fixation variables. When compared with molecular testing, DeepHRD classified 1.8- to 3.1-fold more patients with HRD, which exhibited better OS in high-grade serous ovarian cancer and platinum-specific PFS in metastatic breast cancer.

Prediction of homologous recombination deficiency from routine histology with attention-based multiple instance learning in nine different tumor types

BACKGROUND

Homologous recombination deficiency (HRD) is recognized as a pan-cancer predictive biomarker that potentially indicates who could benefit from treatment with PARP inhibitors (PARPi). Despite its clinical significance, HRD testing is highly complex. Here, we investigated in a proof-of-concept study whether Deep Learning (DL) can predict HRD status solely based on routine hematoxylin & eosin (H&E) histology images across nine different cancer types.

METHODS

We developed a deep learning pipeline with attention-weighted multiple instance learning (attMIL) to predict HRD status from histology images. As part of our approach, we calculated a genomic scar HRD score by combining loss of heterozygosity (LOH), telomeric allelic imbalance (TAI), and large-scale state transitions (LST) from whole genome sequencing (WGS) data of n = 5209 patients across two independent cohorts. The model's effectiveness was evaluated using the area under the receiver operating characteristic curve (AUROC), focusing on its accuracy in predicting genomic HRD against a clinically recognized cutoff value.

RESULTS

Our study demonstrated the predictability of genomic HRD status in endometrial, pancreatic, and lung cancers reaching cross-validated AUROCs of 0.79, 0.58, and 0.66, respectively. These predictions generalized well to an external cohort, with AUROCs of 0.93, 0.81, and 0.73. Moreover, a breast cancer-trained image-based HRD classifier yielded an AUROC of 0.78 in the internal validation cohort and was able to predict HRD in endometrial, prostate, and pancreatic cancer with AUROCs of 0.87, 0.84, and 0.67, indicating that a shared HRD-like phenotype occurs across these tumor entities.

CONCLUSIONS

This study establishes that HRD can be directly predicted from H&E slides using attMIL, demonstrating its applicability across nine different tumor types.

Predictive value of homologous recombination deficiency status for survival outcomes in primary tubo-ovarian high-grade serous carcinoma

OBJECTIVES

This is a protocol for a Cochrane Review (prognosis). The objectives are as follows: To evaluate the predictive value of the prognostic factor HRD status, as determined by various clinically validated HRD assays at the time of staging laparotomy, compared to BRCA1/2 mutation status for progression-free survival and overall survival in patients with tubo-ovarian high-grade serous carcinoma treated in the first-line setting with a combination of surgery and platinum-based chemotherapy and/or maintenance with PARP inhibitors.

The intersection of homologous recombination (HR) and mismatch repair (MMR) pathways in DNA repair-defective tumors

Homologous recombination (HR) and mismatch repair (MMR) defects are driver mutational imprints and actionable biomarkers in DNA repair-defective tumors. Although usually thought as mutually exclusive pathways, recent preclinical and clinical research provide preliminary evidence of a functional crosslink and crosstalk between HRR and MMR. Shared core proteins are identified as key players in both pathways, broadening the concept of DNA repair mechanism exclusivity in specific tumor types. These observations may result in unexplored forms of synthetic lethality or hypermutable tumor phenotypes, potentially impacting the cancer risk management, and considerably expanding in the future the therapeutic window for DNA repair-defective tumors.

Current HRD assays in ovarian cancer: differences, pitfalls, limitations, and novel approaches

Ovarian carcinoma (OC) still represents an insidious and fatal malignancy, and few significant results have been obtained in the last two decades to improve patient survival. Novel targeted therapies such as poly (ADP-ribose) polymerase inhibitors (PARPi) have been successfully introduced in the clinical management of OC, but not all patients will benefit, and drug resistance almost inevitably occurs. The identification of patients who are likely to respond to PARPi-based therapies relies on homologous recombination deficiency (HRD) tests, as this condition is associated with response to these treatments. This review summarizes the genomic and functional HRD assays currently used in clinical practice and those under evaluation, the clinical implications of HRD testing in OC, and their current pitfalls and limitations. Special emphasis will be placed on the functional HRD assays under development and the use of machine learning and artificial intelligence technologies as novel strategies to overcome the current limitations of HRD tests for a better-personalized treatment to improve patient outcomes.

Homologous recombination deficiency should be tested for in patients with advanced stage high-grade serous ovarian cancer aged 70 years and over

OBJECTIVE

Due to limited data on homologous recombination deficiency (HRD) in older patients (≥ 70 years) with advanced stage high grade serous ovarian cancer (HGSC), we aimed to determine the rates of HRD at diagnosis in this age group.

METHODS

From the Phase 3 trial VELIA the frequency of HRD and BRCA1/2 pathogenic variants (PVs) was compared between younger (< 70 years) and older participants. HRD and somatic(s) BRCA1/2 pathogenic variants (PVs) were determined at diagnosis using Myriad myChoice® CDx and germline(g) BRCA1/2 PVs using Myriad BRACAnalysis CDx®. HRD was defined if a BRCA PV was present, or the genomic instability score (GIS) met threshold (GIS ≥ 33 & ≥ 42 analyzed).

RESULTS

Of 1140 participants, 21% were ≥ 70 years. In total, 26% (n = 298) had a BRCA1/2 PV and HRD, 29% (n = 329) were HRD/BRCA wild-type, 33% (n = 372) non-HRD, and 12% HR-status unknown (n = 141). HRD rates were higher in younger participants, 59% (n = 476/802), compared to 40% (n = 78/197) of older participants (GIS ≥ 42) [p < 0.001]; similar rates demonstrated with GIS ≥ 33, 66% vs 48% [p < 0.001]. gBRCA PVs observed in 24% younger vs 8% of older participants (p < 0.001); sBRCA in 8% vs 10% (p = 0.2559), and HRD (GIS ≥ 42) not due to gBRCA was 35% vs 31% (p = 0.36).

CONCLUSIONS

HRD frequency was similar in participants aged < 70 and ≥ 70 years (35% vs 31%) when the contribution of gBRCA was excluded; rates of sBRCA PVs were also similar (8% v 10%), thus underscoring the importance of HRD and BRCA testing at diagnosis in older patients with advanced HGSC given the therapeutic implications.

expHRD: an individualized, transcriptome-based prediction model for homologous recombination deficiency assessment in cancer

BACKGROUND

Homologous recombination deficiency (HRD) stands as a clinical indicator for discerning responsive outcomes to platinum-based chemotherapy and poly ADP-ribose polymerase (PARP) inhibitors. One of the conventional approaches to HRD prognostication has generally centered on identifying deleterious mutations within the BRCA1/2 genes, along with quantifying the genomic scars, such as Genomic Instability Score (GIS) estimation with scarHRD. However, the scarHRD method has limitations in scenarios involving tumors bereft of corresponding germline data. Although several RNA-seq-based HRD prediction algorithms have been developed, they mainly support cohort-wise classification, thereby yielding HRD status without furnishing an analogous quantitative metric akin to scarHRD. This study introduces the expHRD method, which operates as a novel transcriptome-based framework tailored to n-of-1-style HRD scoring.

RESULTS

The prediction model has been established using the elastic net regression method in the Cancer Genome Atlas (TCGA) pan-cancer training set. The bootstrap technique derived the HRD geneset for applying the expHRD calculation. The expHRD demonstrated a notable correlation with scarHRD and superior performance in predicting HRD-high samples. We also performed intra- and extra-cohort evaluations for clinical feasibility in the TCGA-OV and the Genomic Data Commons (GDC) ovarian cancer cohort, respectively. The innovative web service designed for ease of use is poised to extend the realms of HRD prediction across diverse malignancies, with ovarian cancer standing as an emblematic example.

CONCLUSIONS

Our novel approach leverages the transcriptome data, enabling the prediction of HRD status with remarkable precision. This innovative method addresses the challenges associated with limited available data, opening new avenues for utilizing transcriptomics to inform clinical decisions.

Harmonization of homologous recombination deficiency testing in ovarian cancer: Results from the MITO16A/MaNGO-OV2 trial

BACKGROUND

Homologous Recombination Deficiency (HRD) status predicts response to treatment with poly(ADP-ribose) polymerase inhibitors in Ovarian Cancer (OC) patients. The Myriad myChoiceCDx Assay is approved by Food and Drug Agency for the HRD assessment. Here we compared the HRD status obtained by three commercial panels with the results from Myriad reference test.

METHODS

The HRD analysis was performed on DNA from formalin-fixed and paraffin-embedded tumor samples of 100 untreated OC patients for which Myriad assay results were available, using TruSight Oncology 500 HRD assay (Illumina), Oncomine Comprehensive Assay Plus (Thermo Fisher Scientific) and SOPHiA DDM HRD solution panel (SOPHiA Genetics).

RESULTS

A good overall concordance with the reference method was demonstrated at three different levels: BRCA mutational status (from 94.4 % to 97.7 %), the genomic instability value (from 88.2 % to 95.3 %) and for the HRD status (from 90.4 % to 97.6 %). Moreover, a trend in favour of HRD positive patients for response rate, progression-free survival and overall survival similar to Myriad was observed for all three tests.

DISCUSSION

Our data suggest the feasibility of commercial testing for assessing HRD status, with a good concordance with the reference method and association with clinical outcome.

BRCA1 foci test as a predictive biomarker of olaparib response in ovarian cancer patient-derived xenograft models

Standard therapy for high-grade ovarian carcinoma includes surgery followed by platinum-based chemotherapy and poly-ADP ribose polymerase inhibitors (PARPis). Deficiency in homologous recombination repair (HRD) characterizes almost half of high-grade ovarian carcinomas and is due to genetic and epigenetic alterations in genes involved in HR repair, mainly BRCA1/BRCA2, and predicts response to PARPi. The academic and commercial tests set up to define the HRD status of the tumor rely on DNA sequencing analysis, while functional tests such as the RAD51 foci assay are currently under study, but have not been validated yet and are available for patients. In a well-characterized ovarian carcinoma patient-derived xenograft platform whose response to cisplatin and olaparib, a PARPi, is known, we assessed the association between the BRCA1 foci score, determined in formalin-fixed paraffin-embedded tumor slices with an immunofluorescence technique, and other HRD biomarkers and explored the potential of the BRCA1 foci test to predict tumors' response to cisplatin and olaparib. The BRCA1 foci score was associated with both tumors' HRD status and RAD51 foci score. A low BRCA1 foci score predicted response to olaparib and cisplatin, while a high score was associated with resistance to therapy. As we recently published that a low RAD51 foci score predicted olaparib sensitivity in our xenobank, we combined the two scores and showed that the predictive value was better than with the single tests. This study reports for the first time the capacity of the BRCA1 foci test to identify HRD ovarian carcinomas and possibly predict response to olaparib.

In-house homologous recombination deficiency testing in ovarian cancer: a multi-institutional Italian pilot study

AIMS

Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPIs) represent a standard of care for the clinical management of high-grade serous ovarian cancer (HGSOC). The recognition of homologous recombination deficiency (HRD) has emerged as a predictive biomarker of response for first-line PARPIs treatment in patients with HGOSC. On the other hand, this test is extremely complex and therefore it is often externalised. Regrettably, the reliability of outsourced HRD testing can be troubled by inconclusive results and high rejection rates. In this methodological study, we assessed the technical feasibility, interassay and interlaboratory reproducibility of in-house HRD testing using three different commercially available next-generation sequencing assays.

METHODS

A total of n=20 epithelial ovarian cancer samples previously analysed with MyChoice CDx were subjected to HRD retesting using three different platforms in three different major pathology laboratories, that is, SOPHiA DDM HRD Solution, HRD focus and Oncomine homologous recombination repair pathway predesigned panel. Concordance was calculated by Cohen's (dual) and Fleiss (triple) κ coefficients.

RESULTS

In-house BRCA1/2 molecular testing yielded a concordance rate >90.0% among all participating centres. HRD scores were successfully calculated by each institution with a concordance rate of 76.5%. Concerning the external gold standard test, the overall percentage of agreement ranged from 80.0% to 90.0% with a positive percentage agreement ranging from 75.0% to 80.0% and a negative percentage agreement ranging from 80.0% to 100%.

CONCLUSIONS

In-house testing for HRD can be reliably performed with commercially available next-generation sequencing assays.

Identification of CXCL13 as a Promising Biomarker for Immune Checkpoint Blockade Therapy and PARP Inhibitor Therapy in Ovarian Cancer

Ovarian cancer has poor response rates to immune checkpoint blockade (ICB) therapy, despite the use of genomic sequencing to identify molecular targets. Homologous recombination deficiency (HRD) is a conventional indicator of genomic instability (GI) and has been used as a marker for targeted therapies. Indicators reflecting HRD status have shown potential in predicting the efficacy of ICB treatment. Public databases, including TCGA, ICGC, and GEO, were used to obtain data. HRD scores, neoantigen load, and TMB were obtained from the TCGA cohort. Candidate biomarkers were validated in multiple databases, such as the Imvigor210 immunotherapy cohort and the open-source single-cell sequencing database. Immunohistochemistry was performed to further validate the results in independent cohorts. CXCL10, CXCL11, and CXCL13 were found to be significantly upregulated in HRD tumors and exhibited prognostic value. A comprehensive analysis of the tumor immune microenvironment (TIME) revealed that CXCL13 expression positively correlated with neoantigen load and immune cell infiltration. In addition, single-cell sequencing data and clinical trial results supported the utility of CXCL13 as a biomarker for ICB therapy. Not only does CXCL13 serve as a biomarker reflecting HRD status, but it also introduces a potentially novel perspective on prognostic biomarkers for ICB in ovarian cancer.

Stratification of Homologous Recombination Deficiency-Negative High-Grade Ovarian Cancer by the Type of Peritoneal Spread into Two Groups with Distinct Survival Outcomes

BACKGROUND

Homologous recombination deficiency (HRD) has evolved into a major diagnostic marker in high-grade ovarian cancer (HGOC), predicting the response to poly (adenosine diphosphate-ribose) polymerase inhibitors (PARPi) and also platinum-based therapy. In addition to HRD, the type of peritoneal tumor spread influences the treatment response and patient survival; miliary type tumor spread has a poorer predicted outcome than non-miliary type tumor spread.

METHODS

Known methods for HRD assessment were adapted for our technical requirements and the predictive-value integrated genomic instability score (PIGIS) for HRD assessment evolved as an outcome. PIGIS was validated in HGOC samples from 122 patients. We used PIGIS to analyze whether the type of tumor spread correlated with HRD status and whether this had an impact on survival.

RESULTS

We demonstrated that PIGIS can discriminate HRD-positive from HRD-negative samples. Tumors with a miliary tumor spread are HRD-negative and have a very bad prognosis with a progression-free survival (PFS) of 15.6 months and an overall survival (OS) of 3.9 years. However, HRD-negative non-miliary spreading tumors in our cohort had a much better prognosis (PFS 35.4 months, OS 8.9 years); similar to HRD-positive tumors (PFS 34.7 months, OS 8.9 years).

CONCLUSIONS

Our results indicate that in a predominantly PARPi naïve cohort, the type of tumor spread and concomitant cytoreduction efficiency is a better predictor of survival than HRD and that HRD may be an accidental surrogate marker for tumor spread and concomitant cytoreduction efficiency. It remains to be determined whether this also applies for sensitivity to PARPi.

TP53-specific mutations serve as a potential biomarker for homologous recombination deficiency in breast cancer: a clinical next-generation sequencing study

Background

TP53 mutations and homologous recombination deficiency (HRD) occur frequently in breast cancer. However, the characteristics of TP53 pathogenic mutations in breast cancer patients with/without HRD are not clear.

Methods

Clinical next-generation sequencing (NGS) of both tumor and paired blood DNA from 119 breast cancer patients (BRCA-119 cohort) was performed with a 520-gene panel. Mutations, tumor mutation burden (TMB), and genomic HRD scores were assessed from NGS data. NGS data from 47 breast cancer patients in the HRD test cohort were analyzed for further verification.

Results

All TP53 pathogenic mutations in patients had somatic origin, which was associated with the protein expression of estrogen receptor and progestogen receptor. Compared to patients without TP53 pathologic mutations, patients with TP53 pathologic mutations had higher levels of HRD scores and different genomic alterations. The frequency of TP53 pathologic mutation was higher in the HRD-high group (HRD score ≥ 42) relative to that in the HRD-low group (HRD score < 42). TP53 has different mutational characteristics between the HRD-low and HRD-high groups. TP53-specific mutation subgroups had diverse genomic features and TMB. Notably, TP53 pathogenic mutations predicted the HRD status of breast cancer patients with an area under the curve (AUC) of 0.61. TP53-specific mutations, namely HRD-low mutation, HRD-high mutation, and HRD common mutation, predicted the HRD status of breast cancer patients with AUC values of 0.32, 0.72, and 0.58, respectively. Interestingly, TP53 HRD-high mutation and HRD common mutation combinations showed the highest AUC values (0.80) in predicting HRD status.

Conclusions

TP53-specific mutation combinations predict the HRD status of patients, indicating that TP53 pathogenic mutations could serve as a potential biomarker for poly-ADP-ribose polymerase (PARP) inhibitors in breast cancer patients .

Comprehensive genomic profiling and therapeutic implications for Taiwanese patients with treatment-naïve breast cancer

BACKGROUND

Breast cancer is a heterogeneous disease categorized based on molecular characteristics, including hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) expression levels. The emergence of profiling technology has revealed multiple driver genomic alterations within each breast cancer subtype, serving as biomarkers to predict treatment outcomes. This study aimed to explore the genomic landscape of breast cancer in the Taiwanese population through comprehensive genomic profiling (CGP) and identify diagnostic and predictive biomarkers.

METHODS

Targeted next-generation sequencing-based CGP was performed on 116 archived Taiwanese breast cancer specimens, assessing genomic alterations (GAs), including single nucleotide variants, copy number variants, fusion genes, tumor mutation burden (TMB), and microsatellite instability (MSI) status. Predictive variants for FDA-approved therapies were evaluated within each subtype.

RESULTS

In the cohort, frequent mutations included PIK3CA (39.7%), TP53 (36.2%), KMT2C (9.5%), GATA3 (8.6%), and SF3B1 (6.9%). All subtypes had low TMB, with no MSI-H tumors. Among HR + HER2- patients, 42% (27/65) harbored activating PIK3CA mutations, implying potential sensitivity to PI3K inhibitors and resistance to endocrine therapies. HR + HER2- patients exhibited intrinsic hormonal resistance via FGFR1 gene gain/amplification (15%), exclusive of PI3K/AKT pathway alterations. Aberrations in the PI3K/AKT/mTOR and FGFR pathways were implicated in chemoresistance, with a 52.9% involvement in triple-negative breast cancer. In HER2+ tumors, 50% harbored GAs potentially conferring resistance to anti-HER2 therapies, including PIK3CA mutations (32%), MAP3K1 (2.9%), NF1 (2.9%), and copy number gain/amplification of FGFR1 (18%), FGFR3 (2.9%), EGFR (2.9%), and AKT2 (2.9%).

CONCLUSION

This study presents CGP findings for treatment-naïve Taiwanese breast cancer, emphasizing its value in routine breast cancer management, disease classification, and treatment selection.

Therapeutic applications of germline testing for cancer predisposition genes in Asia in the real world

BACKGROUND

Germline genetic testing is traditionally carried out in patients suspected with hereditary cancer syndrome for enhanced cancer surveillance and/or preventive strategies, but is increasingly carried out for therapeutic indications.

MATERIALS AND METHODS

We conducted a retrospective review of patients who underwent germline genetic testing at our centre to determine the prevalence of actionable pathogenic germline variants (PGV) and their clinical utility.

RESULTS

From 2000 to 2022, 1154 cancer patients underwent germline testing, with the majority (945/1154) tested with multi-gene panels. Four hundred and eleven (35.6%) patients harboured a PGV and 334 (81%) were clinically actionable. BRCA1/2 accounted for 62.3% of actionable mutations, followed by mismatch repair (18%), and other homologous recombination repair (HRR) genes (19.7%). One hundred and fifty-two germline-positive patients have advanced cancers, and 79 received germline-directed therapies (poly ADP ribose polymerase inhibitors = 75; immunotherapy = 4). Median duration of immunotherapy and poly ADP ribose polymerase were 20.5 months (range 5-40 months) and 8 months (range 1-76 months), respectively. Among BRCA/HRR mutation carriers who received platinum-based chemotherapy, pathological complete response rate in the neoadjuvant setting was 53% (n = 17 breast cancers) and objective response rate was >80% in the advanced setting (n = 71).

CONCLUSIONS

One-third of cancer patients tested carried a PGV and ∼80% were clinically actionable. Three-quarters of germline-positive advanced cancer patients received germline-directed therapies in the real world, underscoring the practical utility of germline testing to guide cancer therapeutics.

Systematic Analysis of Homologous Recombination Deficiency Testing in Ovarian Cancer-Development of Recommendations for Optimal Assay Performance

Homologous recombination deficiency (HRD) assays are an important element of personalized oncology in ovarian carcinomas, but the optimal tissue requirements for these complex molecular assays remain unclear. As a result, a considerable percentage of assays are not successful, leading to suboptimal diagnoses for these patients. In this study, we have systematically analyzed tumor and tissue parameters for HRD analysis in a large cohort of real-world cancer samples. The aim of this study is to give recommendations for pathologists and gynecologic oncologists for selection of tissue samples to maximize the success rate of HRD analyses. Tumor samples from 2702 patients were sent to the Institute of Pathology of the Philipps-University Marburg between October 2020 and September 2022, of which 2654 were analyzed using the Myriad MyChoice HRD+ CDx assay. A total of 2396 of 2654 samples (90.3%) were successfully tested, of which 984 of 2396 (41.1%) were HRD positive and 1412 (58.9%) were HRD negative. Three hundred sixty-three of 2396 samples (15.2%) were BRCA1/2-mutated; 27 samples had a BRCA1/2 mutation and a genomic instability score (GIS) < 42. Twenty-two samples (0.9%) failed GIS measurement but displayed a BRCA1/2 mutation. BRCA1/2-mutated samples showed significantly (P < .0001) higher GIS values than those with a wild-type BRCA1/2 status. Tumor cell content, tumor area, and histology significantly (P < .0001) affected the probability of successfully analyzing a sample. Based on a systematic analysis of tumor cell content and tumor area, we recommend selecting patient high-grade serous ovarian cancer samples that display a tumor cell content ≥30% and a tumor area ≥0.5 cm2 (based on their hematoxylin and eosin) for HRD testing to allow for optimal chances of a successful analysis and conclusive results. Considering histologic and sample conditions, success rates of up to 98% can be achieved. Our comprehensive evaluation contributes to further standardization of recommendations on HRD testing in ovarian cancer, which will have a large impact on personalized therapeutic strategies in this highly aggressive tumor type.

How BRCA and homologous recombination deficiency change therapeutic strategies in ovarian cancer: a review of literature

About 50% of High Grade Serous Ovarian Cancer exhibit a high degree of genomic instability due to mutation of genes involved in Homologous Recombination (HRD) and such defect accounts for synthetic lethality mechanism of PARP inhibitors (PARP-i). Several clinical trials have shown how BRCA and HRD mutational status profoundly affect first line chemotherapy as well as response to maintenance therapy with PARP-i, hence Progression Free Survival and Overall Survival. Consequently, there is urgent need for the development of increasingly reliable HRD tests, overcoming present limitations, as they play a key role in the diagnostic and therapeutic process as well as have a prognostic and predictive value. In this review we offer an overview of the state of the art regarding the actual knowledge about BRCA and HRD mutational status, the rationale of PARPi use and HRD testing (current and in development assays) and their implications in clinical practice and in the treatment decision process, in order to optimize and choose the best tailored therapy in patients with ovarian cancer.

Targeting BRCA and PALB2 in Pancreatic Cancer

OPINION STATEMENT

An important subgroup of pancreatic ductal adenocarcinomas (PDACs) harbor pathogenic variants in BRCA1, BRCA2, or PALB2. These tumors are exquisitely sensitive to platinum-based chemotherapy and patients may experience deep and durable responses to this treatment. PARP inhibitors offer potential respite from the cumulative toxicities of chemotherapy as they significantly extend progression-free survival compared to a chemotherapy holiday. Given the lack of proven survival benefit, the decision to use a maintenance PARP inhibitor rather than continue chemotherapy should be individualized. Interestingly, in both published clinical trials of maintenance PARP inhibitors, there is a striking range of interpatient benefit: Even in the platinum-sensitive setting, roughly 25% of tumors appear to be PARP inhibitor refractory (progressive disease within 2 months of starting treatment), 50% sustain moderate benefit (up to 2 years), and 25% are hyper-responsive (more than 2 years of benefit). This finding highlights the need to refine our understanding of which patients will respond to maintenance PARP inhibitors, both by being able to identify biallelic loss and by deepening our knowledge of resistance mechanisms and who develops them. Recent data supports that reversion mutations are common in PARP inhibitor refractory patients, but we have little understanding of the mechanisms that drive delayed resistance and long-term responses. Identifying which patients are more prone to certain mechanisms of resistance and tackling them with specific treatment strategies are areas of active investigation. Additionally, given that PARP inhibitors have limited overall efficacy for most patients, upfront combination strategies are an important future strategy.

Predictive and prognostic biomarkers in female genital tract tumours: an update highlighting their clinical relevance and practical issues

The evaluation of biomarkers by molecular techniques and immunohistochemistry has become increasingly relevant to the treatment of female genital tract tumours as a consequence of the greater availability of therapeutic options and updated disease classifications. For ovarian cancer, mutation testing for BRCA1/2 is the standard predictive biomarker for poly(ADP-ribose) polymerase inhibitor therapy, while homologous recombination deficiency testing may allow the identification of eligible patients among cases without demonstrable BRCA1/2 mutations. Clinical recommendations are available which specify how these predictive biomarkers should be applied. Mismatch repair (MMR) protein and folate receptor alpha immunohistochemistry may also be used to guide treatment in ovarian cancer. In endometrial cancer, MMR immunohistochemistry is the preferred test for predicting benefit from immune checkpoint inhibitor (ICI) therapy, but molecular testing for microsatellite instability may have a supplementary role. HER2 testing by immunohistochemistry and in situ hybridisation is applicable to endometrial serous carcinomas to assess trastuzumab eligibility. Immunohistochemistry for oestrogen receptor and progesterone receptor expression may be used for prognostication in endometrial cancer, but its predictive value for hormonal therapy is not yet proven. POLE mutation testing and p53 immunohistochemistry (as a surrogate for TP53 mutation status) serve as prognostic markers for favourable and adverse outcomes, respectively, in endometrial cancer, especially when combined with MMR testing for molecular subtype designation. For cervical cancer, programmed death ligand 1 immunohistochemistry may be used to predict benefit from ICI therapy although its predictive value is under debate. In vulvar cancer, p16 and p53 immunohistochemistry has established prognostic value, stratifying patients into three groups based on the human papillomavirus and TP53 mutation status of the tumour. Awareness of the variety and pitfalls of expression patterns for p16 and p53 in vulvar carcinomas is crucial for accurate designation. It is hoped that collaborative efforts in standardising and optimising biomarker testing for gynaecological tumours will contribute to evidence-based therapeutic decisions.

Early adenocarcinoma mixed with a neuroendocrine carcinoma component arising in the gastroesophageal junction: A case report

BACKGROUND

Early adenocarcinoma mixed with a neuroendocrine carcinoma (NEC) component arising in the gastroesophageal junctional (GEJ) region is rare and even rarer in young patients. Here, we report such a case in a 29-year-old Chinese man.

CASE SUMMARY

This patient presented to our hospital with a 3-mo history of dysphagia and regurgitation. Upper endoscopy revealed an elevated nodule in the distal esophagus 1.6 cm above the GEJ line, without Barrett's esophagus or involvement of the gastric cardia. The nodule was completely resected by endoscopic submucosal dissection (ESD). Pathological examination confirmed diagnosis of intramucosal adenocarcinoma mixed with an NEC component, measuring 1.5 cm. Immunohistochemically, both adenocarcinoma and NEC components were positive for P53 with a Ki67 index of 90%; NEC was positive for synaptophysin and chromogranin. Next-generation sequencing of 196 genes demonstrated a novel germline mutation of the ERCC3 gene in the DNA repair pathway and a germline mutation of the RNF43 gene, a common gastric cancer driver gene, in addition to pathogenic somatic mutations in P53 and CHEK2 genes. The patient was alive without evidence of the disease 36 mo after ESD.

CONCLUSION

Early adenocarcinoma with an NEC component arising in the distal esophageal side of the GEJ region showed evidence of gastric origin.

Cost-effectiveness of olaparib plus bevacizumab versus bevacizumab monotherapy in the maintenance of patients with homologous recombination deficiency-positive advanced ovarian cancer after response to first-line platinum-based chemotherapy

OBJECTIVE

The PAOLA-1 trial confirmed that adding olaparib to bevacizumab significantly increased clinical benefit following response to platinum-based chemotherapy in homologous recombination deficiency-positive ovarian cancer. The objective of this analysis was to determine the cost-effectiveness of olaparib plus bevacizumab compared with bevacizumab alone as maintenance treatment for patients with homologous recombination deficiency-positive advanced ovarian cancer from the Spanish National Health System perspective.

METHODS

A lifetime partitioned survival model with four health states (progression-free, post-progression 1, post-progression 2, and death) and monthly cycles was developed. Long-term survival, defined as 60 months, was included as a landmark to extrapolate progression-free survival from PAOLA-1. Weibull distribution was selected as the most accurate survival model for progression-free survival extrapolation. Time to second progression and overall survival were extrapolated using parametric survival models. Mortality was obtained from the overall survival and adjusted by Spanish women mortality rates. Health state utilities and utility decrements for adverse events were included. An expert panel validated data and assumptions. Direct costs (in 2021 euros (€)) were obtained from local sources and included drug acquisition and administration, subsequent therapies, monitoring costs, adverse events, and palliative care. A 3% annual discount rate was applied to costs and outcomes. The incremental cost-effectiveness ratio was calculated as cost per quality-adjusted life-years (QALYs) gained. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

Compared with bevacizumab alone, olaparib plus bevacizumab increased QALYs and life-years by 2.39 and 2.77, respectively, at an incremental cost of €58 295.31, resulting in an incremental cost-effectiveness ratio of €24 371/QALY. Probabilistic sensitivity analysis demonstrated that olaparib plus bevacizumab had a 49.5% and 90.3% probability of being cost-effective versus bevacizumab alone at a willingness-to-pay threshold of €25 000 and €60 000 per QALY gained, respectively.

CONCLUSION

For patients with homologous recombination deficiency-positive advanced ovarian cancer, olaparib plus bevacizumab is a cost-effective maintenance therapy compared with bevacizumab alone in Spain.

Evaluation of Homologous Recombination Deficiency in Ovarian Cancer

OPINION STATEMENT

Homologous recombination deficiency (HRD) is an important biomarker guiding selection of ovarian cancer patients who will derive the most benefit from poly(ADP-ribose) polymerase inhibitors (PARPi). HRD prevents cells from repairing double-stranded DNA damage with high fidelity, PARPis limit single-stranded repair, and together these deficits induce synthetic lethality. Germline or somatic BRCA mutations represent the narrowest definition of HRD, but do not reflect all patients who will have a durable PARPi response. HRD can also be defined by its downstream consequences, which are measured by different metrics depending on the test used. Ideally, all patients will undergo genetic counseling and germline testing shortly after diagnosis and have somatic testing sent once an adequate tumor sample is available. Should barriers to one test be higher, pursuing germline testing with reflex to somatic testing for BRCA wildtype patients or somatic testing first strategies are both evidence-based. Ultimately both tests offer complementary information, germline testing should be pursued for any patient with a history of ovarian cancer, and somatic testing is valuable at recurrence if not performed in the upfront setting. There is a paucity of data to suggest superiority of one germline or somatic assay; therefore, selection should optimize turnaround time, cost to patients, preferred result format, and logistical burden. Each clinic should implement a standard testing strategy for all ovarian cancer patients that ensures HRD status is known at the time of upfront chemotherapy completion to facilitate comprehensive counseling about anticipated maintenance PARPi benefit.

Harnessing the effects of hypoxia-like inhibition on homology-directed DNA repair

Hypoxia is a hallmark feature of the tumor microenvironment which can promote mutagenesis and instability. This increase in mutational burden occurs as a result of the downregulation of DNA repair systems. Deficits in the DNA damage response can be exploited to induce cytotoxicity and treat advanced stage cancers. With the advent of precision medicine, agents such as Poly (ADP-ribose) polymerase (PARP) inhibitors have been used to achieve synthetic lethality in homology directed repair (HDR) deficient cancers. However, most cancers lack these predictive biomarkers. Treatment for the HDR proficient population represents an important unmet clinical need. There has been interest in the use of anti-angiogenic agents to promote tumor hypoxia and induce deficiency in a HDR proficient background. For example, the use of cediranib to inhibit PDGFR and downregulate enzymes of the HDR pathway can be used synergistically with a PARP inhibitor. This combination can improve therapeutic responses in HDR proficient cancers. Preclinical results and Phase II and III clinical trial data support the mechanistic rationale for the efficacy of these agents in combination. Future investigations should explore the effectiveness of cediranib and other anti-angiogenic agents with a PARP inhibitor to elicit an antitumor response and sensitize cancers to immunotherapy.

GIInger predicts homologous recombination deficiency and patient response to PARPi treatment from shallow genomic profiles

Homologous recombination deficiency (HRD) is a predictive biomarker for poly(ADP-ribose) polymerase 1 inhibitor (PARPi) sensitivity. Routine HRD testing relies on identifying BRCA mutations, but additional HRD-positive patients can be identified by measuring genomic instability (GI), a consequence of HRD. However, the cost and complexity of available solutions hamper GI testing. We introduce a deep learning framework, GIInger, that identifies GI from HRD-induced scarring observed in low-pass whole-genome sequencing data. GIInger seamlessly integrates into standard BRCA testing workflows and yields reproducible results concordant with a reference method in a multisite study of 327 ovarian cancer samples. Applied to a BRCA wild-type enriched subgroup of 195 PAOLA-1 clinical trial patients, GIInger identified HRD-positive patients who experienced significantly extended progression-free survival when treated with PARPi. GIInger is, therefore, a cost-effective and easy-to-implement method for accurately stratifying patients with ovarian cancer for first-line PARPi treatment.

BRCA1 expression, its correlation with clinicopathological features, and response to neoadjuvant chemotherapy in high-grade serous ovarian cancer

AIM

In high-grade serous ovarian cancers (HG-SOC), BRCA1 mutation is one of the predominant mutations reported by various studies. However, the non-mutational mechanisms of BRCA pathway inactivation in HG-SOC are unclear. We evaluated BRCA1 inactivation by estimating its expression with its repressor, ID4, in primary and neoadjuvant chemotherapy (NACT)-treated HG-SOC tumors with known therapeutic responses.

METHODS

We evaluated the expression pattern of BRCA1 protein by immunohistochemistry in 119 cases of HG-SOC from a hospital cohort consisting of primary (N = 69) and NACT-treated (N = 50) tumors. Histological patterns (SET), stromal infiltration by lymphocytes (sTILs), and chemotherapy response score (CRS) were estimated by microscopic examination. Gene expression levels of BRCA1, and its repressor ID4, were estimated by qPCR. The association of BRCA1 protein and mRNA with clinicopathological features was studied. The relevance of the BRCA1/ID4 ratio was evaluated in tumors with different CRS.

RESULTS

BRCA1 protein expression was observed in 12% of primary and 19% of NACT-treated HG-SOC tumors. We observed moderate concordance between BRCA1 protein and mRNA expression (AUC = 0.677). High BRCA1 mRNA expression was significantly associated with a more frequent SET pattern (p = 0.024), higher sTILs density (p = 0.042), and increased mitosis (p = 0.028). BRCA1-negative tumors showed higher expression of ID4 though not statistically significant. A higher BRCA1/ID4 ratio was associated with high sTILs density in primary (p = 0.042) and NACT-treated tumors (p = 0.040).

CONCLUSION

Our findings show the utility of the BRCA1/ID4 ratio in predicting neoadjuvant therapy response, which needs further evaluation in larger cohorts with long-term outcomes.

Theranostic biomarkers and PARP-inhibitors effectiveness in patients with non-BRCA associated homologous recombination deficient tumors: Still looking through a dirty glass window?

Breast cancer susceptibility gene 1 (BRCA1) and breast cancer susceptibility gene 2 (BRCA2) deleterious variants were the first and, still today, the main biomarkers of poly(ADP)ribose polymerase (PARP)-inhibitors (PARPis) benefit. The recent, increased, numbers of individuals referred for counseling and multigene panel testing, and the remarkable expansion of approved PARPis, not restricted to BRCA1/BRCA2-Pathogenic Variants (PVs), produced a strong clinical need for non-BRCA biomarkers. Significant limitations of the current testing and assays exist. The different approaches that identify the causes of Homologous Recombination Deficiency (HRD), such as the germline and somatic Homologous Recombination Repair (HRR) gene PVs, the testing showing its consequences, such as the genomic scars, or the novel functional assays such as the RAD51 foci testing, are not interchangeable, and should not be considered as substitutes for each other in clinical practice for guiding use of PARPi in non-BRCA, HRD-associated tumors. Today, the deeper knowledge on the significant relationship among all proteins involved in the HRR, not limited to BRCA, expands the possibility of a successful non-BRCA, HRD-PARPi synthetic lethality and, at the same time, reinforces the need for enhanced definition of HRD biomarkers predicting the magnitude of PARPi benefit.

Frontiers of Ovarian Carcinosarcoma

OPINION STATEMENT

Ovarian carcinosarcoma (OCS), also known as a malignant mixed Müllerian tumour (MMMT), is a rare and aggressive form of cancer that accounts for less than 5% of ovarian cancers. It is characterized by high morbidity and mortality rates, with a median overall survival (OS) of less than 2 years. Several factors, including advancing age, nulliparity, reduced lactation rates, decreased use of oral contraceptive pills, genetic mutations in BRCA (breast cancer) genes, and the use of assisted reproductive technology, may increase the risk of OCS. Poor prognostic factors include an advanced stage at diagnosis, older age, lymph node metastasis, suboptimal surgical cytoreduction, the presence of heterologous features on histopathology, and increased expression of vascular endothelial growth factor (VEGF), tumour protein p53, and p53 alongside Wilms tumour 1 (WT1). The main treatment approach for OCS is cytoreductive surgery followed by platinum-based chemotherapy, although immunotherapy is showing promise. Homologous recombination deficiency (HRD) testing may enhance outcomes by enabling personalized immunotherapy and targeted therapies for specific patient groups, thereby reducing unnecessary side effects and healthcare costs. However, there is currently a lack of standardised treatment regimens for OCS patients, with most studies consisting of case reports and a shortage of suitable comparator groups. This article aims to provide clinicians with information on the epidemiology, risk factors, prognostic factors, and latest therapeutic advancements in OCS.

Heterogeneity and treatment landscape of ovarian carcinoma

Ovarian carcinoma is characterized by heterogeneity at the molecular, cellular and anatomical levels, both spatially and temporally. This heterogeneity affects response to surgery and/or systemic therapy, and also facilitates inherent and acquired drug resistance. As a consequence, this tumour type is often aggressive and frequently lethal. Ovarian carcinoma is not a single disease entity and comprises various subtypes, each with distinct complex molecular landscapes that change during progression and therapy. The interactions of cancer and stromal cells within the tumour microenvironment further affects disease evolution and response to therapy. In past decades, researchers have characterized the cellular, molecular, microenvironmental and immunological heterogeneity of ovarian carcinoma. Traditional treatment approaches have considered ovarian carcinoma as a single entity. This landscape is slowly changing with the increasing appreciation of heterogeneity and the recognition that delivering ineffective therapies can delay the development of effective personalized approaches as well as potentially change the molecular and cellular characteristics of the tumour, which might lead to additional resistance to subsequent therapy. In this Review we discuss the heterogeneity of ovarian carcinoma, outline the current treatment landscape for this malignancy and highlight potentially effective therapeutic strategies in development.

New Achievements from Molecular Biology and Treatment Options for Refractory/Relapsed Ovarian Cancer-A Systematic Review

Ovarian cancer (OC) has a high rate of mortality and is the fifth most common cause of death in females all over the world. The etiology is still unclear. Numerous factors such as smoking, obesity, and unhealthy diet may affect the risk of OC. Having a family history of breast and OC is one of the main risks for developing OC. Mutations of BRCA1/2 are associated with OC risk as well. The histopathological classification of OC reveals the four most common types: serous, clear cell, endometrioid, and mucinous; these are epithelial OC types, and other types are rare. Furthermore, OC can be subdivided into types I and II. Type I tumors are most probably caused by atypical proliferative tumors. Type II tumors include high-grade carcinoma of the serous type, carcinosarcoma, and carcinoma, which are not differentiated and generally originate from tubal intraepithelial carcinoma of the serous type. Typically, type I tumors are present in early stages, usually with good prognosis. Type II tumors are classified as high-grade tumors and are most often diagnosed at advanced FIGO stages with poor prognosis. High-grade serous OC accounts for 90% of serous OC. Tumor heterogeneity aggravates OC treatment. The standard care for primary epithelial ovarian cancer (EOC) is cytoreductive surgery followed by platinum-based chemotherapy. Neoadjuvant chemotherapy can be used in certain cases followed by cytoreductive surgery. The main prognostic factor is complete tumor resection. However, about 70% of patients relapse. Resistance to chemotherapeutic agents remains a major challenge in EOC treatment, in which many different factors are involved. In recent years, the examination of molecular parameters and their prognostic impact has become increasingly relevant in EOC, and furthermore, the use of immunotherapy has expanded the therapeutic range. As the clinical need is greatest for relapsed patients, this systematic review will focus on recent advances in molecular biology with prognostic and predictive markers and treatment options for recurrent/refractory OC. Inclusion criteria for the review: potential prospective or predictive biomarkers in preclinical or clinical use in relapsed and refractory OC, prognostic impact, clinical and preclinical trials, and immunotherapy. Exclusion criteria for the review: primary OC, no full text or abstract available, not the topic mentioned above, and text not available in English. Risk of bias: the included studies were evaluated descriptively for the topics mentioned above, and data were not compared with each other. The objective is to highlight the molecular mechanisms of the most promising targeted agents under clinical investigation to demonstrate their potential relevance in recurrent/refractory OC.

Validation of the Clinical Use of GIScar, an Academic-developed Genomic Instability Score Predicting Sensitivity to Maintenance Olaparib for Ovarian Cancer

PURPOSE

The optimal application of maintenance PARP inhibitor therapy for ovarian cancer requires accessible, robust, and rapid testing of homologous recombination deficiency (HRD). However, in many countries, access to HRD testing is problematic and the failure rate is high. We developed an academic HRD test to support treatment decision-making.

EXPERIMENTAL DESIGN

Genomic Instability Scar (GIScar) was developed through targeted sequencing of a 127-gene panel to determine HRD status. GIScar was trained from a noninterventional study with 250 prospectively collected ovarian tumor samples. GIScar was validated on 469 DNA tumor samples from the PAOLA-1 trial evaluating maintenance olaparib for newly diagnosed ovarian cancer, and its predictive value was compared with Myriad Genetics MyChoice (MGMC).

RESULTS

GIScar showed significant correlation with MGMC HRD classification (kappa statistics: 0.780). From PAOLA-1 samples, more HRD-positive tumors were identified by GIScar (258) than MGMC (242), with a lower proportion of inconclusive results (1% vs. 9%, respectively). The HRs for progression-free survival (PFS) with olaparib versus placebo were 0.45 [95% confidence interval (CI), 0.33-0.62] in GIScar-identified HRD-positive BRCA-mutated tumors, 0.50 (95% CI, 0.31-0.80) in HRD-positive BRCA-wild-type tumors, and 1.02 (95% CI, 0.74-1.40) in HRD-negative tumors. Tumors identified as HRD positive by GIScar but HRD negative by MGMC had better PFS with olaparib (HR, 0.23; 95% CI, 0.07-0.72).

CONCLUSIONS

GIScar is a valuable diagnostic tool, reliably detecting HRD and predicting sensitivity to olaparib for ovarian cancer. GIScar showed high analytic concordance with MGMC test and fewer inconclusive results. GIScar is easily implemented into diagnostic laboratories with a rapid turnaround.

ShallowHRD status acts as an effective prognostic predictor in ovarian cancer patients treated by poly (ADP-ribose) polymerase inhibitors (PARPis)

PURPOSE

Homologous recombination deficiency (HRD) plays a crucial role in ovarian cancer patients who are treated with Poly (ADP-ribose) polymerase inhibitors (PARPis). It could be defined as a prognosis biomarker. However, many high throughput sequencing methods for evaluating HRD, including HRDetect (WGS 10X), SigMA (WGS 40X or panel 1000X), and scarHRD (WGS 30X), are technically complex, time and data-storage consuming, and costly. Herein, we aimed to develop a low-cost method by low sequencing coverage to identify HRD status for precision medication.

METHODS

We utilized ShallowHRD, a software tool to evaluate tumor HRD based on whole genome sequencing (WGS) at low coverage (1X), and established a novel scoring system, ShallowHRD score system.

RESULTS

Compared with negative ShallowHRD status (ShallowHRD score < 15 or BRCAwild), positive ShallowHRD status (ShallowHRD score ≥ 15 or BRCAmut) presented favorable survival after being treated with PARPis.

CONCLUSION

The ShallowHRD status is a good biomarker for predicting prognosis, which could help guide the clinical application of PARPis in ovarian cancer patients by a cost-effective, time and data-storage saving method.

RediScore: Prospective validation of a pipeline for homologous recombination deficiency analysis

Tumors harboring homologous recombination deficiency (HRD) are considered optimal candidates for poly(ADP-ribose) polymerase 1 (PARP) inhibitor treatment. Such deficiency can be detected by analyzing breast cancer type (BRCA)1/2 gene mutations, as well as mutations in other genes of the homologous recombination pathway. The algorithmic measurement of the HRD effect by identifying genomic instability (GI) has been used as biomarker. As compared with the direct measurement of somatic gene alterations, this approach increases the number of patients who could benefit from PARP inhibitor treatment. In the present study, the performance of the Oncoscan CNV assay, accompanied by appropriate bioinformatic algorithms, was evaluated for its performance in GI calculation and was compared with that of a validated next-generation sequencing (NGS) test (myChoice HRD test). In addition, the clinical utility of the GI score (GIS) and BRCA1/2 tumor analysis were investigated in a cohort of 444 patients with ovarian cancer. For that reason, single nucleotide polymorphism (SNP) arrays and appropriate bioinformatics algorithms were used to calculate GIS in 29 patients with ovarian cancer with known GIS status using a validated NGS test. Furthermore, BRCA1/2 analysis results were compared between the aforementioned assay and the amplicon-based Oncomine™ BRCA Research Assay. BRCA1/2 analysis was performed in 444 patients with ovarian cancer, while GIS was calculated in 175 BRCA1/2-negative cases. The bioinformatics algorithm developed for GIS calculation in combination with NGS BRCA1/2 analysis (RediScore), and the OncoscanR pipeline exhibited a high overall agreement with the validated test (93.1%). In addition, the Oncomine NGS assay had a 100% agreement with the validated test. The BRCA1/2 mutation frequency was 26.5% in the examined patients with ovarian cancer. GIS was positive in 40% of the BRCA1/2-negative cases. The RediScore bioinformatics algorithm developed for GIS calculation in combination with NGS BRCA1/2 analysis is a viable and effective approach for HRD calculation in patients with ovarian cancer, offering a positive prediction for PARP inhibitor responsiveness in 55% of the patients.

DNA repair biomarkers to guide usage of combined PARP inhibitors and chemotherapy: A meta-analysis and systematic review

PURPOSE

The addition of PARP inhibitors to chemotherapy has been assessed in > 80 clinical trials across multiple malignancies, on the premise that PARP inhibitors will increase chemotherapy effectiveness regardless of whether cancers have underlying disruption of DNA repair pathways. Consequently, the majority of combination therapy trials have been performed on patients without biomarker selection, despite the use of homologous recombination deficiency to dictate use of PARP inhibitors in the maintenance setting. An unresolved question is whether biomarkers are needed to identify patients who respond to combination PARP inhibitors and chemotherapy.

METHODS

A systematic literature review identified studies using PARP inhibitors in combination with chemotherapy versus chemotherapy alone, where the study included a biomarker of DNA repair function (BRCA1, BRCA2, homologous recombination deficiency test, ATM, ERCC1, SLFN11). Hazard ratios (HR) were pooled in a meta-analysis using generic inverse-variance, and fixed or random effects modelling. Subgroup analyses were conducted on biomarker selection and type of malignancy.

RESULTS

Nine studies comprising 2547 patients met the inclusion criteria. Progression-free survival (PFS) was significantly better in patients with a DNA repair biomarker (HR: 0.57, 95% CI: 0.48-0.68, p < 0.00001), but there was no benefit in patients who lacked a biomarker (HR: 0.94, 95% CI: 0.82-1.08, p = 0.38). Subgroup analysis showed that BRCA status and SLFN11 biomarkers could predict benefit, and biomarker-driven benefit occurred in ovarian, breast and small cell lung cancers. The addition of PARP inhibitors to chemotherapy was associated with increased grade 3/4 side effects, and particularly neutropenia.

CONCLUSIONS

Combination therapy only improves PFS in patients with identifiable DNA repair biomarkers. This indicates that PARP inhibitors do not sensitise patients to chemotherapy treatment, except where their cancer has a homologous recombination defect, or an alternative biomarker of altered DNA repair. While effective in patients with DNA repair biomarkers, there is a risk of high-grade haematological side-effects with the use of combination therapy. Thus, the benefit in PFS from combination therapy must be weighed against potential adverse effects, as individual arms of treatment can also confer benefit.

Patient Assessment and Therapy Planning Based on Homologous Recombination Repair Deficiency

Defects in genes involved in the DNA damage response cause homologous recombination repair deficiency (HRD). HRD is found in a subgroup of cancer patients for several tumor types, and it has a clinical relevance to cancer prevention and therapies. Accumulating evidence has identified HRD as a biomarker for assessing the therapeutic response of tumor cells to poly(ADP-ribose) polymerase inhibitors and platinum-based chemotherapies. Nevertheless, the biology of HRD is complex, and its applications and the benefits of different HRD biomarker assays are controversial. This is primarily due to inconsistencies in HRD assessments and definitions (gene-level tests, genomic scars, mutational signatures, or a combination of these methods) and difficulties in assessing the contribution of each genomic event. Therefore, we aim to review the biological rationale and clinical evidence of HRD as a biomarker. This review provides a blueprint for the standardization and harmonization of HRD assessments.

The Utility of NGS Analysis in Homologous Recombination Deficiency Tracking

Several tumor types have been efficiently treated with PARP inhibitors (PARPis), which are now approved for the treatment of ovarian, breast, prostate, and pancreatic cancers. The BRCA1/2 genes and mutations in many additional genes involved in the HR pathway may be responsible for the HRD phenomenon. The aim of the present study was to investigate the association between genomic loss of heterozygosity (gLOH) and alterations in 513 genes with targeted and immuno-oncology therapies in 406 samples using an NGS assay. In addition, the %gLOHs of 24 samples were calculated using the Affymetrix technology in order to compare the results obtained via the two methodologies. HR variations occurred in 20.93% of the malignancies, while BRCA1/2 gene alterations occurred in 5.17% of the malignancies. The %LOH was highly correlated with alterations in the BRCA1/2 genes, since 76.19% (16/21) of the BRCA1/2 positive tumors had a high %LOH value (p = 0.007). Moreover, the LOH status was highly correlated with the TP53 and KRAS statuses, but there was no association with the TMB value. Lin's concordance correlation coefficient for the 24 samples simultaneously examined via both assays was 0.87, indicating a nearly perfect agreement. In conclusion, the addition of gLOH analysis could assist in the detection of additional patients eligible for treatment with PARPis.

First-line maintenance therapy with niraparib in advanced platinum-sensitive ovarian cancer: two 'long responder' case reports and review of the current literature

The standard of care for newly diagnosed advanced ovarian cancer is surgical cytoreduction plus platinum-based chemotherapy; however, recurrent disease frequently occurs after treatment. Poly(ADP-ribose) polymerase (PARP) inhibitors as first-line maintenance therapy have been demonstrated to significantly reduce the risk of disease progression or death in patients with advanced ovarian cancer who have a complete or partial response to first-line platinum-based chemotherapy. Niraparib is the only PARP inhibitor that offers a significant progression-free survival benefit compared with placebo in this patient population regardless of the homologous recombination status. However, predictive factors for treatment responses and approaches to dose optimization remain to be investigated. In this study, two Chinese patients with newly diagnosed advanced ovarian cancer exhibited long-term responses to niraparib treatment, and hematological toxicity was successfully managed by dose adjustment. The literature on clinical trials and real-world experience on the efficacy, tolerability, and dose individualization of niraparib treatment in Western and Chinese patients was also reviewed. Future research is warranted to identify the characteristics of 'long responders' to niraparib treatment.

An Overview of PARP Resistance in Ovarian Cancer from a Molecular and Clinical Perspective

Epithelial ovarian cancer (EOC), a primarily high-grade serous carcinoma (HGSOC), is one of the major causes of high death-to-incidence ratios of all gynecological cancers. Cytoreductive surgery and platinum-based chemotherapy represent the main treatments for this aggressive disease. Molecular characterization of HGSOC has revealed that up to 50% of cases have a deficiency in the homologous recombination repair (HRR) system, which makes these tumors sensitive to poly ADP-ribose inhibitors (PARP-is). However, drug resistance often occurs and overcoming it represents a big challenge. A number of strategies are under investigation, with the most promising being combinations of PARP-is with antiangiogenetic agents and immune checkpoint inhibitors. Moreover, new drugs targeting different pathways, including the ATR-CHK1-WEE1, the PI3K-AKT and the RAS/RAF/MEK, are under development both in phase I and II-III clinical trials. Nevertheless, there is still a long way to go, and the next few years promise to be exciting.

HRD Testing of Ovarian Cancer in Routine Practice: What Are We Dealing With?

Assessment of homologous recombination deficiency (HRD) status is now essential for ovarian cancer patient management. The aim of our study was to analyze the influence of ethnic variations, tumor purity, and neoadjuvant chemotherapy (CT) on the determination of HRD scores as well as to evaluate feasibility of HRD testing with the Amoy HRD Focus Assay in routine clinical practice. The HRD status, including the BRCA status and genomic scar score (GSS), was analyzed in 452 ovarian cancer specimens. The successful rate of HRD testing was 86% (388/452). The BRCA mutational rate was 29% (114/388); 252 samples (65%) were classified as HRD-positive. Our data demonstrate the feasibility of internal HRD testing by the AmoyDx HRD Focus Panel for high-grade serous ovarian cancer (HGSOC), showing results similar to other methods. The HRD rate in the Russian population is very similar to those of other European populations, as is the BRCA mutation frequency. The most substantial contribution to HRD level diversity is testing criteria depending on intrahospital arrangements. The analysis shows that biallelic BRCA alterations had higher GSS compared with those with monoallelic inactivation, consistent with positive HRD status. The study indicates that grades 1-2 of the pathological response caused by chemotherapy affect HRD scores and suggests controlling for tumor purity of 40% or more as a critical factor for GSS measurement.

Prevalence of Homologous Recombination Deficiency in First-Line PARP Inhibitor Maintenance Clinical Trials and Further Implication of Personalized Treatment in Ovarian Cancer

Among ovarian cancer patients with BRCA mutation or homologous recombination deficiency (HRD), the efficacy of Poly-ADP-ribose polymerase (PARP) inhibitors such as olaparib, niraparib, veliparib, and rucaparib has been proven in a number of clinical trials. BRCA mutation and HRD are currently indicated for PARP inhibitor maintenance treatment in ovarian cancer. HRD diagnostic tests examine various components, resulting in different HRD status definitions and, as a result, different treatment decisions. A number of HRD diagnostic tests exist, but test results provided by different companies may differ as they use different methods and different cutoffs. HRD prevalence difference was shown between PARP inhibitor maintenance trials. It is important to select an appropriate method that can present accurate HRD phenotypes to predict sensitivity to PARP inhibitors so that patients who are most likely to benefit from treatment are selected. Additionally, in the subset data of the PARP inhibitor maintenance trials, there was a difference in HRD prevalence by race as higher HRD prevalence in Japanese and Chinese ovarian cancer patients was shown. Further large-scale investigations on racial differences in HRD prevalence are needed and this may contribute to changes in determining the treatment plan and personalized treatment in ovarian cancer patients.

Consensus on the management of platinum-sensitive high-grade serous epithelial ovarian cancer in Lebanon

Ovarian cancer is the most lethal gynecologic cancer. The high grade serous epithelial (HGSE) subtype is the most aggressive and it often presents at advanced stages, while screening programs have not proven beneficial. Management of the advanced stages (FIGO III and IV), which constitute the majority of diagnoses, usually consists of platinum-based chemotherapy and cytoreductive surgery (primary or interval) followed by maintenance therapy. Currently, the standard-of-care for advanced newly diagnosed HGSE ovarian cancer, as per international medical societies, starts with upfront cytoreductive surgery, followed by platinum-based chemotherapy (mostly carboplatin and paclitaxel) and/or anti-angiogenic agent bevacizumab, then maintenance therapy with a poly(ADP-ribose) polymerase (PARP) inhibitor with/without/or bevacizumab (continued). PARP inhibitor use depends on the patient's genetic signature, mainly the breast cancer gene (BRCA) mutation and the homologous recombination deficiency (HRD) status. Therefore, genetic testing is recommended at diagnosis to inform treatment and prognosis. In line with the evolving standard-of-care for ovarian cancer, a panel of experts in treating advanced ovarian cancer convened to lay down practical recommendations on the management of advanced ovarian cancer in Lebanon; since the currently applicable guidelines by the Lebanese Ministry of Public Health for cancer treatment have not been updated yet to reflect the treatment paradigm shift brought upon by the development and approval of PARP inhibitors. The current work reviews the leading clinical trials on PARP inhibitors (as maintenance for newly diagnosed advanced and platinum-sensitive relapsed ovarian cancer), presents international recommendations, and proposes treatment algorithms for optimal local practice.

Update Breast Cancer 2023 Part 1 - Early Stage Breast Cancer

With abemaciclib (monarchE study) and olaparib (OlympiA study) gaining approval in the adjuvant treatment setting, a significant change in the standard of care for patients with early stage breast cancer has been established for some time now. Accordingly, some diverse developments are slowly being transferred from the metastatic to the adjuvant treatment setting. Recently, there have also been positive reports of the NATALEE study. Other clinical studies are currently investigating substances that are already established in the metastatic setting. These include, for example, the DESTINY Breast05 study with trastuzumab deruxtecan and the SASCIA study with sacituzumab govitecan. In this review paper, we summarize and place in context the latest developments over the past months.

The Scarface Score: Deciphering Response to DNA Damage Agents in High-Grade Serous Ovarian Cancer-A GEICO Study

Genomic Instability (GI) is a transversal phenomenon shared by several tumor types that provide both prognostic and predictive information. In the context of high-grade serous ovarian cancer (HGSOC), response to DNA-damaging agents such as platinum-based and poly(ADP-ribose) polymerase inhibitors (PARPi) has been closely linked to deficiencies in the DNA repair machinery by homologous recombination repair (HRR) and GI. In this study, we have developed the Scarface score, an integrative algorithm based on genomic and transcriptomic data obtained from the NGS analysis of a prospective GEICO cohort of 190 formalin-fixed paraffin-embedded (FFPE) tumor samples from patients diagnosed with HGSOC with a median follow up of 31.03 months (5.87-159.27 months). In the first step, three single-source models, including the SNP-based model (accuracy = 0.8077), analyzing 8 SNPs distributed along the genome; the GI-based model (accuracy = 0.9038) interrogating 28 parameters of GI; and the HTG-based model (accuracy = 0.8077), evaluating the expression of 7 genes related with tumor biology; were proved to predict response. Then, an ensemble model called the Scarface score was found to predict response to DNA-damaging agents with an accuracy of 0.9615 and a kappa index of 0.9128 (p < 0.0001). The Scarface Score approaches the routine establishment of GI in the clinical setting, enabling its incorporation as a predictive and prognostic tool in the management of HGSOC.