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

Exploring the Prognostic and Predictive Impact of Genomic Loss of Heterozygosity and Homologous Recombination Deficiency Alterations in Patients With Metastatic Colorectal Cancer

PURPOSE

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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Integrating clinical-molecular data to predict PARP inhibitors efficacy in advanced ovarian cancer patients after interval cytoreductive surgery

OBJECTIVE

Selecting the maintenance strategy for advanced tubo-ovarian high-grade serous carcinoma (HGSC) is challenging. This study evaluates the correlation among chemotherapy response score (CRS), homologous recombination deficiency (HRD) status, and KELIM score; identifies predictors of Poly (ADP-ribose) polymerase (PARP) inhibitor (PARPi) efficacy and stratifies recurrence risk in PARPi-treated population.

METHODS

Median Progression-free Survival (mPFS) and hazard ratios (HRs) were retrospectively calculated in HGSC patients after neoadjuvant chemotherapy (3/4 cycles), interval cytoreductive surgery, and adjuvant treatment. Variables included HRD status, disease stage, KELIM, radiological response, residual tumor, and CRS at surgery. A risk-stratification model predicting PARPi efficacy was developed.

RESULTS

Among overall population (N = 373), 66.9 % of CRS3 patients reached favorable KELIM, 17.3 % had complete radiological response, and 97.8 % achieved complete surgery, with higher frequencies than CRS1/2 (p < 0.001). Univariate analysis of PFS on PARPi (N = 210) showed favorable covariates: CRS3 (HR 2.37, 95 % CI 1.39-4.04 and HR 1.59, 95 % CI 1.03-2.47 vs CRS1 and CRS2), BRCA mutation (HR 3.41 95 % CI 2.15-5.39 and HR 2.00 95 % CI 1.13-3.56 vs BRCAwt-HRDneg and -HRDpos) and continuum KELIM (HR 0.66, 95 % CI 0.45-0.96). At multivariate, CRS3 and BRCA mutation were confirmed significant. Combining HRD status, CRS, and KELIM four prognostic groups with different PARPi efficacy were identified (mPFS 38 vs 26 vs 18 vs 6 months for Low, Intermediate, High-Intermediate, and High-risk groups).

CONCLUSIONS

CRS is a prognostic factor in PARPi-treated population as a PARPi efficacy surrogate. Integrating HRD status, CRS, and KELIM allows patients risk stratification and tailored maintenance. These results should be considered hypothesis-generating.

Homologous recombination deficiency (HRD) testing landscape: clinical applications and technical validation for routine diagnostics

The use of poly(ADP-ribose) polymerase inhibitors (PARPi) revolutionized the treatment of BRCA-mutated cancers. Identifying patients exhibiting homologous recombination deficiency (HRD) has been proved useful to predict PARPi efficacy. However, obtaining HRD status remains an arduous task due to its evolution over the time. This causes HRD status to become obsolete when obtained from genomic scars, rendering PARPi ineffective for these patients. Only two HRD tests are currently FDA-approved, both based on genomic scars detection and BRCA mutations testing. Nevertheless, new technologies for obtaining an increasingly reliable HRD status continue to evolve. Application of these tests in clinical practice is an additional challenge due to the need for lower costs and shorter time to results delay.In this review, we describe the currently available methods for HRD testing, including the methodologies and corresponding tests for assessing HRD status, and discuss the clinical routine application of these tests and their technical validation.

Physician knowledge, use, and perceptions of genetic biomarker testing for the management of patients with newly diagnosed advanced ovarian cancer: an international physician survey

AIMS

To explore physician-reported knowledge, use, and perceptions of genetic testing for advanced ovarian cancer management.

MATERIALS & METHODS

Gynecology/oncology specialists (n = 390) in the US, Europe, Canada, Japan, and Australia completed an online survey spanning March 2021 to April 2022.

RESULTS

Physician-reported breast cancer gene mutation (BRCAm) testing rates increased over the 2 years before the survey; most patients underwent testing in the preceding 6 months. Homologous recombination deficiency (HRD) genomic instability testing rates and physicians' confidence interpreting results remained relatively low. Genetic testing was driven by the associated treatment implications of the findings. Poor performance status, inadequate tissue, and patients' willingness to undergo testing were reported barriers to testing.

CONCLUSIONS

Findings indicate that there is a need to improve both access to and information about HRD testing.

Homologous recombination deficiency in ovarian cancer: Global expert consensus on testing and a comparison of companion diagnostics

BACKGROUND

Poly (ADP ribose) polymerase inhibitors (PARPis) are a treatment option for patients with advanced high-grade serous or endometrioid ovarian carcinoma (OC). Recent guidelines have clarified how homologous recombination deficiency (HRD) may influence treatment decision-making in this setting. As a result, numerous companion diagnostic assays (CDx) have been developed to identify HRD. However, the optimal HRD testing strategy is an area of debate. Moreover, recently published clinical and translational data may impact how HRD status may be used to identify patients likely to benefit from PARPi use. We aimed to extensively compare available HRD CDx and establish a worldwide expert consensus on HRD testing in primary and recurrent OC.

METHODS

A group of 99 global experts from 31 different countries was formed. Using a modified Delphi process, the experts aimed to establish consensus statements based on a systematic literature search and CDx information sought from investigators, companies and/or publications.

RESULTS

Technical information, including analytical and clinical validation, were obtained from 14 of 15 available HRD CDx (7 academic; 7 commercial). Consensus was reached on 36 statements encompassing the following topics: 1) the predictive impact of HRD status on PARPi use in primary and recurrent OC; 2) analytical and clinical validation requirements of HRD CDx; 3) resource-stratified HRD testing; and 4) how future CDx may include additional approaches to help address unmet testing needs.

CONCLUSION

This manuscript provides detailed information on currently available HRD CDx and up-to-date guidance from global experts on HRD testing in patients with primary and recurrent OC.

Homologous recombination deficiency (HRD) diagnostics: underlying mechanisms and new perspectives

Homologous recombination deficiency (HRD) is considered a universal and effective sign of a tumor's sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors. HRD diagnostics have undergone several stages of transformations: from detection of point mutations in HR-related genes and large regions with loss of heterozygosity detected using single-nucleotide polymorphism arrays to whole-genome signatures of single-nucleotide variants, large genomic rearrangements (LGRs), and copy number alterations. All these methods have their own advantages and limitations. HRD tests, based on signatures of LGRs and copy number alterations, show in hindsight that some progenitor cells have possessed HRD status but not the current state of the genome. The aim of this review was to compare different methods of HRD detection and mechanisms of formation of HRD-specific LGRs. In the last several years, new data appeared implying a crucial role of proteins BRCA1 and BRCA2 in the resolution of stalled replication forks that may be associated with at least some of LGRs observed in HRD-positive tumors. Reviewing current knowledge on these mechanisms, distributions of different LGR types, and limitations of sequencing technologies and algorithms of data analysis, we offer some new perspectives on HRD diagnostics. We hope that this review will help to accelerate the development of new diagnostic approaches in this important field of molecular oncology.

The Role of Tumor Biomarkers in Tailoring the Approach to Advanced Ovarian Cancer

Growing evidence has demonstrated the role of mutations of tumor biomarkers in diagnosing and treating epithelial ovarian cancer. This review aims to analyze recent literature on the correlation between tumor biomarkers and chemotherapy in nonmucinous ovarian cancer, providing suggestions for personalized treatment approaches. An extensive literature search was conducted to identify relevant studies and trials. BRCA1/2 mutations are central in homologous recombination repair deficiency (HRD) in ovarian cancer, but several other genetic mutations also contribute to varying cancer risks. While the role of MMR testing in ovarian cancer is debated, it is more commonly linked to non-serous ovarian cancer, often associated with Lynch syndrome. A significant proportion of ovarian cancer patients have HRD, affecting treatment decisions in both first-line (especially in advanced stages) and second-line therapy due to HRD's connection with platinum-based therapy and PARP inhibitors' response. However, validated genetic tests to identify HRD have not yet been universally implemented. There is no definitive therapeutic algorithm for advanced ovarian cancer, despite ongoing efforts and multiple proposed tools. Future research should focus on expanding the utility of biomarkers, reducing resistance, and increasing the actionable biomarker pool.

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.

The Evolving Role of Genomic Testing in Early Breast Cancer: Implications for Diagnosis, Prognosis, and Therapy

Multigene prognostic genomic assays have become indispensable in managing early breast cancer (EBC), offering crucial information for risk stratification and guiding adjuvant treatment strategies in conjunction with traditional clinicopathological parameters. The American Society of Clinical Oncology (ASCO) guidelines endorse these assays, though some clinical contexts still lack definitive recommendations. The dynamic landscape of EBC management demands further refinement and optimization of genomic assays to streamline their incorporation into clinical practice. The breast cancer community is poised at the brink of transformative advances in enhancing the clinical utility of genomic assays, aiming to significantly improve the precision and effectiveness of both diagnosis and treatment for women with EBC. This article methodically examines the testing methodologies, clinical validity and utility, costs, diagnostic frameworks, and methodologies of the established genomic tests, including the Oncotype Dx Breast Recurrence Score®, MammaPrint, Prosigna®, EndoPredict®, and Breast Cancer Index (BCI). Among these tests, Prosigna and EndoPredict® have at present been validated only on a prognostic level, while Oncotype Dx, MammaPrint, and BCI hold both a prognostic and predictive role. Oncologists and pathologists engaged in the management of EBC will find in this review a thorough comparison of available genomic assays, as well as strategies to optimize the utilization of the information derived from them.

Concordance between an FDA-approved companion diagnostic and an alternative assay kit for assessing homologous recombination deficiency in ovarian cancer

OBJECTIVE

Authors evaluated the performance of a commercially available next-generation sequencing assay kit; this was based on genomic content from Illumina's TruSight™ Oncology 500 research assay that identifies BRCA variants and proprietary algorithms licensed from Myriad and, with additional genomic content, measures the homologous recombination deficiency (HRD) genomic instability score (GIS) in tumor tissue (TSO 500 HRD assay).

METHODS

Data from the TSO 500 HRD assay were compared with data from the Myriad MyChoice®CDx PLUS assay (Myriad assay). Prevalence rates for overall HRD status and BRCA mutations (a deleterious or suspected deleterious BRCA1 or BRCA2 mutation or both) and assay agreement rates for HRD GIS and BRCA analysis were assessed in ovarian tumor samples. Pearson correlations of the continuous HRD GIS and analytic sensitivity and specificity were evaluated.

RESULTS

The prevalence of overall HRD positivity was 51.2% (TSO 500 HRD assay) versus 49.2% (Myriad assay) and the prevalence of BRCA mutations was 27.6% (TSO 500 HRD assay) versus 25.5% (Myriad assay). After post-processing optimization, concordance of the HRD GIS was 0.980 in all samples and 0.976 in the non-BRCA mutation cohort; the area under the receiver operating characteristic curve was 0.995 and 0.992, respectively.

CONCLUSIONS

Comparison between the Illumina and Myriad assays showed that overall HRD status, the individual components of BRCA analysis, and HRD GIS detection results were highly concordant (>93%), suggesting the TSO 500 HRD assay will approach the analytical accuracy of the FDA-approved Myriad assay.

Cost-Effectiveness Analysis of HRD Testing for Previously Treated Patients with Advanced Ovarian Cancer in Italy

INTRODUCTION

Ovarian cancer (OC) is the eighth most common cancer among women, and homologous recombination deficiency (HRD) is present in approximately 50% of these patients. For this group, poly(ADP-ribose) polymerase (PARP) inhibitors are more likely to be effective. The aim of the study was to investigate the cost-effectiveness of HRD testing versus BRCA testing (which identifies mutations present only in 25% of patients) in Italy to optimize the treatment management, possibly with PARP inhibitors.

METHODS

A cost-effectiveness partition survival model was developed to estimate the expected costs and outcomes (life years, LYs; quality-adjusted life years, QALYs) with lifetime horizon of HRD testing versus BRCA testing alone in women with high-grade serous or endometrioid advanced ovarian cancer. The option to perform the tests in sequence, that is, the BRCA test followed by the HRD test, in patients with BRCA-negative test was also considered, and the model accounted for the National Healthcare Service (NHS) perspective in Italy. The treatments represented the best available options according to the initial test results and according to PARP inhibitors available in Italy. A 3% discount rate was applied. Both deterministic and probabilistic sensitivity analyses were performed to test the robustness of the model results.

RESULTS

HRD testing was shown to be a cost-effective strategy compared to BRCA testing (incremental cost-utility ratio 22,610€/QALY) and a cost-saving strategy compared to the sequence of tests. The probabilistic sensitivity analysis showed that the HRD test is cost-effective compared to BRCA testing in 98.5% of model simulations considering a willingness-to-pay threshold of 50,000€/QALY.

CONCLUSION

The identification of genetic anomalies in patients with advanced OC is a costly process. Regardless, HRD upfront testing compared to BRCA testing had a cost-effective profile, allowing the efficient use of healthcare resources and better life expectancy and quality of life for patients.

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.

A Benchmark of In-House Homologous Recombination Repair Deficiency Testing Solutions for High-Grade Serous Ovarian Cancer Diagnosis

Homologous recombination deficiency (HRD) has become an important prognostic and predictive biomarker for patients with high-grade serous ovarian cancer who may benefit from poly-ADP ribose polymerase inhibitors (PARPi) and platinum-based therapies. HRD testing provides relevant information to personalize patients' treatment options and has been progressively incorporated into diagnostic laboratories. Here, we assessed the performance of an in-house HRD testing system deployable in a diagnostic clinical setting, comparing results from two commercially available next-generation sequencing (NGS)-based tumor tests (SOPHiA DDMTM HRD Solution and AmoyDx® (HRD Focus Panel)) with the reference assay from Myriad MyChoice® (CDx). A total of 85 ovarian cancer samples were subject to HRD testing. An overall strong correlation was observed across the three assays evaluated, regardless of the different underlying methods employed to assess genomic instability, with the highest pairwise correlation between Myriad and SOPHiA (R = 0.87, p-value = 3.39 × 10-19). The comparison of the assigned HRD status to the reference Myriad's test revealed a positive predictive value (PPV) and negative predictive value (NPV) of 90.9% and 96.3% for SOPHiA's test, while AmoyDx's test achieved 75% PPV and 100% NPV. This is the largest HRD testing evaluation using different methodologies and provides a clear picture of the robustness of NGS-based tests currently offered in the market. Our data shows that the implementation of in-house HRD testing in diagnostic laboratories is technically feasible and can be reliably performed with commercial assays. Also, the turnaround time is compatible with clinical needs, making it an ideal alternative to offer to a broader number of patients while maintaining high-quality standards at more accessible price tiers.