Real-World Concordance between Germline and Tumour <i>BRCA1/2</i> Status in Epithelial Ovarian Cancer

Patients diagnosed with epithelial ovarian cancer may undergo reflex tumour BRCA1/ 2 testing followed by germline BRCA1/2 testing in patients with a positive tumour test result. This testing model relies on tumour BRCA1/ 2 tests being able to detect all types of pathogenic variant. We analysed germline and tumour BRCA1/2 test results from patients treated for epithelial ovarian cancer at our specialist oncological referral centre. Tumour BRCA1/2 testing was performed using the next-generation sequencing (NGS)-based myChoice ® companion diagnostic (CDx; Myriad Genetics, Inc.). Germline BRCA1/2 testing was performed in the North West Genomic Laboratory Hub using NGS and multiplex ligation-dependent probe amplification. Between 11 April 2021 and 11 October 2023, 382 patients were successfully tested for tumour BRCA1 and BRCA2 variants. Of these, 367 (96.1%) patients were tested for germline BRCA1/ 2 variants. In those patients who underwent tumour and germline testing, 15.3% (56/367) had a BRCA1/ 2 pathogenic variant (36 germline and 20 somatic). All germline BRCA1/2 pathogenic small sequencing variants were detected in tumour DNA. By contrast, 3 out of 8 germline BRCA1/2 pathogenic large rearrangements were not reported in tumour DNA. The overall concordance of germline BRCA1/2 pathogenic variants detected in germline and tumour DNA was clinically acceptable at 91.7% (33/36). The myChoice ® CDx was able to detect most germline BRCA1/2 pathogenic variants in tumour DNA, although a proportion of pathogenic large rearrangements were not reported. If Myriad's myChoice ® CDx is used for tumour BRCA1/2 testing, our data supports a testing strategy of germline and tumour BRCA1/2 testing in all patients diagnosed with epithelial ovarian cancer aged &lt; 79 years old, with germline BRCA1/2 testing only necessary for patients aged ≥ 80 years old with a tumour BRCA1/2 pathogenic variant. </p

Homologous recombination deficiency in newly diagnosed FIGO stage III/IV high-grade epithelial ovarian cancer: a multi-national observational study

OBJECTIVE: Olaparib plus bevacizumab maintenance therapy improves survival outcomes in women with newly diagnosed, advanced, high-grade ovarian cancer with a deficiency in homologous recombination. We report data from the first year of routine homologous recombination deficiency testing in the National Health Service (NHS) in England, Wales, and Northern Ireland between April 2021 and April 2022. METHODS: The Myriad myChoice companion diagnostic was used to test DNA extracted from formalin-fixed, paraffin-embedded tumor tissue in women with newly diagnosed International Federation of Gynecology and Obstetrics (FIGO) stage III/IV high-grade epithelial ovarian, fallopian tube, or primary peritoneal cancer. Tumors with homologous recombination deficiency were those with a BRCA1/2 mutation and/or a Genomic Instability Score (GIS) ≥42. Testing was coordinated by the NHS Genomic Laboratory Hub network. RESULTS: The myChoice assay was performed on 2829 tumors. Of these, 2474 (87%) and 2178 (77%) successfully underwent BRCA1/2 and GIS testing, respectively. All complete and partial assay failures occurred due to low tumor cellularity and/or low tumor DNA yield. 385 tumors (16%) contained a BRCA1/2 mutation and 814 (37%) had a GIS ≥42. Tumors with a GIS ≥42 were more likely to be BRCA1/2 wild-type (n=510) than BRCA1/2 mutant (n=304). The distribution of GIS was bimodal, with BRCA1/2 mutant tumors having a higher mean score than BRCA1/2 wild-type tumors (61 vs 33, respectively, χ2 test p<0.0001). CONCLUSION: This is the largest real-world evaluation of homologous recombination deficiency testing in newly diagnosed FIGO stage III/IV high-grade epithelial ovarian, fallopian tube, or primary peritoneal cancer. It is important to select tumor tissue with adequate tumor content and quality to reduce the risk of assay failure. The rapid uptake of testing across England, Wales, and Northern Ireland demonstrates the power of centralized NHS funding, center specialization, and the NHS Genomic Laboratory Hub network

Implementation of Multigene Germline and Parallel Somatic Genetic Testing in Epithelial Ovarian Cancer: SIGNPOST Study

We present findings of a cancer multidisciplinary-team (MDT) coordinated mainstreaming pathway of unselected 5-panel germline BRCA1/BRCA2/RAD51C/RAD51D/BRIP1 and parallel somatic BRCA1/BRCA2 testing in all women with epithelial-OC and highlight the discordance between germline and somatic testing strategies across two cancer centres. Patients were counselled and consented by a cancer MDT member. The uptake of parallel multi-gene germline and somatic testing was 97.7%. Counselling by clinical-nurse-specialist more frequently needed >1 consultation (53.6% (30/56)) compared to a medical (15.0% (21/137)) or surgical oncologist (15.3% (17/110)) (p 0.001). The median age was 54 (IQR = 51–62) years in germline pathogenic-variant (PV) versus 61 (IQR = 51–71) in BRCA wild-type (p = 0.001). There was no significant difference in distribution of PVs by ethnicity, stage, surgery timing or resection status. A total of 15.5% germline and 7.8% somatic BRCA1/BRCA2 PVs were identified. A total of 2.3% patients had RAD51C/RAD51D/BRIP1 PVs. A total of 11% germline PVs were large-genomic-rearrangements and missed by somatic testing. A total of 20% germline PVs are missed by somatic first BRCA-testing approach and 55.6% germline PVs missed by family history ascertainment. The somatic testing failure rate is higher (23%) for patients undergoing diagnostic biopsies. Our findings favour a prospective parallel somatic and germline panel testing approach as a clinically efficient strategy to maximise variant identification. UK Genomics test-directory criteria should be expanded to include a panel of OC genes.Peer reviewe

Cascade screening in HBOC and Lynch syndrome: guidelines and procedures in a UK centre

In the 33 years since the first diagnostic cancer predisposition gene (CPG) tests in the Manchester Centre for Genomic Medicine (MCGM), there has been substantial changes in the identification of index cases and cascade testing for at-risk family members. National guidelines in England and Wales are usually determined from the National Institute of healthcare Evidence (NICE) and these have impacted on the thresholds for testing BRCA1/2 in Hereditary Breast Ovarian Cancer (HBOC) and in determining that all cases of colorectal and endometrial cancer should undergo screening for Lynch syndrome. Gaps for testing other CPGs relevant to HBOC have been filled by the UK Cancer Genetics Group and CanGene-CanVar project (web ref. https://www.cangene-canvaruk.org/)We present time trends (1990-2020) of identification of index cases with germline CPG variants and numbers of subsequent cascade tests, for BRCA1, BRCA2, and the Lynch genes (MLH1, MSH2, MSH6 and PMS2). For BRCA1/2 there was a definite increase in the proportion of index cases with ovarian cancer only and pre-symptomatic index tests both doubling from 16-32% and 3.2%-&gt;8% respectively. A mean of 1.73-1.74 additional family tests were generated for each BRCA1/2 index case within 2 years. Overall close to one positive cascade test was generated per index case resulting in &gt;1000 risk reducing surgery operations. In Lynch syndrome slightly more cascade tests were performed in the first two years potentially reflecting the increased actionability in males with 42.2% of pre-symptomatic tests in males compared to 25.8% in BRCA1/2 (p&lt;0.0001).<br/

Appraising the Costs of Genomic Testing for Histology-Independent Technologies : An Illustrative Example for NTRK Fusions

Objective: Histology-independent (HI) technologies are authorised for advanced/metastatic cancer patients if they express a particular biomarker regardless of its position in the body. Although this represents an important advancement in cancer treatment, genomic testing to identify eligible individuals for HI technologies will require substantial investment and impact their cost-effectiveness. Estimating these costs is complicated by several issues which not only impact the overall cost of testing, but also on the distribution of testing costs across tumour types. Methods: Key issues that should be considered when evaluating the cost of genomic testing to identify those eligible for HI technology are discussed. These issues are explored in illustrative analyses where costs of genomic testing for NTRK fusions in England for recently approved HI technologies are estimated. Results: The prevalence of mutation, testing strategy adopted and current testing provision impact the cost of identifying eligible patients. The illustrative analysis estimated the cost of RNA-based NGS to identify one individual with an NTRK fusion ranged between £377 and £282,258. To improve cost-effectiveness, testing costs could be shared across multiple technologies. An estimated, additional ~4,000 patients would need to be treated with other HI therapies for testing in advanced/metastatic cancer patients to be cost-effective. Conclusions: The cost of testing to identify individuals eligible for HI technologies impact the drug’s cost-effectiveness. The cost of testing across tumour types varies owing to heterogeneity in the mutation’s prevalence and current testing provision. The cost-effectiveness of HI technologies may be improved if testing costs could be shared across multiple agents