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.

Lynch syndrome: influence of additional susceptibility variants on cancer risk.

Some patients with Lynch syndrome (LS) have extreme phenotypes, i.e. cancer before the recommended screening age, or cancer for which there are no screening guidelines. We made the hypothesis that additional germline variants in cancer susceptibility genes (CSG) could explain some of these phenotypes. We compared the prevalence of additional CSG variants in LS patients with a cancer diagnosis before age 30 (early-onset, EO group) and after 40 (usual-onset, UO group). While there was no overall difference, we did find an excess of pathogenic variants and variants of unknown significance in EO cases when only gastrointestinal CSG were considered (OR 2.25; 95% CI: 1.01-5.06, p value = 0.04). Four EO cases stood out: two with POLE/POLD1 variants in the key exonuclease domain, one with a BMPR1A duplication and one with an EPCAM deletion. Additional germline variants should be considered in future screening recommendations, as they might influence cancer risk.

DNA damage repair gene germline profiling for metastatic prostate cancer patients of different ancestries.

BACKGROUND: Germline and somatic mutations in DNA damage repair genes (DDRg) are now recognized as new biomarkers for the management of metastatic prostate cancers (mPC). We evaluate the frequency of germline DDRg mutations among French mPC patients of European and African ancestries. METHODS: Targeted next-generation sequencing of 21 DDRg was performed on germline DNA from 557 mPC patients, including 15.1% of cases with an African origin. RESULTS: Forty-seven germline mutations in 11 DDR genes were identified in 46 patients of the total cohort (8.3%). BRCA2 (4.1%) and ATM (2.0%) were the most frequently mutated genes. There was no difference in DDRg mutation frequency between mPC patients of European ancestry and those of African origin. Germline mutations of BRCA2 were associated with a positive family history of breast cancer (p = 0.02). The mean age at metastatic stage (59.7 vs. 67.0; p = 0.0003) and the mean age at death (65.2 vs. 73.9; p = 0.0003) were significantly earlier for carriers of BRCA2 mutation than for non-carriers. Moreover, the Cox model showed that BRCA2 positive status was statistically associated with poorer survival (hazard ratio: 0.29; 95% confidence interval 0.18-0.48; p < 0.0001). CONCLUSION: We showed that, in France, BRCA2 and ATM are the main predisposing DDR genes in mPC patients, with a particular aggressiveness for BRCA2 leading to early metastatic stage and death.

Detection of a pathogenic Alu element insertion in PALB2 gene from targeted NGS diagnostic data.

Despite routine analysis of a large panel of genes, pathogenic variants are only detected in approximately 20% of families with hereditary breast and/or ovarian cancer. Mobile element insertions (MEI) are known to cause genetic diseases in humans, but remain challenging to detect. Retrospective analysis of targeted next-generation sequencing (NGS) data from 359 patients was performed using a dedicated MEI detection pipeline. We detected one MEI in exon 9 of the PALB2 gene in a woman with a family history of breast cancer. The pathogenic variant, c.2872_2888delins114AluL2, disrupts the PALB2 coding sequence and leads to the production of a truncated protein, p.(Gln958Valfs*38). This is the first report of a pathogenic MEI in PALB2. This study illustrates that MEI analysis may help to improve molecular diagnostic yield and can be performed from targeted NGS data used for routine diagnosis.

Classification of 101 BRCA1 and BRCA2 variants of uncertain significance by cosegregation study: A powerful approach.

Up to 80% of BRCA1 and BRCA2 genetic variants remain of uncertain clinical significance (VUSs). Only variants classified as pathogenic or likely pathogenic can guide breast and ovarian cancer prevention measures and treatment by PARP inhibitors. We report the first results of the ongoing French national COVAR (cosegregation variant) study, the aim of which is to classify BRCA1/2 VUSs. The classification method was a multifactorial model combining different associations between VUSs and cancer, including cosegregation data. At this time, among the 653 variants selected, 101 (15%) distinct variants shared by 1,624 families were classified as pathogenic/likely pathogenic or benign/likely benign by the COVAR study. Sixty-six of the 101 (65%) variants classified by COVAR would have remained VUSs without cosegregation data. Of note, among the 34 variants classified as pathogenic by COVAR, 16 remained VUSs or likely pathogenic when following the ACMG/AMP variant classification guidelines. Although the initiation and organization of cosegregation analyses require a considerable effort, the growing number of available genetic tests results in an increasing number of families sharing a particular variant, and thereby increases the power of such analyses. Here we demonstrate that variant cosegregation analyses are a powerful tool for the classification of variants in the BRCA1/2 breast-ovarian cancer predisposition genes.

Utility of a mainstreamed genetic testing pathway in breast and ovarian cancer patients during the COVID-19 pandemic.

INTRODUCTION: Mainstreamed genetic testing (MGT) obviates the need for a cancer genetics consultation, since trained oncologists (O) and gynaecologists (G) provide counseling, prescribe testing and deliver results. We report results from our MGT program and emphasize its utility during the COVID-19 lockdown, when cancer genetics clinics had suspended their activity. METHODS: An MGT pathway for breast and ovarian cancer (BC/OC) patients was established in Jan-2018 between the Assistance Publique - Hôpitaux de Paris.Sorbonne Université Cancer Genetics team and the Oncology/Gynecology departments at one teaching and two regional hospitals. Trained O + G evaluated patients with the Manchester Scoring System. A 12-point threshold was recommended for testing. Next-generation sequencing of BRCA1, BRCA2, PALB2, RAD51C and RAD51D was performed. Results were delivered to the patient by O/G. Pathogenic variants (PV) carriers were referred to the genetics clinic. Results are reported for the 2nd-Jan-2018 to 1st-June-2020 period. That includes the eight-week COVID-19 lockdown and three-week de-confinement phase 1. RESULTS: Results were available for 231/234 patients. Twenty-eight (12.1%) carried a PV. Of the 27 patients tested during the COVID-19 period, three carried a PV, two in BRCA1 and one in RAD51C. The clinical impact was immediate for the two BRCA1 BC cases undergoing neo-adjuvant chemotherapy, since double mastectomy and salpingo-oophorectomy will now be performed using two-step strategies. CONCLUSIONS: MGT guaranteed care continuity in BC/OC patients during the critical phases of the COVID-19 pandemic, with immediate implications for PV carriers. More broadly, we report for the first time the successful implementation of MGT in France.

Molecular tumor testing in patients with Lynch-like syndrome reveals a de novo mosaic variant of a mismatch repair gene transmitted to offspring.

In Lynch-like syndrome, patients have tumors with microsatellite instability but no germline pathogenic variant in mismatch repair genes or somatic methylation of the MLH1 promoter. Identification of the mechanism that causes these tumors is crucial for guiding screening of the patients and their relatives. Double somatic hits are the usual explanation for these cases; however, we have previously reported a de novo mosaic pathogenic variant in a patient with Lynch-like syndrome. Using tumoral NGS analysis of a series of 16 patients with Lynch-like syndrome, we found six patients with double somatic hits, including one patient with mosaicism of a de novo pathogenic variant in MSH2. This variant was transmitted to the patient's offspring, which has significant implications for genetic counseling.

[Clinical Cancer Genetics: A guide for the pathologist]. / Les trois temps de la prise en charge oncogénétique : la consultation, l'analyse en laboratoire et le suivi personnalisé.

It is paramount to identify patients whose cancer is associated with genetic susceptibility to the disease, since their long-term management depends on it. Anatomical and molecular pathologists play a key role in the process. Indeed, their diagnosis supports or even sometimes warrants germline genetic testing. For example, a colorectal cancer with mismatch repair protein expression loss suggests Lynch syndrome, while a rare type of renal cell carcinoma with fumarate hydrate expression loss is highly evocative of hereditary leiomyomatosis and renal cell carcinoma syndrome. Similarly, the presence of the T790M EGFR variant before treatment in a non-small-cell lung carcinoma warrants further testing as the variant is likely of germline origin. Patients with suspected genetic susceptibility to cancer are referred to the nearest clinical cancer genetics clinic. The cancer geneticist, assisted by a genetic counsellor, then collects detailed personal and familial information, sometimes feeds them into bioinformatics tools or clinico-pathological scores, decides whether germline genetic analysis is justified, determines which genes should be analysed and prescribes testing. Germline testing is carried out on a blood sample by expert laboratories using next generation sequencing on panels of cancer susceptibility genes. The cancer geneticists then return the result to the patient. When a pathogenic variant is identified, the patient's management is modified, with recommendations ranging from intensified surveillance to risk-reducing surgery. Treatment is sometimes adapted to the pathogenic variant. In addition, relatives can undergo genetic testing, should they wish to know whether they carry the familial variant. In the near future, we expect clinical cancer genetics to move towards strengthened partnerships with molecular pathologists and medical oncologists. Somatic genetic analyses are now routine, at least in metastatic cancer, and a proportion of the tumoral variants identified are actually of germline origin. As for the oncologists, the development of mainstreaming programs where they are allowed to prescribe germline testing under the supervision of a cancer genetics team is unavoidable.

Everolimus and Octreotide for Patients with Recurrent Meningioma: Results from the Phase II CEVOREM Trial.

PURPOSE: Aggressive meningiomas that progress after surgery/radiotherapy represent an unmet medical need. Strong and constant expression of SSTR2A receptors and activation of the Pi3K/Akt/mTOR pathway have been demonstrated in meningiomas. The combination of everolimus, an mTOR inhibitor, and octreotide, a somatostatin agonist, has shown additive antitumor effect in vitro. The phase II CEVOREM trial investigated the efficacy of this combination on recurrent meningiomas. PATIENTS AND METHODS: Patients with documented recurrent tumor progression ineligible for further surgery/radiotherapy were eligible to receive octreotide (30 mg/d, day 1) and everolimus (10 mg/d, days 1-28). The primary endpoint was the 6-month progression-free survival rate (PFS6). The secondary endpoints were overall survival, response rate, tumor growth rate according to central review, and safety. RESULTS: A total of 20 patients were enrolled, including 2 with World Health Organization (WHO) grade I tumors, 10 with WHO grade II tumors, and 8 with WHO grade III tumors; furthermore, 4 patients harbored NF2 germline mutation. The overall PFS6 was 55% [95% confidence interval (CI), 31.3%-73.5%], and overall 6- and 12-month survival rates were 90% (95% CI, 65.6%-97.4%) and 75% (95% CI, 50.0%-88.7%), respectively. A major decrease (>50%) was observed in the growth rate at 3 months in 78% of tumors. The median tumor growth rate decreased from 16.6%/3 months before inclusion to 0.02%/3 months at 3 months (P < 0.0002) and 0.48%/3 months at 6 months after treatment (P < 0.0003). CONCLUSIONS: The combination of everolimus and octreotide was associated with clinical and radiological activity in aggressive meningiomas and warrants further studies. Decrease in the tumor volume growth rate should be considered a complementary and sensitive endpoint to select potentially effective drugs for recurrent meningiomas.