Germline Testing for Patients With BRCA1/2 Mutations on Somatic Tumor Testing

Case report: olaparib use in metastatic lung adenocarcinoma with BRCA2 pathogenic variant

Poly (ADP-ribose) polymerase (PARP) inhibitors have been approved in malignancies associated with germline BRCA1 or BRCA2 pathogenic variants, such as breast, ovarian, prostate, and pancreatic cancer. In malignancies not associated with germline BRCA1 or BRCA2 pathogenic variants, the therapeutic relevance of PARP inhibitors is less clear. Non-small-cell lung cancer (NSCLC) is known to demonstrate somatic alterations in BRCA1 or BRCA2 gene. The current report is on a gentleman with metastatic lung adenocarcinoma with a somatic BRCA2 pathogenic variant, who was effectively treated with olaparib. Furthermore, we discuss the existing data for use of PARP inhibitors in NSCLC. This study highlights the utility of next-generation sequencing in identifying gene mutations and demonstrates how such information can be used to select targeted therapies in patients with actionable molecular alterations.

Somatic tumor mutations in moderate risk cancer genes: Targets for germline confirmatory testing

BACKGROUND

Recent changes in oncology practice guidelines indicate that mutations in cancer susceptibility genes identified on tumor genomic profiling (TGP) should prompt confirmatory germline testing. Our study aimed to determine the proportion of patients with TGP-identified mutations in moderate risk breast and ovarian cancer genes who previously would not have been considered for germline testing.

METHODS

From January 2013 to September 2020, 7468 adult Stanford Health Care patients underwent TGP on solid tumor samples and 166 had TGP-identified mutations in moderate risk breast and ovarian cancer susceptibility genes (ATM, BRIP1, CHEK2, PALB2, RAD51C and RAD51D). Retrospective chart reviews were performed on 160 patients. Cases were analyzed to determine eligibility for germline testing using established NCCN criteria, and somatic and germline results were compared where both were available.

RESULTS

Nearly half (45.3% [73/160]) of patients would not have been eligible for germline testing if not for a TGP-identified mutation in a moderate risk breast or ovarian cancer gene. Of the 64 cases that underwent germline testing, about half (51.5% [33/64]) had results that confirmed germline origin of the TGP finding. High rates of germline confirmation were found in PALB2 (100% [5/5]), ATM (40% [14/35]), CHEK2 (61.5% [8/13]), and BRIP1 (57.1% [4/7]).

CONCLUSION

Our study shows that the presence of TGP-identified mutations in moderate risk breast and ovarian cancer genes increases eligibility for germline testing beyond those that would be eligible based largely on personal and family history criteria alone. Additionally, results of germline testing in these newly eligible cases supports that this expanded eligibility captures individuals with hereditary cancer syndromes that would not have otherwise been identified.

Germline sequencing for presumed germline pathogenic variants via tumor-only comprehensive genomic profiling

BACKGROUND

The European Society for Medical Oncology Precision Medicine Working Group (ESMO-PMWG) published recommendations regarding confirmatory germline testing for presumed germline pathogenic variants (PGPVs) in tumor-only comprehensive genomic profiling (CGP). However, the clinical validity of these recommendations has not been investigated in a real-world practice.

METHODS

Medical records of 180 consecutive patients who obtained the results of a tumor-only CGP (FoundationOne^® CDx, Foundation Medicine, Inc, Cambridge, MA, USA) between October 2018 and March 2020, were retrospectively reviewed. After excluding patients with no reported variants in 45 actionable genes (n = 6), or no archived germline DNA samples (n = 31), 143 patients were investigated. The PGPVs were selected from the CGP report and germline sequencing were performed using DNA samples archived in Clinical Bioresource Center in Kyoto University Hospital (Kyoto, Japan).

RESULTS

A total of 195 variants were classified as PGPV based on the conventional criteria. Germline sequencing disclosed that 12 variants (6.2%) were of germline origin. In contrast, after filtering these 195 variants through the ESMO-PMWG recommendation criteria for confirmatory germline testing, following seven PGPVs, BRCA2 (n = 2), BRIP1 (n = 1), BAP1 (n = 1), PMS2 (n = 1), MSH2 (n = 1), and SDHB (n = 1) remained and six variants (85.7%) were confirmed to be of germline origin.

CONCLUSION

Our current data suggested that the application of ESMO-PMWG criteria is helpful in selecting PGPVs with a high likelihood of germline origin in a tumor-only CGP in daily clinical practice.

Preoperational diagnosis and management of breast ductal carcinoma in situ arising within fibroadenoma: Two case reports

BACKGROUND

Ductal carcinoma in situ (DCIS) arising within fibroadenoma is a type of tumor that is rarely encountered in clinic, with only about 100 cases of carcinoma arising within a fibroadenoma reported in the literature. Here, we present two cases of breast DCIS arising within a fibroadenoma and discuss their clinical and imaging findings as well as treatment.

CASE SUMMARY

The patients did not have cancer-related personal and family histories. Case 1 (a 49-year-old woman) was diagnosed with a bilateral breast nodule in May 2018 and was followed (preoperative imaging data including ultrasound and mammography) for 3 years; she underwent an excisional biopsy to address an enlargement in nodule size. Case 2 (a 37-year-old woman) was diagnosed with a left breast nodule in June 2021 and consequently received vacuum-assisted biopsy of the tumor which appeared as “irregularly shaped” and “unevenly textured” tissue on ultrasound. The pathological diagnosis was clear in both cases. Both patients underwent breast-conserving surgery and sentinel lymph node biopsy. The two cases received or planned to receive radiotherapy as well as endocrine therapy (tamoxifen).

CONCLUSION

Breast DCIS arising within a fibroadenoma is rare, but patients treated with radiotherapy and endocrine therapy can have good prognosis.

Identification and Management of Pathogenic Variants in BRCA1, BRCA2, and PALB2 in a Tumor-Only Genomic Testing Program

PURPOSE

Tumor-only genomic testing can uncover somatic and germline pathogenic variants (P/LPs) in cancer predisposition genes. We describe the prevalence of P/LPs in BRCA1/2 and PALB2 (B1B2P2) across malignancies and the frequency of clinical germline testing (CGT) in patients with P/LPs in B1B2P2 identified on tumor-only testing.

EXPERIMENTAL DESIGN

Among 7,575 patients tested between 2016-2018 with the OncoPanel tumor-only sequencing assay, we characterized P/LP frequencies by tumor type, receipt of CGT prior to or within 12 months (m) after OncoPanel, and factors associated with CGT.

RESULTS

272 (3.6%) had OncoPanel-detected P/LPs in B1B2P2: 37.5% of P/LPs were in BRCA-related cancers; the remainder were in non-BRCA tumors. P/LPs were detected in {greater than or equal to}5% of breast, pancreatic, prostate, ovarian, non-melanoma skin, endometrial, small-cell lung and colorectal cancers. 37.9% of patients with P/LPs received GCT prior to OncoPanel; an additional 10.7% underwent CGT within 12m of OncoPanel. Among 132 with CGT, 88.6% had {greater than or equal to}1 clinical factor for CGT compared to 47.1% who did not undergo CGT. Patients with BRCA-tumors were more likely to have CGT compared to those without (81.4% vs. 29.0%, p<0.0001). Among patients with CGT, 70.5% (93/132) of P/LPs were germline.

CONCLUSION

Tumor-only genomic testing identified P/LPs in B1B2P2 in 3.6% of patients. 52.9% of patients with tumor-detected P/LPs and without CGT did not meet personal or family history criteria for CGT. Additionally, some patients with tumor-detected P/LPs were not referred for CGT, especially those with non-BRCA tumors. Given implications for treatment selection and familial cancer risk, processes to reliably trigger CGT from tumor-genomic findings are needed.

PARP Inhibitors: A Major Therapeutic Option in Endocrine-Receptor Positive Breast Cancers

Simple Summary

OlympiAD and EMBRACA trials demonstrated the efficacy of PARPi, compared to chemotherapy, in patients with HER2-negative metastatic breast cancers (mBC) carrying a germline BRCA mutation. Patients with ER+/HER2-BRCA-mutated mBC seemed to have a higher risk of early disease progression while on CDK4/6 inhibitors and benefit from PARPi, especially when prescribed before chemotherapy. Importantly, the frequency of BRCA pathogenic variant (PV) carriers among ER+/HER2- breast cancer patients has been underestimated, and 50% of all BRCA1/2 mutated breast cancers are actually of ER+/HER2- subtype. Recent studies also highlight the benefit of PARPi in BRCA wild type mBC with HRD representing up to 20% of ER+/HER2- breast cancers. The OLYMPIA trial also demonstrated PARPi utility in patients with ER+/HER2- early breast cancers with BRCA PV at high risk of relapse. Consequently, implementation of early genotyping and new strategies for identifying patients with high-risk ER+/HER2- HRD breast cancers likely to benefit from PARPi is of high importance.

Abstract

Recently, OlympiAD and EMBRACA trials demonstrated the favorable efficacy/toxicity ratio of PARPi, compared to chemotherapy, in patients with HER2-negative metastatic breast cancers (mBC) carrying a germline BRCA mutation. PARPi have been largely adopted in triple-negative metastatic breast cancer, but their place has been less clearly defined in endocrine-receptor positive, HER2 negative (ER+/ HER2-) mBC. The present narrative review aims at addressing this question by identifying the patients that are more likely benefit from PARPi. Frequencies of BRCA pathogenic variant (PV) carriers among ER+/HER2- breast cancer patients have been underestimated, and many experts assume than 50% of all BRCA1/2 mutated breast cancers are of ER+/HER2- subtype. Patients with ER+/HER2- BRCA-mutated mBC seemed to have a higher risk of early disease progression while on CDK4/6 inhibitors and PARPi are effective especially when prescribed before exposure to chemotherapy. The OLYMPIA trial also highlighted the utility of PARPi in patients with early breast cancers at high risk of relapse and carrying PV of BRCA. PARPi might also be effective in patients with HRD diseases, representing up to 20% of ER+/HER2- breast cancers. Consequently, the future implementation of early genotyping strategies for identifying the patients with high-risk ER+/HER2- HRD breast cancers likely to benefit from PARPi is of high importance.

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.

The Future of Parallel Tumor and Germline Genetic Testing: Is There a Role for All Patients With Cancer?

Under the traditional paradigm of genetic testing in cancer, the role of germline testing was to assess for the inherited risk of cancer, whereas the role of tumor testing was to determine therapeutic selection. Parallel tumor-normal genetic testing uses simultaneous genetic testing of the tumor and normal tissue to identify mutations and allows their classification as either germline or somatic. The increasing adoption of parallel testing has revealed a greater number of germline findings in patients who otherwise would not have met clinical criteria for testing. This result has widespread implications for the screening and further testing of at-risk relatives and for gene discovery. It has also revealed the importance of germline testing in therapeutic actionability. Herein, we describe the pros and cons of tumor-only versus parallel tumor-normal testing and summarize the data on the prevalence of incidental actionable germline findings. Because germline testing in patients with cancer continues to expand, it is imperative that systems be in place for the proper interpretation, dissemination, and counseling for patients and at-risk relatives. We also review new therapeutic approvals with germline indications and highlight the increasing importance of germline testing in selecting therapies. Because recommendations for universal genetic testing are increasing in multiple cancer types and the number of approved therapies with germline indications is also increasing, a gradual transition toward parallel tumor-normal genetic testing in all patients with cancer is foreseeable.

Prostate Cancer in 2021: Novelties in Prognostic and Therapeutic Biomarker Evaluation

Simple Summary

In 2021, the identification of effective biomarkers became a major focus of prostate cancer (PCa) in order to improve outcomes and select potentially responsive patients. The aim of this contribution is to review the main 2021 novelties in prognostic and therapeutic markers in PCa, with special reference to PCa grading, aggressive variant PCa and molecular markers predicting significant disease or response to therapy.

Abstract

The 2021 novelties in prognostic and therapeutic tissue markers in patients with prostate cancer (PCa) can be subdivided into two major groups. The first group is related to prognostic markers based on morphological and immunohistochemical evaluations. The novelties in this group can then be subdivided into two subgroups, one involving morphologic evaluation only, i.e., PCa grading, and the other involving both morphologic and immunohistochemical evaluations, i.e., aggressive variant PCa (AVPCa). Grading concerns androgen-dependent PCa, while AVPCa represents a late phase in its natural history, when it becomes androgen-independent. The novelties of the other major group are related to molecular markers predicting significant disease or response to therapy. This group mainly includes novelties in the molecular evaluation of PCa in tissue material and liquid biopsies.

Tumor Genomic Testing: Identifying Characteristics Associated With Germline Risk for Developing Malignancy

Tumor genomic testing is used primarily to facilitate the selection of the best possible treatment for a malignancy based on the genomic characteristics of the tumor. Germline genomic testing has implications for care and recommendations for cancer prevention and early detection for the patient and their family. Careful review of specific components of tumor genomic testing reports and of the family history of malignancy can help ensure that families with potential germline risk are identified and referred for genetic counseling and genetic testing.

Paired tumor sequencing and germline testing in breast cancer management: An experience of a single academic center

BACKGROUND

Genetic testing for cancer predisposition is recommended to women with breast cancer who meet the criteria for such testing. After the FDA approvals of the poly ADP ribose polymerase (PARP) inhibitors, olaparib and talazoparib, for treatment of metastatic breast cancer, carrying germline mutations in BRCA1 and BRCA2 genes, the genetic testing result has become critical in their care. With the recent FDA approval of alpelisib for the treatment of PIK3CA-mutated hormone-receptor positive metastatic breast cancer, tumor molecular profiling to identify somatic mutations and potential molecularly targeted agents is increasingly utilized in the treatment of advanced breast cancer.

AIM

Combining germline and somatic sequencing (paired testing) offers an advantage over a single technique approach. Our study evaluates the role of paired testing on the management of breast cancer patients.

METHODS AND RESULTS

Forty-three breast cancer patients treated at Rush University Medical Center underwent paired germline and somatic variant testing in 2015 to 2017. A retrospective chart review was conducted with the analysis of demographic, clinical, and genomic data. Three actionable germline variants were found in the CHEK2 (2) and ATM (1) genes. 95% of tumors had somatic mutations. Seventy-seven percent of tumors had genomic alterations targetable with agents approved for breast cancer and 88% had molecular targets for agents approved for other cancers. Clinical examples of such use are described and potential future directions of tumor and paired testing are discussed.

CONCLUSIONS

Germline variants were present in a relatively small patient group not routinely tested for inherited alterations. Potentially targetable somatic alterations were identified in the majority of breast cancers. Paired testing is a feasible and efficient approach that delivers valuable information for the care of breast cancer patients and eliminates serial testing.