Utility of Expedited Hereditary Cancer Testing in the Surgical Management of Patients with a New Breast Cancer Diagnosis.

BACKGROUND: Knowledge of a germline pathogenic/likely pathogenic variant (PV) may inform breast cancer management. BRCA1/2 PV often impact surgical decisions, but data for multi-gene panel testing are lacking. Expedited genetic testing reduces turn-around times based on request for treatment-related decision making. This report aims to describe the clinical utility of expedited multi-gene panel testing for patients with newly diagnosed breast cancer. METHODS: Clinical and demographic information were reviewed for patients with newly diagnosed female breast cancer undergoing expedited panel testing between 2013 and 2017. The National Comprehensive Cancer Network guidelines (NCCN, version 1.2018) were evaluated in terms of published management recommendations for the genes in which PVs were identified. RESULTS: The overall PV yield was 9.5% (678/7127) for women undergoing expedited panel testing, with 700 PVs identified among 678 women. PVs were identified in genes other than BRCA1/2 in 55.9% (391/700) of cases. The NCCN guidelines recommend management for the genes in which 96.6% (676/700) of PVs are identified. The NCCN guidelines also recommend risk-reducing mastectomy for 46.0% (322/700) of PVs identified. An additional 45.6% (319/700) of PVs were identified in genes for which NCCN recommends mastectomy based on family history. In addition, 49.9% (349/700) of PVs were in genes with NCCN guidelines recommending prophylactic surgery for tissues other than breast. CONCLUSION: A majority of the patients with newly diagnosed breast cancer were candidates for surgical intervention according to the NCCN guidelines, and half of these patients would have been missed if only BRCA1/2 testing had been ordered. Expedited multi-gene hereditary cancer panel testing should be considered as a first-line approach to provide comprehensive information for breast cancer management.

Low penetrance pancreatitis phenotype in a Venezuelan kindred with a PRSS1 R122H mutation.

CONTEXT: Hereditary pancreatitis is typically caused by the PRSS1 R122H or N29I mutations resulting in high penetrance (about 80%) autosomal dominant disorder that is usually reported in North America, Northern Europe and Northeast Asia, but not South America, Africa or India. CASE REPORT: Here we report a kindred from Venezuela, South America with the PRSS1 R122H variant. Only the proband, an 11-year old boy with severe chronic pancreatitis, and a maternal grandmother with pancreatitis at age 60 years (confirmed PRSS1 R122H), are symptomatic. CONCLUSIONS: Issues of mutation prevalence, non-penetrance, and disease recognition in various countries are discussed.

Genetics of pancreatitis: an update for clinicians and genetic counselors.

With novel genetic technologies available, there is a paradigm shift in the way that risk assessments, diagnoses,and therapies for genetic susceptibility syndromes are addressed. Hereditary pancreatitis is among these conditions, for which genetic counseling and next generation sequencing, help families better understand, cope with and live healthier lives. Identifying a genetic etiology to a condition formally believed to be solely environmentally induced can alter the path for treatment for many patients. This finding introduces the concept of gene-environment interactions in human disease and the relationship between genetic predisposition and exposure risk in disease development. The genetic counseling process is complex with medical explanations, psychosocial issues relating to coping with diagnosis, potential future health problems, recurrence risks and family planning. These sometimes difficult conversations can be facilitated by a genetic counselor as a member of the multidisciplinary team. This chapter addresses the intricate medical and psychosocial issues that can arise in the setting of treating patients with hereditary pancreatitis.

Differences in cancer prevalence among CHEK2 carriers identified via multi-gene panel testing.

PURPOSE: Although CHEK2 is a well-established cancer gene, questions remain including whether risks vary substantially between different variants and whether biallelic carriers have higher risks than heterozygotes. We report on a cohort of individuals with CHEK2 pathogenic and likely pathogenic variants (collectively, PV) in order to better characterize this gene. METHODS: We retrospectively queried samples submitted for multi-gene hereditary cancer testing to identify individuals with CHEK2 PVs and assessed differences in phenotypes among various genotypes. RESULTS: CHEK2 PVs were identified in 2508 individuals, including 32 individuals with biallelic CHEK2 PVs. Breast (female, 59.9% and male, 11.8%), prostate (20.1%), and colorectal (3.5%), were among the most frequently reported cancers. Select missense PVs showed similar cancer prevalence to truncating PVs while some others showed lower prevalence. No significant differences were observed between biallelic carriers and heterozygotes. CONCLUSIONS: Our data support that some, but not all, CHEK2 missense PVs demonstrate lower cancer prevalence; further studies are needed to continue characterizing possible variant specific risks. In addition, biallelic CHEK2 PVs do not appear to be associated with a more severe phenotype than single CHEK2 PVs. Furthermore, co-occurrences with PVs in other cancer risk genes are common among CHEK2 heterozygotes and often warrant additional management.

Apparently Heterozygous TP53 Pathogenic Variants May Be Blood Limited in Patients Undergoing Hereditary Cancer Panel Testing.

Heterozygous (HET) TP53 pathogenic variants (PVs) are associated with Li-Fraumeni syndrome (LFS), a dominantly inherited condition causing high risk for sarcoma, breast, and other cancers. Recent reports describe patients without features of LFS and apparently HET TP53 PVs in blood cells but not fibroblasts (FBs), suggesting the variant occurred sporadically during hematopoiesis and rose to high allele fraction through clonal expansion. To explore possible clonal hematopoiesis in patients undergoing hereditary cancer testing, FB testing was performed for patients with apparently HET or mosaic TP53 PVs identified in blood, oral rinse, or buccal specimens via next-generation sequencing panels. Among 291 individuals with TP53 PVs, 146 (50.2%) appeared HET and 145 (49.8%) were mosaic. Twenty-eight HET cases were proven constitutional through familial testing. FB testing was completed for 17 apparently HET and 36 mosaic patients. FB testing was positive in 11 of 17 (64.7%) apparently HET patients, only one of whom met Chompret criteria. Of 36 mosaic patients, 5 (13.9%) were also mosaic in FBs, indicating constitutional mosaicism. Breast cancers in patients with constitutional TP53 PVs were diagnosed at younger ages (P < 0.0001) and more likely to demonstrate human epidermal growth factor receptor 2 overexpression (P = 0.0003). These results demonstrate the utility of cultured FB testing to clarify constitutional status for TP53 PVs identified on next-generation sequencing panels, particularly for patients not meeting LFS or Chompret criteria.

Inherited pancreatic cancer syndromes.

Pancreatic cancer remains one of the most challenging of all cancers. Genetic risk factors are believed to play a major role, but other than genes coding for blood group, genetic risks for sporadic cases remain elusive. However, several germline mutations have been identified that lead to hereditary pancreatic cancer, familial pancreatic cancer, and increased risk for pancreatic cancer as part of a familial cancer syndrome. The most important genes with variants increasing risk for pancreatic cancer include BRCA1, BRCA2, PALB2, ATM, CDKN2A, APC, MLH1, MSH2, MSH6, PMS2, PRSS1, and STK11. Recognition of members of high-risk families is important for understanding pancreatic cancer biology, for recommending risk reduction strategies and, in some cases, initiating cancer surveillance programs. Because the best methods for surveillance have not been established, the recommendation to refer at-risk patients to centers with ongoing research programs in pancreatic cancer surveillance is supported.

Hereditary breast-ovarian cancer: clinical findings and medical management.

Approximately 5% to 10% of breast and ovarian cancers are related to an inherited gene mutation. Of these cases, 84% of hereditary breast cancer and more than 90% of hereditary ovarian cancer are caused by mutations in the BRCA1 or BRCA2 genes. Family histories of cancer are an essential tool in identifying features of and individuals at risk for hereditary breast-ovarian cancer syndrome. The risk to carry an identifiable BRCA gene mutation can be assessed by trained healthcare providers using various pre-test risk models. Individuals who carry a BRCA gene mutation have increased lifetime risks of developing hereditary breast and ovarian cancer syndrome-related cancers. Genetic testing for the BRCA gene mutations is offered in accordance with American Society of Clinical Oncology guidelines. In accordance with guidelines, patients are informed of the risks, benefits, and limitations of testing prior to electing to undergo the testing process. Upon receipt of results, healthcare providers offer the patient with appropriate medical management recommendations.