Germline SDHA mutations in children and adults with cancer.

Mutations in succinate dehydrogenase complex genes predispose to familial paraganglioma-pheochromocytoma syndrome (FPG) and gastrointestinal stromal tumors (GIST). Here we describe cancer patients undergoing agnostic germline testing at Memorial Sloan Kettering Cancer Center and found to harbor germline SDHA mutations. Using targeted sequencing covering the cancer census genes, we identified 10 patients with SDHA germline mutations. Cancer diagnoses for these patients carrying SDHA germline mutations included neuroblastoma (n = 1), breast (n = 1), colon (n = 1), renal (n = 1), melanoma and uterine (n = 1), prostate (n = 1), endometrial (n = 1), bladder (n = 1), and gastrointestinal stromal tumor (GIST) (n = 2). Immunohistochemical staining and assessment of patient tumors for second hits and loss of heterozygosity in SDHA confirmed GIST as an SDHA-associated tumor and suggests SDHA germline mutations may be a driver in neuroblastoma tumorigenesis.

Cowden syndrome and the PTEN hamartoma tumor syndrome: systematic review and revised diagnostic criteria.

BACKGROUND: PTEN hamartoma tumor syndrome (PHTS) refers to a spectrum of disorders caused by mutations in the phosphatase and tensin homolog (PTEN) gene. Diagnostic criteria for Cowden syndrome, the principal PTEN-related disorder, were first established in 1996 before the identification of the PTEN gene and the ability to molecularly confirm a clinical diagnosis. These consortium criteria were based on clinical experience and case reports in the existing literature, with their inherent selection biases. Although it was initially reported that approximately 80% of patients with Cowden syndrome had an identifiable germline PTEN mutation, more recent work has shown these diagnostic criteria to be far less specific. In addition, increasing evidence has documented the association of a broader spectrum of clinical features with PTEN mutations. Our goal was to develop revised, evidence-based diagnostic criteria and to include features of the broader spectrum of PTEN-related clinical syndromes. METHODS: We performed a systematic search and review of the medical literature related to clinical features reported in individuals with a PTEN mutation and/or a related clinical diagnosis. RESULTS: We found no sufficient evidence to support inclusion of benign breast disease, uterine fibroids, or genitourinary malformations as diagnostic criteria. There was evidence to include autism spectrum disorders, colon cancer, esophageal glycogenic acanthosis, penile macules, renal cell carcinoma, testicular lipomatosis, and vascular anomalies. CONCLUSIONS: We propose revised, evidence-based criteria covering the spectrum of PTEN-related clinical disorders. Additional research on clinical features associated with PTEN mutations is warranted.

Colorectal cancer risk perception on the basis of genetic test results in individuals at risk for Lynch syndrome.

PURPOSE: Lynch syndrome is associated with inherited germline mutations in mismatch repair (MMR) genes. Genetic testing in high-risk individuals may yield indeterminate results if no mutation is found or if a mutation of unclear pathogenic significance is observed. There are limited data regarding how well patients with Lynch syndrome understand the clinical implications of genetic test results. This study examines colorectal cancer (CRC) risk perception in individuals tested for MMR mutations and identifies the factors associated with an appropriate interpretation of their cancer risk. PATIENTS AND METHODS: A total of 159 individuals who met the Revised Bethesda Guidelines and had previously undergone genetic testing completed a questionnaire eliciting demographic data, cancer history, genetic test results, and an estimate of their CRC risk. Associations between clinical factors, genetic test results, and CRC risk perception were explored using multivariable analyses. RESULTS: Of the 100 individuals with a pathogenic mutation (true positive), 90 (90%) correctly estimated their CRC risk as "high" or "very high" compared with other individuals their age. However, only 23 (62%) of 37 individuals with an indeterminate genetic test result correctly estimated their risk. Individuals with a history of Lynch syndrome-associated cancer (odds ratio [OR], 0.1; 95% CI, 0.1 to 0.6) or indeterminate genetic test results (OR, 0.2; 95% CI, 0.1 to 0.6) were significantly less likely to estimate their CRC risk as increased. CONCLUSION: Patients at risk for Lynch syndrome with an indeterminate genetic test result may be falsely reassured. It is important that health care providers continue to discuss the implications of uninformative results on lifetime cancer risk.