Sofia Fragoso

APC or MUTYH mutations account for the majority of clinically well-characterized families with FAP and AFAP phenotype and patients with more than 30 adenomas

Patients presenting familial adenomatous polyposis (FAP), attenuated familial adenomatous polyposis (AFAP) or multiple colorectal adenomas (MCRAs) phenotype are clinically difficult to distinguish. We aimed to genetically characterize 107 clinically well‐characterized patients with FAP‐like phenotype, and stratified according to the recent guidelines for the clinical management of FAP: FAP, AFAP, MCRA (10–99 colorectal adenomas) without family history of colorectal cancer or few adenomas (FH), MCRA (10–99) with FH, MCRA (3–9) with FH. Overall, APC or MUTYH mutations were detected in 42/48 (88%), 14/20 (70%) and 10/38 (26%) of FAP, AFAP and MCRA patients, respectively. APC and MUTYH mutations accounted for 81% and 7% of FAP patients and for 30% and 40% of AFAP patients, respectively. Notably, MCRA patients did not present APC mutations. In 26% of these patients, an MUTYH mutation was identified and the detection rate increased with the number of adenomas, irrespectively of family history, being significantly higher in MCRA patients presenting more than 30 adenomas [7/12 (58%) vs 2/14 (14%), p = 0.023]. We validate the recently proposed guidelines in our patients cohort and show that APC or MUTYH germline defects are responsible for the majority of clinically well‐characterized patients with FAP and AFAP phenotype, and patients with more than 30 colorectal adenomas. The different mutation frequencies according to family history and to the number of adenomas underscore the importance of an adequate familial characterization, both clinically and by colonoscopy, in the management of FAP‐like phenotypes. The phenotypes of the mutation‐negative patients suggest distinct etiologies in these cases.

Aggressive phenotype of MYH-associated polyposis with jejunal cancer and intra-abdominal desmoid tumor: report of a case.

ABSTRACT: MYH-associated polyposis is an inherited autosomal recessive disease, linked to biallelic germline MYH mutations, which predisposes to the development of multiple colorectal adenomas and cancer. The colonic and extracolonic phenotype of this syndrome is very heterogeneous. We report the case of a young male patient with an aggressive MYH-associated polyposis phenotype. He presented at aged 30 years with more than 100 colonic polyps and 4 colonic adenocarcinomas. At aged 35 years, Spigelman Stage IV duodenal adenomatosis was detected. When he was 39 years old, he developed three synchronous jejunal adenocarcinomas and a mesenteric desmoid tumor. Based on this report, we believe that screening of the entire small bowel should be recommended in MYH-associated polyposis patients, especially in those with duodenal adenomas. Similar to patients with familial adenomatous polyposis, desmoid tumors also may be part of the clinical spectrum of MYH-associated polyposis and may prove to be a significant clinical problem in patients submitted to prophylactic colectomy.

Men seeking counselling in a Breast Cancer Risk Evaluation Clinic

Background Hereditary breast and ovary cancer syndrome affects both genders but little is known about the uptake of genetic services by men. The objective of this study is to characterise the male population counselled through a multidisciplinary breast/ovarian program. Methods Descriptive analysis of male patients counselled from January 2000 to December 2015. Data in this analysis include new cancer diagnoses during prospective follow up. Results From 4,320 families registered, 362 male patients were identified: 236 (65.2%) from hereditary cancer families (HCF) and 126 (34.8%) from non-HCF. In HCF, 121 patients (51.3%) were mutation carriers (MC): BRCA2 – 102 (84.3%), BRCA1 – 16 (13.2%), CHEK2 – 1 (0.8%) and TP53 – 2 (1.7%). Non-HCF included 126 patients: 85 (67.5%) belonged to families without pathogenic mutations or with variants of unknown clinical significance; 22 (17.5%) refused testing after counselling and 19 (15.0%) did not meet criteria for testing. Both HCF and non-HCF included patients with previous cancer diagnoses: HCF- Breast Cancer (BC) - 18; prostate cancer (PC) - 13; melanoma - 1; others - 7) and non-HCF (BC - 77; PC - 20; gastric cancer (GC) - 1; melanoma - 8; bladder cancer - 1; others - 22). From the 121 MC identified (including the TP53 and CHEK2 carriers), 97 patients (80.2%) adhered to prospective surveillance. With a median follow-up of 36.9 months, 17 cancers were diagnosed in 14 patients, PC being the most frequently diagnosed neoplasia (5 cases). Eleven patients (78.6%) are alive and three patients died of advanced cancer (2 with GC, 1 with disseminated adenocarcinoma). Conclusion We observed a high adherence to counselling, genetic testing and active surveillance by men belonging to hereditary BC families. Male carriers of pathogenic DNA variants are at risk for several cancers and should be included in prospective follow-up studies.