Arnold, Julie

3567 Background: The ability to genotype large numbers of people rapidly and inexpensively for research purposes highlights the need to develop guidelines for providing medically-relevant research results - including unanticipated findings - to study participants. The Colon Cancer Family Registry (C-CFR) is the oldest and largest international colon cancer population-based registry; its experience managing genetic research findings can offer guidance to clinicians and researchers. The C-CFR has enrolled 10,019 cases with colon cancer and 24,708 family members in six registries in the US, Canada, Australia, and New Zealand. Deleterious (“high risk”) germline mutations have been identified in DNA mismatch repair (MMR) genes (MLH1, MSH2, MSH6, PMS2) and the MutYH gene. The aims of this presentation are to: (1) report the uptake of genetic test results by C-CFR participants; (2) systematically compare disclosure protocols and barriers to uptake by registry; (3) make recommendations to guide clinicians and researchers. Methods: Uptake of genetic test results was calculated from data collected by the C-CFR; key investigators (KIs) from each registry completed a survey about disclosure decision-making; KIs also took part in discussions to generate recommendations. Results: Registry-wide molecular testing has identified deleterious MMR germline mutations for at least one member of 424 families (4%) and 48 biallelic MutYH gene carriers. Uptake of test results ranged from 56-86% (n= 1542) across registries. Barriers to disclosure include: (1) lack of pre-existing notification protocols; (2) logistics of re-consent; (3) limited involvement of genetic counselors at some registries; (4) in the US, the requirement that genetic testing be performed in a CLIA approved laboratory; (5) IRBs declining approval; and (6) budget constraints. Conclusions: Based on our international registry’s findings we recommend that researchers generating genetic information establish plans for disclosure at the outset; obtain subject consent a priori; consider subject knowledge and disclosure preferences; provide guidance and budget for clinical follow-up; and involve genetic counselors.

Abstract Background: Previous reports suggest that relatives of colorectal cancer (CRC)-affected probands carrying the BRAF p.V600E mutation are at an increased risk of CRC and extracolonic cancers (ECC). In this study, we estimated the association between a family history of either CRC or ECC and risk of CRC with a BRAF p.V600E mutation. Methods: Population-based CRC cases (probands, ages 18–59 years at diagnosis), recruited irrespective of family cancer history, were characterized for BRAF p.V600E mutation and mismatch repair (MMR) status. ORs and 95% confidence intervals (CI) were estimated using multivariable logistic regression. Results: The 690 eligible probands showed a mean age at CRC diagnosis of 46.9 ± 7.8 years, with 313 (47.9%) reporting a family history of CRC and 53 (7.7%) that were BRAF-mutated. Probands with BRAF-mutated, MMR-proficient CRCs were less likely to have a family history of CRC than probands that were BRAF wild-type (OR, 0.46; 95% CI, 0.24–0.91; P = 0.03). For probands with a BRAF-mutated CRC, the mean age at diagnosis was greater for those with a CRC-affected first- or second-degree relative (49.3 ± 6.4 years) compared with those without a family history (43.8 ± 10.2 years; P = 0.04). The older the age at diagnosis of CRC with the BRAF p.V600E mutation, the more likely these probands were to show a family history of CRC (OR, 1.09 per year of age; 95% CI, 1.00–1.18; P = 0.04). Conclusions: Probands with early-onset, BRAF-mutated, and MMR-proficient CRC were less likely to have a family history of CRC than probands that were BRAF-wild-type. Impact: These findings provide useful insights for cancer risk assessment in families and suggest that familial or inherited factors are more important in early-onset, BRAF-wild-type CRC. Cancer Epidemiol Biomarkers Prev; 22(5); 917–26. ©2013 AACR.