Genetic testing in families with hereditary nonpolyposis colon cancer

Context Genetic testing for hereditary nonpolyposis colon cancer (HNPCC) is available, but the rates of acceptance of testing or barriers to participa tion are not known. Objective To investigate rates and predictors of utilization of genetic tes ting for HNPCC. Design Cohort study conducted between July 1996 and July 1998, Setting Hereditary nonpolyposis colon cancer family registry, Participants Adult male and female members (n = 208) of 4 extended HNPCC fa milies contacted for a baseline telephone interview. Interventions Family education and individual genetic counseling. Main Outcome Measure Participant acceptance of HNPCC test results. Results Of the 208 family members, 90 (43%) received test results and 118 ( 57%) declined. Of 139 subjects (67%) who completed a baseline telephone int erview, 84 (60%) received test results and 55 (40%) declined. Of the 84 sub jects who received test results, 35 (42%) received information indicating t hat they had HNPCC-associated mutations and 49 (58%) that they did not. Tes t acceptors had higher education levels (odds ratio [OR], 3.74; 95% confide nce interval [CI], 2.49-5.61) and were more likely to have participated in a previous genetic linkage study (OR, 4.30; 95% CI, 1.84-10.10). The presen ce of depression symptoms significantly reduced rates of HNPCC test use (OR , 0.34; 95% CI, 0.17-0.66). Although rates of test use were identical among men and women, the presence of depression symptoms resulted in a 4-fold de crease in test use among women (OR, 0.25; 95% CI, 0.08-0.80) and a smaller, nonsignificant reduction among men (OR, 0.49; 95% CI, 0.19-1.27). Conclusions Despite having significantly elevated risks of developing colon cancer, a relatively small proportion of HNPCC family members are likely t o use genetic testing. Barriers to test acceptance may include less formal education and the presence of depression symptoms, especially among women. Additional research is needed to generalize these findings to different cli nical settings and racially diverse populations.