Prevention benefits from predictive genetic testing for cancer will only be fully realized if appropriate screening is adopted after testing. The current study assessed screening and preventive behaviors during 12 months after predictive genetic testing for hereditary nonpolyposis colorectal carcinoma (HNPCC) in an Australian clinical cohort.
Participants received predictive genetic testing for HNPCC at one of five Australian familial cancer clinics. Data on self-reported screening behaviors (colonoscopy, and endometrial sampling and transvaginal ultrasound for women) and prophylactic surgery (colectomy, and hysterectomy and bilateral oophorectomy for women) were collected using postal questionnaires before (baseline) and 12 months after receipt of genetic test results. Age, gender, perceived risk of cancer, and cancer-specific distress were assessed as predictors of colonoscopic screening.
In the current study, 114 participants returned baseline questionnaires (32 carriers and 82 noncarriers of an HNPCC mutation). Ninety-eight participants also returned a 12-month follow-up questionnaire. Of those > or = 25 years, 73% reported having had a colonoscopy before genetic testing. At follow-up, 71% (15 of 25) of carriers and 12% (8 of 65) of noncarriers reported having a colonoscopy in the 12 months after receipt of test results. The reduction in colonoscopy among noncarriers was statistically significant (P < 0.001). High perceived risk was associated with colonoscopy at baseline. At follow-up, mutation status was the only variable significantly associated with colonoscopy. Among female mutation carriers, 47% reported having transvaginal ultrasonography and 53% endometrial sampling during follow-up. There was low uptake of prophylactic surgery for colorectal, endometrial, or ovarian carcinomas.
The majority of individuals reported appropriate screening behaviors after predictive genetic testing for HNPCC. The small group of noncarriers who had screening after genetic testing might benefit from additional counseling.