Cancer Prevention Program

Genetic Counseling for Participants of the Colon Cancer Family Registry – Seattle

PI: Polly A. Newcomb, PhD

Lynch Syndrome is caused by specific gene mutations that are generally inherited and result in a predisposition to cancer. Individuals with this syndrome have an early onset of colorectal cancer (CRC) and an elevated risk, increased by up to 80%, for CRC and other cancers. The children of individuals with Lynch Syndrome have a 50% chance of inheriting this risk. Intensive surveillance in those with Lynch Syndrome gene mutations greatly reduces the risk of dying from CRC and probably other cancers. The Seattle Colorectal Cancer Family Registry (C-CFR) has been enrolling individuals with a diagnosis of CRC and their family members since 1998 as part of an international collaboration studying the causes of CRC. Currently our study includes 255 enrolled family members of Lynch Syndrome mutation-positive probands that have provided blood for genetic testing as part of the C-CFR. In this study we propose a cohort study of genetic screening and counselling in 255 relatives of Lynch Syndrome positive CRC cases from the Seattle C-CFR and a comparison group of 105 relatives of Seattle C-CFR cases with a strong family history of cancer, but no specific gene mutation has been identified, and who will not receive genetic testing and counselling. The aims of this project are to determine the impact of genetic testing and counselling for Lynch Syndrome on: 1) quality of life, 2) health related behaviours, such as cancer surveillance, and 3) individual costs, including cost of genetic screening, counselling, and cancer surveillance. For this research, participants will complete a series of standardized questionnaires covering cancer worry, general anxiety, and overall quality of life. Additional standard questionnaires will collect information on health behaviours, such as smoking, physical activity, and CRC surveillance in the 12 months prior to enrolment. Individuals declining disclosure will be asked questions about the reason for their refusal. At 2 and 12 months, individuals participating in the study will complete follow-up surveys. Scores for anxiety and quality of life will be constructed using established methods in conjunction with the survey instruments, and changes in these scores (baseline vs. 2 month follow-up and baseline vs. 12 month follow-up) will be calculated. Regression analyses with be used to provide estimates of the impact of Lynch Syndrome screening and counselling on quality of life and health behaviours; t-tests will be used to compare the mean cost of Lynch Syndrome screening, counselling, and cancer surveillance between individuals with identified mutations and those without mutations. To date, no study has reported on the quality of life impact or cost to the individual of Lynch Syndrome screening and counselling. Without this critical information, uncertainty will continue to hinder the uptake of Lynch Syndrome screening and counseling, an intervention that has the potential to significantly improve health outcomes in a group with a high risk of cancer.