Understanding patterns of health communication in families at risk for hereditary nonpolyposis colorectal cancer: examining the effect of conclusive versus indeterminate genetic test results.

In families meeting criteria for hereditary nonpolyposis colorectal cancer (HNPCC), genetic testing may or may not identify a mutation. Communication about genetic testing and risk in families with identified HNPCC mutations is associated with individual and relational factors. Similar communication patterns would be expected in families with similar clinical and pathological characteristics, but without an identified HNPCC mutation; however, previous studies have not included such families. Social network analysis was used to compare communication networks and associated individual and relational factors in families with and without identified HNPCC mutations. Respondents from families without identified mutations communicated about genetic counseling and testing and risk for HNPCC with a significantly smaller proportion of network members, compared to respondents from mutation-positive families. Members of families without identified mutations were also more likely to share thoughts about risk for HNPCC with network members whose advice they take, compared to members of families with known mutations. These findings extend our knowledge of communication in families at risk of HNPCC to include the many families in which a causative mutation has not yet been identified. Differences in the breadth of communication about genetics and risk for HNPCC, and the possibility that members of families without identified mutations may seek advice from those with whom they communicate about risk, provide new avenues for future research. Understanding existing communication patterns could help improve education and counseling processes, and facilitate the development of interventions designed to assist in family discussions of risk.