Sharing genetic test results in Lynch syndrome: communication with close and distant relatives

Clinical genetic testing can help direct cancer screening for members of Lynch syndrome families; however, there is limited information about family communication of genetic test results.

A total of 174 probands who had genetic testing for Lynch syndrome were enrolled through 4 US cancer genetics clinics. Subjects were asked whether they had disclosed their genetic test results to first-, second-, and third-degree relatives. Univariate and multivariate analyses were used to identify clinical and demographic factors associated with informing immediate and extended family of genetic test results.

One hundred seventy-one of 174 probands (98%; 95% confidence interval, 95%-100%) reported that they had disclosed their genetic test result to a first-degree relative. Communication of test results to other relatives occurred significantly less often, with only 109 of 162 (67%; 95% confidence interval, 59%-74%) subjects with second- or third-degree relatives sharing their results. Individuals with a pathogenic mutation were significantly more likely to inform distant relatives than were subjects with a negative or indeterminate test result (odds ratio, 2.49; 95% confidence interval, 1.14-5.40). Probands' age, sex, and cancer status did not influence communication of genetic test results. Lack of closeness and concerns that relatives would worry or not understand the implications of test results were the primary reasons for not sharing genetic test results.

Most individuals who undergo genetic testing for Lynch syndrome share their test results with first-degree family members; however, these results reach more distant relatives significantly less often. Interventions to improve communication of genetic test results to members of the extended family are necessary to provide optimal cancer prevention care to at-risk families.