Cancer genetic testing alerts mutation carrier members to their elevated risk before disease onset, when early detection and even prevention may be possible. Little is known about the effect of genetic test reporting on prevention behaviors, as prior studies have focused on screening. Familial melanoma presents an ideal context in which to examine the impact of genetic test reporting on prevention behaviors because avoidance of UVR, a well-established risk factor in this population, represents a quantifiable prevention measure. We hypothesize that melanoma genetic test reporting will improve patient compliance with prevention and screening recommendations above that observed with counseling alone, and that specific cognitive and individual difference characteristics will be associated with compliance and non-compliance in the familial melanoma population. More broadly, our research strategy permits elucidation of cognitive processes that determine a patient's response to genetic test reporting. Thus, it may ultimately be possible to tailor genetic test results to maximize compliance with prevention recommendations. To accomplish these goals, four specific aims will be prospectively evaluated in 300 members of high-risk melanoma families. In Aim 1 we will measure UVR exposure in unaffected mutation carriers, compared to counseling-only matched controls, using a wristwatch-type UVR dosimeter and reflectance spectroscopy device. This will allow us to disentangle the effects of counseling from those of genetic test reporting in the reduction of UVR exposure, our primary prevention outcome. Aim 2 will similarly determine if counseling and/or reporting improve the frequency and thoroughness of skin self-examinations (SSEs) and professional total body skin examination (TBSEs). Aim 3 will identify specific cognitive and emotional consequences of receiving a definitive positive genetic test result compared to counseling-only controls, and whether such changes mediate modification in prevention behaviors. Aim 4 will identify patient subgroups at risk for poor adherence and psychological distress following reporting. Taken together, these Aims will allow determination of whether genetic test reporting improves prevention and screening adherence and if so, why and for whom.