LAUSR

Dermatologists recognize the ‘ripple effect’ that occurs when a patient’s new diagnosis or death from melanoma creates demand among the individual’s relatives to be screened for melanoma. Population impact would be even greater if such teachable moments about skin cancer risk could be spread to secondary connections beyond the melanoma patient’s immediate family. Providing personalized genomic risk information about melanoma holds the potential to trigger such spread. Indeed, among those already known to have a high personal, familial, or genetic melanoma risk, provision of genetic data has been shown to prompt useful discussions about melanoma risk, early detection and prevention with multiple family members. What has been unknown is whether providing melanoma genomic test data might also trigger useful skin cancer prevention discussions among a social network of people unselected for genetic or phenotypic melanoma risk. Conversely, it remained possible that an alternative, perverse consequence might occur if the provision of melanoma genomic data to those at low genetic risk reduced melanoma discussions by reassuring patients and dispelling their concerns about skin cancer. In research reported in last month’s BJD, Smit et al. studied 103 participants recruited from a registry of Australian adults willing to enroll in cancer research studies. Enrollees with a personal history of melanoma were excluded but family history was allowed, and approximately one-quarter of those participating in the registry had a family history of melanoma. Participants were surveyed 3 months after they received a booklet explaining their genomic risk estimate based on salivary DNA testing with the MassARRAY iPLEX Gold assay. The findings were that 74% of participants discussed their information with relatives and 49% discussed it with friends. A smaller proportion discussed their data with health professionals, and that number was greater for individuals with high genetic risk (41%) than average (16%) or low risk (12%). These results suggest that natural synergies within kinship networks make it easy for people to reach out to family members to discuss their ‘shared risk.’ The kinship network is ideal for promoting discussion and receiving encouragement from relatives. Ironically, the findings also demonstrate the difficulty that people have appraising how much risk they actually share with those others. Without complete testing of relatives, the complexity of the data included in the risk estimate (reflecting multiple risk alleles across 21 genes with incomplete penetrance) leaves inferences about shared risk open to wide differences in interpretation. This ambiguity is evident from the divergent decisions that individuals at high melanoma genetic risk made about whether to share their risk information with family members. Those who chose to discuss their genetic test data with family members reported a felt duty to convey a mutual genetic risk. Those who chose not to discuss their risk information with family members reasoned that family members were not at high risk even though they, personally, were at high risk. In the study by Smit et al, cultural norms about supporting family members served to initiate conversations about primary and secondary prevention of melanoma among family members across the spectrum of people from low (MC1R) to high (CDKN2A) genomic risk, even though the justification for discussion was only weakly grounded by a basis in shared genetics. In essence, a relative’s portrayal of ‘shared risk’ became a story-telling device that drew upon emotional connection to proactively open a dialogue about cancer preventive strategies. Story-telling narratives can have uniquely persuasive effects in overcoming preconceived beliefs and cognitive biases. Recognizing the importance of familial conversations highlights that it may also be feasible to prompt similar conversations about shared risk among friends to help spread the skin cancer prevention message more broadly throughout the population. The conditions that create susceptibility to melanoma (common genes, prevalent fair skin types, normatively poor sun protection behaviours) are widely shared with others, including friends. This commonality of attributes constitutes genuine grounds to discuss shared risk with friends as well as relatives, thereby spreading skin cancer risk awareness even more broadly. Such discussions could be quite catalytic of broadly increased skin cancer awareness and preventive efforts, given that the average participant who discusses genomic risk data with friends speaks with four additional people. Who was more likely to share health information? Who was informed? In the Smit et al. study, older participants (age 45–69 years) were disseminators of information and were motivated by the ‘duty to inform’ their relatives. Older family members may be a critical source of family health information and of emotional and tangible support. For example, they may help to create a culture of sun safety within the family, wherein all members of the family collaborate on making lifestyle changes. Other studies report that women are more likely to share health information and to encourage sun protection among family members. Many families identify a ‘family health communicator’, who serves as a resource for family members by disseminating information and providing