Self-assessed improved sun protection after diagnosis of melanoma is associated with improved survival

Although ultraviolet radiation is the most important risk factor for skin cancer in general, its role in disease control after the diagnosis of melanoma remains to be elucidated.

To analyse the association between survival and self-assessed sun protection behaviour after a melanoma diagnosis.

This was a questionnaire-based pilot study. We used patient data from the Molecular Markers of Melanoma Study programme to select patients with a histologically verified, invasive cutaneous melanoma, diagnosed at stage I or II according to the American Joint Committee on Cancer's AJCC Cancer Staging Manual 8th edition, between 1981 and 2014. In total, 843 patients with melanoma were asked whether their diagnosis had influenced their sun protection behaviour and, if 'Yes', they were asked to describe, in their own words, how the diagnosis affected their behaviour. We excluded 33 patients who were unable to answer and included 810 patient responses for analysis. Reports on sun protection behaviour before and after melanoma diagnosis were recorded.

We found a significant association of increased melanoma-specific survival (P = 0.001) with improved self-assessed sun protection behaviour. After adjusting for age, sex, AJCC stage, localization of the primary tumour and prior ultraviolet light exposure (outdoor occupation, solarium use and sun cream use), improved sun protecting behaviour after melanoma diagnosis resulted in a decreased hazard ratio (HR) for melanoma-specific survival (adjusted HR 0.491, 95% confidence interval 0.270-0.896; P = 0.020). Stratification showed that those who benefited from improved sun protection were, in particular, male patients, patients diagnosed with melanoma after 50 years of age, patients with stage II melanomas and those carrying an MC1R gene variant.

Self-assessed improved sun protection after diagnosis was significantly associated with reduced mortality due to melanoma. These results highlight the importance of improved sun awareness for patients after melanoma diagnosis, not only for preventing further melanomas but also reducing mortality risk.