Sun exposure in melanoma

The authors aimed to determine the effect of sun exposure on cutaneous melanoma development.

Cutaneous melanoma is the most common form of melanoma and can occur on all areas of the skin. One of the main factors involved in melanoma development is sun exposure. Solar elastosis, also known as actinic elastosis, is a disorder that makes the skin appear yellow, wrinkled or thickened as a result of sun damage from long-term sun exposure.

The aim of this study was to determine the effect of long-term sun exposure on cutaneous melanoma development.

510 patients were used in this study. Patients were separated into three groups based on the extent of solar elastosis in the tissue beside their tumor – nil/mild damage, moderate damage or marked damage. 286 patients were nil/mild, 128 patients were moderate and 96 patients were marked.

418 patients had trunk (torso) melanomas. Of these, 41 patients had marked damage. Marked trunk damage was positively associated with the highest levels of total sun exposure (over 6 hours per day). The risk of experiencing increased solar elastosis was over 5 times as likely in the patients with the highest level of sun exposure compared to patients who experienced the lowest levels of sun exposure (less than 1 hour per day) – particularly in patients who spent long-term periods in the sun as a result of work or recreational activities.

92 patients had head or neck melanomas.The most strongly associated factor resulting in marked damage in neck/head melanoma was the presence of more than 7 actinic keratoses (pre-cancerous patch of thick, scaly or crusty skin).

Trunk melanoma patients were nearly 3 times more likely to report over 10 sunburns during secondary school and nearly 8 times more likely to experience patches of thick, scaly or crusty skin leading to solar elastosis. They were also significantly more likely to have facial freckles than patients with head/neck lesions, but were significantly less likely to have non-cancerous birthmarks or beauty marks on the skin.

Overall, moderate to marked solar elastosis damage was associated with 37% of trunk melanomas and 77% of head/neck melanomas.

The authors concluded that about one in three melanomas were associated with moderate-marked damage and that patient history can be used to distinguish between cutaneous melanoma patients.

The group of head/neck melanoma patients was smaller than the trunk melanoma patients so comparisons between the two were limited. 

If you are concerned about your level of sun exposure or lesions on your skin please consult your doctor immediately.