Seasonal variation in diagnosis of invasive cutaneous melanoma in Eastern England and Scotland

BACKGROUND: Worldwide, the incidence of cutaneous melanoma has been reported to be highest in the summer and lowest in the winter. Northern Irish data suggested seasonal variation for women only, especially those with thinner melanomas, sited on limbs. We interrogated two larger UK cancer registries for temporal differences in melanoma diagnosis and associated patient characteristics.

METHODS: Melanomas diagnosed from 2006 to 2010 in the Eastern England and Scottish cancer registries (n=11,611) were analysed by month of diagnosis, patient demographics and melanoma characteristics, using descriptive and multivariate modelling methods.

RESULTS: More patients with melanoma were diagnosed in the summer months (June 9.9%, July 9.7%, August 9.8%) than the winter months (December 7.2%, January 7.2%, February 7.1%) and this pattern was consistent in both regions. There was evidence that the seasonal patterns varied by sex (p=0.015), melanoma thickness (p=0.002), body site (p=0.006), and type (superficial spreading melanomas p=0.005). The seasonal variation was greatest for diagnosis of melanomas occurring on the limbs.

CONCLUSION: This study has confirmed seasonal variation in melanoma diagnosis in Eastern England and Scotland across almost all population demographics and melanoma characteristics studied, with higher numbers diagnosed in the summer months, particularly on the limbs. Seasonal patterns in skin awareness and related help-seeking are likely to be implicated. Targeted patient interventions to increase sun awareness and encourage year-long skin inspection are warranted.