Risk factors in cutaneous melanoma

About the project

Cutaneous melanoma is the most aggressive and lethal form of skin cancer. It is one of the most rapidly increasing cancers and a major public health challenge in fair-skinned populations. Notably, Norway is ranked fifth worldwide in melanoma incidence. We use data from a unique large cohort study, the Norwegian Women and Cancer study, and the Cancer Registry of Norway to gain more knowledge about melanoma risk factors.

Objectives

We aimed to study melanoma risk factors, the associations between them, and the associations with melanoma risk. Our main focus in this project is host pigmentary characteristics, ultraviolet radiation exposure from the sun and indoor tanning devices, and physical activity.

Outcomes

• Sunscreen use increased from 1997 to 2007, but this increase was not accompanied by a decrease in sunburn (Ghiasvand et al, Br J Dermatol 2015).
• Use of sun protection factor (SPF) ≥ 15 rather than SPF < 15 sunscreens reduced melanoma risk (Ghiasvand et al, J Clin Oncol 2016).
• Melanoma risk increased with increasing cumulative number of indoor tanning sessions, and women who started indoor tanning prior to 30 years of age were younger at melanoma diagnosis than never users (Ghiasvand et al, Am J Epidemiol 2017).
• Our results support the hypothesis of divergent pathways to melanoma: similar associations for lower limb and trunk melanomas arising through the nevus-associated pathway, while upper limb and head/neck melanomas arise through the long-term sun-exposure pathway (Ghiasvand et al, JAMA Dermatol 2019).
• Fair pigmentary score was associated with thinner trunk melanomas, and high number of nevi with thicker nodular melanomas (Ghiasvand et al, Acta Derm Venerol 2021)
• No support was found for a positive association between physical activity and melanoma risk as found in previous studies, important for public health guidelines promoting regular physical activity (Perrier et al, Prev Med 2021, Perrier et al, Clin Epidemiol 2022).
• Physical activity is unlikely to be associated with melanoma tumor thickness at diagnosis (Perrier et al, Br J Dermatol 2023).

Funding

Stiftelsen DAM, Norwegian Cancer Society.

Collaborations

• Tonje Braaten, Kristin B Borch, Eiliv Lund and Torkjel M Sandanger, University of Tromsø. 
• Adele Green, QIMR Berghofer Medical Research Institute, Brisbane, Australia.
• Trude E Robsahm, Cancer Registry of Norway.
• Elisabete Weiderpass, International Agency for Research on Cancer, Lyon, France.

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