Malignant Melanoma: The Relationship Between Sunscreen Use and Cancer Risk - A Systematic Review and Meta-analysis

Solar radiation represents the most important environmental risk factor for skin cancer. Despite growing awareness of the importance of regular sun protection products, the incidence of malignant melanoma continues to rise. This raises the question of whether sunscreen use truly provides a protective benefit against the risk of melanoma. The aim of this study was to assess the relevance of sunscreen use for melanoma risk.

A systematic review and meta-analysis were conducted using PubMed database. The use of sunscreen was compared based on the categories "ever" vs. "never". The study quality and level of evidence were assessed using recognized assessment tools. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Moderation analyses were conducted to explore the influence of sex, study quality, and geographical location on the overall effect estimate.

A total of 23 relevant studies were identified. An OR of 0.98 (95%CI=0.79-1.21, p=0.83) for the categories sunscreen use "ever" vs. "never/rarely" and an OR of 0.95 (95%CI=0.75-1.20, p=0.66) for the categories sunscreen use ever vs. never indicate no significant association between sunscreen use and melanoma risk. This means that a protective effect for sunscreen use and melanoma risk could not be proven. There was significant heterogeneity between the studies, which could not be explained despite sensitivity analyses, subgroup analyses, and examination of funnel plots. As an asymmetric funnel plot and a significant Egger's test occurred, the results should be interpreted with caution.

No association was found between melanoma risk and sunscreen use. Many of the studies showed methodological inaccuracies and further studies examining sunscreen application frequency and behavior towards sun exposure in more detail are needed.