Sunscreen Use and Subsequent Melanoma Risk: A Population-Based Cohort Study

Area of Science:

• Dermatology
• Epidemiology
• Oncology

Background:

• Melanoma is a significant public health concern.
• Sunscreen use is a common sun protection behavior.
• Understanding the relationship between sunscreen SPF and melanoma risk is crucial.

Purpose of the Study:

• To evaluate melanoma risk associated with sunscreen usage.
• To compare the efficacy of high-SPF versus low-SPF sunscreens in preventing melanoma.
• To analyze sunbathing habits in relation to sunscreen use and melanoma risk.

Main Methods:

• Prospective population-based cohort study (Norwegian Women and Cancer Study).
• Inclusion of 143,844 women aged 40-75 years with 1,532,247 person-years of follow-up and 722 melanoma cases.
• Multivariable Cox proportional hazards regression to estimate hazard ratios and 95% confidence intervals for melanoma risk based on sunscreen SPF categories (never, <15, ≥15).

Main Results:

• Sunscreen users reported more sunburns, sunbathing vacations, and indoor tanning.
• Use of SPF ≥ 15 sunscreen was associated with a significantly decreased melanoma risk (HR, 0.67; 95% CI, 0.53-0.83) compared to SPF < 15.
• General use of SPF ≥ 15 sunscreen in women aged 40-75 could potentially reduce melanoma incidence by 18% (95% CI, 4%-30%).

Conclusions:

• Sunscreen use with SPF ≥ 15 demonstrates a protective effect against melanoma.
• Switching from SPF < 15 to SPF ≥ 15 sunscreens is recommended to reduce melanoma risk.
• A potential 18% reduction in melanoma incidence is achievable with widespread adoption of SPF ≥ 15 sunscreen use among women aged 40-75.