Using SPF 15 or Greater Could Reduce Melanoma Incidence

September 13, 2016

The use of sunscreen with an SPF of 15 or greater was associated with about a 30% reduction in the risk for melanoma among a group of Norwegian women.

The use of sunscreen with an SPF of 15 or greater was associated with about a 30% reduction in the risk for melanoma among a group of Norwegian women, according to the results of a population-based study published in the Journal of Clinical Oncology.

If all women in Norway aged 40 to 75 years used sunscreen with an SPF of 15 or greater, there would potentially be a decrease in the melanoma rate of about 18%, estimated researchers led by Reza Ghiasvand, Oslo Centre for Biostatistics and Epidemiology, Norway.

According to the researchers, unlike studies of sunscreen and melanoma conducted in Australia where exposure to ultraviolet radiation is unintentional, a 2014 Norwegian survey found that almost 75% of respondents agreed with the statement, “I sunbathe to get a tan.” Therefore, Ghiasvand and colleagues assessed whether or not use of sunscreen according to SPF was associated with melanoma risk among a group of Norwegian women.

They used data from the Norwegian Women and Cancer Study, which included 143,844 women aged 40 to 75. During a mean follow-up of about 10 years, there were 722 cases of melanoma.

Among study participants, users of sunscreen were more likely to be younger, to live in areas with high ambient ultraviolet radiation, have higher education, light skin color, blond or red hair, and freckling when sun bathing (P < .001). In addition, sunscreen users were more likely to report significantly more sunburns and sunbathing vacations and indoor tanning (P < .001).

Looking at the participants according to SPF use, the researchers found that use of sunscreen with an SPF of 15 or greater at least once was associated with a significant decrease in the risk for melanoma compared with consistently using sunscreen with an SPF of less than 15 (hazard ratio, 0.67 [95% CI, 0.53–0.83]).

“We used SPF <15 as the referent because the non-users of sunscreen were a small group and had different sun exposure compared with sunscreen users,” the researchers wrote. “Non-users were more likely to live in areas of low ambient ultraviolet radiation and to report no sunbathing vacations, no sunburns, and never use of indoor tanning devices.”

Data showed that non-use of sunscreen was associated with a decreased risk of melanoma compared with women who reported use of sunscreen with an SPF of less than 15.

“The upward trend of using broad spectrum high-SPF sunscreens along with improvement in application has the potential to decrease the incidence of melanoma and lower its burden in coming years,” the researchers wrote.

The researchers estimated that if women aged 40 to 75 used sunscreen with an SPF of 15 or greater the total melanoma incidence could decrease by 18%. Among women with blond or red hair, this increased to reduction of 21%, and if it included all women who used sunscreen with an SPF of less than 15 it increased to a 33% reduction in melanoma incidence.

Commenting in a statement from the American Society of Clinical Oncology (ASCO), Howard Sandler, MD, MS, FASTRO, ASCO Expert in melanoma, said: “Research on sunscreen use and melanoma risk has historically been limited to populations in very sunny climates. This Norwegian study reassures us that there is value in using SPF 15 or higher sunscreen even for individuals living in less sunny climates. According to the study, if used widely, sunscreen could have a major impact on the rate of melanoma, reducing it by nearly 20%.”