The Latest in Photoprotection for Melanoma

While there are improvements in early detection of melanoma, more work needs to be done in primary prevention via photoprotection, said Darrel S. Rigel, MD, clinical professor of dermatology at Mount Sinai Icahn School of Medicine, New York, New York, during the 2021 Fall Clinical Dermatology Conference for PAs & NPs, held November 12-14, in Orlando, Florida, and virtual.¹

“The overwhelming majority of melanoma are caused by UV exposure,” Rigel said during the “Photoprotection Update” session.

Studies have demonstrated reduced melanoma risk after regular sunscreen use, according to Rigel. A large Queensland, Australia, study, for example, demonstrated a “significant difference” for residents who used sunscreen daily vs those who used it on a discretionary basis. “They had about half the chance of getting melanoma if they used sunscreen every day,” Rigel said.²

However, there is new information on sunscreen and SPFs that can be confusing for practitioners and patients.

“How high is high enough for SPFs?” Rigel asked. In a Journal of the American Academy of Dermatology study, SPF 100+ sunscreen was significantly more effective in protecting against sunburn than the SPF 50+ sunscreen for all skin types evaluated, he noted.³

“These findings demonstrate that there is a need for sunscreens labeled with SPFs greater than 50+ to provide consumers with better choices for sunburn protection,” Rigel said.

However, determining the correct SPF is difficult, because “patients often do not apply the right amount. To cover your whole body takes the size of a golf ball or shot glass,” Rigel said.⁴

Sunscreen SPFs are tested using a thickness of 2 mg/cm2. Investigations show that sunscreen under natural conditions is applied insufficiently with amounts about 0.39 to 1.0 mg/cm2, he noted. “Missing areas and UV radiation exposure before sunscreen application are other pitfalls that reduce the protective effect of sunscreens considerably,” Rigel said.

The FDA is now suggesting a cap of 60 or more for SPF, but in very sunny areas such as Florida, or for those who ski in Colorado, “you need higher than that,” Rigel said.

Rigel also addressed oxybenzone in sunscreens.

The FDA asked industry and interested parties to provide data for 12 ingredients—including oxybenzone—that the agency says has insufficient data to determine them a Generally Recognized as Safe and Effective (GRASE).⁵

Oxybenzone works well and is an ingredient in most sunscreens in the US, so it would be difficult for manufacturers not to have it available, Rigel said.

The agency is expected to finalize its sunscreen regulations in 2022, he said, “but I don’t think they’re going to impact what we are going to be telling our patients. Continue to recommend photoprotection for your patients,” he added. Explain to patients that “there is strong data to support sunscreen usage lowers skin cancer risk.”

References:

1. Rigel, D. Photoprotection Update. PA & NP Fall Clinical Dermatology Conference 2021. November 12-14, 2021. Orlando, FL and virtual.
2. Green AC, Williams GM, Logan V, Strutton GM. Reduced melanoma after regular sunscreen use: randomized trial follow-up. JCO. 2011;29(3):257-263.
3. Ou-Yang H, Stanfield J, Cole C, Appa Y, Rigel D. High-SPF sunscreens (SPF ≥ 70) may provide ultraviolet protection above minimal recommended levels by adequately compensating for lower sunscreen user application amounts. Journal of the American Academy of Dermatology. 2012;67(6):1220-1227.
4. Petersen B, Wulf HC. Application of sunscreen − theory and reality: Application of sunscreen − theory and reality. Photodermatol Photoimmunol Photomed. 2014;30(2-3):96-101.
5. Sunscreen drug products for over-the-counter human use. Federal Register: The Daily Journal of the United States Government. National Archives. Accessed November 14, 2021. https://www.federalregister.gov/documents/2019/02/26/2019-03019/sunscreen-drug-products-for-over-the-counter-human-use