In 2016, about twice as many people will die of skin cancer than all other cancers combined in the United States, according to projections from the American College of Surgeons. Friday’s “New and Emerging Therapies” (S011) featured presentations detailing developments in the treatment of melanoma, basal cell carcinoma (BCC), and squamous cell carcinoma (SCC).
With more than 10,000 deaths from melanoma predicted for 2016, gloom hangs over the disease. Still, there is good news; new melanoma treatments, such as vaccines and targeted therapies, are being developed, albeit slowly.
“Melanoma is a worldwide problem,” said Darrell S. Rigel, MD, clinical professor of dermatology at New York University Medical Center. “We are losing the battle. Melanoma is one of few cancers that is still rising in rate compared to other cancers.”
Analysis of melanoma thickness trends show that U.S. surveillance and early detection efforts have not reduced the impact of the disease, he said. This lack of progress means many patients have advanced melanoma, where treatment options are limited.
Established treatments that show varying success are the use of imiquimod, pulsed dye laser treatments with and without imiquimod and/or systemic therapy, and sentinel node biopsy, he said.
A new approach is the use of monovalent vaccines in which melanoma cell antibodies are generated and injected back into the cell.
“That is a theory that should work, but the problem is surface antigens in melanoma are constantly in flux,” Dr. Rigel said, adding that a better option may be to combine several common antigens for the vaccine.
The other approach drawing attention is targeted therapies, with a focus on BRAF inhibitors. This is effective only if a BRAF mutation exists, and in blocking the BRAF pathway, the treatment may stimulate mutations in the RAS pathway, he said.
Nonmelanoma skin cancers
Several new options are being studied to treat nonmelanoma skins cancers (NMSC), including photodynamic therapy (PDT), lasers, topical therapies, and smoothened inhibitors, said Abel Torres, MD, JD, professor and chairman of the department of dermatology at Loma Linda University Medical Center.
PDT is effective for low-risk, superficial BCCs, especially when a patient has multiple lesions. The cosmetic results are excellent, he said, but it is not recommended for high-risk BCCs.
With regard to using lasers to treat NMSC, several studies show various laser treatments have been successful. CO2 ablation is effective for superficial BCCs. Curettage + PCO2 lasers and super-pulsed CO2 lasers have been successful in treating superficial and nodular BCCs. A pulsed dye laser was used to treat all types of BCCs, Dr. Torres said.
Topical treatments that have had varying success are fluoracil and imiquimod, both of which have been effective for superficial BCCs, and ingenol mebutate, which “may be effective” and is still being studied, he said.
Smoothened inhibitors that are being used to treat BCCs include vismodegib and sonidegib. Vismodegib targets the Hedgehog pathway and does not have high response rates, but is a good choice when surgery is not an option. It also may be used as an adjuvant to surgery. Sonidegib also targets the Hedgehog pathway and has had a good response rate, Dr. Torres said.
For SCCs, prevention remains the best option. Dr. Torres encouraged everyone to join the AADA’s effort to support proposed FDA regulations that would limit the use of tanning beds. The AADA has made it easy to send a letter of support. Simply visit www.aad.org/stopskincancer.