Skin cancer risk reduced by Topical immunotherapy

A mixture of two topical creams already proven to clear precancerous skin abrasions from sun-injured skin also decreases the danger of patients developing squamous cell carcinoma of the skin.

“Squamous cell carcinoma of the skin is the second most common cancer in the U.S., and its incidence is continuing to rise,” stated Washington University dermatologist and co-author of research: Lynn A. Cornelius, MD, the Winfred A. and Emma R. Showman, director of the Division of Dermatology. “This skin cancer and its treatment can be disfiguring, costly and even life-threatening, making it essential to improve preventive strategies.”

The therapy combines a cream design of a common chemotherapy drug (5-fluorouracil) with a manmade form of vitamin D (calcipotriol). Typical treatment for the precancerous skin lesions (actinic keratosis) is topical 5-fluorouracil only. Calcipotriol is a standard treatment for psoriasis (an autoimmune disorder that results in red scales).

The team has shown that calcipotriol triggers the T cells, which then strike the tumor cells. In a past clinical trial conducted at Siteman Cancer Center, it was seen that a mixture of this immunotherapy and chemotherapy cleaned actinic keratoses better than only standard chemotherapy.

The researchers acquired follow-up data on more than 50% of the 132 patients in the trial for three years following the original treatment. The investigators discovered that of 30 patients (recipient of the combination therapy), 7% got skin squamous cell carcinoma in the span of three years. From 40 patients (recipient of standard therapy), 28% got skin squamous cell carcinoma.

“This finding provides the first clinical proof-of-concept that an immunotherapy directed against premalignant tumors can prevent cancer,” stated senior author Shawn Demehri, MD, Ph.D., of Massachusetts General Hospital and Harvard Medical School. “We hope our findings will establish that the use of premalignant lesions as personalized therapeutic targets can train the immune system to fight against the progression to cancer.”

The researchers established that the treatment decreased the development of skin squamous cell carcinoma on the scalp and the face but not on the arms. They guessed that topical therapies might enter the skin on the face and scalp more easily than the arms. The treatment routine was comparatively short also. Topical treatments were used twice daily for only 4 days. A lengthier regimen may be needed so as to be effective on the arms and other body parts as well.