A systematic review and meta-analysis of 40 randomized clinical trials and five nonrandomized clinical trials evaluated the efficacy and safety of treatments for basal cell carcinoma, the most common form of skin cancer. At the end of his effort, Aaron M. Drucker of Brown University (Rhode Island) andthe University of Toronto, the study’s coordinator, commented on the findings, “I was very surprised by the lack of scientific evidence behind several interventions that are often used to treat this cancer.”
Drucker gave the example of curettage and electrodissection surgery, in which the superficial part of the tumor is scraped off and then the base of the tumor is burned: ” It is one of the most frequently used treatments for basal cell carcinoma located on the chest or back, but we have not found any clinical trials that have evaluated its efficacy at these sites.”
Surgical removal is widely believed to be the gold standard for the treatment of basal cell carcinoma, but the relative safety and efficacy of the various techniques are unclear.
The work of the American researchers made it possible to calculate the average recidivism rates, which were similar after excision (3.3 percent), Mohs surgery (3.8 percent), curettage and diathermy (5.9 percent), and external radiation (3.2 percent), while they were substantially higher after cryotherapy, curettage and cryotherapy, 5-fluorouracil administration, imiquimod treatment, and photodynamic therapy (PDT) with methyl-aminolevulinic acid or aminolevulinic acid.
Surgical excision without intraoperative margin assessment was associated with the lowest rates of lack of histologic clearance. Rates for other treatments were higher but inaccurately estimated.
The authors also examined patients’ reactions to the cosmetic results, which were found to be better after photodynamic therapy than after standard excision, cryotherapy, or PDT combined with laser preparation of the lesion.
Drucker AM, Adam GP, Rofeberg V, Gazula A, Smith B, Moustafa F, Weinstock MA, Trikalinos TA. Treatments of Primary Basal Cell Carcinoma of the Skin: A Systematic Review and Network Meta-analysis. Ann Intern Med. 2018 Sep 18. [Epub ahead of print]
