A single course of fluorouracil 5% cream applied to the face and ears reduces the 1-year risk of squamous cell carcinoma (SCC) requiring surgery in high-risk patients, according to a study published in JAMA Oncology.1

For the phase 4 VA Keratinocyte Carcinoma Chemoprevention Trial trial (ClinicalTrials.gov Identifier: NCT00847912), 932 patients with a history of at least 2 keratinocyte carcinomas were randomly assigned to apply fluorouracil or a vehicle control cream to the face and ears twice daily for 2 to 4 weeks. Upon completing the study treatment protocol, patients were evaluated every 6 months; median follow-up was 2.8 years.

In total, 299 and 108 patients developed basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), respectively, over 4 years; there were 95 cases of BCC and 25 cases of SCC in year 1. No differences in time to first keratinocyte, BCC, or SCC were observed between the study groups.

A 75% reduction in SCC risk was, however, observed among patients in the fluorouracil arm (1%) vs the placebo-arm (4%; 95% CI, 35%-91%; P = .002).

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An insignificant risk reduction for BCC was observed in year 1. Although there were no significant effects on keratinocyte carcinoma risk, there was a reduction in keratinocyte carcinomas treated with Mohs surgery.

The authors concluded that “further study is needed to better define the effect of fluorouracil on BCC risk and the risk of BCC that requires Mohs surgery, as well as SCC risk in patients who have received transplants and other special high-risk populations.”

Reference

  1. Weinstock MA, Thwin SS, Siegel JA, et al. Chemoprevention of basal and squamous cell carcinoma with a single course of fluorouracil, 5% cream. JAMA Oncol. 2018 Jan 3. doi: 10.1001/jamadermatol.2017.3631 [Epub ahead of print]