MONDAY, Dec. 22, 2025 (HealthDay News) -- For adults with Bowen disease (BD), the additional risk for recurrence after 5-fluorouracil (5FU) and surgical excision (SE) and the risk for developing a cutaneous squamous cell carcinoma during long-term follow-up after treatment are insignificant, according to a study published online Dec. 12 in the Journal of the American Academy of Dermatology.Myrthe M.G. Moermans, M.D., from Maastricht University Medical Center in the Netherlands, and colleagues compared the long-term efficacy of 5FU, methylaminolevulinate photodynamic therapy (MAL-PDT), and SE in a multicenter, noninferiority randomized controlled trial involving 250 adults older than 18 years with BD (82 in 5FU group, 84 in MAL-PDT group, and 84 in SE group). Participants were invited for long-term follow-up three to five years after treatment.Treatment failure was observed in 27 patients during the first year of follow-up. Only one additional patient developed a recurrence during long-term follow-up, five years after MAL-PDT. The researchers found that the four-year cumulative probability of tumor-free survival was 97.5, 86.2, and 82.7 percent for SE, 5FU, and MAL-PDT, respectively. None of the patients developed a cutaneous squamous cell carcinoma in the treated area."Based on the one-year results of this trial, it was concluded that 5FU was noninferior to excision, but for MAL-PDT noninferiority could not be concluded," the authors write. "The lack of any additional recurrences three to five years posttreatment in the current study indicates that these conclusions remain valid in the long term."Abstract/Full Text (subscription or payment may be required)