Comparison of topical methyl aminolevulinate photodynamic therapy with cryotherapy or Fluorouracil for treatment of squamous cell carcinoma in situ: Results of a multicenter randomized trial.

OBJECTIVE To compare the efficacy, tolerability, and cosmetic outcome of photodynamic therapy (PDT) using topical methyl aminolevulinate with cryotherapy or topical fluorouracil for treatment of squamous cell carcinoma in situ. DESIGN Randomized, placebo-controlled study, with follow-up at 3 and 12 months after last treatment. SETTING Forty outpatient dermatology centers in 11 European countries. PATIENTS Random sample of 225 patients with histologically confirmed squamous cell carcinoma in situ (lesion size, 6-40 mm) and no evidence of progression. INTERVENTIONS Treatment with PDT with methyl aminolevulinate (160 mg/g; n = 96) or matching placebo cream (n = 17), cryotherapy (n = 82), or topical fluorouracil (5% cream; n = 30). Methyl aminolevulinate or placebo cream was applied for 3 hours before illumination with broadband red light (75 J/cm2, 570-670 nm). Treatment was repeated 1 week later. Cryotherapy was performed with liquid nitrogen spray. Fluorouracil was applied for 4 weeks. Lesions with a partial response at 3 months were re-treated. MAIN OUTCOME MEASURES Clinically verified complete response of lesions; blinded and on-site assessment of cosmetic outcome (4-point rating scale). RESULTS At 12 months, the estimated sustained lesion complete response rate with methyl aminolevulinate PDT was superior to that with cryotherapy (80% vs 67%; odds ratio, 1.77; 95% confidence interval, 1.01-3.12; P = .047), and better than that with fluorouracil (80% vs 69%; odds ratio, 1.64; 95% confidence interval, 0.78-3.45; P = .19). Cosmetic outcome at 3 months was good or excellent in 94% of patients treated with methyl aminolevulinate PDT vs 66% with cryotherapy and 76% with fluorouracil, and was maintained at 12 months. CONCLUSION Methyl aminolevulinate PDT is an effective treatment option for squamous cell carcinoma in situ, with excellent cosmesis.