Comparison of Topical Methyl Aminolevulinate Photodynamic Therapy With Cryotherapy or Fluorouracil for Treatment of Squamous Cell Carcinoma In Situ

Abstract

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/cm 2 , 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 retreated. 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.

Monitoring the accumulation and dissipation of the photosensitizer protoporphyrin IX during standard dermatological methyl-aminolevulinate photodynamic therapy utilizing non-invasive fluorescence imaging and quantification

“…The clinical clearance rates are similar to standard treatment methodologies for these conditions (e.g. surgical excision and curettage) (9)(10)(11)(12)(13)(14)(15)(16). Furthermore PDT negates several other issues that commonly arise in the standard treatment of these indications, including lesion size and multiplicity as well as also resulting in a better cosmetic outcome (17).…”

BritishAssociation ofDermatologists' guidelines for the management of squamous cell carcinomain situ(Bowen's disease) 2014

“…68 Complete clinical clearance rates of 88-100% are reported 3 months after one cycle of MAL-PDT, with 68-89% of treated lesions remaining clear over follow-up periods of 17-50 months. 40,[70][71][72][73] A multicentre, randomized study compared MAL-PDT with cryotherapy or 5-FU in 225 patients with 275 SCCs in situ.…”

Non-melanoma Skin Cancer in Canada Chapter 3: Management of Actinic Keratoses

“…AK research is singularly well suited to intraindividual comparison studies-for example, split-face or split-scalp studies, in which different therapies are used to treat otherwise-identical areas of photodamaged skin. 22,26,[32][33][34] Efficacy outcomes differ across studies in the AK literature, making comparisons difficult. In particular, some studies report the proportion of lesions that respond to treatment, whereas others report the rate of complete clearance within the treatment field.…”