Background: Bowen's disease (BD; intraepithelial squamous cell carcinoma) is therapeutically challenging because lesions, which may be multiple, are frequently located at sites that heal poorly. There is a small risk of progression to invasive carcinoma. Photodynamic therapy (PDT) is an effective treatment for certain non melanoma skin cancers, but comparison studies with other, better-established therapies are limited.
Objectives: To compare the efficacy and tolerability of PDT and topical 5-fluorouracil (5-FU) in BD.
Methods: Forty patients from two centres were randomized to either topical PDT or 5-FU. The PDT group was treated with 20% 5-aminolaevulinic acid (ALA) applied 4 h before illumination with 100 J cm-2 narrowband red light (630 +/- 15 nm). 5-FU was applied to lesions for 4 weeks. A repeat treatment cycle was performed after 6 weeks if required. Results Twenty-nine of 33 (88%) lesions treated with PDT initially responded completely, compared with 22 of 33 (67%) after 5-FU. After 12 months, two recurrences in the PDT group and six in the 5-FU group reduced complete clinical clearance rates to 82% and 48%, respectively. PDT was significantly more effective (P = 0.006, odds ratio 4.78, 95% confidence interval 1.56-14.62). In the 5-FU group, severe eczematous reactions developed around seven lesions, ulceration in three and erosions in two. No such reactions occurred following PDT. There was no difference in overall pain experienced during each therapy.
Conclusions: Topical ALA-PDT is more effective than topical 5-FU in the treatment of BD, with fewer adverse events. ALA-PDT should be considered one of the first-line therapeutic options for BD.