Overall treatment success after treatment of primary superficial basal cell carcinoma: a systematic review and meta-analysis of randomized and nonrandomized trials

Background Several noninvasive treatment modalities are available for superficial basal cell carcinoma (sBCC). Objectives This systematic review aims to determine residue, recurrence and tumour-free survival probabilities of patients with primary sBCC treated with the currently most frequently used therapies. Methods The PubMed (January 1946 to October 2010), EMBASE (January 1989 to October 2010) and Cochrane (January 1993 to October 2010) databases, and reference lists were searched without date restriction. Inclusion criteria were studies that included primary, histologically proven sBCCs, that reported on residue and/or recurrence probabilities after treatment, and had a minimum follow-up period of 12 weeks. Both randomized and nonrandomized studies were included. The primary and secondary outcomes were the probability of complete response and tumour-free survival, respectively. Two independent reviewers selected 36 studies (14 randomized and 22 nonrandomized), and extracted residue, cumulative recurrence and tumour-free survival probabilities. Results Pooled estimates of percentages of sBCC with complete response at 12 weeks post-treatment, derived from 28 studies, were 86.2% [95% confidence interval (CI) 82-90%] for imiquimod treatment, and 79.0% (95% CI 71-87%) for photodynamic therapy (PDT). With respect to tumour-free survival at 1 year, the pooled estimates derived from 23 studies were 87.3% for imiquimod (95% CI 84-91%) and 84.0% for PDT (95% CI 78-90%). Only a small number of studies reported on the results of sBCC treatment with 5-fluorouracil (one), surgical excision (one) and cryotherapy (two). Conclusions Pooled estimates from randomized and nonrandomized studies showed similar tumour-free survival at 1 year for imiquimod and PDT. The PDT tumour-free survival was higher in studies with repeated treatments. However, these results were largely derived from nonrandomized studies, and randomized studies with head-to-head comparison of imiquimod and PDT are lacking. There is a need for head-to-head comparison studies between PDT, imiquimod and other treatments with long-term follow-up to enable better recommendations for optimal sBCC treatment.