Occlusion with imiquimod 5% cream does not improve efficiency in the treatment of superficial and nondular basal cell carcinomas

Journal of Drugs in Dermatology, April, 2003

Two separate studies were conducted to examine the effect of imiquimod 5% cream with occlusion for the treatment of basal cell cancers (BCC). Patients diagnosed with BCCs were enrolled into either the superficial or nodular study, depending on their histopathologic diagnosis. Within each study, patients were randomized to one of four dosing regimens: 2 days per week with or without occlusion, or 3 days per week with or without occlusion. Ninety three patients enrolled in the superficial BCC study and 90 patients participated in the nodular BCC study. Six weeks following a 6-week treatment period, the entire target tumor area was excised and histologically examined for evidence of residual tumor.

Within the superficial BCC study group, the highest complete response rates were seen in the 3 days per week treatment groups with rates of 87% for patients with occlusion and 76% for patients without occlusion. In comparison, the response rates for the 2 days per week treatment groups were 43% and 50% for patients with and without occlusion, respectively. Occlusion did not have a statistically significant different in response rate for either the 3 times per week or the 2 times per week treatment groups.

The nodular BCC study group showed less effectiveness as compared to the superficial BCC group. Complete response rates in the 3 days per week treatment groups was 65% for patients with occlusion and 50% without occlusion. For those patients assigned to the 2 days per week treatment protocol, complete response rates were 50% and 57% with and without occlusion, respectively. No significant differences of complete response were detected between the four treatment groups.

The authors conclude that, overall, occlusion did not have an effect on complete response in the treatment of basal cell carcinomas, whether of the superficial or the nodular type, and regardless of the frequency of dosing. However, the 87% complete response rate seen in the 3 days per week with occlusion (for superficial BCCs) is similar to results obtained in previous studies using daily and 5 days per week dosing.

Sterry W et al. Imiquimod 5% cream for the Treatment of Superficial and Nodular Basal Cell Carcinoma: Randomized Studies Comparing Low-frequency Dosing with and without Occlusion. British Journal of Dermatology 2002; 147: 1227-1236.