The effect of topical diclofenac 3% and calcitriol 3 μg/g on superficial basal cell carcinoma (sBCC) and nodular basal cell carcinoma (nBCC): A phase II, randomized controlled trial

Abstract

Nonsteroidal anti-inflammatory drugs and vitamin-D derivatives can target signaling pathways activated in basal cell carcinoma (BCC). We investigated the efficacy of topically applied diclofenac sodium 3% gel, calcitriol 3μg/g ointment, and a combination of both in superficial BCC (sBCC) and nodular BCC. Patients with a primary, histologically proven sBCC (n=64) or nodular BCC (n=64) were randomized to topical diclofenac, calcitriol, combination of both, or no topical treatment (control group). After self-application twice daily under occlusion (8weeks), tumors were excised. Primary outcome wasposttreatment expression levels of proliferation (Ki-67) and antiapoptosis (B-cell lymphoma [Bcl-2])immunohistochemical markers. Secondary outcomes were histologic clearance, adverse events, application-site reactions, and patient compliance. sBCC treated with diclofenac showed a significant decrease in Ki-67 (P<.001) and Bcl-2 (P=.001), and after combination therapy for Ki-67 (P=.012). Complete histologic tumor regression was seen in 64.3% (P=.0003) of sBCC (diclofenac) and 43.8% (P=.007) of sBCC (combination therapy) compared with 0.0% of controls. No significant changes were found in nodular BCC. Application-site reactions were mostly mild to moderate. The sample size was small. Our results suggest that topical diclofenac is a promising new treatment for sBCC. Its mode of action differs from available noninvasive therapies, and thus has an additive value.