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

Background Nonsteroidal anti-inflammatory drugs and vitamin-D derivatives can target signaling pathways activated in basal cell carcinoma (BCC). Objective We investigated the efficacy of topically applied diclofenac sodium 3% gel, calcitriol 3 μg/g ointment, and a combination of both in superficial BCC (sBCC) and nodular BCC. Methods 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 (8 weeks), tumors were excised. Primary outcome was posttreatment 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. Results sBCC treated with diclofenac showed a significant decrease in Ki-67 ( P 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. Limitations The sample size was small. Conclusion 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.