OBJECTIVE: We aim to compare the rates of basal cell carcinoma (BCC) and cutaneous SCC (cuSCC) in patients with metastatic melanoma treated with anti-programmed cell death 1 (anti-PD1), BRAF inhibitor monotherapy (BRAFi) or dabrafenib and trametinib combination therapy (CombiDT) with a group of control patients having similar risks.
METHODS: We reviewed the records of melanoma patients on anti-PD1, BRAFi or CombiDT from Westmead Hospital, Australia. As controls, we also reviewed the records of all patients seen at the High Risk Melanoma Clinic, Westmead Hospital.
RESULTS: In all, 342 patients were included; 82 on anti-PD1, 134 on BRAFi, 69 on CombiDT and 57 controls. BRAFi had the highest incidence of BCC (12.7%), followed by CombiDT (10.1%) and anti-PD1 (2.4%). The incidence of BCCs was significantly lower in patients on anti-PD1 (2.4% versus 19.4%, p<0.001) compared to controls, and patients on anti-PD1 were 8.33 times less likely to develop a BCC than controls (hazard ratio [HR] 0.120 [95%CI 0.027-0.539], p=0.006). BRAFi and CombiDT showed no significant differences in BCC incidence compared to controls. BRAFi had the highest cuSCC incidence (23.9%), followed by anti-PD1 (7.3%) and CombiDT (2.9%). The incidence of cuSCC was significantly higher in patients on BRAFi (23.9% versus 3.5%, p<0.001) compared to controls, but anti-PD1 and CombiDT showed no differences in cuSCC incidence compared to controls.
CONCLUSION: We found anti-PD1 therapy significantly decreases the incidence of BCC but not cuSCC, in patients with metastatic melanoma. Future studies investigating the role of anti-PD1 in preventing or treating BCC may be warranted.