Apparent increased risk of skin cancer seen with initiation of systemic psoriasis treatment

Background Psoriasis treatment has been revolutionized by treatments that target specific immune pathways involved in disease pathogenesis. These drugs have excellent safety profiles; however, nonmelanoma skin cancer (NMSC) rates are higher during the 3- to 4-month initiation of active therapy than placebo. Rapid drug-induced skin cancer development seems improbable. Purpose To assess whether detection differences because of clearing extensive psoriasis could account for higher NMSC rates. Methods Randomized controlled trials were analyzed to evaluate NMSC incidence in patients with patients treated with systemic drugs vs placebo. ꭓ2 analysis compared short-term NMSC incidence between active treatments vs placebo and short-term and long-term NMSC incidence for systemic treatments. Results PubMed searches yielded 268 articles and were filtered to 23 articles. The short-term NMSC rate was 0.65 of 100 patient-years (PY) for systemic treatment and 0.36 of 100 PY for placebo. For systemic treatments for which both short-term and long-term data were available, the short-term NMSC rate was 0.53 of 100 PY, whereas the long-term rate was 0.37 of 100 PY. Conclusions NMSC incidence was higher in patients with psoriasis given systemic treatment vs placebo in the first 16 weeks of treatment. However, the NMSC rate was lower after the initial treatment period, consistent with improved NMSC detection in the short term, attributable to systemic treatment efficacy.