Anti-TNF agent etanercept augments UV-induced skin cancer development in SKH-1 mice(dagger)

Background: Despite being employed in the treatment of inflammatory disorders for more than 20 years all over the world, data regarding photocarcinogenic risks of anti-TNF agents is scarce. Objective: To assess photocarcinogenic potential of anti-TNF agents. Methods: This was a placebo controlled, split-body (UVB-treated versus -untreated) study on mice. Treatment groups were infliximab (n = 11), etanercept (n = 11), cyclosporine (n = 11) and vehicle control (n = 11). Agents were introduced on the 10th week of phototherapy and continued through 24th week. The macroscopic, histological and immunohistochemical analysis of test sites were carried out. Results: Overall 132 tumors were detected on test sites. All of these tumors developed on UV-exposed sides. Histologic examination of these tumors was compatible with keratinocytic neoplasia in 128, mastocytosis in 3, epidermal cyst in 1. Median tumor burden in the UVB exposed areas for ETN, IFX, CYC, and control groups were 14.91, 10.20, 6.28, and 3.14 cm(2), respectively. ETN group demonstrated both higher tumor burden and keratinocytic neoplasia numbers than controls (p = .03, p = .025). Although there were 1.8 and 1.7 times more keratinocytic neoplasms in IFX and CYC groups compared to controls, these differences didn't reach statistically significant levels (p = .14; p = .19). Conclusion: This study points out to a significant photocarcinogenic potential of anti-TNF agent etanercept.