[Non-melanoma skin cancer during treatment with TNF inhibitors in psoriasis and rheumatoid arthritis]

OBJECTIVE: To investigate if there was a difference in time to the occurrence of first non-melanoma skin cancer (NMSC) and in the incidence of NMSC between psoriasis patients and rheumatoid arthritis (RA) patients on TNF inhibitors. DESIGN: Prospective observational cohort study. METHOD: We compared the time to first NMSC (expressed as hazard ratio) and the incidence of NMSC (expressed as incidence ratio) in psoriasis and RA patients in the Netherlands who were treated with TNF inhibitors and had a follow-up of at least one year. Cox regression and Poisson regression analyses were used; both were corrected for confounders (age, gender, disease duration, prior NMSC, duration of anti-TNF and other systemic therapies). RESULTS: The NMSC risk was significantly higher in the psoriasis group (fully adjusted hazard ratio: 6.0 [1.6 - 22.4 95% CI]) and time to first NMSC in psoriasis compared with RA was also shorter (1.6 years and 3.7 years, respectively). The incidence of NMSC was 5.5 times higher in psoriasis patients (2.2 - 13.4 95% CI) than in those with RA. CONCLUSION: The time to first NMSC was significantly shorter and the incidence of NMSC was significantly higher in psoriasis than in RA. This indicates that disease-related factors such as phototherapy may be important contributing factors to the occurrence of NMSC in psoriasis patients treated with TNF inhibitors