Systematic dermatological screening for melanomas and non-melanoma skin cancers (NMSCs) before and during treatment with biologics has long been recommended for patients with chronic inflammatory rheumatic diseases (CIRD).

To determine the incidence of skin cancers in biologic-treated patients with CIRD and to identify associated risk factors.

We retrospectively included all patients with CIRD who initiated biologics and were followed up in the dermatology department at Amiens University Hospital between January 2013 and March 2024. Risk factors were assessed using Cox proportional hazards models. If a significant association between the occurrence of skin cancer occurrence and exposure to therapeutic agent was found in univariate analysis, propensity scores were applied in multivariate analysis.

Among the 636 patients screened at biologic initiation, only one skin cancer was detected. Among the 377 patients followed up over a mean (standard deviation) of 5 (3) years, the incidence rates were 10.1/1000 patient-years for NMSCs and 3.7/1000 for melanomas. The most common skin cancers diagnosed were basal cell carcinomas (22/38) with no recurrence after excision. In a univariate analysis, age, rheumatoid arthritis, immunosuppression, exposure to corticosteroids and anti-interleukin 6 were significantly associated with the occurrence of NMSCs. In a multivariate propensity-score-weighted analysis, exposure to these two medications was not significant. Exposure to biologics was not significantly associated with the occurrence of melanoma.

Apart from rheumatoid arthritis, the risk factors for skin cancer in biologic-treated patients with CIRD are similar to those observed in the general population. Our findings might lead to more targeted dermatological monitoring.