Risk of cancer in patients with rheumatoid arthritis under tocilizumab: Data from the French national registry REGATE

Our study aimed to estimate the incidence and risk factors of cancer among rheumatoid arthritis (RA) patients treated with tocilizumab (TCZ) and followed for five years in the French registry (REGATE).

The REGATE registry is a French prospective cohort study investigating the safety of TCZ in RA (registration n^o: 910346). Data were collected using an e-CRF between 2011 and 2016 and with a questionnaire specifically distributed to participating centers that reported malignancies in REGATE. We mainly focused on solid cancers, hematological malignancies, and non-melanoma skin cancers (NMSC). To identify potential risk factors associated with cancer, we performed a univariate analysis and a multivariate analysis using Cox proportional hazards models.

Our study included 1496 patients with RA who were treated with TCZ for a mean duration of 32.0 (±22.0) months and followed for an average of 47 (±15.2) months, resulting in a total exposure of 3990.9 patient-years (PY). Of these patients, 63 (4.2%) were diagnosed with a total of 75 cancers during the follow-up period (35 solid neoplasms, 11 hematological malignancies, 3 melanomas, and 26 NMSC). The overall incidence of cancer excluding NMSC was 7.5/1000 PY (exposure time). Our multivariate analysis revealed that high age (HR=1.05 [1.02-1.08]), current smoker (HR=2.65 [1.27-5.53]) and male 2.38 [1,18-4,80]) were independent risk factors for solid cancers. Age and active smoking were associated with higher risk of hematological malignancies.

We found no additional risk factors of cancer for RA patients under TCZ, beyond those already known in the general population.