Increased Risk for Cancer Observed in Abatacept-Treated Rheumatoid Arthritis

The use of abatacept as an initial biologic disease-modifying antirheumatic drug (bDMARD) for the treatment of patients with rheumatoid arthritis (RA) is associated with a slightly elevated risk for cancer overall, and in particular for nonmelanoma skin cancer, compared with the use of other bDMARDs, according to the results of a population-based, real-world cohort study published in Rheumatology.

The primary study outcome was overall cancer. Separate analyses of certain malignancies, including nonmelanoma skin cancer, melanoma, breast cancer, lung cancer, and lymphoma, were also performed. All new users of a bDMARD, including abatacept, on or after January 1, 2007, through December 31, 2014, were included in the study.

The cohort comprised 4328 patients with RA who were taking abatacept and 59,860 individuals with RA who were receiving treatment with other bDMARDs. Among these individuals, 409 abatacept-treated patients were diagnosed with any type of cancer (incidence rate, 4.76 per 100 person-years), as well as 4197 of those treated with other bDMARDs (incidence rate, 3.41 per 100 person-years).

Compared with other bDMARDs, abatacept therapy was associated with an increased incidence of cancer overall (adjusted hazard ratio, 1.17; 95% CI, 1.06-1.30). 

When evaluated according to specific cancer site, a significantly increased incidence of nonmelanoma skin cancer was reported among abatacept-treated patients compared with those patients who received treatment with other bDMARDs (adjusted hazard ratio, 1.20; 95% CI, 1.03-1.39). 

No significant differences were reported between treatments with respect to other specific cancer sites.

When methotrexate was combined with bDMARD therapy, there was no higher risk for cancer compared with the use of bDMARD monotherapy.

The investigators concluded that the results of this study warrant replication in additional large population-based studies. It is suggested that patients with RA who are exposed to abatacept be carefully monitored for the development of nonmelanoma skin cancer.

Reference

Montastruc F, Renoux C, Dell’Aniello S, et al. Abatacept initiation in rheumatoid arthritis and the risk of cancer: a population-based comparative cohort study [published December 7, 2018]. Rheumatology (Oxford). doi: 10.1093/rheumatology/key352