In an analysis of DANBIO registry data, use of biologic DMARDs (bDMARDs) was not associated with an increased risk of a second malignant neoplasm among patients with rheumatoid arthritis and a history of a primary cancer diagnosis, compared with those not treated with bDMARDs (HR 1.11, 95% CI 0.74–1.67). The result was similar whether bDMARDs were used before or after the first cancer, or both, and was independent of the type of bDMARD used. No clear conclusion could be drawn regarding the influence of bDMARD treatment on mortality in patients with a history of cancer.