abstract details

The summaries are free for public use. ARTHROS will continue to add and archive summaries of articles deemed relevant to ARTHROS by our Faculty.

Lymphoma risks in patients with rheumatoid arthritis treated with biological drugs-a Swedish cohort study of risks by time, drug and lymphoma subtype


Rheumatology (Oxford). 2020 Aug 18;keaa330. doi: 10.1093/rheumatology/keaa330.Online ahead of print.

Karin Hellgren 1, Daniela Di Giuseppe 1, Karin E Smedby 1, Christer Sundström 2, Johan Askling 1, Eva Baecklund 3

Author Information

1 Clinical Epidemiology Division, Department of Medicine Solna, Karolinska Institutet, Stockholm.

2 Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala.

3 Unit of Rheumatology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.

Free article


Objectives: To estimate the association between biological DMARDs (bDMARDs; overall and by drug) as used in RA and the risk of malignant lymphomas including subtypes.

Methods: By linking nationwide Swedish registers we identified cohorts of patients with RA initiating treatment with a bDMARD (n = 16 392), bDMARD-naïve (n = 55 253), an age- and sex-matched general population comparator cohort (n = 229 047), and all incident lymphomas 2001-16. We used Cox regression to calculate hazard ratios (HRs) of lymphoma taking calendar period and other factors into account.

Results: There were 82 lymphomas among the bDMARD-treated patients with RA, crude incidence rate 76/100 000 person-years, and 310 lymphomas among the bDMARD-naïve patients with RA, crude incidence rate 90/100 000 person-years. This resulted in an adjusted HR (aHR) associated with bDMARD treatment (vs not) of 1.08 (95% CI: 0.83, 1.41). The corresponding aHR for bDMARD-treated and bDMARD-naïve vs the general population was 1.65 (95% CI: 1.31, 2.08) and 1.56 (95% CI: 1.37, 1.78) respectively. Restricting follow-up period to after 2006, the aHR of lymphoma for patients with RA starting a first bDMARD vs bDMARD-naïve was 0.69 (95% CI: 0.47, 1.00), and for bDMARD treated vs patients with RA switching from one conventional synthetic DMARDs to another, aHR was 0.46 (95% CI: 0.28, 0.73). There were no signals of different risks with any particular TNF inhibitor (TNFi) agent. We found no different lymphoma subtype pattern following bDMARD therapy.

Conclusion: Treatment with bDMARDs, including both TNFi and non-TNFi bDMARDs, does not further increase the lymphoma risk in RA; instead, bDMARD treatment may actually reduce the excess lymphoma risk in RA.