Disease activity and risk of lymphoma in patients with rheumatoid arthritis: nested case-control study
BMJ 1998; 317 doi: https://doi.org/10.1136/bmj.317.7152.180 (Published 18 July 1998) Cite this as: BMJ 1998;317:180
- Eva Baecklund (Eva.Baecklund@swipnet.se), rheumatologista,
- Anders Ekbom, associate professorb,
- Pôr Sparén, statisticianb,
- Nils Feltelius, associate professora,
- Lars Klareskog, professorc
- aDepartment of Medicine, University Hospital, S-751 85 Uppsala, Sweden
- bDepartment of Medical Epidemiology, Karolinska Institute, Box 281, S-171 11 Stockholm, Sweden
- cDepartment of Medicine, Karolinska Hospital, S-171 76 Stockholm, Sweden
- Correspondence to: Dr Baecklund
- Accepted 27 January 1998
Inflammatory diseases such as rheumatoid arthritis and their treatment may have a pathogenic relation with cancer. The possible relation also has practical implications for the care and control of rheumatic patients.
Patients with rheumatoid arthritis have been shown to have an increased risk of developing lymphomas. 1 2 The underlying mechanisms for this association are unclear. We performed a study to assess to what extent disease activity, various secondary manifestations of rheumatic disease, and drug treatment were independent risk factors for the development of lymphoma in patients with rheumatoid arthritis.
Subjects, methods, and results
We performed a nested case-control study using a previously described population based cohort of all patients admitted to hospital with rheumatoid arthritis during 1965-83 in Uppsala health care region, Sweden.3 We identified 42 cases of lymphoma in the 11 683 patients with rheumatoid arthritis through …