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Ann Rheum Dis 64:699-703 doi:10.1136/ard.2004.030528
  • Extended report

Tumour necrosis factor blockers do not increase overall tumour risk in patients with rheumatoid arthritis, but may be associated with an increased risk of lymphomas

  1. P Geborek1,
  2. A Bladström4,
  3. C Turesson2,
  4. A Gulfe1,
  5. I F Petersson3,
  6. T Saxne1,
  7. H Olsson5,
  8. L T H Jacobsson2
  1. 1Department of Rheumatology for SSATG, Lund University Hospital, S-221 85 Lund, Sweden
  2. 2Department of Rheumatology, Malmö University Hospital, Sweden
  3. 3Spenshult Hospital for Rheumatic Diseases, Halmstad, Sweden
  4. 4Department of Cancer Epidemiology, Regional Tumour Registry, University Hospital, Lund, Sweden
  5. 5Department of Oncology, University Hospital, Lund, Sweden
  1. Correspondence to:
    Dr P Geborek
    Department of Rheumatology, Lund University Hospital, SE 221 85 Lund, Sweden; Pierre.geborekreum.lu.se
  • Accepted 3 January 2005
  • Published Online First 4 February 2005

Abstract

Objective: To determine whether TNF blockers increase tumour risk in patients with RA.

Material and methods: The South Swedish Arthritis Treatment Group register (SSATG) comprises over 90% of anti-TNF treated patients with RA in the area. 757 patients treated with etanercept or infliximab included between 1 February 1999 and 31 December 2002 were identified. 800 patients with conventional antirheumatic treatment in a community based cohort served as a comparison cohort. Tumours and deaths were identified in the cancer registry and population census registers. Patients were followed up from initiation of anti-TNF treatment or 1 July 1997 for the comparison group, until death or 31 December 2002.

Results: In the anti-TNF group, 16 tumours (5 lymphomas) were identified in 1603 person-years at risk, and in the comparison group 69 tumours (2 lymphomas) in 3948 person-years. Standardised incidence ratios (SIRs) for total tumour relative risk for the anti-TNF group and the comparison group were 1.1 (95% confidence interval (CI) 0.6 to 1.8) and 1.4 (95% CI 1.1 to 1.8), respectively. The lymphoma relative risk (RR) was 11.5 (95% CI 3.7 to 26.9) and 1.3 (95% CI 0.2 to 4.5), respectively The total tumour RR excluding lymphoma was 0.79 (95% CI 0.4 to 1.42) and 1.39 (95% CI 1.08 to 1.76), respectively. Proportional hazard analysis for lymphomas yielded RR 4.9 (95% CI 0.9 to 26.2) in anti-TNF treated versus untreated patients.

Conclusion: Community based patients with RA treated conventionally had an increased overall tumour risk compared with the background population. A possible additional increased risk for lymphoma associated with TNF blockers was based on few cases and needs confirmation.

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