Low incidence of colorectal cancer in patients with rheumatoid arthritis

Clin Exp Rheumatol. Sep-Oct 1996;14(5):551-3.

Abstract

Objective: Aspirin (ASA) and also nonsteroidal anti-inflammatory drug (NSAID) use has been associated with a low incidence of colorectal cancer. The incidence of colorectal cancer in a cohort of patients with rheumatoid arthritis (RA) is reported here.

Methods: Cancer incidence was studied in a cohort of 9469 persons hospitalized for RA during 1970-1991 in Finland. The follow-up time was about 65,400 person-years.

Results: The incidence of colon cancer was significantly lower than in the general population [standardized incidence ratio (SIR) 0.57; 95% confidence interval (CI) 0.33-0.93], and the combined SIR for colorectal cancer was 0.62 (95% CI 0.42-0.88), while the combined incidence of all malignancies (SIR 1.16; 95% CI 1.07-1.26) was higher in RA patients than in the general population.

Conclusion: Chronic use of NSAIDs or ASA, including antiinflammatory doses, is probably the main explanation for the low incidence of colorectal cancer in RA patients.

MeSH terms

  • Adult
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Arthritis, Rheumatoid / complications*
  • Aspirin / therapeutic use*
  • Cohort Studies
  • Colorectal Neoplasms / complications
  • Colorectal Neoplasms / epidemiology*
  • Female
  • Finland
  • Humans
  • Incidence
  • Male
  • Middle Aged

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Aspirin