Five-year cancer survival is significantly reduced in patients with inflammatory polyarthritis, according to a current study published in the March issue of Arthritis and Rheumatism. British scientists also found out, that cancer incidence is not increased among patients with inflammatory arthritis compared to the general population - except for hematopoietic cancers, which are more common in polyarthritic patients.
Alan Silman and his colleagues from the University of Manchester examined more than 2.000 patients with new-onset inflammatory polyarthritis diagnosed between 1990 and 1999. They compared cancer incidence and survival, ascertained by linkage to hospital and death records, with regional rates. The authors considered only primary cancers that occurred at least one year after the onset of the arthritis symptoms.
Follow-up was maintained until 2004. During this period, the researchers found 123 incident cases of cancer among patients with inflammatory polyarthritis. “The overall incidence of cancer among this cohort was not increased compared with that in the regional population”, the investigators write; though the relative risk for hematopoietic cancers was higher in the arthritis group.
The main result of the survey was, that the five-year cancer survival rate is significantly reduced in patients with inflammatory polyarthritis. “Compared with an increased incidence of cancer, reduced cancer survival might be a greater contributor to the increased cancer mortality observed in some rheumatoid arthritis populations”, the scientists conclude. JG
Arthritis Rheum (2007); 56: 790-8
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