By David Liu, PHD

Monday Dec 17, 2012 (foodconsumer.org) -- A study in Rheumatology suggests that non-biologic disease-modifying therapy indicated to treat rheumatoid arthritis (RA) may increase risk of cancer.

The study led by Louise K. Mercer1 of University of Manchester, Manchester Academic Health Science Centre in Manchester, UK and colleagues found the overall cancer risk 28 percent higher in rheumatoid arthritis who received non-biologic therapy, compared to the UK general population.

Mercerl et al. found the increase in cancer risk in rheumatoid arthritis patients after comparing 3,771 individuals with rheutamoid arthritis recruited to the British Society for Rheumatology Biologics Register from 2002 to 2009 with the UK general population during a 13,315 person-year follow-up during which 182 cancers were identified with 156 solid and 26 myelo- or lymphoproliferative malignancies.

Standardized incidence of lung cancer, Hodgkin lymphoma, and non-Hodgkin lymphoma in rheumatoid arthritis patients using non-biologic therapy was 2.39. 12.82 and 3.12 times as high as that in the UK general population, respectively.  

Within the cohort of patients with rheumatoid arthritis, cancer risk was more than 2-fold higher in current or ex-smokers than non-smokers.

The researchers concluded "The overall incidence of cancer was increased in this national cohort of subjects with rheumatoid arthritis.  The association of RA with certain cancers needs to be considered when studying the effects of biologic therapy, such as anti-TNF, on cancer risk."