The objective was to compare cancer risk in a RA cohort population treated with TNF antagonists, and identify the characteristics of the patients at higher risk.
The study involved 1114 RA patients treated with anti-TNF agents after failing to respond to traditional DMARDs, 1064 of whom were evaluable for adverse events over an average observational period of 23.32 months. The relative cancer risks (expressed as hazard ratios) in the anti-TNF treated patients were estimated using univariate and multivariate analyses. The rate of cancer in this cohort was compared with that in the general population using data from the Varese and Milan Cancer Report.
There were 18 incident cases (1.7%), 4 of which involved lymphomas. Comparison with the general population showed that the overall cancer risk was similar, but the risk of lymphoma was about five times higher in the RA patients treated with a biological agent. Higher RR were found in males (HR 4.95, 95% CI 1.97-12.48; p=0.001) and patients aged >65 years (HR 2.72, 95% CI 1.08-6.84; p=0.034); combined therapy with methotrexate seemed to be protective (HR 0.31, 95% CI 0.11-0.87; p=0.026).
The overall cancer risk in RA patients treated with anti-TNF seemed to be similar to that in the general population in the same geographical area, but the risk of haematological cancer was significantly greater. The demographic and clinical factors associated with a higher risk of cancer in our cohort were male gender and an age of >65 years.