Background Patients with RA have been shown to have an increased risk for malignancies compared with the general population.1 This has raised concerns, particularly with widespread use of immune modulating therapies, including biologic DMARDs.
Objectives To update the previously published meta-analysis1 quantifying the incidence of malignancies in patients with RA compared with the general population.
Methods An updated literature search consistent with and similar to the previous study1 was conducted. MEDLINE, BIOSIS Previews, Embase, Derwent Drug File and SciSearch databases were searched using specified search terms and predefined inclusion criteria for identification of relevant observational studies from 2007 through 2013 that provide estimates of relative risk of malignancy in patients with RA compared with the general population. Data on overall malignancy and four site-specific malignancies (lymphoma, lung, colorectal and breast) were extracted. Study-specific estimates of relative risk, as measured by standardized incidence ratios (SIRs) relative to the general population were compared with previously published rates.
Results A total of 7 new publications met the inclusion criteria; 4 reported SIRs for overall malignancy, 3 for lymphoma, 7 for lung, 7 for colorectal and 7 for breast cancer. Compared with the general population, the SIR estimates in patients with RA suggest a modest increased risk in overall malignancy compared with those observed previously (Figure). For the cancer sub-types, patients with RA continue to have an increased risk of lymphoma and lung cancer compared with the general population. This was observed in the previous evaluation of the literature.1 Most of the SIR estimates represented as data points in the figure for both colon and rectal, and breast cancer continue to show no increase in risk for patients with RA when compared with the general population.
Conclusions Patients with RA are at an increased risk for lung and lymphoma malignancies. The additional data shown here are consistent with previously reported data. It is important to quantify differences in malignancy rates between non-biologic and biologic DMARD-treated patients with RA to understand the malignancies that may be related to treatment versus underlying disease.
Smitten AL, et al. Arthritis Res Ther 2008;10:R45.
Disclosure of Interest T. Simon Employee of: BMS, A. Thompson Employee of: BMS, K. Gandhi Employee of: BMS, M. Hochberg Grant/research support: NIH, Consultant for: BMS, Eli Lilly Co., EMD Serono Inc., Genentech/Roche, Novartis Pharma AG, Pfizer Inc, UCB Inc, S. Suissa Consultant for: BMS, Genentech, Roche