No previous published studies have been able to address the question as to whether anti-TNF therapy influences the rate of malignancy in patients with prior malignancy. Using data from the British Society for Rheumatology Biologics Register (BSRBR), researchers conducted this study in an attempt to answer this question.

A total of 293 patients with a prior malignancy were identified from over 14,000 patients with rheumatoid arthritis (RA) and the rates of incident malignancy were analysed in 177 anti-TNF treated patients and 117 patients with active RA treated with traditional DMARDs, all with prior malignancy.

The rates of incident malignancy were 25.3 events/ 1000 person years in the anti-TNF cohort and 38.3 / 1000 person years in the DMARD cohort, generating an age- and sex-adjusted incidence rate ratio of 0.58 (0.23 to 1.43) for the anti-TNF treated cohort compared to the DMARD cohort.  Three of 17 (18%) patients with prior melanomas in the anti-TNF cohort developed an incident malignancy compared to 0/10 in the DMARD cohort.

The researchers conclude from these findings that “the way in which UK rheumatologists are selecting patients with RA and prior malignancy to receive anti-TNF therapy is not leading to an increased risk of incident malignancy. Although reassuring, these results should not be interpreted as indicating that it is safe to treat all RA patients with prior malignancy with anti-TNF therapy.”