Anti-TNF therapy and malignancy in spondyloarthritis in the Leuven spondyloarthritis biologics cohort (BIOSPAR).

OBJECTIVES

To report the incidence of malignancy in a large single-centre cohort in Belgium of patients with spondyloarthritis (SpA) treated with one or more anti-TNF therapies and to compare the results with the incidence of malignancy in the Belgian population.

METHODS

From September 2000 until March 2010, all SpA patients that started treatment with one or more anti-TNF therapies were included in this single-centre prospective longitudinal observational study. The primary outcome of this study was the incidence of malignancy after starting anti-TNF treatment. Incidence rates were compared with the incidence rates of malignancy in Belgium in 2008 for the 45-50 year-old population, as documented by the Belgian Cancer Registry.

RESULTS

231 patients with a mean age of 47.86 y were included for a total of 1020.74 patient years of treatment and 1199.83 patient years follow-up after the start of treatment. In our study population, 6 out of 231 patients (2.6 %) developed a malignancy after the start of anti-TNF treatment. The overall incidence rate of malignancy in our study population is 500.1 per 100000 patient years, indicating a higher incidence compared to the Belgian population. We see a higher incidence rate in females as well in males; standardised incidence ratios are in the same range for both (154.3 for females and 130.6 for males).

CONCLUSIONS

We see a tendency towards a higher incidence of malignancy in SpA patients treated with anti-TNF therapy. However, it is not clear whether this increased risk is disease-related or treatment-related.