Incidence of cancer in patients with spondyloarthritis treated with anti-TNF drugs.

OBJECTIVE: To determine the incidence of cancer in TNF inhibitor (TNFi)-treated spondyloarthritis (SpA) patients entered in the GISEA registry, and identify the factors associated with its development.

METHODS: This observational study involved an open cohort of 3321 SpA patients selected from the GISEA registry, designed to collect real-world clinical data concerning patients with RA or SpA treated with biological drugs. The baseline information includes demographics and clinical parameters. The overall incidence of neoplasias was compared to this observed in the general population according to the Italian Association of Medical Oncology.

RESULTS: Of the 3321 SpA patients (1731 males, 52.2%; mean age 47±13years; median disease duration three years, interquartile range [IQR] 0-8), 50 developed at least one of 56 malignancies during the follow-up period of up to 12years of treatment with TNFi. The overall incidence was 6.3/1000 patient-years of follow-up (95% confidence interval [CI] 4.7-8.2): 7.3/1000 patient-years (95% CI 4.1-11.8) in those treated with ADA; 6.1/1000 patient-years (95% CI 3.8-9.4) in those treated with ETN; and 5.8/1000 patient-years (95% CI 3.5-9.1) in those treated with INF while in the general population was 5.1/1000 patient-years. Univariate analysis showed that age at the time of starting TNFi (P=0.001), the presence of comorbidities (P=0.012), the number of comorbidities (P<0.001), and HAQ-DI score (P=0.002) were associated with a higher risk of malignancies. Stepwise regression models showed that only previous neoplasia was a significant predictor of a new malignancy. The type of drug was not associated with the risk of malignancy.

CONCLUSIONS: The incidence of malignancies among SpA patients treated with the three TNFi was higher than in general population; having had a previous solid cancer is predictive of a new malignancy.