Risk for Second Cancer Not Linked to bDMARD Treatment in RA

Treatment with biological disease-modifying antirheumatic drugs (bDMARDs) was not associated with an increased risk for a second malignant neoplasm in patients with rheumatoid arthritis (RA) who have a history of cancer, according to a study published in the Annals of Rheumatic Diseases.

However, the researchers could not draw any clear conclusions regarding the effect of bDMARDs on mortality for patients with RA and a history of cancer.

The study included 1678 patients with rheumatoid arthritis who had been registered in the Danish DANBIO registry with a primary cancer. The researchers divided the participants into 4 groups: patients treated with bDMARDs only before primary cancer (n=190), patients treated with bDMARDs only after primary cancer (n=220), patients treated with bDMARDs both before and after primary cancer (n=92), and patients never treated with bDMARDs (n=1176).

Patients with previous cancer who had ever used bDMARDs did not show an increased risk for secondary malignant neoplasm compared with those who did not use bDMARDs (hazard ratio [HR], 1.11; 95% CI, 0.74-1.67). The researchers found similar results when they stratified ever use of bDMARDs according to timing (before and/or after cancer).

During the follow-up period, 342 patients died. Patients with cancer who had ever previously used bDMARDs had increased risk of mortality (HR, 1.25; 95% CI, 0.71-2.18). However, after adjusting for the extent of cancer disease, the researchers found that the HRs moved in different directions depending on whether the use of bDMARDs started before and/or after cancer diagnosis.

“The underlying explanation could be that bDMARDs induce more aggressive tumours or that extent of disease influences the choice of RA treatment after the cancer diagnosis,” wrote the researchers. “The observation of a stronger association after adjustment for extent of disease among patients treated both before and after first cancer speaks against the first mentioned explanation.”

Reference

Dreyer L, Cordtz RL, Hansen IM, et al. Risk of second malignant neoplasm and mortality in patients with rheumatoid arthritis treated with biological DMARDs: a Danish population-based cohort study [published online December 7, 2017]. Ann Rheum Dis. 2017;0:1-5.