Copehagen, Denmark—Biologic disease–modifying antirheumatic drugs (DMARDs) suppress the immune system to help control rheumatoid arthritis (RA) disease activity and prevent joint damage. For years, concerns have been raised about whether the biologics might also increase the risk of recurrence in patients with a history of cancer. 

A new study presented at the 2017 American College of Rheumatology/Association of Rheumatology Health Professionals (ACR/ARHP) Annual Meeting showed no increased risk of a second malignant neoplasm, however. To reach those conclusions, University of Copenhagen–led researchers conducted a study of 1,678 RA patients from a national Danish registry, also looking at mortality rates among these patients.

“Second malignancy is an increasing challenge, as the survival after the first, primary tumor has improved substantially for most types of cancer,” explained lead author Lene Dreyer, MD, associate professor of rheumatology at the University of Copenhagen. “The concern for second malignancy or cancer recurrences in patients with a history of cancer diagnosis has led to some reluctance in treating this subset of arthritis patients with biologics, especially TNF-inhibitors. Consequently, some RA patients with a previous cancer are suffering from inadequate treatment of their arthritis.”

Included in the study were RA patients with a primary cancer diagnosis from 2000 to 2011 in the DANBIO Registry, a national medical records database. Most of the participants, 1,176 patients, never received biologics, with 190 getting biologics only before their primary cancer diagnosis, 220 patients receiving biologics only after their primary cancer diagnosis, and 92 patients receiving biologics both before and after their primary cancer diagnosis.

Among the 502 patients who received a biologic at any time, the hazard ratio for developing a second malignancy was 1.11 compared to 1.00 for those who were never treated with a biologic, study authors report, adding that the difference was not statistically significant.

A clear conclusion could not be drawn about the significance of increases in mortality rates among RA patients with a history of cancer. Results indicate the hazard ratio for death was 1.20 among the RA patients treated with a biologic only before their cancer diagnosis, compared to 1.00 for those who were never treated with a biologic. At the same time, patients who were treated with a biologic only after their cancer occurred had a hazard ratio for death of 1.36, and those who received biologics both before and after their cancer diagnosis had a hazard ratio for death of 1.22.

“It is reassuring that these results indicate no increased risk of a second malignancy in RA patients with a past cancer who used biologic therapy, and that there was no major indication of an increased mortality rate among users of these medications,” Dreyer suggested. “However, the number of patients who suffered a second malignancy was small, so our statistical analyses must be interpreted with caution. Further studies are required to confirm our findings. In the meantime, our data does provide some reassurance that biologics don’t pose an immediate danger in patients with a history of cancer.”