Psoriatic arthritis patients treated with conventional disease-modifying antirheumatic drugs (DMARDs) were at higher risk for cancer, while those who took biological DMARDs were not. That’s according to a meta-analysis, which covers nine cohort studies of 43,115 PsA patients, published in Seminars in Arthritis & Rheumatism.

Those who took conventional DMARDs, a class of drugs that slows rheumatoid arthritis disease progression, were 75 percent likelier to get cancer than was the general public, while PsA patients who took the biologics were slightly less likely (a relative risk of 0.957) than the general public to get cancer. That’s what Yunyun Fei, of Peking Union Medical College in Beijing, and colleagues found.

“Large-scale longitudinal studies will be essential to draw firm conclusions regarding PsA-associated risk for treatment-induced malignancy,” the researchers noted.

“Clinical efficacy has been clearly demonstrated for various DMARDs and biologics, but it’s not yet clear if there are long-term risks for rare adverse events such as cancer with these treatments,” reports MedPage. “Some studies have found increased risks of malignancies such as breast cancer, while other reports found no increases among patients with PsA.”