PHILADELPHIA — Two studies showed an increased risk for nonmelanoma skin cancer in rheumatoid arthritis patients who take anti–tumor necrosis factor therapies, and should prompt rheumatologists to evaluate the use of these drugs in patients who are at risk for skin cancer, according to the researchers.
Previous studies have been too small to show a definitive link between biologic therapy for RA and skin malignancy, although RA previously has been well established as a risk factor for skin cancer, according to Dr. Prahba Ranganathan, who presented the results of her retrospective cohort study of RA patients in the Department of Veterans Affairs national database at the annual meeting of the American College of Rheumatology.
Among 16,829 patients with RA, 3,096 were treated with anti-TNFs at the VA between Oct. 1, 1998 and Sept. 30, 2006, she said. The incidence of nonmelanoma skin cancer was 25.9 per 1,000 patient-years in this cohort, compared with 19.6 per 1,000 patient-years in the biologic-naive cohort, a 34% increased risk. The melanoma incidence was increased as well, with 3.7 cases per 1,000 patient-years seen in the anti-TNF–treated group, vs. 2.6 cases per 1,000 patient-years in the biologic-naive cohort. The differences were significant.
A second study presented at the press conference confirmed these findings. Dr. Kimme Hyrich of the University of Manchester (England) looked at RA patients from the British Society for Rheumatology's biologics register, a prospective cohort study begun in 2001 to monitor the long-term safety of anti-TNFs.
Dr. Hyrich found that among 11,598 RA patients who were treated with anti-TNFs and had no prior nonmelanoma skin cancer, the incidence of a malignancy was 3.5 per 1,000 patient-years. In contrast, among 8,975 similar patients who were treated with nonbiologic therapies, the incidence of new nonmelanoma skin cancers was 2.4.
That was a 70% increased risk for the anti-TNF–treated patients, although the data were not significant, Dr. Hyrich reported, pointing out that patients treated with anti-TNF drugs typically have more contact with their physicians, which could have introduced a surveillance bias.
Dr. Ranganathan cautioned that even in patients with multiple skin cancer risks—including being male and older, and having a history of skin cancer—anti-TNFs are still a good choice for patients who've failed other treatments.
While patients at risk may need periodic skin exams, “I don't think [having risk factors] would be an absolute contraindication,” she said.
Dr. Ranganathan, Dr. Hyrich, and their respective research teams did not report having any financial disclosures relative to their studies.