PHILADELPHIA — Two studies showed an increased risk for nonmelanoma skin cancer in patients who take anti–tumor necrosis factor therapies, and should prompt physicians 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 rheumatoid arthritis (RA) and skin malignancy, although RA previously has been well established as a risk factor for skin cancer, according to Dr. Prahba Ranganathan.
She 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.
According to Dr. Ranganathan, among 16,829 patients with RA, 3,096 were treated with anti-TNFs at the VA between Oct. 1, 1998, and Sept. 30, 2006. 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 incidence of melanoma also was increased by about 50%, with about 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. Both results 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.
Dr. Hyrich pointed 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 anti-TNFs are still a good choice for patients who've failed other treatments. “People with risk factors should be watched more closely and maybe have periodic skin exams,” she said.
Dr. Ranganathan, Dr. Hyrich, and their respective research teams did not report having any financial conflicts relative to their studies.