Clinical Newswire Nov 11, 2006 (WASHINGTON, DC) - Newer biologic therapies for rheumatoid arthritis (RA) are not associated with any elevated risk of any cancers, other than skin cancer, the results of a large review of registry data presented at the American College of Rheumatology (ACR) Annual Scientific Meeting suggested.
Dr. Frederick Wolfe (National Data Bank for Rheumatic Disease, Wichita, KA), the lead author, explained the rationale of this study: "We now have a series of powerful biologic agents (for RA) which alter the immune response. In general, when patients have reduced immune responses they tend to be at increased risk for the development of malignancies. For example, people on immunosuppression for renal transplant have greatly increased risk for cancer." A recent meta-analysis of clinical trial data published in JAMA suggested that anti-tumor necrosis factor (TNF) antibodies were associated with an approximately 3-fold increased risk for malignancies (Bongartz et al. JAMA 2006;295:2275-85).
This study looked at the incidence of cancer among 13,000 patients participating in a study of RA outcomes (National Data Bank for Rheumatic Disease) that included 49,000 patient years of observation over the years 1998-2005. For every patient, all drug use including biologics and diagnoses of cancer were recorded. Data was compared to cancer rates in the overall population using the US National Cancer Institute SEER data bank.
There were 623 cases of non-melanotic skin cancer and 537 new cases of other cancers, and 48% of subjects had taken a biologic. Consistent with previous reports, overall RA patients did not have a significantly increased overall risk of cancer.
The use of a biologic agent was not associated with any overall increased risk of cancer (OR 1.0, 95%CI 0.8-1.2), nor with any major specific cancer such as breast cancer (OR 0.9, 0.5-1.3) or lymphoma (OR 1.0, 0.5-2.0). There was however an increased risk for any skin cancer (OR 1.5, 1.2-1.8; p<0.001) and for melanoma in particular (n=32; OR 2.3, 0.9-5.4; p=NS). Furthermore, there was no correlation with any specific biologic (infliximab, etanercept, adalimumab) and cancer.
"In contradiction to the metaanalysis of clinical trials we found no overall increase in the rate of cancer related to the use of biologic therapies, except for basal cell carcinomas and melanoma," concluded Dr. Wolfe. Commenting on the increase in skin cancer, he explained that "skin cancers are the most susceptible to immune suppression. RA patients should pay attention to spots on their skin."
"These reports, which confirm registry data studies conducted in Europe, offer valid measurements of cancer rates in rheumatoid arthritis," said Dr. Wolfe. "The bottom line from our study is that in general these drugs are safe. The data from this very large series does indicate that the rate of cancer is not increased (with biologics) except for these two skin cancers."
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