Newswise — An increased risk of non-melanoma skin cancer has been identified among a group of veterans taking anti-TNF therapy for rheumatoid arthritis, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in Philadelphia, Pa. Rheumatoid arthritis is a chronic disease that causes pain, stiffness, swelling, and limitation in the motion and function of multiple joints. Though joints are the principal body parts affected by RA, inflammation can develop in other organs as well. An estimated 1.3 million Americans have RA, and the disease typically affects women twice as often as men.
Disease-modifying antirheumatic drugs, or DMARDS as they are commonly called, are often the therapy of choice for patients with RA as they not only reduce inflammation and pain, but can slow the overall progression of the disease. TNF-antagonists (anti-TNF therapy; among drugs called biologics) are a class of drugs that have been used since 1998; overall, they have been given to more than 600,000 people worldwide. These drugs are given to lessen inflammation by interfering with biologic substances that cause or worsen inflammation.
Researchers recently conducted a study to determine the frequency (often called the incidence rate) and risk factors for both non-melanoma (basal and squamous cell) and melanoma skin cancer related to taking non-biologic therapies and anti-TNF therapies among a group of U.S. veterans with RA.
They studied 16,829 patients with RA who had been identified through the Department of Veteran Affairs national administrative databases. The participants were divided into two groups: those treated with non-biologic DMARDs and those treated with anti-TNF DMARDs, and the researchers defined skin cancer as the first occurrence of non-melanoma or melanoma skin cancer after taking a DMARD.
Of the 16,829 patients, 3,096 were on anti-TNF treatment, and the incidence of non-melanoma skin cancer was 25.9 per 1,000 people each year and the incidence of melanoma skin cancer was 3.7 per 1,000 people each year among this group. The incidence rate of non-melanoma skin cancer for those taking non-biologic DMARDs was 19.6 per 1,000 people each year and 2.6 per 1,000 people each year for melanoma.
Researchers concluded that those patients on anti-TNF therapy had a higher risk of developing non-melanoma skin cancer than those on non-biologic DMARDs. Factors that increased this risk were older age, male gender, steroid use, a history of prior malignancies and the duration of time spent on anti-TNF therapy.
“Older patients with rheumatoid arthritis on anti-TNF therapy need to be watched closely for the development of skin cancer, especially if they are male, have been on these treatments for a long time, and have a history of other cancers,” explains Prabha Ranganathan MD, MS; assistant professor of medicine, division of rheumatology, Washington University School of Medicine, St. Louis, Mo., and lead investigator in the study.
“Our results are more robust for non-melanoma compared to melanoma skin cancer as we found the diagnosis codes for non-melanoma skin cancer to be more accurate in the administrative database compared to those for melanoma.” The ACR is an organization of and for physicians, health professionals, and scientists that advances rheumatology through programs of education, research, advocacy and practice support that foster excellence in the care of people with or at risk for arthritis and rheumatic and musculoskeletal diseases. For more information on the ACR’s annual meeting, see www.rheumatology.org/annual.
Editor’s Notes: Dr. Ranganathan will present this research during the ACR Annual Scientific Meeting at the Pennsylvania Convention Center from 9 - 11 AM on Tuesday, October 20 in Hall D. Dr. Ranganathan will be available for media questions and briefing at 8:30 AM on Sunday, October 18 in the on-site press conference room, 109 A.
Presentation Number: 1379
Non-Melanoma and Melanoma Skin Cancer Risk in a National Cohort of Veterans with Rheumatoid Arthritis
Wassila Amari, MD, IM/Div of Rheumatology, Washington University, St Louis, MO Angelique L. Zeringue, MS, St. Louis Veterans Affairs Medical Center, St. Louis, MO Jay R. McDonald, MD, Infectious Disease, St. Louis Veterans Affairs Medical Center, St. Louis, MO Liron Caplan, M.D , Div of Rheumatology, Univ of CO Denver School of Med, Aurora, CO Fran Cunningham, VA Pharmacy Benefits Management, Hines, IL Seth A. Eisen, MD, Rheumatology, St. Louis Veterans Affairs Medical Center, St. Louis, MO Prabha Ranganathan, MD, Division of Rheumatology, Washington University, St Louis, MO
Purpose: Although previous studies have examined the risk of malignancy, including skin cancer, in patients with rheumatoid arthritis (RA), only one prior study has looked primarily at skin cancer risk. Our aim was to determine the incidence and risk factors for non-melanoma (NMSC) and melanoma skin cancer (MM) in a national cohort of veterans with RA treated with non-biologic versus tumor necrosis factor (TNF) antagonist DMARDs.
Methods: We examined a retrospective cohort of 16,829 patients with an International Classification of Disease, Version 9, (ICD-9) diagnosis of RA from the Department of Veterans’ Affairs (VA) national administrative databases enrolled between October 1, 1998 and September 30, 2006. The cohort was divided into 2 medication groups: patients treated with non-biologic and those treated with anti-TNF DMARDs. Skin cancer was defined as the first occurrence of an ICD-9 code for NMSC and MM after initiation of a DMARD. Outcome risk was described using hazard ratios with Cox proportional hazards regression for time-to-event analysis and logistic regression. Chart review was performed to validate the diagnosis of both cancer types.
Results: Of the 16,829 RA patients, 3,096 were on anti-TNF treatment. The incidence of NMSC was 25.9 per 1000 patient-years in patients on TNF antagonists and 19.6 per 1000 patient-years in those on non-biologic DMARDs. Patients on anti-TNF agents had a higher risk of developing NMSC than those on non-biologic DMARDs with a hazard ratio of 1.34 (95% CI 1.15-1.58; p<0.0001). Factors that increased the risk of NMSC included older age, male gender, glucocorticoid use, a history of prior malignancies, and duration of anti-TNF therapy. The incidence of MM was 3.7 per 1000 patient-years in patients on TNF antagonists and 2.6 per 1000 patient-years in those on non-biologic DMARDs. Patients on anti-TNF agents had a higher risk of MM with a hazard ratio of 1.5 (95% CI 1.01-2.24; p<0.05). Risk factors for MM included a history of previous malignancies. The increased risk of both NMSC and MM was a drug class effect and not associated with individual TNF antagonists. There was substantial agreement between diagnosis by ICD-9 codes and chart review for NMSC (κ=0.61) but only moderate agreement for MM (κ=0.45).
Conclusion: Anti-TNF therapy in veterans with RA is associated with an increased risk of NMSC. Although our data suggest an association with MM, the modest agreement between the ICD-9 codes for MM and chart validation precludes a firm conclusion. Other risk factors for NMSC in RA include older age, male gender, a history of prior malignancies, glucocorticoid use and duration of anti-TNF therapy. These results should prompt rheumatologists to carefully evaluate the use of TNF antagonists in RA patients with such risk factors who may be more prone to develop skin cancer.
Disclosure: W. Amari, None; A. L. Zeringue, None; J. R. McDonald, None; L. Caplan, None; F. Cunningham, None; S. A. Eisen, None; P. Ranganathan, None.
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