Biologic treatment of RA associated with increased risk of nonmelanotic skin cancer and melanoma

Key Points

The use of biologic treatment for rheumatoid arthritis (RA) is associated with an increased risk of nonmelanotic skin cancer and melanoma, according to a large observational study published in the journal Arthritis & Rheumatism.

This study included 13,001 patients with RA who were members of the US National Data Bank for Rheumatic Diseases (NDB) longitudinal study of RA outcomes.

Biologic use was defined as a patient's use of etanercept, infliximab, anakinra, or adalimumab. Among patients who developed cancer, only biologics used before the diagnosis were counted as biologic treatments. The most frequently used biologic among study participants at baseline was infliximab (19.9%); 7.6% of patients used entanercept, 0.4% of patients used adalimumab, and 0.3% of patients used anakinra. Approximately half of the patients (45.6%) were treated with prednisone.

There was no increased risk in the overall rate of cancer with biologic treatment compared with SEER data (SIR=1.0; 95% CI, 0.8–1.2); however, use of biologics was associated with an increased risk of nonmelanotic skin cancer (OR=1.5; 95% CI, 1.2–1.8) and melanoma (OR=2.3; 95% CI, 0.9–5.4). Compared with SEER data, RA was not associated with an increased risk in the overall rate of cancer (SIR=1.0; 95% CI, 1.0–1.1); however, RA was associated with an increased risk of lymphoma (standardized incidence ratio [SIR]=1.7; 95% CI, 1.3–2.2) and melanoma (SIR=1.7; 95% CI, 1.3–2.3). Patients with RA demonstrated an SIR of 1.2 (95% CI, 1.0–1.4) for lung cancer.

Individual analyses of infliximab and etanercept demonstrated increased risks of melanoma (OR=2.6; 95% CI, 1.0–6.7; P=.056 and OR=2.4; 95% CI, 1.0–5.8; P=.054, respectively) and nonmelanotic skin cancer (OR=1.7; 95% CI, 1.3–2.2; P<.001 and OR=1.2; 95% CI, 1.0–1.5; P=.081, respectively).

SOURCES

Wolfe F, Michaud K. Biologic treatment of rheumatoid arthritis and the risk of malignancy: Analyses from a large US observational study. Arthritis Rheum. 2007;56:2886–2895.