Melanoma Risk in Rheumatoid Arthritis Refuted

Apr 11, 2017

A large international study shows there is no increased risk of melanoma in rheumatoid arthritis disproving previous analyses.

An international study shows that there is no increased risk of melanoma in rheumatoid arthritis (RA) patients treated with TNFi therapy, other biologic disease modifying drugs and non-biologic therapy, researchers reported in Annals of the Rheumatic Diseases.

While previous studies have shown a possible association between tumor necrosis factor (TNF) inhibitors and an increased risk of melanoma, this study of 11 biologic registers and 130,315 RA patients from nine European countries (mean age 58 years) contradicts those findings.

Of 130,315 patients in the study, only 287 developed a first-time melanoma. Pooled SIRs for biologic-naive, TNFi and rituximab-exposed patients were 1.1 (95% CI 0.9 to 1.4), 1.2 (0.99 to 1.6) and 1.3 (0.6 to 2.6), respectively. Incidence rates in tocilizumab and abatacept-exposed 130,315 RA patients were also not significantly increased. IRR versus biologic-naive patients were: TNFi 1.1 (95% CI 0.8 to 1.6); rituximab 1.2 (0.5 to 2.9).

“In all treatment groups the incidence of invasive melanoma was slightly higher in RA than in the corresponding general populations of the participating countries. Nevertheless, even with this large European collaborative project the previous signal of an increased risk of melanoma following TNFi reported by Artis and Danbio was not replicated across the other registries in this study. We did not detect a significant overall increase in the age and sex standardized incidence ratios. No significant differences in the melanoma incidence were observed between biologic-naive patients and patients exposed to TNFi, rituximab (RTX), tocilizumab (TOC) or abatacept (ABT),” researchers wrote.

A previous meta-analysis of randomized controlled trials and observational cohort studies raised concerns about an increased risk of melanoma and non-melanoma skin cancer in rheumatoid arthritis patients treated TNFi therapy. Researchers from those studies suggested a causal pathway from TNF inhibition to developing melanoma.

Additional findings:

  • Overall, 160 melanomas were reported in biologic-naive patients.
  • A total of 106 patients developed a first melanoma in patients exposed to TNFi. A larger variation was observed in the SIR in TNFi-exposed patients between registries.
  • The overall SIR observed in registers with data linkage to cancer registries (Sweden, Denmark, UK) was numerically higher 1.3 (0.85 to 2.1), but did not achieve statistical significance.
  • Limited data were available for TOC and ABT-treated patients.

 

References:

Louise K Mercer, Johan Askling, Pauline Raaschou, et al. "Risk of invasive melanoma in patients with rheumatoid arthritis treated with biologics: results from a collaborative project of 11 European biologic registers," Annals of the Rheumatic Diseases. Published in print 1 February 2017. http://dx.doi.org/10.1136/annrheumdis-2016-209285

 

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