Biologic Therapy Not a Factor in Melanoma Risk, Study Shows

There has always been some concern that rheumatoid arthritis patients who are prescribed a biologic, are at increased risk of developing melanoma, which disproportionately affects patients with impaired immunity.

But a new study, published in the June 15 issue of the Annals of the Rheumatic Diseases, shows that no such risk seems to exist.

“No significant differences in the melanoma incidence were observed between biologic-naive patients and patients exposed to tumor necrosis factor inhibitors, rituximab, abatacept, or tocilizumab,” researchers wrote.

Led by Joachim Listing of Germany, researchers pooled information from 11 biologic registries from nine European countries and ultimately included 130,315 patients with rheumatoid arthritis (mean age between 50 and 62), which was equivalent to 579,983 patient years. They found that 287 patients developed a first melanoma as compared to 160 melanomas reported in the biologic-naive patients. [[{"type":"media","view_mode":"media_crop","fid":"49659","attributes":{"alt":"(©Charnsitr/Shutterstock.com)","class":"media-image media-image-right","id":"media_crop_6675701333816","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"6014","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"font-size: 13.008px; line-height: 1.538em; float: right;","title":"(©Charnsitr/Shutterstock.com)","typeof":"foaf:Image"}}]]

Pooled standardized incidence ratios 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 patients were also not significantly increased. Incidence rate ratios versus biologic-naive patients were:  TNFi 1.1 (95% CI 0.8 to 1.6); rituximab 1.2 (0.5 to 2.9).

Although the incidence rate of invasive melanoma was found to be slightly higher in rheumatoid arthritis patients as compared to the general population, the degree to which rheumatoid arthritis patients are at increased risk of developing melanoma in general is unclear.

Some researchers suspect that TNFi may encourage the growth or recurrence of melanoma. In fact, previous studies have shown a possible connection between TNFi therapy and an increased risk of melanoma. But those findings were not confirmed in the new study.

Although the authors’ findings were consistent across countries and registers, the authors caution that certain study limitations, such as differences in the ascertainment of melanoma, means that rheumatologists cannot completely rule out an increased risk for melanoma in those with rheumatoid arthritis who are using biologic therapy.

References:

Mercer LK, Askling J, Raaschou P, et al. “Risk of invasive melanoma in patients with rheumatoid arthritis treated with biologics: results from a collaborative project of 11 European biologic registers.” Ann Rheum Dis. 2016 Jun 15. pii: annrheumdis-2016-209285. doi: 10.1136/annrheumdis-2016-209285