Thein a systematic review and meta-analysis published in .
The studies included in the analysis, however, had limitations, including a lack of those comparing biologic and conventional systemic therapy in psoriasis and inflammatory bowel disease (IBD), according to Shamarke Esse, MRes, of the division of musculoskeletal and dermatological sciences at the University of Manchester (England) and colleagues. “We advocate for more large, well-designed studies of this issue to be performed to help improve certainty” regarding this association, they wrote.
Previous studies that have found an increased risk of melanoma in patients on biologics for psoriasis, rheumatoid arthritis, and IBD have “typically used the general population as the comparator,” they noted. There is a large amount of evidence that has established short-term efficacy and safety of biologics, compared with conventional systemic treatments, but concerns about longer-term cancer risk associated with biologics remains a concern. Moreover, they added, “melanoma is a highly immunogenic skin cancer and therefore of concern to patients treated with TNFIs [tumor necrosis factor inhibitors] because melanoma risk increases with suppression of the immune system and TNF-alpha plays an important role in the immune surveillance of tumors.12,13
In their review, the researchers identified seven cohort studies from MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases published between January 1995 and February 2019 that evaluated melanoma risk in about 34,000 patients receiving biologics and 135,370 patients who had never been treated with biologics, and were receiving conventional systemic therapy for psoriasis, RA, or IBD. Of these, four studies were in patients with RA, two studies were in patients with IBD, and a single study was in patients with psoriasis. Six studies examined patients taking TNF inhibitors, but only one of six studies had information on specific TNF inhibitors (adalimumab, etanercept, and infliximab) in patients with RA. One study evaluated abatacept and rituximab in RA patients.
The researchers analyzed the pooled relative risk across all studies. Compared with patients who received conventional systemic therapy, there was a nonsignificant association with risk of melanoma in patients with psoriasis (hazard ratio, 1.57; 95% confidence interval, 0.61-4.09), RA (pooled relative risk, 1.20; 95% CI, 0.83-1.74), and IBD (pRR, 1.20; 95% CI, 0.60-2.40).
Among RA patients who received TNF inhibitors only, there was a slightly elevated nonsignificant risk of melanoma (pRR, 1.08; 95% CI, 0.81-1.43). Patients receiving rituximab had a pRR of 0.73 (95% CI, 0.38-1.39), and patients taking abatacept had a pRR of 1.43 (95% CI, 0.66-3.09), compared with RA patients receiving conventional systemic therapy. When excluding two major studies in the RA subgroup of patients in a sensitivity analysis, pooled risk estimates varied from 0.91 (95% CI, 0.69-1.18) to 1.95 (95% CI, 1.16- 3.30). There were no significant between-study heterogeneity or publication bias among the IBD and RA studies.
Mr. Esse and colleagues acknowledged the small number of IBD and psoriasis studies in the meta-analysis, which could affect pooled risk estimates. “Any future update of our study through the inclusion of newly published studies may produce significantly different pooled risk estimates than those reported in our meta-analysis,” they said. In addition, the use of health insurance databases, lack of risk factors for melanoma, and inconsistent information about treatment duration for patients receiving conventional systemic therapy were also limitations.
“Prospective cohort studies using an active comparator, new-user study design providing detailed information on treatment history, concomitant treatments, biologic and conventional systemic treatment duration, recreational and treatment-related UV exposure, skin color, and date of melanoma diagnosis are required to help improve certainty. These studies would also need to account for key risk factors and the latency period of melanoma,” the researchers said.
Mr. Esse disclosed being funded by a PhD studentship from the Psoriasis Association. One author disclosed receiving personal fees from Janssen, LEO Pharma, Lilly, and Novartis outside the study; another disclosed receiving grants and personal fees from those and several other pharmaceutical companies during the study, and personal fees from several pharmaceutical companies outside of the submitted work; the fourth author had no disclosures.
SOURCE: Esse S et al. JAMA Dermatol. 2020 May 20; .