The risk of melanoma appears to be higher in RA patients compared to the general population regardless of whether they’ve been treated with anti-TNFs, data from ARAD shows.

Presenting the findings at a session on biologics registries Professor Lyn March said it was probably the rheumatoid arthritis status itself, and possibly methotrexate exposure, that increased skin cancer risk rather than biologics themselves.

The study, which is currently under peer review and yet to be published, matched data from RA patients involved in ARAD to national cancer records.

Standardised incidence ratios were then calculated and adjusted for age, gender and year of diagnosis.

Overall there were about 2,000 patients treated with biologics and just under 1,000 who were biologic naive.

“We’re only talking anti-TNF treated patients as this was the only group that we had enough numbers to look at,” March told delegates.

In the biologic naive group there were five invasive melanomas which equated to a nearly three fold increase in risk compared to the general population.

For the anti-TNF treated patients there was a two-fold increased risk.  However when risk was compared between the two ARAD patient groups there was no increased risk relating to biologics.

When they looked at methotrexate exposure they discovered that at least 80 percent of patients in the biologic naive group had been exposed to methotrexate at some stage.

“Fortunately melanoma incidence is low in this ARAD cohort but melanoma risk is increased compared to the general population,” March said.

“We feel it’s probably the rheumatoid arthritis status and possibly the methotrexate exposure that’s responsible for that rather than the biologics,” she added.