For the clinical practice there is uncertainty as to what degree the therapeutic immunomodulation of rheumatoid arthritis (RA) is associated with a weakening of protective tumor immunity. Neoplasms of the skin in particular are known to exhibit increased incidence rates in association with therapeutic immunosuppression in transplantation medicine; however, the immunosuppression required for the prevention of allogenic graft rejection is much more intensive and thus not directly transferable to the potential risks for an onset or relapse of melanoma or non-melanoma skin cancers (NMSC), e. g. spinocellular and basal cell carcinomas in association with the antirheumatic treatment of RA. This review covers the association of RA and its pharmacotherapy with conventional synthetic (cs) and biologic disease-modifying antirheumatic drugs (DMARD) on the basis of a systematic literature search. The incidence rates of NMSC are twice as high in biologic-naive RA patients compared to the general population, whereas the respective incidence rates for melanoma do not differ. A biologic treatment with tumor necrosis factor (TNF) blockers compared with administration of csDMARD only has a minor, if any effect on the increase of NMSC risk but is associated with a trend towards an elevated incidence rate of new onset melanoma although significance level was not reached in all of the reviewed studies. The data on non-TNF blocking biologics is sparse. Accordingly, it is inappropriate to draw any strong conclusions on potentially associated skin cancer risks from the present lack of safety signals. The consideration of individual risk factors, recommendations on sufficient UV protection and regular skin monitoring may serve to improve the safety of DMARD therapy in RA.
Keywords: Basal cell carcinoma; Biologics; Disease modifying antirheumatic drugs; Melanoma; Spinocellular carcinoma.