Occurrence of Basal Cell and Squamous Cell Carcinomas of the Skin Under Different DMARD Therapies
Authors: Anja Strangfeld et al.
In this large observational data analysis from the German Rabbit registry, the authors analyzed the incidence of new-onset skin carcinomas (melanomas were excluded). Among the ~14’ thousand patients, the authors observed 137 incident cases of skin carcinomas. Of the various families of second line antirheumatic therapies, only abatacept was associated consistently with an increased risk of skin carcinoma (HR 2.0 – 2.2, p < 0.003). Interestingly, no such trend was found with JAK-inhibitors. Other factors associated with an increased risk of skin carcinomas were older age and more comorbidities.
The recent results of the ‘Oral Surveillance’ phase 4 study with tofacitinib have underscored the potential of antirheumatic drugs to favor cancer occurrence in RA patients. In this analysis only abatacept was associated with an increased risk of skin carcinoma, which is potentially interesting given the mechanisms of action of this drug. Previous observational studies with abatacept had already suggested a slight increase in total malignancy risk, but the risk never reached significance for any specific cancer. These results certainly need confirmation before any clinical implication can be reached. It should also be noted that the absolute risk difference for skin cancers in this study was fairly small, and that the ‘number needed to harm’ (NNH) is certainly very large with abatacept.