Methotrexate may be linked to an elevated risk of three types of skin cancer, according to a new study published by Polesie et al in the British Journal of Cancer. Additionally, among patients taking the drug to treat moderate to severe psoriasis, an increased risk was observed only for basal cell carcinoma. In a study of over 131,000 patients, it was more common for patients who developed any of three types of skin cancer—either basal cell carcinoma, squamous cell carcinoma, or melanoma—to have been previously treated with methotrexate. Further, researchers discovered that the increased risk of developing any of the three skin cancers after taking methotrexate was 20% to 38% for basal cell carcinoma, 37% to 89% for squamous cell carcinoma, and 13% to 61% for melanoma—and that patients who had taken higher doses of methotrexate were at higher risk for squamous cell carcinoma and basal cell carcinoma, but not for melanoma. When the researchers confined the study to patients with psoriasis, they found no statistical correlation linking methotrexate to an increased risk of squamous cell carcinoma or melanoma, but they did identify an increase in the risk of developing basal cell carcinoma.
May 24, 2023