Evaluation of the incidence of melanoma and non-melanoma skin cancer in patients with systemic lupus erythematosus and systemic sclerosis

Background: The incidence of skin cancer in patients with systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) has only been investigated with retrospective studies enrolling a low number of patients. The aims of our study were to assess the incidence of skin cancer in two large cohorts of patients, one with SLE and the other with SSc and investigating possible risk factors. Methods: Ninety SLE, 53 SSc patients and 392 control subjects were enrolled. A questionnaire including personal and medical details was fulfilled. The severity of photoaging, photosensitivity and sun exposure habits was assessed. Skin lesions were evaluated using a video-dermatoscope. Suspicious lesions were surgically removed. Results: The incidence of skin cancer was not different to those of controls. However, a decrease in the incidence of basal cell carcinoma was found in patients with SLE. This finding associated negatively with photosensitivity. SSc patients with skin malignancies did not report photosensitivity and did not adopt a careful photoprotection. A positive association was found between skin cancer and diffuse cutaneous sclerosis, pitting scars, severe photoaging and treatment with Iloprost. Conclusions: Regular avoidance of sun exposure and photoprotection are effective in reducing the development of skin cancer in patients with autoimmune diseases.