Bernatsky S, Ramsey-Goldman R, Urowitz MB, et al. - In systemic lupus erythematosus (SLE) patients, smoking was identified as a key modifiable risk factor, especially for lung cancer. SLE activity was positively related to hematologic cancer and was negatively related to nonmelanoma skin cancer.

• In 1,668 incident SLE patients with an average 9 years follow-up, 65 cancers developed.

• Past/current smokers developed half of the cancers (including all lung cancers), vs one-third of patients without cancer.

• In multivariate analyses, overall cancer risk was associated mainly with male gender and older age at SLE diagnosis.

• For the risk of breast cancer, age was positively related and antimalarial drugs were negatively related.

• There was no clear link of immunosuppressive medications with higher risk except for cyclophosphamide and nonmelanoma skin cancer.

• A negative association of antimalarials with breast cancer and nonmelanoma skin cancer risk was evident.

• Additional follow-up is needed because the absolute number of cancers was small.