Malignancies associated with systemic lupus erythematosus in Taiwan: a nationwide population-based cohort study.

Patients with systemic lupus erythematosus (SLE) are suggestive to have a higher cancer risk. The aim of this study is to evaluate the possible association of malignancy and SLE in Taiwan. We used the data of the National Health Insurance system of Taiwan to assess this issue. The SLE cohort contained 2,150 patients, and each patient was randomly frequency matched to 8 people without SLE on age and sex. The Cox's proportion hazard regression analysis was conducted to estimate the effects of SLE on the cancer risk. In patients with SLE, the risk of developing overall cancer was marginally significantly higher [adjusted Hazard ratio (HR) = 1.26, 95% confidence interval (95% CI) = 0.99-1.59] and was significantly higher for developing prostate cancer (adjusted HR = 3.78, 95% CI = 1.30-11.0). Our study unexpectedly found that Taiwanese patients with SLE have a higher risk to develop prostate cancer.