Reduced Risk of Cancer in Patients with Bipolar Affective Disorder

Background: research focusing on incidence of cancer amongst bipolar affective disorder (BAD) is sparse. Aim: to ex-amine the incidence of cancer in a cohort of BAD inpatients. Methods: the study sample was comprised of BAD patients who had been admitted to a tertiary care mental health center during the period: 1990 to 2006. The data for the sample was cross-referenced with the National Cancer Registry. Analyses of Standardized Incidence Rates (SIR) for all organ systems malignancies were performed. Results: of 1,638 BAD patients included in the present study, 72 (0.04%) were diagnosed as suffering from co-morbid malignancy. This reflects a significantly reduced risk; SIR of 0.27 (95% CI 0.21－0.34). Reduced risk of cancer held true for both males and females (0.20 and 0.34, respectively). Nineteen women developed breast cancer; SIR = 0.42 (95% CI 0.25－0.66). Conclusions: the present study demonstrates reduced rates of cancer amongst patients suffering from BAD - with special reduction in breast cancer.