A Case-Control Study of Endometrial Cancer after Antipsychotics Exposure in Premenopausal Women

Objective: Most endometrial cancers are related to hormonal imbalance, and antipsychotics are a common cause of hyperprolactinemia. We investigated the possible relation between the use of antipsychotics and the risk of endometrial cancer. Methods: A case-control study was conducted on premenopausal women at the Chiba University Hospital between 1989 and 2000. The cases were 41 patients with histologically confirmed endometrial cancer. For each case, there were 3 controls matched by age and date of visit. Subsequently 123 women without endometrial cancer were enrolled as controls. Detailed information including obesity, parity, hypertension, diabetes mellitus, use of exogenous estrogen and use of antipsychotics was analyzed. Odds ratios, two-sided p values and 95% confidence intervals were estimated by a conditional logistic regression analysis. Radioimmunoassays of serum luteinizing hormone, follicle-stimulating hormone, prolactin, estradiol and progesterone were performed in 4 of 5 patients with endometrial cancer who were using antipsychotics. Results: Use of antipsychotics, diabetes mellitus and obesity were identified as independent variables with risk estimates of 5.4, 9.3 and 4.9, respectively. Serum progesterone, estradiol and prolactin levels ranged from 0.4 to 0.7 ng/ml, 32 to 110 pg/ml and 34 to 258 ng/ml, respectively. Conclusions: Use of antipsychotics is a risk factor for endometrial cancer, and hyperprolactinemia associated with antipsychotics may impart the risk of endometrial cancer in premenopausal women.