Sasamoto N, et al. - Among 815 premenopausal women from the New England Case Control Study (NEC), researchers assessed factors that were predictive of CA125 levels. They generated linear and dichotomous (≥ 35 U/ mL) CA125 prediction models. Among 473 premenopausal women in the European Prospective Investigation into Cancer and Nutrition Study (EPIC), they sought to obtain external validation for an abridged model restricting to available predictors. On the basis of the abridged model (including age, race, and menstrual phase at blood draw), similar correlation coefficients in NEC(r=0.22) and in EPIC(r=0.22) were reported for the correlation between observed and predicted CA125 levels. Age, tubal ligation, endometriosis, prior personal cancer diagnosis, family history of ovarian cancer, number of miscarriages, menstrual phase at blood draw and smoking status were included in the dichotomous CA125 prediction model, yielding an AUC of 0.83. In NEC and in EPIC, similar AUCs were shown by the abridged dichotomous model (including age, number of miscarriages, menstrual phase at blood draw, and smoking status).