PRL and breast cancer: Intriguingly, the RR (95% CI) was determined to be 1.27 (1.13, 1.43) and 0.99 (0.84, 1.16) for postmenopause and premenopause patients, respectively, thereby revealing a positive association between plasma prolactin levels and risk of breast cancer among the postmenopause patients, but not in the premenopause women.