Effects of Mammary Surgery on Prolactin Secretion in Common and in Triple Negative Breast Cancer Patients

Abstract

Despite the well documented potential stimulatory activity of prolactin (PRL) on mammary tumors, hyperprolactinemia following breast surgery has proven to be able to predict a more favourable prognosis in breast cancer. This apparent controversial result is probably due to mammary stimulation that induces PRL secretion in normal conditions, therefore the failure of PRL increase after breast surgery could reflect an alteration in the neuroendocrine control of mammary tissue growth and differentiation. On this basis, a study was planned in order to investigate the effects of breast surgery on PRL secretion in Triple Negative Breast Cancer (TNBC), which represents the most malignant subtype of mammary tumors. The study included 100 breast cancer patients treated by quadrantectomy, evaluating PRL serum levels before and 7 days after surgery. The diagnosis of TNBC occurred in 16/100 investigated patients. Postsurgical hyperprolactinemia was observed in 53/84 (63%) patients with common breast cancer and in only 2/16 (13%) TNBC patients. This difference was statistically significant. The present preliminary study, demonstrates a lower frequency of surgery-induced hyperprolactinemia in TNBC compared to the other mammary tumorhistotypes and furthermore it suggests that the more aggressive behavior of TNBC could depend to some extent on a more pronounced alteration in the neuroendocrine control of mammary tissue.