Prolactin secretion in benign breast diseases.

In order to evaluate the importance of prolactin in the pathogenesis of benign breast diseases (BBD), serum prolactin (PRL) levels were determined before and during a TRH challenge test in 50 patients affected by various BBD studied during the luteal phase of their cycle. They were compared to 15 normal women also studied during the luteal phase. In all the subjects estradiol (E2) and progesterone (P) were also measured. The patients were studied as a total group and in different subgroups according to the type of their disease, before and after 3 months of treatment with a potent progestin, lynestrenol. No significant differences appeared between any group of patients and the control group either on the basal prolactin secretion or on its dynamic secretory pattern after TRH injection before and during treatment. The only significant difference observed between patients and controls was the progesterone values, respectively 6.86 +/- 0.9 ng/ml and 21.2 +/- 1.4 ng/ml. It can therefore be concluded that benign breast diseases are more likely to be related to an inadequate luteal phase than to any abnormality of prolactin secretion.