[Pre- and postoperative differences in the circadian secretion of prolactin in carcinoma of the human breast].

The authors study the nyctohemeral changes of prolactin and growth hormone during the evolution of breast cancer and in fibrocystic mastopathy. Prolactin shows a circadian rhythm with higher amounts during sleep in cancer patients. Changes are not significant for fibrocystic mastopathy, although there is a tendency towards higher concentrations than in the control group. No significant changes were observed for the growth hormone.