Plasma and tumor prolactin in colorectal cancer patients.

Fifteen consecutive patients with recently diagnosed colorectal cancer were studied for plasma and tumor tissue prolactin content. In eight patients (four men and four postmenopausal females), preoperative high plasmatic prolactin was found (mean 1553 nmol; range 516-3677 nmol). In three of them, prolactin was also present in the tumor cells.