Prognostic significance of serum prolactin levels in advanced breast cancer.
Dowsett M., McGarrick GE., Harris AL., Coombes RC., Smith IE., Jeffcoate SL.
Serum prolactin concentrations were measured in 135 postmenopausal patients with advanced breast cancer prior to their treatment with one of 3 endocrine therapies: aminoglutethimide (AG), tamoxifen (T) + AG, or T + AG + danazol. The mean level of prolactin was higher, and there were more individuals with levels of prolactin greater than or equal to 500 mIUl-1, in the group of patients who did not respond to treatment. Of the patients whose disease progressed, those with prolactin levels greater than or equal to 500 mIUl-1 had a significantly shorter survival. It appears that high prolactin levels indicate a poor prognosis to endocrine therapy and the probability of a shorter than average survival time.