Postoperative hyperprolactinemia could predict longer disease-free and overall survival in node-negative breast cancer patients

Objectives: Breast manipulation determines a physiological increase in prolactin (PRL) blood levels, but the clinical and biological impact of surgery-induced changes in PRL secretion still has to be clarified. The postoperative hyperprolactinemia has been related to aggressiveness of the tumor, early disease relapse or metastases, and poor overall survival in node-negative breast cancer patients. Surgery-induced hyperprolactinemia may be associated with a longer disease-free survival in both patients with or without node involvement.

Methods: One hundred twenty-seven consecutive node-negative breast cancer patients, who were hospitalized from June 1985 to September 1990, were included in this study. The median follow-up was 12 years. To evaluate PRL secretion, venous blood samples were obtained at day 7th after surgery. In order to exclude the influence of stress and gonadal status, GH and estradiol serum levels were measured in the same blood samples. All endocrine examination were made during the morning, starting at 8.00 a.m. after overnight fasting. Hormonal serum levels were determined by the double antibody radioimmunoassay method.

Results: Hyperprolactinemia was significantly more frequent in women younger than 50 years compared with the older ones, while the premenopausal status and T1 stage showed only a borderline significant association with hyperprolactinemia. Patients with normal postsurgical prolactinemia had 5- and 10-year disease-free survival rates of 64 and 56%, respectively, and 5- and 10-year overall survival rates of 84 and 70%, respectively. Patients with postsurgical hyperprolactinemia had 5- and 10-year disease-free survival rates of 89 and 81%, respectively, and 5- and 10-year overall survival rates of 94 and 81%, respectively. The difference in overall survival between the hyperprolactinemic and the normoprolactinemic groups, assessed by the log-rank test, was statistically significant (p = 0.02), and the difference in disease-free survival was highly significant (p = 0.0008).

Conclusions: Our study shows that postsurgical hyperprolactinemia is associated with a significantly lower recurrence rate and longer disease-free and overall survival in operable node-negative breast cancer patients. Our data suggest that postoperative hyperprolactinemia could be crucial in the development of recurrence in operable breast cancer. Looking at results, the recurrence rate of node-negative patients who did not show postoperative hyperprolactinemia would be, in theory, similar to that of patients with node-positive disease, suggesting that normal postoperative PRL levels could identify a group of node-negative patients at high risk for recurrence.