Comparison of the prognostic value of plasma prolactin with that of receptors for prolactin, epidermal growth factor, estrogen, and progesterone in patients with stage III breast cancer

Plasma prolactin (PRL) levels have been reported to be a prognosticator and indicator of disease progression in patients with advanced breast cancer. In an effort to further explore the role of plasma PRL, its prognostic significance has been compared with that of prolactin receptors (PRLRs), epidermal growth factor receptors (EGFRs), estrogen receptors (ERs), and progesterone receptors (PRs) in 37 patients with stage III breast cancer. Patients were divided into two groups on the basis of a cutoff level for each prognosticator : PRL, 20.0 ng/mL ; PRLR, 0.8 % ; EGFR, 1.0 fmol/mg membrane protein ; ER and PR, 10.0 fmol/mg cytosol protein. Sixty-five percent (24/37) of the patients had hyperprolactinemia, 76% (28/37) were PRLR-, 81% (30/37) were EGFR+, 62% (23/37) were ER+, and 65% (24/37) were PR+. Hyperprolactinemic (PRL > 20.0 ng/mL) patients had significantly lower overall survival (P < 0.05) than patients with PRL < 20.0 ng/mL plasma. In contrast, overall survival did not differ significantly between the two subgroups of PRLRs, EGFRs, ERs, and PRs. Patients with PRLR - tumors or EGFR+ tumors and hyperprolactinemia had poorer prognosis than patients with PRL < 20.0 ng/mL plasma (P < 0.05).