SERUM LEVELS OF INSULIN-LIKE GROWTH-FACTOR-I IN OPERABLE BREAST-CANCER IN RELATION TO THE MAIN PROGNOSTIC VARIABLES AND THEIR PERIOPERATIVECHANGES IN RELATION TO THOSE OF PROLACTIN

Aims and background: In addition to estrogens, prolactin (PRL) and IGF -I have also appeared to stimulate breast cancer growth. The present s tudy was performed to evaluate IGF-I blood levels in operable breast c ancer in relation to PRL values and the main prognostic variables. Met hods: The study included 40 patients, clinical stage T1-3NO-2MO. Venou s blood samples were collected before and 7 days after surgery. PRL an d IGF-I were measured by radioimmunoassay. The control group consisted of 50 healthy women. Results: Mean serum levels of IGF-I were signifi cantly higher in patients than in controls, without any apparent relat ion to the main prognostic variables, including estrogen receptor and node status. Surgery-induced hyperprolactinemia occurred in 22/40 pati ents. IGF-I mean concentrations observed in the postoperative period i n patients with surgery-induced hyperprolactinemia were significantly lower than those seen in patients showing no postoperative PRL rise. C onclusions: The study showed that operable breast cancer may be associ ated with abnormally high levels of tumor growth factor IGF-I, and tha t surgery was followed by an IGF-I decline only in patients who showed surgery-induced hyperprolactinemia. Our previous studies have shown t hat postoperative hyperprolactinemia is a favorable prognostic factors for operable breast cancer. The present study, by showing that a post operative PRL rise is associated with a fall in IGF-I, would suggest t hat surgery-induced hyperprolactinemia may determine a lower tumor rel apse rate by determining a diminished secretion of breast tumor growth factor IGF-I.