Concentration of serum HER-2/neu as a prognostic factor in locally advanced breast cancer (LABC) and metastatic breast cancer (MBC).

AIM to determine whether serum HER-2/neu level could be used as a prognostic factor in locally advanced breast cancer (LABC) and metastatic breast cancer (MBC). METHODS a prospective cohort study was done in LABC and MBC patients in dr. Sardjito Hospital Yogyakarta from April 2006 to March 2008. Serum concentration of HER-2/neu was measured by ELISA done before and after chemotherapy. HER-2/neu expression tissue examination was done by immunohistochemistry. The clinical responses on therapy, survival and progression were recorded. RESULTS twenty seven cases were obtained. Average concentration of serum HER-2/neu was 21.02 ± 7.1 ng/ml. The level of serum HER-2/neu in LABC was lower than MBC (17.21 ng/ml vs 28.64 ng/ml; p=0.32). Average concentration of serum HER-2/neu in partial responders was 13.20 ng/ml (95% Cl 0.142 - 26.25), stable responders was 19.42 ng/ml (95% Cl -0.255 - 39.09) and 29.35 ng/ml(95% Cl 1.95 - 56.74) in progressors (p=0.468). Patients with better clinical response had a lower average HER-2/neu serum level (16.12 ng/ml vs 29.35 ng/ml; p=0.247). HER-2/neu over expression was found in 40.7% of the tissues, 44% of LABC and 33.3% of MBC tissues (p=0.692). Negative HER-2/neu tissue protein expression had better clinical response (75% vs 45.5% p=0.224), and longer survival (p=0.08). CONCLUSION neither the expression of HER-2/neu in the tissue nor the level of serum HER-2/neu can be used as clinical prognosis factor on advanced stage breast cancer in our study population.