[2035] Prognostic value of serum HER-2 in early stage breast cancer (BC) patients.
Gori S, Ludovini V, Mosconi A, Pistola L, Rulli E, Rulli A, Anastasi P, Basurto C, Sidoni A, Tofanetti FR, Colozza M.. Azienda Ospedaliera Perugia, Perugia, Italy, Italy; Mario Negri, Milano, Italy, Italy; University of Perugia, Perugia, Italy, Italy
Background: HER2 is amplified and/or overexpressed in approximately 20-30% of invasive BC and is associated with poor prognosis. It is also a predictive marker of response to trastuzumab. The extracellular domain of the HER2 protein (sHER2) is frequently cleaved and released into the circulation where it can be detected by ELISA in up to 45% of advanced BC. We evaluated HER2 expression in paired serum and tissue samples of operable BC pts to analyze 1) the correlation between sHER2 and HER2 tumor status 2) their relationship with clinical-pathological parameters and 3) their impact on the outcome.
Patients and Methods: 188 consecutive stage I-III BC pts were included in this study from May 2000 to July 2005. sHER2 was measured by ELISA (manual Kit 
Oncogene Science Diagnostics
and automated version ADVIA Centaur, Bayer Diagnostics) before the local treatment. Tumor tissue was analyzed by IHC with CB11 antibody and scored with Dako Hercept-test. HER2 amplification was determined using the VentanaTM FISH assay in patients with 2+ by IHC. Chi-squared test was used to evaluate the association between HER2 and patients
clinical-pathological features. Survival outcomes were analyzed using Coxs model.
Results: Median age was 56.6 years; 122 pts received adjuvant chemotherapy, 54 endocrine therapy and 83 both. Forty-three pts (23%) had HER2 overexpression/amplification in tumor tissue and 25 pts (13%) had sHER2 levels 
15ng/ml (cut-off level) with a concordance of 85%. Both high sHER2 levels and HER2 tumor expression were associated with high histological grade (p=.02 and p<.0001 respectively) and negativity of ER (p=.0035and p<.0001) and PgR (p=.0056 and p=. 002). At a median follow-up of 2.4 years we observed 8 deaths and 19 relapses. At univariate analysis high sHER2 levels (evaluated as continuous variable) were significantly correlated with shorter DFS (p=0.0002) even if at multivariate analysis high sHER2 levels, after adjustment for stage and ER status, were associated with a shorter DFS with borderline significance (p=0.06).
Discussion: Our preliminary data indicate that measurement of sHER-2 at diagnosis appears to be a useful tool for identifying high-risk BC pts and helping with treatment decisions.
Friday, December 15, 2006 7:00 AM
Poster Session II: Prognosis and Response Prediction: Prognostic Factors I (7:00 AM-9:00 AM)