Shc test as a strong prognostic indicator of disease outcome in early stage gastric cancer
10090 Background: Treatment planning for gastric cancer is primarily based on clinical staging of disease. Markers predicting likelihood of disease outcome would help guide treatment decisions, especially for early stage disease. The Shc proteins, implicated in many aggressive cancers, and measured in tumor specimens by the immunohistochemical (IHC) Shc Test, have shown strong ability to predict disease outcome in breast cancer. We report here that the Shc Test is a strong prognostic indicator of disease outcome in early stage gastric cancer. Methods: Histopathology was examined in one hundred and seventeen (117) primary gastric cancer patient samples from Rhode Island Hospital in tissue microarray format (21 disease recurrences; 63 disease-specific deaths; average follow-up of 2.7 yrs). IHC staining of the Shc proteins was independently scored on a 0–5 scale by two pathologists, blinded to patient information. Results: Stage I or II gastric cancers (n=62) could be clearly separated at a cutpoint of 1.1 on a 0–5 scale, into good prognosis (16% 4yr relapse risk; demonstrating high PY-Shc) and poor prognosis (46% 4yr relapse risk; showing low PY-Shc) (log-rank, P=0.003). p66 Shc showed similar prognostic abilities. High PY-Shc in patients with early stage disease showed a significant protective effect on overall survival (P=0.003) by univariate log rank analysis. As a continuous variable, PY-Shc had a strong predictive ability (HR = 0.09, P=0.055) that approached significance. By univariate Cox proportional hazards, patients with high PY-Shc had a 5-fold reduction in disease specific death (DSD) compared to patients with low PY-Shc (P=0.002). By multivariate Cox proportional hazards, adjusted for grade, stage, chemotherapy and radiation therapy, only PY-Shc (HR = 0.22, P=0.015) and Intestinal tumor type (HR = 0.38, P=0.046) remained as significant predictors of survival. Conclusions: The Shc Test shows a strong prognostic ability to stratify early stage gastric cancer patients by risk, making it a valuable tool in selecting therapy for these patients. [Table: see text]