Prognostic significance of c-erbB2 overexpression in patients with metastatic gastric cancer

Abstract

Overexpression of the gene c-erbB2, which encodes a receptor tyrosine kinase, has been associated with prognosis and response to therapy in several solid tumors. This study was designed to test whether c-erb-B2 overexpression can be related to prognosis of patients with metastatic gastric cancer.

Between 2005 and 2010, 46 cases of metastatic gastric cancer were evaluated immunohistochemically for c-erb-B2 overexpression. Overall survival (OS) and time-to-progression (TTP) served as the main outcome measures.

c-erbB2 was overexpressed in 19 (41.3 %) cases and 8 patients (17.4 %) had a c-erbB2 score of 3+ (a strong complete membrane staining observed in > 10 % of the tumor cells). c-erbB2 expression was not associated with the clinicohistological characteristics of the study participants. The mean OS was 11.48 +/- A 1.03 months, whereas the mean TTP was 8.28 +/- A 0.8 months. Compared with patients with a score of 2+ or less (n = 38), those with a c-erbB2 score of 3+ (n = 8) had both a significantly lower OS (15.55 +/- A 1.63 vs. 8.22 +/- A 0.88 months, respectively, p < 0.05) and TTP (10.72 +/- A 1.81 vs. 6.11 +/- A 0.61 months, respectively, p < 0.05). After allowance for potential confounders, Cox regression analysis identified a c-erbB2 score of 3+ as an independent predictor of both OS (hazard ratio = 1.9; 95 % confidence interval = 1.1-3.7, p < 0.05) and TTP (hazard ratio = 1.8; 95 % confidence interval = 1.1-4.1, p < 0.05).

Our results suggest that c-erbB-2 overexpression may have a prognostic significance in patients with metastatic gastric cancer.