OBJECTIVETo investigate the expression of protein peak (3144 m/z) in serum and of its association with clinical pathological characteristics and prognosis in patients with gastric cancer.

METHODSThree hundred and twenty seven pathologically confirmed gastric cancer patients were recruited from February 2006 to October 2008 in the Zhejiang Cancer Hospital. SELDI-TOF-MS was employed to detect the expression of protein peak (3144 m/z) in preoperative serum.

RESULTSThe positive rate of 3144 m/z protein peak was 33.9% (111/327), significantly higher than that of CEA (21.1%,69/327), and the difference was statistically significant (P<0.01). The positive rate of combined detection of protein peak (3144 m/z)and CEA was 45.6% (149/327). The expression of protein peak (3144 m/z) was associated with clinical staging (P<0.01), nervous invasion (P<0.01), tumor size (P<0.01), vascular invasion (P<0.05), lymph node metastasis (P<0.05), expression of CEA (P<0.05), and depth of infiltration (P<0.05). Significant difference was observed in 3-year survival rate between the patients with protein peak and patients without protein peak (44.7% vs. 64.4%, P<0.01). However, 3144 m/z protein peak was not an independent prognostic factor on multivariate Cox regression analysis (P=0.057).

CONCLUSIONProtein peak (3144 m/z) may be used as a diagnostic or prognostic marker of gastric cancer.