OBJECTIVETo investigate the expression of transcription factor SP1, vascular endothelial growth factor(VEGF) and CD34 in serosa-infiltrating gastric cancer and their relationship with biological behavior and survival rate.

METHODSImmunohistochemical technique was used to detect the expression of SP1, VEGF and CD34(described by microvessel density, MVD) in 68 specimens with serosa-infiltrating gastric cancer.

RESULTSThe positive expression rates of SP1 and VEGF in serosa-infiltrating gastric cancer were 50.0% and 52.9% respectively. In positive SP1 specimens, the positive rate of VEGF(73.5%) was significantly higher than that of negative SP1 specimens (32.4%, chi(2)=11.57, P=0.01). The mean tumor MVD was correlated with the expression levels of SP1 and VEGF(P<0.01). There was a significant correlation of the SP1 expression with tumor size and growth pattern(P =0.01). The expression levels of VEGF and MVD were correlated with Borrmann types, cell differentiation, metastatic lymph nodes and growth pattern(P<0.01). Univariate analysis revealed that SP1 and VEGF expression, MVD, Borrmann types, lymph node metastasis, tumor size and growth pattern were significant prognostic factors related to survival time. Multivariate analysis showed that SP1 expression, MVD and growth pattern were independently prognostic factors of poor survival.

CONCLUSIONSThe activation of SP1 contributes to angiogenesis and metastasis in gastric cancer through the up-regulation of VEGF. SP1, VEGF and MVD may serve as valuable indicators of biological behavior of gastric cancer. SP1 protein expression is not related with the number of metastatic lymph nodes. SP1 expression and MVD may serve as valuable indicators of prognosis in gastric carcinoma.