OBJECTIVETo investigate the correlation between helicobacter pylori L-form (Hp-L) infection in human esophageal carcinoma (EC) and tumor angiogenesis, and study the effect of Hp-L on the malignant biological behaviors of EC.

METHODSHp-L was examined in 98 patients with EC and 30 controls by Gram stain, electronmicroscopic technique and immunohistochemical stain (ABC method). VEGF, p53 protein and microvessel density (MVD) were examined by immunohistochemical stain (SP method) with their relationship with the clinicopathologic factors analyzed.

RESULTSThe positive rate of Hp-L was 60.2% in EC group. Two types of Hp-L were detected in the tissue of EC by electronmicroscopic technique, which lay in the outer or inner carcinoma cells. The positive rates of Hp-L, MVD, VEGF and p53 in the cancer group were significantly higher than those in control group (P < 0.005-0.001). The positive rates of MVD, VEGF and p53 in the Hp-L positive group of EC were significantly higher than those in Hp-L negative group (P < 0.005-0.001). The positive rate of Hp-L was correlated with MVD (r = 0.46, P < 0.01) and the expression of VEGF and p53 (r = 0.31, P < 0.01). The positive rate of Hp-L in the EC group was correlated with vessel invasion, depth of invasion, metastasis to the para-esophageal and distant lymph nodes except tumor size.

CONCLUSIONHp-L infection in EC is closely related with tumor angiogenesis and may be an important promoting factor in esophageal carcinoma growth, invasion and metastasis.