Expression of Ets-1 transcription factor is correlated with penetrating tumor progression in patients with squamous cell carcinoma of the esophagus

BACKGROUND. The Ets-1 transcription factor is proposed to play a role in tumor invasion. To evaluate the biologic significance of Ets-1 in the progression of squamous cell carcinoma of the esophagus, the authors investigated Ets-1 expression in tumors from 90 patients using immunohistochemical procedures. METHODS. The Ets-1 positive ratio (Ets-1 ratio) was determined in the center and deep margin areas of invasive sites and in the center and outer edge areas of intraepithelial spread contiguous with invasive disease. RESULTS. Ets-1 expression was heterogeneous within tumor tissue. The Ets-1 ratio was significantly higher at invasive sites compared with intraepithelial spread sites, and at deep margin areas compared with center areas (P < 0.0001 and P < 0.05, respectively, by two-way analysis of variance). No differences were noted in the Ets-1 ratio at the deep margin areas at each depth of invasion. Investigating the Ets-1 ratio at deep margin areas in each pathologic phenotype, the ratio of the small nest type was found to be higher than that of the large nest type (P < 0.0001). CONCLUSIONS. The authors propose that Ets-1 plays an important role in penetrating tumor progression, even very early in the invasive process (especially in the case of infiltrative invasive type tumors) at the deep margin areas of invasive sites in patients with squamous cell carcinoma of the esophagus. (C) 2000 American Cancer Society.