The prognostic significance of microvessel density and thymidine phosphorylase expression in squamous cell carcinoma of the esophagus.

Squamous cell carcinoma (SCC) of the esophagus is among the most malignant of neoplasms and is associated with a dismal prognosis. Although tumor microvessel density (MVD) is an important prognostic factor in several carcinomas, its role in SCC of the esophagus is still controversial. Also, the role of thymidine phosphorylase (dThdPase), a key angiogenic growth factor, is yet to be delineated in this disease. Immunohistochemical staining using monoclonal antibodies was used to quantify microvessel and dThdPase expression in archival tissue specimens from 93 patients with SCC of the esophagus. High dThdPase expression and high MVD were associated with tumor progression (size and stage) and lymph node metastasis, but only MVD was a predictor of survival. dThdPase expression was significantly correlated with depth of tumor invasion (P = 0.015). In multivariate analysis, MVD was an independent predictor of survival in the lymph node negative cases. A significant correlation was noted between MVD and dThdPase expression, with a correlation coefficient of 0.083 (P = 0.002). MVD is an independent factor in determining the prognoses of lymph node negative patients with SCC of the esophagus. dThdPase could be a key factor in the angiogenesis of this disease and may be responsible for its aggressive behavior.