Tumor invasion and angiogenesis in early esophageal squamous cell carcinoma

Although the relationship between angiogenesis and tumor proliferation or malignant potential has been previously demonstrated in several studies, early stage of cancer invasion and angiogenesis has seldom been investigated.

From the esophageal specimens of eight recently resected cases with esophageal squamous cell carcinoma, 25 areas of carcinoma-in-situ or microinvasive carcinoma were selected, and then a serial histologic investigation and immunohistochemical staining for the detection of Factor VIII-related antigen to investigate microvessels in the lamina propria mucosae beneath the lesions as a measure of angiogeneses and staining for laminin to visualize basement membrane was performed. Lymphocyte infiltration below the lesions were also estimated. In view of early cancerous invasion, histologic patterns of the growth of the lesions were divided into "flat," "expansive," and "downgrowth" patterns.

Although downgrowth patterns are thought to be more invasive, relationships between the histologic patterns, and basement membrane staining patterns, and lymphocyte infiltration patterns were not demonstrated. However, the angiogenetic ratio (the number of vessels/cm under the lesions divided by that under normal epithelium) was observed to be significantly and closely related to tumor invasion patterns (P < 0.01), although it was not related to the destruction of the basement membrane or lymphocyte infiltration below the lesions.

The angiogenesis of esophageal squamous cell carcinoma is closely correlated to the tumor invasion patterns in early esophageal cancerous lesions.