Computer assisted analysis of the microvasculature in metastasized and nonmetastasized squamous cell carcinomas of the tongue.

Abstract

BACKGROUND: Quantification of microvessels in solid malignancies is regarded as a potential test to predict their clinicobiologic behavior. However, discordant results have been reported for head and neck cancer that may be explained by varying methods. METHODS: In this retrospective study, we therefore quantified the microvasculature in 20 nonmetastasized and 20 metastasized squamous cell carcinomas of the tongue, using recently developed methods. For immunohistochemical visualization of the vessels, we used anti-CD34 with a signal amplification step based on the catalyzed deposition of biotinylated tyramine. This protocol results in enhanced staining quality compared with standard protocols. For each tumor, a representative tissue section was systematically sampled with 40 to 60 standardized test fields. True color image analysis system was used to measure microvessel density (MVD) and to obtain additional information with regard to size categories of vessels. RESULTS: Remarkably, in the group of nonmetastasized tumors, the MVD was greater than in the metastasized tumors (p =.007). However, the microvessels with a diameter in the range of 10 to 15 microm predominated in the group of metastasized tongue carcinomas (p =.03). A logistic regression model based on the percentage of vessels smaller than 5 microm, classified 85% of patients with a metastasized tumor correctly and 75% of patients with a nonmetastasized tumor, independently of the clinical stage of the tumor. CONCLUSIONS: These results suggest that only vessels with a diameter larger than 10 microm, consistent with functional vessels, play a role in the process of metastasis. Further research more specifically into structural and functional characterization of blood and lymphatic vessels might help provide more insight into the relationship between microvasculature and the pathogenesis of metastasis in tongue carcinomas.