대한대장항문학회

The growth and maintenance of solid tumors are dependent on new capillary<br>ingrowth: a process called "angiogenesis." Thus, after a new tumor has attained a small<br>size of a few millimeters in diameter(about 10<sup>6</sup> cells), further expansion of<br>the tumor-cell population requires the induction of new capillary blood vessels. These<br>new vessels also increase the opportunity for hematogenous or lymph node metastasis.<br>Thus this study was designed to examine the microvessel count at the invasive margin<br>in colorectal carcinoma to determine how angiogenesis correlates with clinicopathologic<br>factors and prognosis. Paraffinembedded tissues from 127 patients with primary<br>colorectal carcinomas that had been completely removed were retrieved and analyzed for<br>angiogenesis. Vessels were immunostained with anti-factor VIII polyclonal antibody, and<br>areas with the most discrete microvessels were counted in a 200?ield, which were<br>defined as angiogenesis score(AS).<br>The mean AS for anti-factor VIII antibody in this study was 55?8; therefore, cases<br>were classified into two subgroups : AS high group(n=67), for which AS was greater<br>than 55 and AS low group(n=60), for which AS was equal to 55 or less. There were no<br>significant intergroup difference regarding sex ratio, histologic grade, depth of invasion,<br>or lymphatic invasion. AS was, however, significantly related to tumor size, venous<br>invasion, lymph node metastasis, and liver metastasis(P=0.000, P=0.001, P=0.021, and<br>P=0.004, respectively). The incidence of high AS group in Antler-Coller D was<br>significantly greater than that in Antler-Coller A and B, and Antler-Coller C(P<0.05,<br>respectively). The recurrence rate in high AS group was 32.0%, which was, though<br>statistically insignificant, higher than that in low AS group(17.2%). The 3 year survival<br>rates of high AS group were significantly (P=0.004 both for overall cases and<br>curatively-resected ones) worse than those of low AS group.<br>This study suggests that the growth of colorectal carcinoma is dependent on ingrowth<br>of new blood vessels, and that angiogenesis assessed by the microvessel count using<br>immunohistochemical stains is an important predictor of tumor behavior and may<br>identify patients at higher risk for recurrence and early death.<br>