Microvessel density of hepatocellular carcinoma: its relationship with prognosis

Purpose: To elucidate the relationship between angiogenesis and prognosis a fter curative resection of hepatocellular carcinoma (HCC). Methods: An immu nohistochemical study using anti-CD34 monoclonal antibody was carried out o n surgical specimens from 78 HCC patients who had undergone curative resect ion; microvessel density (MVD) was counted and the overall survival and dis ease-free survival were analyzed retrospectively. Results: Blood vessels in the tumor were strongly stained by anti-CD34 antibody, but not those in th e surrounding liver parenchyma. There were three types of tumor vessels: ca pillary-like (n = 59), sinusoidlike (n = 16) and mixed-type (n = 3). The me dian MVD count was 100 per field. The HCC were designated as hypovascular ( n = 36) with an MVD count below 100, and hypervascular (n = 42) with an MVD count of 100 or more per field. The 5-year survival and disease-free survi val rates were 49.7% and 42.8% respectively, and statistical analysis showe d that the MVD level was not correlated with tumor size, capsule status, Ed mondson's grade, alpha-fetoprotein level, associated cirrhosis, gamma-gluta myltransferase, and serum HBsAg status. The sinusoid-like tumor vessels app eared more frequently in the more differentiated tumors (P < 0.05). No stat istical difference in overall and disease-free survival between different M VD levels and microvessel types was found. Tumor size was the only predicti ng factor in the entire series. In patients with small HCC (less than or eq ual to 5 cm, n = 40), 5-year survival and disease-free survival rates were 58.9% and 52.7% respectively, higher than the values in large HCC (39.8% an d 32.0% respectively, P < 0.05). The MVD level was an independent predictin g factor of disease-free survival, 5-year disease-free survival in the hypo vascular group (74.6%) being better than that in the hypervascular group (3 4.7%, P < 0.05). Conclusions: The MVD level was not related to tumor size, capsule statue, Edmondson's grade, alpha-fetoprotein level, associated cirr hosis, gamma-glutamyltransferase and serum HBsAg status. In the entire seri es, tumor size was the only factor influencing survival after curative rese ction. However, in patients with small HCC, the MVD level was an independen t factor of disease-free survival. The pathological and clinical implicatio ns of different types of tumor vessels in HCC remain to be studied.