A high peripheral microvessel density count correlates with a poor prognosis in pancreatic cancer

Background. Microvessel density (MVD) has been shown to be associated with a poor prognosis in gastric, colorectal, breast, and lung cancers. However, there are few positive results in pancreatic cancer. We hypothesized that high counts of MVD, determined by the lumen method as compared with the hot-spot method, would show a significant correlation with a poor prognosis in pancreatic cancer. Methods. Thin slices from the center and periphery of 41 resected pancreatic tumors were immunostained with factor VIII monoclonal antibody. MVD was determined under high magnification by the lumen method, which counts only those structures showing vessel formation positive for factor VIII. The relationship between MVD and clinical and histological variables and the development of liver metastases and survival was assessed with logistic and Cox regression analyses, respectively. Results. Liver metastasis developed in 22 patients (54%) after surgery. Peripheral MVD, as measured by the lumen method, and N-category (TNM classification) were both significantly associated with liver metastasis. Survival rates were 50%, 15%, and 10% for 1, 3, and 5 years, respectively. Poor survival was significantly associated with male sex; high peripheral MVD, as measured by the lumen method; arterial invasion; and T-category ranking (TNM classification). Conclusions. High peripheral MVD, as assessed by the lumen method, is associated with the occurrence of liver metastasis and with a poorer prognosis in pancreatic cancer.