Proliferation and maturation of intratumoral blood vessels in non-small cell lung cancer

Non-small cell lung carcinoma is one of the most common leading causes of cancer mortality, and studying the features of intratumoral vessels, especially their generation and maturation, has become more important because of the recent application of antiangiogenic therapy. Vasohibin-1 has been recently considered one of the immunohistochemical markers for identifying neovascularization in archival materials. In addition, the functional maturation of blood vessels is considered to be related to pericyte formation around endothelial cells. Therefore, in this study, we evaluated the status of angiogenesis and maturation of intratumoral blood vessels in 93 patients with non-small cell lung carcinoma (50 with adenocarcinoma and 43 with squamous cell carcinoma) using immunohistochemistry of vasohibin-1, endoglin, CD31, and nestin. The vasohibin-1/CD31-positive ratio was significantly (P =.03) correlated with the Ki-67/CD31 ratio, confirming that the vasohibin-1/CD31-positive ratio represented the status of neovascularization in lung cancer. There were no statistically significant differences in vasohibin-1/CD31 ratios between adenocarcinoma and squamous cell carcinoma in both inner (P =.39) and outer areas (P =.36) of the tumor. The vasohibin-1/nestin-positive ratio, which represents the degrees of vascular maturation in proliferative vessels, was significantly lower in inner areas of adenocarcinoma (0.4 ± 0.1) than those in squamous cell carcinoma (0.8 ± 0.1) (P =.02). These results demonstrated that the degrees of maturation in newly formed blood vessels were less developed in inner areas of squamous cell carcinoma than adenocarcinoma, which may account partly for the complications of antivascular endothelial growth factor therapy more frequently detected in patients with squamous cell carcinoma.