Association Of Microvessel Density With Prognosis Of Renal Cell Carcinoma:Evidence From A Single Central Investigation And Meta Analysis

Background and Objective:Renal cell carcinoma (RCC) as one of the commonest malignancy accounts for approximately3%of adult solid tumor, and its incidence and morbidity is increasing. About a third of the patients with newly diagnosed RCC have metastatic disease, and about20%have locally advanced disease, with the remainder having localized cancer. RCC is usually highly vascularized, which is reasonable for metastasis. Angiogenesis, the formation of new blood vessels out of pre-existing capillaries, plays a key role in the growth and metastasis of solid tumors. The study was designed to clarify the significance between microvessel desity (MVD) and prognosis of RCC in retrospective investigation and meta-analysis.Materials and methods:(1) A total of79patients (50males and29females) with ccRCC from department of urology, the2nd hospital of Tianjin Medical University undergoing radical nephrectomy (RN), accession from January2005through December2006. were included in the study. The mean age was56.4±10.9years with a range of35-83years. Tissues from all cases of RCC stained by immunohistochemistry were assessed without knowledge of the patient’s clinicopathological characteristics by respective two pathologists through double blind method using Olympus microscope. For each slide, the most vascular area within the tumour mass was chosen. The MVD, defined as capillaries and small venules, was assessed in10consecutive high-power fields (HPF, x400) in these vascular areas. The continuous and categorized variables were showed with mean±SD and percent, respectively. The comparison between two series was analyzed using t test, or else ANOVA test was used to compare the present relationship between prognostic variables and MVD. The survival curves (SCs) were determined according to the Kaplan-Meier method and the difference between groups tested using the log-rank test. Cox regression analysis was used for uni～and multivariate statistical analysis. In all tests P<0.05was considered to indicate statistical significance.(2) Three investigators carried out the comprehensive literature searches independently using the electronic databases MEDLINE, ISI Web of Knowledge, Embase electronic databases and Cochrane Library without date or with RCC after RN, and no significance was observed (HR=1.15;95%CI=0.75-1.79; P=0.52).Conclusion:(1) The MVD level was variable in different stages, and low MVD might cause coagulation necrosis in ccRCC.(2) Age and TNM stage, but not MVD or the presence of necrosis, were independent predictors of prognosis.(3) MVD was a predictor of prognosis of RCC. The best efficiency of predict value was observed when addressing the relationship of MVD, measured by CD34, and CSS of ccRCC.(4) Future research should focus on the predicting effect of MVD on prognosis of RCC.