Microvessel Density and Impact of Angiogenesis on Survival of Resected Pancreatic Cancer Patients: A Systematic Review and Meta-analysis.

Angiogenesis plays a major role in tumor progression and metastasis; however, its role in pancreatic cancer (PC) remains unclear. The aim of the study was to explore the cumulative evidence concerning the impact of microvessel density (MVD), an estimator of angiogenesis, on resected PC patients. A systematic review of literature and a meta-analysis of relevant reports were performed. Overall survival and disease-free survival were scrutinized. One thousand five hundred patients were analyzed. Overall survival (hazard ratio, 2.0; 95% confidence interval, 1.57-2.54; P < 0.001) and disease-free survival (hazard ratio, 1.99; 95% confidence interval, 1.24-3.2; P = 0.004) were in favor of the low-MVD group. Use of CD105 antibody and of a computerized image analysis system was found to significantly reduce the heterogeneity. Disease staging, tumor location, and grading showed significant effect on survival. High-MVD expression was strongly associated with poorer survival and recurrence among resected PC patients, demonstrating a negative prognostic value. Use of CD105 antibody and of a computerized image analysis system is recommended in future studies because they reduce heterogeneity of results. The potential role of MVD as a marker to select PC patients who would benefit from antiangiogenetic treatment should be further explored in clinical trials.