Vascular endothelial growth factor receptor 1 expression in pelvic lymph nodes predicts the risk of cancer progression after radical prostatectomy

Recent studies suggest that vascular endothelial growth factor receptor (VEGFR) 1-positive hematopoietic progenitor cells precede the arrival of tumor cells and form clusters that may portend sites of future metastatic disease. The aim of the present study was to clarify whether VEGFR1 expression in pelvic lymph nodes predicts the risk of prostate cancer progression after radical prostatectomy. VEGFR1 expression in pelvic lymph nodes was examined by immunohistochemistry in 95 patients who underwent radical prostatectomy for prostate cancer. A cluster of VEGFR1-positive cells was considered positive. Expression of VEGFR1 in pelvic lymph nodes and biochemical recurrence after radical prostatectomy were examined by univariate survival analysis and multivariate Cox proportional hazards regression analysis. Thirty-seven of 79 lymph node-negative patients (46.8%) were found to have VEGFR1-positive cells in their pelvic lymph nodes, whereas 16 of 16 lymph node metastasis-positive patients (100%) had VEGFR1 clusters. There was a significant correlation between pathological stage and VEGFR1 staining (P = 0.002). Univariate analysis showed that pathological stage >= pT3 and VEGFR1 expression in pelvic lymph nodes were each significantly associated with biochemical recurrence after radical prostatectomy. Multivariate analysis showed VEGFR1 expression to be an independent predictor of biochemical recurrence after radical prostatectomy (risk ratio = 5.715, P = 0.010), as was preoperative prostate-specific antigen (PSA) level >= 10 ng/mL. Although larger validation studies are required, our results suggest that VEGFR1 expression in pelvic lymph nodes predicts the risk of biochemical PSA recurrence after radical prostatectomy. (Cancer Sci 2009; 100: 1047-1050).