Changes in Lymphangiogenesis and Vascular Endothelial Growth Factor Expression by Neo-Adjuvant Hormonal Therapy in Prostate Cancer PatientsChanges in Lymphangiogenesis and Vascular Endothelial Growth Factor Expression by Neo-Adjuvant Hormonal Therapy in Prostate Cancer Patients 前立腺癌患者における術前内分泌療法によるリンパ管新生とVEGF（vascular endothelial growth factor）発現の変化
BACKGROUND: The anti-cancer mechanism of neo-adjuvant hormonal therapy (NHT) is not well understood. Lymphangiogenesis plays an important role in cancer progression and is regulated by a complex mechanism that includes vascular endothelial growth factor (VEGF) signaling. However, there is little information regarding relationship between lymphangiogenesis and androgen deprivation. The aim of this study was to clarify changes in lymphangiogenesis and VEGF expression induced by androgen deprivation in prostate cancer in vivo and in vitro. METHODS: Patients who had undergone a radical prostatectomy were enrolled in the study (NHT, n = 60 and non-NHT, n = 64). Lymph vessels were identified by D2-40 immunoreactivity and lymph vessel density and lymph vessel area (LVD and LVA, respectively) were measured from micrographs. The expression of VEGF-A, -B, -C, and -D was evaluated by immunohistochemistry. The prognostic value of LVD and LVA for biochemical recurrence was also investigated.
RESULTS: Mean LVD ± SD was higher in the NHT than in the non-NHT group (11.3 ± 3.0 vs. 7.1 ± 3.4 per high power field; P < 0.001). LVA was larger in the NHT than in the non-NHT group (512.8 ± 174.9 vs. 202.7 ± 72.8 µm2; P < 0.001). VEGF-A expression was lower whereas VEGF-C and -D levels were higher in the NHT than in the non-NHT group. VEGF-B expression in specimens with NHT was lower than that in biopsy specimens at diagnosis. These results were confirmed by in vitro studies used androgen-sensitive prostate cancer cell line. LVA was found to be an independent predictor of biochemical recurrence in patients who received NHT.
CONCLUSIONS: Our results demonstrate that NHT stimulates lymphangiogenesis via upregulation of VEGF-C and -D, which may increase LVA and affect the outcome of prostate cancer patients. This findings were supported by in vitro data of prostate cancer cell.