Topographic distribution of lymphatic vessels in the normal human prostate

The expression of vascular endothelial growth factor-C correlates with lymphatic microvessel density and lymph node metastasis in prostate carcinoma: An immunohistochemical study

Aim:

To evaluate the expression of two different lymphatic vascular density (LVD) markers (D2-40 and LYVE-1) and a lymphangiogenic cytokine (Vascular Endothelial Growth Factor-C, [VEGF-C]) in prostate carcinoma and to investigate their relationship with the lymph node status.

Settings and Design:

Archival material study of 92 non-consecutive radical prostatectomy specimens.

Materials and Methods:

The mean LVD was assessed immunohistochemically in 24 prostate carcinoma specimens from patients with clinically localized disease, who were found to have nodal metastasis (pN1), and was compared with 68 pN0 cases. Furthermore, the mean LVD, VEGF-C expression, and lymphatic invasion were examined in relation to lymph node involvement.

Results:

Peritumoral (but not intratumoral) mean LVD assessed by D2-40 was higher in pN1 tumors (P = 0.015). LYVE-1 expression was limited and not associated with lymph node status. The VEGF-C expression was higher in the N1 cases and also correlated with the increased mean LVD in both the peri- and intratumoral compartments. Lymphatic invasion was strongly associated with nodal metastasis and higher VEGF-C expression.

Conclusions:

Our results indicate that increased peritumoral (but not intratumoral) LVD in the tumor specimen is associated with lymph node metastasis. Increased expression of VEGF-C is associated with higher LVD (in both intratumoral and peritumoral compartments) and with positive lymph node status, indicating a possible dual role in both lymphangiogenesis and lymphatic vessel invasion.

Distribution of the lymphatic vessels in the prostatic fascia

BACKGROUND

The prostatic fascia-preserving procedure is effective for the early recovery of erectile function after radical prostatectomy; however, the long-term influence of on cancer control was unknown. This study clarified the distribution of lymphatic vessels in the prostatic fascia.

MATERIAL AND METHODS

The lymphatic vessels were analyzed in 10 prostates obtained from fixed Japanese cadavers (aged, 71-90 years old). Specimens were taken from the apex, the middle part, and the base of the right-hand side of the prostate. Lymphatic vessels were detected by immunohistochemical stain using an antibody specific for the lymphatic endothelial cells (clone D2-40). The lymphatic vessels were counted in the prostate capsule and the prostatic fascia of each section by light microscopy at low power (100×).

RESULTS

The median number of lymphatic vessels in the prostatic capsule per prostatic half was 21.0, 14.0, and 21.0 in the apex, middle, and base part of the prostate, respectively. In the prostatic facia the median number of lymphatic vessels per prostatic half was 8.0, 3.0, and 13.0 in the apex, middle, and the base part of the prostate, respectively. In the apex and the middle part the lymphatic vessels in the prostatic fascia were fewer than those in the prostatic capsule. However, in the base part the number of lymphatic vessels in the prostatic fascia was similar to that in the prostatic capsule.

CONCLUSIONS

The present study suggested the surgeon to pay more attention for the dissection of the fascia at the base of the prostate.

Quantitative analysis of lymph vessel characteristics in organ confined prostate cancer

BACKGROUND

The objective of this study was to analyze the characteristics of lymphatic vasculature in normal and (peri)tumoral prostate tissue, applying accurate and objective quantification techniques based on digital image analysis.

METHODS

Radical prostatectomy specimens of 27 patients were selected containing organ confined peripheral zone tumors, which were restricted to one side of the prostate (pT2a). Lymph vessels were visualized by immunohistochemistry against D2-40. Lymphatic vessel density, perimeter, and area were assessed over the entire tumor and corresponding contralateral normal tissue. Also, morphology (area, perimeter, and diameter) of individual lymph vessels were measured in (peri)tumoral and normal tissue.

RESULTS

No differences were found in the overall lymph vasculature between tumor and normal peripheral zone. However, the area, perimeter, and diameter of individual lymph vessel profiles were significantly decreased in (peri)tumoral as compared to normal tissue. No differences were seen for these parameters between peritumoral and tumoral area. Comparing the coefficient of variation between compartments (normal, (peri)tumoral), no differences were observed for any parameter.

CONCLUSIONS

Although differences exist between the morphology of individual lymph vessels in tumor versus normal tissue, the overall vascular bed (number and summed area and perimeter of lymphatics per area unit tissue) is unaffected in tumor. Peritumoral lymphatics resemble lymphatics in tumor tissue rather than normal lymphatics.

Histopathological predictor for regional lymph node metastasis in gastric cancer

Regional lymph node metastasis in gastric cancer is a definitive indicator of the patient's prognosis. The goal of this study was to identify the predictors for lymph node metastasis among all the possible histopathological parameters, especially by conducting an objective discrimination of the lymphatic and blood vessels. A total of 210 resected primary gastric cancers with or without lymph node metastasis were evaluated based on the conventional histopathological parameters together with immunohistochemistry using antisera-recognizing lymphatic endothelial hyaluronan receptor-1 (LYVE-1), von Willebrand factor, and lymphangiogenesis promoter vascular endothelial growth factor-C (VEGF-C) antibodies. A multivariate regression analyses of the results indicated that only lymphatic invasion was a significant independent predictor of lymph node metastasis at any stage of cancer invasion. VEGF-C expression was partially related to lymph node metastasis in early gastric cancer. The identification of lymphatic invasion by LYVE-1 antibody is therefore useful to predict regional lymph node metastasis in gastric cancer.

Histopathologic determinants of regional lymph node metastasis in early colorectal cancer

BACKGROUND

Early colorectal cancer (ECC) is curable by endoscopic local resection; however, 10% of patients with ECC exhibit lymph node (LN) metastasis. In the current study, accurate predictors for LN metastasis in patients with ECC were examined by using immunohistochemistry with the lymphatic endothelial hyaluronan receptor 1 (LYVE-1) antibody to discriminate between lymphatics and blood vessels.

METHODS

Colorectal tissue specimens obtained from 71 patients with ECC, including 28 patients with regional LN metastasis, were immunostained with antibodies against LYVE-1, beta-catenin, claudin-3, claudin-4, and cytokeratin. The significance of the histopathologic variables for LN metastasis in ECC was investigated on the basis of specific histopathologic parameters.

RESULTS

Lymphatic invasion confirmed by LYVE-1 immunohistochemistry was observed mainly in the submucosal area around the primary tumor and rarely was observed in the tumor. Expression patterns of beta-catenin, claudin-3, and claudin-4 in cancer cells at the invasive front were irrelevant to LN status. Tumor size, depth of invasion, histologic tumor type, budding formation, and lymphatic invasion were statistically significant to LN status in univariate analysis; however, only 2 factors--lymphatic invasion and budding formation at the invasive front-were independent predictors of LN metastasis in ECC.

CONCLUSIONS

LYVE-1 immunohistochemistry appeared to be a useful method for detecting lymphatics invaded by cancer cells, and detailed examination of the submucosa around the tumor may be important for predicting LN metastasis. When lymphatic invasion and budding formation are observed histopathologically in patients with ECC, additional therapy, such as adjuvant chemotherapy or a curative resection of the regional LN, may be required.

The role of the lymphatic system and its specific growth factor, vascular endothelial growth factor C, for lymphogenic metastasis in prostate cancer

OBJECTIVE

To compare prostate carcinoma, with and with no lymph node metastasis, to benign prostatic hyperplasia (BPH) tissue for lymphatic vessel density (LVD) and the expression of the lymph-endothelial specific growth factor, vascular endothelial growth factor C (VEGF-C), to determine their role in lymphogenic metastasis.

PATIENTS, MATERIALS AND METHODS

Lymphatic vessels were stained using lymphatic vessel endothelial hyaluronan receptor 1 and assessed in standard areas. The expression of VEGF-C was assessed by the number of positive epithelial cells. The data were compared with the clinical staging.

RESULTS

The lowest LVD was found in tumorous areas as opposed to periphery and nontumorous tissue (P = 0.007; P < 0.001). The highest LVD was in BPH tissue (P < 0.001). There was no correlation with clinical staging. There was more VEGF-C staining in pN1 than in pN0 and in BPH specimens (P = 0.002).

CONCLUSION

LVD is not a prognostic variable for the process of lymphogenic metastasis in prostate cancer. VEGF-C is up-regulated in prostate cancer and its correlation with lymph node status suggests a role for the development of lymph node metastasis, e.g. via an increased permeability of lymphatic vessels.

Targeting of pericytes diminishes neovascularization and lymphangiogenesis in prostate cancer

BACKGROUND

The walls of capillaries in prostate cancer are composed of endothelial cells, and pericytes. NG2 is a transmembrane proteoglycan on nascent pericytes with a functional role in neovascularization.

METHODS

The anti-angiogenic effect of hydron pellets containing NG2 neutralizing antibody was quantified in intracorneal PC-3 and LNCaP xenografts. TRAMP and TRAMP-C1 tumors grafted in NG2 knockout mice represented intrinsic pericyte targeting. TRAMP and TRAMP-C1 grafts were analyzed with confocal microscope for microvascular density (MVD) and lymphatic vascular density (LVD).

RESULTS

NG2 neutralizing antibody decreased corneal neovascularization in PC3 (P<0.0001), and LNCaP (P=0.0079) xenografts. Mean MVD in TRAMP and TRAMP-C1 tumors in NG2 knockout mice were 71% (P=0.0006) and 63% (P=0.0011) lower than wild type controls, respectively. Mean LVD in TRAMP and TRAMP-C1 tumors in NG2 knockout mice were 73% (P=0.0003) and 84% (P<0.0001) lower than wild type controls, respectively.

CONCLUSIONS

Targeting of pericyte-NG2 decreases neovascularization and lymphangiogenesis in prostate cancer significantly.