title: Different significance between intratumoral and peritumoral lymphatic vessel density in gastric cancer: a retrospective study of 123 cases.
abstract: BACKGROUND
  Patients with gastric cancer in China have worse outcome and poorer prognosis. Tumor-induced lymphangiogenesis plays a crucial role in metastasis and tumor progression. The intratumoral and peritumoral lymphatics were supposed to have different biological effects. Three major growth factors, vascular endothelial growth factor- (VEGF)-A, VEGF-C and VEGF-D, are involved in the activation process via their receptors (VEGFRs). The purpose of current study is to investigate the significant difference between intratumoral and peritumoral lymphatic vessel density (LVD) in gastric cancer and their correlations with lymphangiogenetic growth factors.
  
  
  METHODS
  Intratumoral LVD (I-LVD) and peritumoral LVD (P-LVD) of 123 patients with primary gastric cancer were assessed after staining with D2-40, and confirmed by double staining with D2-40/CD34. Proliferative activity of lymphatics endothelium was evaluated by double staining with D2-40/Ki-67. The associations were analyzed between I-LVD/P-LVD and the expression level of VEGF-A, VEGF-C, VEGF-D and the receptor VEGFR-3, which was measured by immunohistochemistry (IHC). The correlations of I-LVD and P-LVD with patient prognosis were also valued.
  
  
  RESULTS
  (1) The peritumoral lymphatics (PTLs) were relatively enlarged with dilated lumen compared with the intratumoral lymphatics (ITLs). Increased P-LVD was significantly higher than I-LVD (P < 0.05). (2) P-LVD was found significantly associated with lymph node metastasis (LNM) (P < 0.001), lymphatic vessel invasion (LVI) (P < 0.001), VEGF-C (P = 0.003), VEGF-D expression level (P = 0.005) and VEGFR-3 expression level (P < 0.001) in peritumoral tissues, despite no significant association was found between above variants with I-LVD. However, increased I-LVD was demonstrated to be associated with decreased tumor volume (P < 0.001). Neither I-LVD nor P-LVD was correlated with VEGF-A expression (P > 0.05). (3) Proliferative activity of lymphatics endothelium was observed in PTLs, in spite of ITLs. (4) Increased P-LVD, but not I-LVD, was indicated to be an independent risk factor for lymph node metastasis by multivariate logistic regression analysis, and was related to worse disease-free survival and overall survival.
  
  
  CONCLUSIONS
  PTLs play roles in gastric cancer progression. Increased P-LVD, but not I-LVD, was significantly associated with VEGF-C/-D/VEGFR-3 system, and could be an independent risk factor for lymph node metastasis and a prognostic factor in gastric cancer.
authors.affiliation: Department of Gastroenternology, Institute of Digestive Disease, Tongji Hospital affiliated to Tongji University, Shanghai 200065, PR China. xlwang2006@163.com
authors.forename: Xiao-Lei
authors.initials: XL
authors.lastname: Wang
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Fang
authors.forename: Ru-Yong
authors.initials: RY
authors.lastname: Tang
authors.forename: Xi-Mei
authors.initials: XM
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D018952:Antigens, CD34 / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D049109:Cell Proliferation; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D004729:Endothelium, Lymphatic / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D019394:Ki-67 Antigen / Q000032:analysis; D016015:Logistic Models; D042583:Lymphangiogenesis; D008207:Lymphatic Metastasis; D042601:Lymphatic Vessels / Q000737:chemistry / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016017:Odds Ratio; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000737:chemistry / Q000401:mortality / Q000473:pathology* / Q000556:secondary; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis; D042582:Vascular Endothelial Growth Factor C / Q000032:analysis; D042643:Vascular Endothelial Growth Factor D / Q000032:analysis; D040321:Vascular Endothelial Growth Factor Receptor-3 / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D018952:Antigens, CD34; D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; C467484:VEGFA protein, human; C467486:VEGFC protein, human; D042461:Vascular Endothelial Growth Factor A; D042582:Vascular Endothelial Growth Factor C; D042643:Vascular Endothelial Growth Factor D; C500987:monoclonal antibody D2-40; D040321:Vascular Endothelial Growth Factor Receptor-3