Intratumoral but not peritumoral lymphatic vessel density measured by D2-40 expression predicts poor outcome in gastric cancer--ROC curve analysis to find cut-off point.

BACKGROUND: Neolymphangiogenesis, a process of lymphatic vessel development in neoplastic tissue, may be a key event in the transmission of cancer cells into lymph nodes. The current study examined the relationship between lymphatic vessel density (LVD) measured by podoplanin (D2-40) expression, clinicopathological parameters and patient survival in gastric cancer.

MATERIALS AND METHODS: D2-40 expression was examined by immunohistochemistry in formalin-fixed paraffin-embedded tissue specimens obtained from 60 patients with gastric cancer. D2-40 immunoreactivity was analyzed in intratumoral and peritumoral compartments of tumors and correlated with tumor grade, type in Lauren's classification, lymph node status, distant metastasis, presence of ulceration, inflammatory infiltration, angio-invasion, lymphangio-invasion and patient survival using a Receiver Operating Characteristic (ROC) curve analysis to find cut-off points that enabled fair decision making in survival analysis.

RESULTS: The mean values of intratumoral and peritumoral LVD were 6.63 and 11.25, respectively. Enhanced intratumoral LVD measured by D2-40 immunoexpression was correlated with the presence of lymph node metastases (p=0.04). Our study revealed a statistically significant correlation between intratumoral LVD measured by D2-40 expression and survival of patients with gastric cancer: an intratumoral LVD higher than 4.68 is significantly correlated with unfavorable prognosis, with a probability of death of approximately 80%. No significant relationship was identified between peritumoral LVD, lymph node status and survival in patients with gastric cancer.

CONCLUSION: A high intratumoral LVD measured by D2-40 expression in specimens from primary tumors is strongly associated with lymph node metastasis and predicts worse clinical outcome. Increased intratumoral D2-40 immunoreactivity is a putative predictor of aggressive gastric cancer behavior.