Podoplanin expression in advanced-stage gastric carcinoma and prognostic value of lymphatic microvessel density.

In gastric cancer, lymph node metastasis is a major prognostic factor. Tumor lymphangiogenesis promotes metastasis in experimental models, but in human tumors data about the presence and clinical significance of lymphatic vessels in the tumor area are controversial. We investigated 70 patients with advanced-stage gastric carcinoma and the pathological examination showed 40 cases with intestinal subtype and 30 cases with diffuse subtype. Forty three from 70 cases had regional lymph node metastasis. Additional slides were stained with an antibody against podoplanin, and lymphatic microvessel density (LMVD) was evaluated in the tumoral and peritumoral areas. Lymphatic vessels were identified in tumor area in all cases and LMVD was higher in the peritumoral than in the tumor area. Podoplanin-positive vessels in tumor area were usually small, with narrow lumen. A significant correlation was found between LMVD and stage of the tumor (p<0.002) and lymph node metastasis (p<0.031), but not with the pathological subtype and grade of the tumor. We found tumor cells in the lumen of lymphatic vessels in 11 cases, whereas tumor cells expressing podoplanin were found in 4 cases of less differentiated diffuse subtype gastric carcinoma. In conclusion, our results suggest that LMVD predicts tumor stage and lymph node metastasis, and podoplanin-positive tumor cells select a subgroup of tumors with high potential of invasion and metastasis.

Immunohistochemical expression of vascular endothelial growth factor (VEGF) in intestinal type gastric carcinoma.

BACKGROUND: Gastric cancer still represents a difficult problem in the field of oncology, in terms of morbidity and mortality. The local progression and systemic spread is significantly influenced by tumor angiogenesis and lymphangiogenesis. In spite of many studies on the topic, data about the significance of growth factors in gastric cancer is controversial. AIM: to investigate the immunohistochemical expression of VEGF and to evaluate the relationships with the tumors stage and grade. MATERIAL AND METHODS: The immunohistochemical expression of VEGF was investigated on 80 patients with intestinal type gastric carcinoma. Specimens were fixed in buffer formalin, embedded in paraffin, and sections were stained with Hematoxylin-Eosin and immunohistochemistry was performed for VEGF (clone VG-1). Evaluation was performed using the VEGF score, based on the intensity of reaction and percent of positive cells. RESULTS: The reaction for VEGF was positive in 52 from 80 cases (70%). The final product of reaction was found in the cytoplasm of tumor cells, with granular pattern. Positive reaction was also found in eight from 28 cases with associated intestinal metaplasia, and in six from nine cases with gastric dysplasia. In the adjacent apparently normal mucosa, the reaction was positive in hyperplastic gastric pits and parietal cells. A strong correlation was found between VEGF expression and lymph node status and grade of the primary, but not with the stage of the tumor. CONCLUSIONS: The investigation of the immunohistochemical expression of VEGF in the intestinal type of gastric carcinoma showed positive reaction in 70% of the cases. It was demonstrated the expression of VEGF in intestinal metaplasia and gastric dysplasia, which could signify an early angiogenic switch during tumorigenesis.