Extent of spontaneous apoptosis in gastric cancer: relation to proliferative index, p53 expression, CD 34 expression...

Gastric cancer, characterized by poor prognosis, remains a global health problem. Thus, it is important to describe the biological factors which can affect the prognosis in this disorder. The aim of our study was the determination of the relationship between apoptotic index (AI) and other clinicopathological features (Ki67 labeling index = Ki-67 LI, neovascularity defined as CD-34 immunoreactivity - intratumoral microvessel density = IMVD, p53 immunopositivity, grade of malignancy, histological type, depth of tumour invasion, lymph node status) in 49 cases of gastric carcinoma. Recognition of apoptotic cells was performed applying the terminal deoxynucleotydil transferase mediated dUTP-digoxigenin nick end labeling technique (TUNEL). Among the tumours, 30 were intestinal type and 19 were diffuse type, including 17 cases of well and moderately differentiated tumours (G1 and G2) and 32 poorly differentiated tumours (G3). Apoptotic index was determined in all the examined tumours, and the mean value of AI was 5.8% +/- 4.7%. We found a significant relationship between AI, grade of malignancy and Ki-67 LI. Significantly higher AI -8.1% +/- 5.7% was observed in G1-G2 tumours in comparison to 4.7 +/- 3.8% (p<0.05) in G3 tumours. In tumours with high proliferative potential (above mean value of Ki-67 LI -29.77% +/- 24.9%) we observed higher apoptotic index, mean value 7.9% +/- 5.7%, and in tumours with low proliferation (Ki-67 LI below 29%) mean AI was 4.4% +/- 3.7% (p<0.05). The p53 positive immunoreactivity was found in 30 out of 49 cases (mean AI = 6.75% +/- 4.8%). No apparent correlation between AI, histopathological type of gastric cancer, lymph node status and p-53 and CD-34 immunoreactivity was found.