Prognostic value of bcl-2 expression in gastric cancer

The bcl-2 protein has been shown to prevent apoptosis or programmed cell death and may play an important role for the regulation of tumour growth. Although expression of bcl-2 has been shown to correlate with a better prognosis in breast and lung carcinomas, information concerning the prognostic role of bcl-2 in gastric cancer on a considerable number of tumours is still lacking. In the present study, therefore, the expression and prognostic role of the bcl-2 protein was investigated immunohistochemically in 413 curatively resected gastric carcinomas. Bcl-2 expression was detected in 11.4% (n = 47) of the tumours and was significantly associated with the tumour classification according to Lauren (P < 0.001), 95% of the bcl-2-positive tumours being intestinal type, whereas all diffuse type or signet ring cell carcinomas were bcl-2-negative. No correlation was found between bcl-2 expression and the prognostic parameters depth of invasion (pT category), blood vessel and lymphatic vessel invasion. However, well and moderately differentiated tumours were more often bcl-2-positive than poorly differentiated tumours (P < 0.001), and lymph node negative tumours were more often bcl-2-positive than nodal positive tumours (P < 0.006). Concerning survival, there were no statistically significant differences between patients with bcl-2-positive tumours and patients with bcl-2-negative tumours. According to our results on 413 gastric carcinomas, in contrast to breast and lung cancer, bcl-2 expression has no prognostic impact in gastric cancer.