Prognostic significance of biological apoptosis factors in gastric cancer

PURPOSE

Gastric cancer is a biologically heterogeneous disease containing many genetic and epigenetic alterations. In our study, the expression status of apoptosis-inducing p53 and apoptosis-inhibiting Bcl-2 in gastric cancer and their relation with prognosis, if any, was investigated.

METHODS

Patients that were being followed in our clinic and had histopathologically diagnosed gastric adenocarcinoma were included in this study. The p53 and bcl-2 expressions were investigated immunohistochemically and patients were grouped according to p53 and Bcl-2 expression as follows: group A: both p53 and Bcl-2 negative; group B: p53 positive and Bcl-2 negative; group C: p53 negative and Bcl-2 positive; group D: both p53 and Bcl-2 positive.

RESULTS

In 19 (51.4%) patients positive immunostaining with p53 was observed, while negative in 18 (48.6%). A significant relationship between the metastatic ability of the tumor and p53 expression was determined (p=0.004). In 78.6% of the metastatic tumors no p53 expression was observed, while in 69.6% of the non-metastatic tumors p53 expression was positive. No significant relationship was detected between p53 expression and survival. Positive immunostaining with Bcl-2 was observed in 9 (16.7%) patients, and negative in 45 (83.3%). No significant relationship was determined between the Bcl-2 expression and the depth of invasion, dissemination to lymph nodes and metastatic ability of the tumor. A borderline statistically significant relationship was determined between the Bcl-2 expression and survival (p=0.051). Group B patients showed a statistically significant survival difference compared with the other groups (p=0.022).

CONCLUSION

The results of this study suggest that concurrent evaluation of p53 and Bcl-2 in patients with gastric adenocarcinoma may have prognostic importance.

The predictive role of Bcl-2 expression in operable locally advanced or metastatic gastric carcinoma

PURPOSE

Gastric carcinoma is an aggressive disease with different epidemiologic and clinical profiles. Combination chemotherapy containing docetaxel, cisplatin and 5-fluorouracil/5-FU (DCF) is a frequently used regimen in metastatic gastric cancer. We studied the role of B-cell lymphoma 2 (Bcl-2) expression in predicting the response to DCF combination chemotherapy in metastatic gastric carcinoma.

METHODS

This study included patients with pathologically confirmed locally advanced, surgically inoperable gastric carcinoma, or with metastatic disease. For immunohistochemical staining of Bcl-2 oncoprotein, lyophilized mouse monoclonal antibody (clone100/D5, 1:50, Thermo Scientific, Fremont, ABD) was used. Bcl-2 expression was evaluated with respect to the nuclear and cytoplasmic staining of the cells. Staining > 10% was accepted as positive and ≤ 10% as negative.

RESULTS

Bcl-2 expression was positive in 5 (23.8%) patients and negative in 16 (76.2%), while partial response was achieved in 12 (57%) patients. No complete response was seen in any patient. The effect of positive Bcl-2 expression on survival was statistically significant by log-rank test (p=0.035).

CONCLUSION

The patient group that expressed Bcl-2 survived longer confirming that Bcl-2 expression is a good prognostic factor in advanced-stage patients. We believe that Bcl-2 expression has an additional contribution in predicting response to this chemotherapy combination.