Expression of P53 Protein and Dna Flow Cytometry in Gastric Adenocarcinoma: Implications in Patients Treated with Adjuvant Etoposide, Adriamycin and Cisplatin

Abstract

We evaluated the prognostic value of p53 protein, DNA content and S-phase fraction in patients with adenocarcinoma of the stomach or the gastroesophageal junction treated with adjuvant etoposide, doxorubicin and cisplatin. Thirty-five consecutive patients with stage II or III gastric or gastroesophageal junction adenocarcinoma treated with at least two cycles of adjuvant etoposide, doxorubicin and cisplatin after curative gastric resection were included. The expression of p53 protein was determined by immunohistochemistry and DNA content by flow cytometry. The presence of p53 expression and DNA content was compared with clinicopathological features. Median age was 54 years (range, 31-71). P53 expression was detected in 42.9% (15 of 35) of gastric cancer tissues of the patients. Aneuploidy was observed in 31.4% of patients, and S-phase fraction was more than 10% in 22.9%. P53 immunoreactivity (33.3% vs 47.8%) was more common in advanced disease. There was no association among p53 immunoreactivity, DNA content and S-phase fraction. We also found no significant relationship between p53 immunoreactivity, DNA content, S-phase fraction or other clinicopathological parameters. In univariate analysis, the involvement of lymph nodes was a significant predictor of a poor outcome (P = 0.001). Also, p53-positive patients had a poor survival close to the level of significance (P = 0.051). Likewise, p53 immunoreactivity (P = 0.0071), in addition to lymph node involvement (P = 0.0016), were the independent prognostic factors in multivariate analysis. This trial supports the results of previous reports that p53 immunoreactivity is a prognostic factor for patients with adenocarcinoma of stomach or gastroesophageal junction treated with adjuvant chemotherapy.