Aim: To investigate adjuvant chemotherapy, p53 and carcinoembryonic antigen (CEA) expression and prognosis after D2 gastrectomy for stage II/III gastric adenocarcinoma.
Methods: A total of 286 patients with stage II or III gastric adenocarcinoma who underwent D2 radical gastrectomy between May 2007 and December 2010 were enrolled into this study. One hundred and sixty-nine of these patients received surgery plus adjuvant chemotherapy, and 117 patients received surgery alone. Tumor expression of p53 and CEA proteins in all patients was evaluated immunohistochemically and correlated with clinicopathological parameters. The Kaplan-Meier curves for overall survival (OS) and disease-free survival (DFS) with log-rank testing were used to compare the survival difference. A Cox proportional hazard regression model was used for multivariate analysis.
Results: Patients with adjuvant chemotherapy had a significantly better median OS (50.87 mo vs 30.73 mo, P = 0.000) and median DFS (36.30 mo vs 25.60 mo, P = 0.001) than patients with surgery alone in the entire cohort. Consistent results with the entire cohort were found in stage II (P = 0.006 and P = 0.047), stage III (P = 0.005 and P = 0.030), and stage IIIB/IIIC patients (P = 0.000 and P = 0.001). The median OS and DFS advantages were confirmed by multivariate analysis (P = 0.000 and P = 0.008) and maintained when the analyses were restricted to fluoropyrimidine monotherapy (P = 0.003 and P = 0.001) and fluoropyrimidine plus platinum regimen (P = 0.001 and P = 0.007), however, not the fluoropyrimidine plus taxane (P = 0.198 and P = 0.777) or platinum plus taxane (P = 0.666 and P = 0.687) regimens. Median OS and median DFS did not differ significantly between the patients with p53(+) and p53(-) tumors (P = 0.608 and P = 0.064), or between patients with CEA(+) and CEA(-) tumors (P = 0.052 and P = 0.989), which were maintained when the analyses were restricted to surgery alone (p53: P = 0.864 and P = 0.431; CEA: P = 0.142 and P = 0.948), adjuvant chemotherapy (p53: P = 0.802 and P = 0.091; CEA: P = 0.223 and P = 0.946) and even different chemotherapy regimens (P > 0.05).
Conclusion: Patients after D2 gastrectomy for stage II/III gastric adenocarcinoma had significantly better survival after fluoropyrimidine monotherapy and fluoropyrimidine plus platinum. p53 and CEA were not prognostic.
Keywords: Adjuvant chemotherapy; Carcinoembryonic antigen; Gastric adenocarcinoma; Immunohistochemistry; p53.