Prognostic Value Of Early Postoperative Tumor Marker Responses In N3 Stage Gastric Cancer

Objective:The clinical significance of tumor markers after radical gastrectomy has not been well characterized.The purpose of this study was to evaluate the prognostic value of early postoperative tumor marker normalization in N3 stage gastric cancer patients.Method:From January 2004 to October 2011,a total of 259 N3 stage gastric cancer(GC)patients with preoperatively elevated carcinoembryonic antigen(CEA,>5 ng/mL)or carbohydrate antigen(CA19-9,>37U/mL)levels who underwent radical gastrectomy in the Qilu Hospital of Shandong University were analyzed retrospectively.Early postoperative tumor marker response was considered as a normalization of CEA or CA19-9 levels as determined at 4 weeks after surgery.The median disease-free survival(DFS)and median overall survival(OS)were analyzed.Results:N3 stage GC patients were divided into N3a(n=157)and N3b(n=102)groups according to the 8th TNM stage system.Early tumor marker response was identified in 96 of 157 N3a patients(61.15%)and 57 of 102 N3b patients(55.88%).In N3 stage GC patients with a tumor marker response versus those lacking a tumor marker response significant increases were obtained in both median DFS(25.2 vs 12.5 months,P<0.001)and median OS(32.5 vs 18.5 months,P<0.001).N3b patients with a tumor marker response showed more favorable outcomes than N3a patients lacking a tumor marker response with significant differences observed for both median DFS(19.2 vs 13.6 months,P=0.019)and median OS(25.8 vs 19.0 months,P=0.013).Univariate analysis showed that several factors were risk factors for median DFS including tumor marker response(P<0.001),N3 sub-classification(P=0·016),depth of invasion(P=0.001),metastatic lymph node rate(P<0.001),tumor location(P=0.025),type of surgery(P=0.002)and lymph vessel invasion(P=0.047).Meanwhile,the risk factors for median OS were tumor marker response(P<0.001),N3 sub-classification(P=0.022),depth of invasion(P=0.001),metastatic lymph node rate(P<0.001),tumor size(P=0.011),tumor location(P=0.034),type of surgery(P=0.004).Multivariate analysis revealed that early tumor marker response was an independent factor of median DFS and median OS in N3 stage GC,as well as for depth of invasion and metastatic lymph node rate(all P<0.05).Conclusion:Early postoperative CEA or CA19-9 normalization serves as a strong prognostic indicator in N3 stage gastric cancer.Both N3a and N3b patients with increased early postoperative tumor marker levels showed poor outcomes.Such patients should receive aggressive follow-up procedures.