P-0068 The 7th Edition of the TNM Classification for Gastric Cancer and a Proposal of a New Classification for D2 Gastrectomy

Abstract

IntroductionStudies on Asian, US, and German patients have moved some criticisms on the validity of the 7th edition of the AJCC classification to discriminate outcome of gastric cancer stages. We investigated the effect of this AJCC classification in a high-quality surgical populations of patients receiving D2 lymphadenectomy. MethodsFrom the prospective database at San Salvatore Hospital, Pesaro, we identified 515 patients with gastroesophageal junction (GEJ, Siewert II and III) or stomach adenocarcinoma who underwent gastrectomy with curative intent from 1998 to 2010. Lymphadenectomy extended to the 3rd level 12p/b nodes (D2/D3) was performed in all patients. Overall survival (OS) probabilities, calculated from the date of surgery to the date of death, from any cause, were estimated using the Kaplan-Meier method and compared using the log-rank test. Results58% of patients were male, median age was 73 years (range 36-96); 75 patients (15%) had GEJ tumors. According to the Lauren's classification, 313 (61%) patients had intestinal type tumors, 159 (31%) diffuse and 43 (8%) mixed type tumors. Median number of examined lymph nodes was 32 (range, 1-89), and only 8.9% of patients had less than 15 examined lymph nodes; 94 patients received adjuvant chemotherapy and 3 patients chemoradiotherapy. As shown in the table, the 7th edition of AJCC classification did not differentiate outcome significantly between stages IA and IB, IIA and IIB, IIB and IIIA, IIIC and IV. On the basis of survival data, we proposed a revised staging system (Pesaro Staging System, PSS), which performs better than the 7th edition of AJCC classification in terms of survival differences between stages. ConclusionThis study confirms once again that the 7th edition of the AJCC classification does not discriminate adequately the outcome from stage to stage. In a European population of patients undergoing gastrectomy plus at least D2 lymphadenectomy, the revised PSS better defines patient prognosis. [Display omitted]