D2 lymphadenectomy with para-aortic sampling improves lymph node staging for gastric cancer

Abstract

BACKGROUND: An important aspect dealing with gastric cancer is the role of lymphadenectomy in gastric cancer staging. AIM: To verify if lymphadenectomy with stations separation increases the number of dissected lymph nodes and establish comparison between TNM 2002 and JGCA 1998 evaluating lymph nodal status (N). METHODS: This is a retrospective analysis of the patients that underwent curative gastrectomy and D2 dissections for adenocarcinoma between 2004 and 2006. Between January of 2004 and June of 2005 (group 1), lymphadenectomy was performed en-bloc with gastrectomy and only TNM system was used. After June of 2005 (group 2), the surgeon himself dissected lymph nodal stations, allowing use of TNM and JGCA systems. Studied aspects were age, Borrmann classification, histological grade, venous or lymphatic invasion, depth of invasion, peritoneal cytology and type of gastrectomy. End points were number of dissected lymph nodes, number of positive lymph nodes and agreement between staging systems. Chi-square test and T-test were used for statistical analysis. RESULTS: One hundred forty-five gastrectomies were performed, 76 in group 1 and 69 in group 2. In group 1, mean age was of 61 years and 59 years in group 2 (P=0,12). Eighty per cent of tumors were advanced in both groups. Venous or lymphatic invasion and positive peritoneal cytology were more frequent in group 1, 65.6% vs 35,3% (P= 0,001) e 13.9% vs 3.1% (P=0,03), respectively. Borrmann classification, histological grade, Lauren classification and type of gastrectomy were not different between the groups. In group 1, mean number of lymph nodes was 32,7 and 37,35 in group 2 (P= 0,09). Rates of positive lymph nodes in groups 1 and 2 were 72.2% and 53%, respectively (P= 0,02). Migration analysis of lymph node status (N) realized only in group 2 (69 patients) showed agreement between TNM and JGCA in 50 patients (72,5%). Using JGCA system, modification in 19 patients occurred (27,5%), with upstaging in 13 (18,8%) and downstaging in six (8,7%). CONCLUSION: In this study, a tendency of increase in number of lymph nodes was verified when the surgeon himself dissected lymph nodal stations. JGCA system modified the lymph nodal staging in comparison to TNM system in 30% of all cases.