The role of superextended lymphadenectomy (D4) in gastric cancer

AIM: The outcome of surgery in gastric cancer differs in Japan and Western countries and the extension of lymphadenectomy may play a crucial role in survival. In Japan the choice of performing extended (D2) and superextended (D4) lymphadenectomies is based on retrospective studies, and a prospective randomized study comparing D2 and D4 is still in course. In Western countries the randomized trials comparing D1 and D2 could not provide definite indications, D2 is not yet performed as a routine procedure and D4 is accepted only by few surgeons. We report our experience and discuss indications and results. METHODS: Since January 2000 through December 2002 we performed 27 superextended lymphadenectomies for the radical treatment of advanced gastric cancer. Early gastric cancers and patients over 80 years of age received conventional D2 gastrectomies. Selection of patients for D4 was made after laparotomy, when intraoperative peritoneal lavage cytology could rule out the presence of malignant cells, while D2 was done in case of peritoneal micrometastases. RESULTS: Every patients had 39.5 nodes removed on average (range 17-94), and micrometastases in tier 16 were found in 7 cases (26%). Early post-operative surgical morbidity was 18% (5 patients) and mortality was 3.7% (1 patient). As much as 30% of patients complained of diarrhea as a late complication. The follow up could demonstrate a 3 year overall actuarial survival of 76%. Actuarial survival was 100% for N- and 70% for N+. A remarkable data was that 4 out of 5 patients who died from recurrence in the follow-up, were N4+. Actuarial survival at 3 years for N4+ patients was 34%, and the difference in survival between N4+ and other N+ was statistically significant (p<0.05). CONCLUSIONS: Superextended lymphadenectomy in gastric cancer is feasible with postoperative morbidity and mortality rates not exceeding the rates of other lymphadenectomies. Actuarial survival at 3 years with D4 was better than in previous personal experience with D2, although the patients who underwent D4 were selected by intraperitoneal lavage cytology, while D2 patients had not been selected. The prognosis for N4- patients was better than for N4+ with micrometastases in tier 16. The presence of N4 micrometastases worsens the prognosis, but it is still uncertain whether D4 does improve survival: it is undoubtedly a new means of more accurate staging in gastric cancer surgery. The newer TNM classification regards the number of nodes removed as an indicator of radicality. Every surgeon should consider that superextended lymphadenectomies could comply with R0 radicality, and perform it within the ranges of low morbidity and mortality, until randomized trials with definitive results are available.