Introduction: In western countries, the benefit of the Japanese extended D3 lymph node dissection in gastric cancer patients who have been operated on in curative intent has not been proven and higher rates of side effects are expected. The present matched-pair study retrospectively compared the new D3 method (1995-1999) with the historic D2 dissection (1982-1995).
Methods: Two 1:1 matched-pair populations were created: (1) regarding intra- and postoperative course, morbidity and mortality, 2 x 67 patients stratified to "age", "gender", "surgical procedure", "splenectomy" and "extended resections"; and (2) regarding early oncologic outcome, 2 x 32 patients additionally stratified to "UICC-stage" and "Laurén-classification". The D3 dissection was performed according to the Japanese method without routine pancreaticosplenectomy.
Results: D3 dissection harvested significantly (P = 0.004) more lymph nodes per patient: 56.4 vs. 46.8. Postoperative mortality was 3% (n = 2) in both groups, the overall complication rate of 30% (D3) vs. 25% (D2) was equivalent (P = 0.678) and the rate of surgical complications was identical (21%). Non-surgical complications of 21% after D3 dissection were not significantly elevated (vs. 10%; P = 0.143). Operative time [289 min (D3) vs. 218 min (D2); P = 0.0001] and postoperative stay [17.4 days (D3) vs. 14.5 days (D2); P = 0.003] were significantly longer after the extended procedure. The were no statistically significant differences between 2-year overall survival, locoregional-, distant- and overall recurrence-free survival.
Conclusions: Compared to the D2 method, D3 dissection is feasible without disadvantages in the patients. However, D3 dissection cannot routinely be recommended because--possibly due to the short follow-up period and the small number of patients so far observed--an oncologic benefit could not be shown.