Learning Curve for D2 Lymphadenectomy in Gastric Cancer

Background. D2 lymphadenectomy is a demanding technique which is associated with high morbidity in the West. We report our experience with D2 lymphadenectomy after a training period in Japan. Methods. Prospective, descriptive study in 133 consecutive patients undergoing radical gastrectomy for gastric adenocarcinoma from 2005 to 2011. We analysed the number of lymph nodes removed, observed morbidity/mortality compared with the predictions of POSSUM and O-POSSUM, survival, and disease-free interval for patients with D1 and D2 lymphadenectomy. Results. The morbidity rate in patients with D1 lymphadenectomy was 59.4%. For D2 it was 47.7%. The mortality rate in patients with D1 was 6.7%. In the D2 group it was 6.8%. Median survival was 42.9 months in D1 and 55 months in D2. The disease-free interval was 49 months for D1 and 58 months for D2. Conclusion. The learning curve for D2 lymphadenectomy presents acceptable rates of morbidity and mortality, providing that the technique is learnt at a center with extensive experience. 1. Introduction Deciding on the type of lymphadenectomy to perform in gastric cancer is a controversial matter. Groups in Asia contend that lymph node involvement in gastric cancer in the absence of distant metastases is a localized disease and that curative surgical treatment should be performed. They advocate D2 lymphadenectomy on the grounds that it improves staging and locoregional control of disease. In the West, lymph node involvement tends to be considered a systemic disease with low likelihood of cure. In the last two decades, the literature has shown that the results of gastric cancer surgery are far better in Asia, where D2 lymphadenectomy is considered the standard five-year survival rates in Japan are around 50–60% [1], compared with the figures of 10–30% reported in the West [2]. D2 lymphadenectomy is a demanding technique, especially in patients with higher body mass index, as is generally the case in the West. Patients in our setting also tend to be older and more likely to present comorbidity. As a result, D1 lymphadenectomy is considered the standard in the West, although certain groups now advocate D2 lymphadenectomy [3]. The evidence available to compare D1 and D2 lymphadenectomy is limited and has serious shortcomings. Most of the literature consists of retrospective cohort studies with substantial bias; only two methodologically sound, prospective, randomized, and multicenter studies have been published, but both present serious problems regarding treatment selection. Studies performed in Japan are retrospective and