Is retrieval of at least 15 lymph nodes sufficient recommendation in early gastric cancer?

PURPOSE: The evaluation and extent of lymph node (LN) retrieval is clinically relevant for staging because lymphatic invasion is the most common mechanism leading to up-staging of carcinoma. However, the optimal number of LN retrievals for early gastric cancer (EGC) is unclear. With the aim of clarification, we analyzed our database to investigate the optimal number of retrieved LNs in EGC. METHODS: Three hundred twenty-six gastric cancer patients who underwent curative gastrectomy with D2 LN dissection at Ewha Womans University Hospital (Dongdaemun and Mokdong) were analyzed according to sex, age, tumor location, size of tumor, macroscopic type, histological classification, depth of invasion, LNs metastasis, TNM stage and type of surgery. RESULTS: In LN negative cases, patients with 15-25 retrieved LNs had a 5- and 10-year survival rate of 88% and 54%, respectively, whereas retrieval of ≥26 LNs was associated with 5- and 10-year survival rate of 90% and 75%, respectively (P = 0.105). In LN positive cases, the 5- and 10-year survival rate was 50% and 30% for the 15-25 group, and 77% and 67% for the ≥26 group, respectively (P = 0.044). CONCLUSION: LN metastasis is an independent factor of survival and the number of retrieved LNs significantly relate to the long-term survival benefit in node metastatic EGC. Also, our data suggest that the retrieval of at least 15 LNs may not be sufficient to warrant recommendation for more curative surgery, and that qualified LN dissection should be considered if LN metastasis is in doubt, even in EGC.