PURPOSE: This study evaluated the adequacies of lymph node (LN) dissection according to the second version (determined by tumor location) or third/fourth version (determined by surgery extent) of the Japanese gastric cancer treatment guidelines.METHODS: Prospectively collected data of 3,948 gastric cancer patients who underwent gastrectomy were analyzed. The prevalence of LN metastasis and 5-year survival were analyzed according to tumor invasion depth and tumor location. In early gastric cancer (EGC), the frequency of LNs were evaluated. In advanced gastric cancer (AGC), the frequency of LN metastasis and the 5-year survival rate of patients with positive LN were evaluated.RESULTS: For lower-third EGC, the positive rates for the #1 and #4sb were 0.93% and 0%. For upper-third EGC, the positive rates for #4d, #5, #6, and #11p were 0.3%, 0%, 0.76%, and 1.22%. For lower-third AGC, the positive rates for #4sb and #14v were 2.48% and 7.64%, and the 5-year survival rates were 69.2% and 12.5%, respectively. For upper-third AGC, the positive rates for #5, #6, and #12a were 2.33%, 2.57%, and 2.03%, and the 5-year survival rates were 21.8%, 64.3%, and 0%, respectively.CONCLUSION: According to our analysis, in EGC, LN dissection in second edition seems more suitable, however LN dissection in #11p would be mandatory in upper third EGC. In AGC, LN dissection in third/fourth edition seems more suitable in terms of frequency of LN metastasis and survival rate.
Asian Continental Ancestry Group ; Gastrectomy ; Humans ; Lymph Node Excision ; Lymph Nodes ; Neoplasm Metastasis ; Prevalence ; Prospective Studies ; Stomach Neoplasms ; Survival Rate

PURPOSE: Gastric cancer with lymph node metastasis (LNM) more than 15 (N3b) was defined as stage IV until the 6th AJCC system. However, it has been reclassified as a localized disease (stage IIb or III) since the 7th system. The aim of this study is to demonstrate that the survival of N3b is comparable to cytology-only positive (CY1-only) stage IV and to propose a new TNM system interpreting N3b as an eligibility criterion for receiving more intensive chemotherapy regimens. MATERIALS AND METHODS: 1,430 patients who underwent gastric cancer surgery at Seoul National University Hospital from 2007 to 2012 were retrospectively analyzed. The 5-year survival rate (5YSR) and 3-year recurrence-free survival (RFS) were evaluated according to the 7th and 8th systems, as well as a new categorization based on N-classification; N0-2 (LNM<7), N3a (LNM 7–15), or N3b (LNM>15). RESULTS: The survival of N3b is comparable to that of CY1-only stage IV (log rank test, P=0.671) and is distinct from that of grossly stage IV (log rank test, P<0.001). The survival of the remaining stage IIIc (T4bN3a) was comparable to those of N3b and CY1-only stage IV. Most N3b patients had significantly shorter 3-year RFS and mean RFS than those with IIb–IIIc, as if N3b itself was a higher TNM stage. CONCLUSIONS: In terms of survival, T4bN3a, N3b, and CY1-only stage IV were unified as stage IVa, while grossly stage IV was defined as stage IVb. N3b can be regarded as an eligibility criterion for undergoing more intensive chemotherapy regimens.
Classification ; Drug Therapy ; Humans ; Lymph Nodes ; Neoplasm Metastasis ; Retrospective Studies ; Seoul ; Stomach Neoplasms ; Survival Rate

Purpose: The impact of the interval between previous endoscopy and diagnosis on the treatment modality or mortality of undifferentiated (UD)-type gastric cancer is unclear. This study aimed to investigate the effect of endoscopic screening interval on the stage, cancerrelated mortality, and treatment methods of UD-type gastric cancer. Materials and Methods: We reviewed the medical records of newly diagnosed patients with UD gastric cancer in 2013, in whom the interval between previous endoscopy and diagnosis could be determined. The patients were classified into different groups according to the period from the previous endoscopy to diagnosis (<12 months, 12–23 months, 24–35 months, ≥36 months, and no history of endoscopy), and the outcomes were compared between the groups. In addition, patients who underwent endoscopic and surgical treatment were reclassified based on the final treatment results. Results: The number of enrolled patients was 440, with males representing 64.1% of the study population; 11.8% of the participants reported that they had undergone endoscopy for the first time in their cancer diagnosis. The percentage of stage I cancer at diagnosis significantly decreased as the interval from the previous endoscopy to diagnosis increased (65.4%, 63.2%, 64.2%, 45.9%, and 35.2% for intervals of <12 months, 12–23 months, 24–35 months, ≥36 months, and no previous endoscopy, respectively, P<0.01). Cancer-related mortality was significantly lower for a 3-year interval of endoscopy (P<0.001). Conclusions A 3-year interval of endoscopic screening reduces gastric-cancer-related mortality, particularly in cases of UD histology.