Evaluation of Lymph Node Metastasis Among Adults With Gastric Adenocarcinoma Managed With Total Gastrectomy.

Importance: It is unclear whether proximal gastrectomy (PG) can replace total gastrectomy (TG), even in cases of advanced gastric carcinoma. Objectives: To evaluate the oncologic safety of PG based on the lymph node (LN) metastasis rate and develop a selection diagram for PG eligibility. Design, Setting, and Participants: In this cohort study, a retrospective analysis of a prospective database of gastric carcinoma surgery was performed including procedures that took place between December 1, 2000, and December 31, 2015, in the National Cancer Center, Korea, a high-volume carcinoma center with a structured database and accurate long-term follow-up. Among 9952 patients who underwent surgery for gastric carcinoma, 2347 underwent TG. Six-hundred fifty-five (564 in a second statistical analysis) had gastric carcinoma in the upper third of the stomach. The inclusion criteria were age 18 to 85 years, histologically proven adenocarcinoma (any size or differentiation) located in the upper third of the stomach, curative R0 TG performed, and postoperative follow-up for at least 3 years. Exclusion criteria included Borrmann type 4 carcinoma, T4 category, use of neoadjuvant chemotherapy, and a history of other carcinomas. Data analysis was performed from December 1, 2019, to May 30, 2020. Exposures: Total gastrectomy and LN dissection. Main Outcomes and Measures: The primary end point was the rate of LN metastasis at LN stations 4d, 5, and 6, which are usually not dissected during PG. Results: Among the 655 study patients, the mean (SD) age was 57.7 (11.9) years, and 462 (70.5%) were men. Only those with poorly differentiated cT3 category carcinomas had an increased incidence of LN metastasis at stations 4d (2 of 32 [6.3%]) and 11d (T3N0: 2 of 22 [9.1%], T3N1: 3 of 27 [11.1%]), independent of tumor size. For cT1-T3N0/1M0 category carcinomas, the incidence of station 5 LN metastasis was 0, irrespective of tumor size and differentiation. The LN metastasis rate at stations 4d and 6 for cT1-T3N0/1M0 differentiated tumors was also 0. Tumor size greater than or equal to 4.1 cm was associated with significantly increased LN metastasis compared with tumors less than 4.1 cm (40.0% vs 20.4%, P = .001). Conclusions and Relevance: The findings of this study suggest that PG can be safely performed for cT1-T2N0/1M0 tumors less than 4.1 cm in diameter that are located in the upper third of the stomach. The cT3N0/1M0-differentiated tumors less than 4.1 cm may also be eligible for PG, whereas poorly differentiated cT3 tumors and any cT4 or cN2/3 diseases require TG.