Assessment of Lymph Node Metastasis in Patients With Gastric Cancer to Identify Those Suitable for Middle Segmental Gastrectomy

Question Can metastasis at key lymph node (LN) stations be used to inform surgical management in patients with gastric cancer? Findings In this cohort study of 9952 patients who underwent surgery for gastric cancer, the rates of LN metastasis were 0% at LN station 5 for cT1-3N0/1M0 cancers, station 4sa for cT1-2N0/1M0 cancers, station 2 for cT1N0/1M0 cancers, station 6 for cT1N1M0 cancers, station 11d for cT1N1M0-cT2N0/1M0 cancers, and station 12a for cT1N0/1M0-T2N1M0 cancers, regardless of size and differentiation. Well-differentiated tumors were associated with lower rates of LN metastasis vs poorly differentiated tumors, and tumors 4 cm or smaller were also associated with lower rates of LN metastasis vs those 4.1 cm or larger. Meaning These findings suggest that middle segmental gastrectomy with dissection of LN stations 1, 3, 4sb, 4d, 7, 8a, 9, 11p, and 12a can be recommended for high-body and middle-body cT1N0/1M0 gastric cancers 4 cm or smaller and well-differentiated cT2N0/1M0 cancers. This cohort study assesses lymph node (LN) metastasis in patients with gastric cancer to identify those suitable for middle segmental gastrectomy. Importance Segmental gastrectomy, a type of function-preserving surgery, is not broadly studied but can improve postoperative function and quality of life among patients with gastric cancer (GC). Objective To establish an indication for middle segmental gastrectomy (MSG) as a treatment for middle-body (MB) and high-body (HB) GC. Design, Setting, and Participants This cohort study analyzed patients with GC undergoing surgery between January 2000 and December 2015 in the National Cancer Center, Goyang, Korea, a high-volume cancer center with a structured database and accurate long-term follow-up. Inclusion criteria were age 18 to 85 year, histologically proven adenocarcinoma located in the HB or MB, cT1 to cT3 category cancers, curative resection with negative margins performed, and follow-up for at least 3 years. Exclusion criteria were Borrmann type 4 GC, T4 category cancer, neoadjuvant chemotherapy, and a history of other cancers. Data analysis was performed from December 2018 to May 2020. Exposures Total or subtotal gastrectomy and LN dissection. Main Outcome and Measures The primary outcome was the rate of metastasis at LN stations 2, 4sa, 5, 6, and 11d, which cannot be dissected during MSG. Results Among 9952 patients who underwent surgery for GC, 8219 underwent either laparoscopic or open total or subtotal gastrectomy. Seven hundred seventy-three patients (mean [SD] age, 56.21 [12.16] years; 464 men [60.0%]) had GC in the MB or HB of the stomach. Among the 701 patients included in the final analysis after exclusion of the cN2/N3 carcinomas, the mean (SD) age was 56.35 (12.24) years, and 418 (59.6%) were men. The incidence of LN metastasis was 0% at station 5 for cT1-3N0/1M0 cancers, station 4sa for cT1-2N0/1M0 cancers, station 2 for cT1N0/1M0 cancers, station 6 for cT1N1M0 cancers, station 11d for cT1N1M0-cT2N0/1M0 cancers, and station 12a for cT1N0/1M0-T2N1M0 cancers, regardless of size and differentiation. The rates of LN metastasis for cT1N0M0 cancers were 0.3% (1 of 396 LNs) at station 6 and 0.8% (1 of 129 LNs) at station 11d. Tumors 4 cm or smaller were associated with a lower risk of LN metastasis compared with tumors 4.1 cm or larger (odds ratio, 2.10; 95% CI, 1.20-3.67; P = .009), and well-differentiated tumors were associated with lower risk of LN metastasis compared with poorly differentiated tumors (odds ratio, 2.88; 95% CI, 1.45-5.73; P = .002). Conclusions and Relevance These findings suggest that MSG with dissection of stations 1, 3, 4sb, 4d, 7, 8a, 9, 11p, and 12a could be done for HB and MB cT1N0/1M0 gastric cancers 4 cm or smaller and well-differentiated cT2N0/1M0 cancers.

Automated summary

This study suggests that middle segmental gastrectomy can be considered for high-body and middle-body gastric cancers with cT1N0/1M0 staging and tumor size ≤4 cm, as well as well-differentiated cT2N0/1M0 cancers.