Well-differentiated tumors are associated with lower rates of lymph node (LN) metastasis compared with poorly differentiated tumors, and those 4 cm or smaller are also associated with lower rates of LN metastasis compared with larger tumors, according to a study in JAMA Network Open.
Researchers analyzed data from 9952 patients who had surgery for gastric cancer from January 2000 to December 2015 at a cancer center in Korea. They sought to establish an indication for middle segmental gastrectomy as a treatment for patients with middle-body and high-body gastric cancer.
Eligible participants were aged 18 to 85 years and had histologically proven adenocarcinoma in the high-body or middle-body of the stomach, cT1 to cT3 categories, had previously undergone curative R0 resection, and maintained postoperative follow-up for a minimum of 3 years.
The study authors performed statistical analysis in 2 steps: initial analysis of 773 cases that included cN2/N3 carcinomas and the final statistical analysis after the cN2/N3 carcinomas were excluded. A total of 701 patients (mean [Standard Deviation (SD)] age, 56.35 [12.24] years; 418 [59.6%] men) who had cT1-3N0/1 adenocarcinomas in the middle-body or high-body were included in the final analysis.
In the final analysis, LN metastasis incidence 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-T2N1MO cancers, regardless of tumor size and differentiation.
Tumor metastasis was significantly more common in tumors that were 4.1 cm or larger (odds ratio [OR], 2.10; 95% CI, 1.20-3.67; P =.009) compared with smaller tumors, according to logistic regression analysis. In addition, poorly differentiated tumors were more highly associated with LN metastasis compared with well differentiated or moderately differentiated tumors (OR, 2.88; 95% CI, 1.45-5.73; P =.002 for univariate analysis; OR, 2.38; 95% CI, 1.12-5.05; P =.02 for multivariate analysis).
The researchers noted limitations to their study, including its retrospective nature and the potential for stage migration between T2 and T3 tumors. Additionally, detailed LN data were not available for all patients.
“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,” stated the investigators.
Khalayleh H, Kim Y-W, Yoon HM, Ryu KW. Assessment of lymph node metastasis in patients with gastric cancer to identify those suitable for middle segmental gastrectomy. JAMA Netw Open. 2021;4(3):e211840.