Endoscopic resection versus gastrectomy for clinical T1a gastric adenocarcinoma: Predictors of nodal upstaging

Abstract

Background: Endoscopic resection is increasingly favored as a first-line curative treatment over surgery for early gastric cancer with minimal risk of lymph node metastasis. Our objective is to identify factors that may guide the treatment decision between endoscopic resection and gastrectomy in early gastric cancer.

Methods: A retrospective analysis of the National Cancer Database from 2010 to 2021 for patients with cT1aN0M0 gastric adenocarcinoma was performed comparing endoscopic resection versus gastrectomy. Our main outcomes of interest were overall survival and lymph node upstaging. Multivariate logistic regression and Cox proportional hazards models were used.

Results: A total of 2,177 patients were identified; 1,007 (46.3%) had endoscopic resection and 1,170 (53.7%) had gastrectomy. On average, endoscopic resection patients were more likely to be male (72.6% vs 61.1%, P < .01), older (69.7 ± 10.9 vs 65.4 ± 13.1 years, P < .01), and non-Hispanic White (80.3% vs 67%, P < .01). Compared with gastrectomy, tumors undergoing endoscopic resection were smaller, lower grade, more often in the cardia, and had lower rates of lymphovascular invasion and signet morphology. Endoscopic resection resulted in higher margin positivity (15.3% vs 4.6%, P < .01), but both approaches had similar survival (log-rank P = .24). There was a pathologic lymph node upstaging rate of 15.6% in gastrectomy. Factors predicting lymph node upstaging included larger tumor size (odds ratio: 1.01, 95% confidence interval: 1.01-1.02), poor differentiation (odds ratio: 2.65, 95% confidence interval: 1.15-6.09), lymphovascular invasion (odds ratio: 13.15, 95% confidence interval: 7.86-22.01), and positive margins (odds ratio: 5.85, 95% confidence interval: 2.30-14.87). Although signet morphology did not predict lymph node upstaging, it predicted having those aforementioned high-risk features for lymph node upstaging (odds ratio: 12.02, 95% confidence interval: 4.60-31.39).

Conclusion: In the real-world analysis of early gastric cancer treatment, endoscopic resection alone achieved similar survival to gastrectomy for cT1aN0M0 early gastric cancer. Despite these early gastric cancer staged as cN0, approximately 15% of gastrectomy patients had lymph node upstaging. We found tumor size, grade, margin positivity, and particularly lymphovascular invasion to be important clinical predictors of pathologic lymph node upstaging that should be considered in early gastric cancer treatment decision-making.