Background
The American Joint Committee on Cancer’s 8th edition introduced ypStage, a separate staging system for patients with gastric cancer having undergone preoperative therapy. Overall, ypN0 patients have better survival outcomes than ypN+ patients. However, whether patients with cN+/ypN0 disease (“downstaged N0”) and those with cN0/ypN0 disease (“natural N0”) have similar survival is unknown.
Methods
An institutional database was reviewed to identify gastric adenocarcinoma patients who underwent potentially curative R0 resection after induction chemotherapy or chemoradiation. Patients were categorized into three groups based on nodal status: cN0/ypN0, cN+/ypN0, and ypN+. Univariable and multivariable Cox regression models were used to identify clinicopathologic factors associated with overall survival (OS).
Results
We identified 316 patients who met the study criteria. Ninety-four patients (30%) had cN0/ypN0 disease, 93 (29%) had cN+/ypN0 disease, and 129 (41%) had ypN+ disease. The median OS was 7.7 years, and the 5-year OS was 60.3%. In the multivariate analysis, OS did not differ between the cN0/ypN0 and cN+/ypN0 patients (hazard ratio, 0.90 [95% CI 0.54–1.48]; p = 0.666), but it was shorter in ypN+ patients (hazard ratio, 1.82 [95% CI 1.15–2.87]; p = 0.01).
Conclusions
In gastric cancer patients who underwent preoperative therapy, we found similar OS in cN0/ypN0 and cN+/ypN0 patients. Because ypN+ patients had poor OS, achieving ypN0 status is an important hallmark demonstrating the effectiveness of preoperative therapy for gastric cancer.