Pathologic nodal response in gastric cancer: Do all patients need adjuvant therapy?

107Background: Recent data from the MAGIC trial show that pathologically positive lymph nodes (ypN+) despite neoadjuvant (NA) chemotherapy are associated with poorer survival. Although the use of NA therapy has increased, pathologic disease response to multimodality therapy (MMT) and its impact on outcome have not been well-defined. Methods: This retrospective cohort study of the National Cancer Database included patients with cN+ gastric cancer who underwent NA therapy followed by surgical resection between 2006 and 2012. Patients were categorized by NA treatment (chemotherapy or concurrent chemoradiation). Pre-treatment clinical (cN) and pathologic nodal staging (ypN) were used to determine downstaging rates from cN+ to ypN0. The association between overall risk of death and NA treatment, nodal response, and the use of adjuvant therapy was evaluated with multivariable Cox regression. Results: Among 1,489 patients with cN+ gastric cancer receiving NA therapy, 45.5% were treated with chemotherapy and 54.5...