Lymph node response to neoadjuvant chemotherapy as an independent prognostic factor in gastric cancer.

Previous studies have revealed the usefulness of neoadjuvant chemotherapy (NAC) followed by surgery for clinical stage III gastric cancer (GC). The tumor volume at the primary tumor site (PT) is sometimes difficult to measure because of the luminal structure; therefore, evaluation of the lymph node (LN) response to NAC may help to more accurately predict survival outcomes. The present study therefore evaluated the LN response to NAC for prediction of survival outcomes in patients with GC. The study involved 160 patients with clinical stage III GC who underwent NAC (n=14) and upfront surgery (n=146). PT and LN responses to NAC were evaluated, various clinicopathological factors were evaluated and Cox proportional hazard regression analyses were performed to determine survival outcomes. Overall survival (OS) and disease-free survival (DFS) were not significantly different between patients who underwent NAC and those who underwent upfront surgery (OS, P=0.71; DFS, P=0.50). However, although there were no significant differences in PT responses, patients classified as LN non-responders to NAC had a significantly worse prognosis compared with patients classified as LN responders in terms of DFS (PT, P=0.93; LN, P<0.01) and OS (PT, P=0.84; LN, P<0.01). Moreover, a higher neutrophil-lymphocyte ratio tended to be associated with poor DFS [univariate: hazard ratio (HR)=4.23, P=0.06; multivariate: HR=6.45, P=0.04]. Finally, an LN response to NAC was significantly better for prediction of recurrence (univariate, HR=7.79, 95% confidence interval=1.16-63.51, P=0.02; multivariate, HR=7.44, P=0.01). Overall, the current study revealed the clinical importance of the LN response to NAC for predicting survival outcomes in patients with GC. These findings highlight the potential clinical impact of optimizing treatment strategies to improve the selection and management of patients.