Impact of the number of lymph node dissections and a novel risk stratification on the prognosis in elderly locally advanced esophageal adenocarcinoma.

Elderly patients with locally advanced esophageal adenocarcinoma (EAC) have a poor prognosis. The purpose of this study was to identify prognostic factors and construct a risk stratification for assessing the prognosis of elderly (≥ 70 years old) EAC patients who receiving neoadjuvant chemoradiotherapy (NCRT) and esophagectomy. A total of 688 patients with non-metastatic locally advanced EAC who underwent NCRT and esophagectomy were selected from the Surveillance Epidemiology and End Results (SEER) database. Multivariable Cox analysis was used to identify prognostic factors of overall survival (OS). Restricted Cubic Splines (RCS) was used to examine the linear relationship between the number of lymph node dissection (LND) and OS. RCS showed a linear relationship between LND and OS (P = 0.690). As the number of LND increased, the risk of death decreased. Multivariable analysis demonstrated that LND > 23, grade III/IV, and regional node positive were independent prognostic factors. Subgroup analysis indicated that enlarged lymph node dissection (LND > 23) did not improve OS in patients with grade I/II or T1-2 stage, whereas enlarged lymph node dissection significantly improved OS in patients with grade III/IV or T3-4 stage. Furthermore, we constructed a novel risk score based on LND, grade, and regional node status, which stratified patients into low-, medium-, and high-risk groups. Patients in the high-risk group (risk score = 3) had a worse prognosis. Enlarged lymph node dissection (LND > 23) improved OS in patients with grade III/IV or T3-4 stage. Moreover, a novel risk score was constructed, which facilitated risk stratification and postoperative surveillance in elderly EAC patients.