Prognostic value of pathological node status after neoadjuvant radiotherapy for rectal cancer

Background The prognostic value of pathological lymph node status following neoadjuvant radiotherapy (ypN) remains unclear. This study was designed to determine whether ypN status predicted overall survival. Methods Patients with locally advanced rectal adenocarcinoma who underwent neoadjuvant long‐course radiation between 2005 and 2014 were identified from the National Cancer Data Base, and divided into ypN0, ypN1 and ypN2 groups. The primary outcome was overall survival. Univariable and multivariable analyses were used to determine factors associated with overall survival. Results Of 12 271 patients, 3713 (30·3 per cent) were found to have residual nodal positivity. A majority of patients with ypN1 (1663 of 2562) and ypN2 (878 of 1151) disease had suspected lymph node‐positive disease before neoadjuvant therapy, compared with 3959 of 8558 with ypN0 tumours (P