Prognostic Value of Sterilized Lymph Nodes After Preoperative Chemoradiotherapy for Patients with ypN0 Rectal Cancer

Patients with ypN0 rectal cancer who have received preoperative chemoradiotherapy can be divided into those who initially were node negative and those whose positive nodes have been sterilized by preoperative therapy. The long-term prognosis for ypN0 patients with sterilized lymph nodes (LNS) is unknown. This study aimed to assess the prognostic value of LNS after preoperative chemoradiotherapy for patients with ypN0 rectal cancer. From January 2007 to March 2014, 206 patients with ypN0 tumors of the mid or lower rectum treated by chemoradiotherapy and radical surgery were enrolled in the study. Of these 206 patients, 49 had ypN0 tumors with LNS (LNS+ group), and 157 had ypN0 tumors without LNS (LNS- group). The patients in both groups were comparable in terms of tumor characteristics, type of chemoradiotherapy, type of surgery, R0 resection rate, and postoperative complication rate. The mean follow-up period was 40.5 +/- 27 months. The 1- and 3-year OS rates in the LNS+ group were respectively 100 and 95.5% versus 99.4 and 91.6% in the LNS- group (P = 0.549). The 1- and 3-year DFS rates in the LNS+ group were respectively 100 and 94.2% versus 94.7 and 87.1% in the LNS- group (P = 0.117). The multivariate analysis showed that the presence of LNS did not affect OS (P = 0.918) or DFS (P = 0.209). The prognosis is excellent for patients with ypN0 rectal cancer who have LNS after preoperative chemoradiotherapy. The presence of LNS in ypN0 rectal cancer patients after chemoradiotherapy should not be considered a factor for a poor prognosis.