Received: 10 August 2017
Accepted: 9 September 2017
Prognostic significance of the distribution of lymph node
metastasis in rectal cancer after neoadjuvant chemoradiation
Soo Young Lee MD, PhD
Chang Hyun Kim MD, PhD
Young Jin Kim MD, PhD
Hyeong Rok Kim MD, PhD
Department of Surgery, Chonnam National
University Hwasun Hospital and Medical
School, Hwasun, Korea
Hyeong Rok Kim, MD, PhD, Department of
Surgery, Chonnam National University
Hwasun Hospital and Medical School, 322
Seoyang-ro Hwasun-eup, Hwasun-gun
Jeonnam 58128, Korea.
Chonnam National University Hwasun
Hospital Institute for Biomedical Science,
Grant number: HCRI17913-1
Background: This study aimed to evaluate the prognostic significance of lymph node
distribution (LND) in rectal cancer after neoadjuvant chemoradiation.
Methods: A total of 519 patients with primary rectal cancer who underwent curative
resection after neoadjuvant chemoradiation were included. LND was classified into
four groups: LND0, no lymph node metastasis (368/519, 70.9%); LNDp, lymph node
metastasis along the inferior mesenteric artery (proximal) (15/519, 2.9%); LNDm,
lymph node metastasis at the mesorectum (109/519, 21.0%); and LNDpm, lymph node
metastasis at both the proximal and mesorectal areas (27/519, 5.2%). Clinicopatho-
logic characteristics were analyzed to identify independent prognostic factors.
Results: In patients with positive lymph nodes, LND showed superior discrimination for
3-year DFS (LNDp 67.7%, LNDm 48.9%, and LNDpm 26.8%, P = 0.003) and 3-year
LRFS (LNDp 93.3%, LNDm 81.4%, and LNDpm 60.5%, P = 0.009) compared to ypN
stage (3-year DFS, N1 47.8%, N2 40.0%, P = 0.184; 3-year LRFS, N1 79.4%, N2 75.2%,
P = 0.527). On multivariate survival analysis, LND was an independent prognostic
factor for LRFS (P = 0.030) in patients with positive lymph nodes.
Conclusions: LND may improve the prognostic value of the ypTNM staging system for
patients with node-positive rectal cancer after neoadjuvant chemoradiation,
particularly in terms of local recurrence.
distribution, lymph node, prognosis, rectal cancer, recurrence
The treatment strategies for rectal cancer have been gradually
developed in the recent past. In addition to the establishment of the
surgical concept called “total mesorectal excision,”
chemoradiation (CRT) was introduced to reduce the incidence of local
recurrence after rectal cancer surgery.
Accordingly, recent guidelines
recommend neoadjuvant CRT followed by radical surgery as a
standard management protocol in locally advanced rectal cancer.
The drawback is that the tumor-node-metastasis (TNM) staging
system of colorectal cancer is commonly used in rectal cancer after
neoadjuvant CRT, which does not accurately reflect prognosis
influenced by radiotherapy. The prognostic impact of pathologic stage
in rectal cancer differs according to the administration of neoadjuvant
Particularly, neoadjuvant CRT affects the number and status of
the lymph nodes, which might change the prognostic significance of
Therefore, for accurate staging after neoadjuvant CRT, a
distinctive staging system is needed in rectal cancer.
Currently, the distribution of lymph node metastasis (LND) is not
taken into consideration in determining TNM staging. LND has been
studied as a prognostic factor in colorectal cancer, although the results
Considering that the radiation field is generally
© 2017 Wiley Periodicals, Inc. wileyonlinelibrary.com/journal/jso J Surg Oncol. 2018;117:514–522.