The clinicopathological significance of inferior mesenteric lymph node metastasis in colorectal cancer.
OBJECTIVE
There are few studies reporting survival or recurrence patterns in colorectal cancer patients with inferior mesenteric lymph node metastasis (IMLN+). The present study evaluated the prognostic significance of patients being IMLN+ or IMLN- in colorectal cancer.


METHODS
Survival, recurrence pattern and treatment protocols were compared between 63 IMLN+ patients and 108 IMLN- patients with stage III and IV rectal and sigmoid cancer undergoing curative surgery. Lymph node sampling was routinely performed prior to inferior mesenteric artery ligation and excision flush with aorta. Limited principal node dissection including IMLN was performed in cases of identified node metastasis.


RESULTS
The 5-year disease-free survival rates were 50% in IMLN- and 31% in IMLN+ patients (P=0.004). The 5-year disease-free survival rate was greater in the N1 group than the N2 group (P=0.038). Cox regression analysis showed IMLN+, lymphovascular tumour invasion, T4, M1, and pre-operative serum CEA level over 6 ng/ml were independently associated with unfavorable disease-free survival. The prognostic significance of M category was greater when the IMLN+ was included in the M1 as opposed to the N category. In patients undergoing absolute curative surgery, post-operative recurrence rates were 34% for IMLN- and 57% for IMLN+ patients (P=0.009; OR, 2.611; 95% CI, 1.313-5.194). For IMLN+ patients, post-operative adjuvant treatment independently correlated with disease-free survival (P=0.029).


CONCLUSIONS
IMLN+ is an independent survival factor enhancing the prognostic significance of the M category in the AJCC staging. Curative radical surgery and post-operative chemoradiotherapy appears to be warranted for IMLN+ colorectal cancer patients as it resulted in 5-year disease-free survival rates of up to 31% compared to 50% in IMLN- patients.
Kim
J C
JC
Department of Surgery, University of Ulsan College of Medicine and Asan Medical Center, 388-1 Poongnap-2-Dong Songpa-Ku, Seoul 138-736, South Korea. jckim@amc.seoul.kr
Lee
K H
KH
Yu
C S
CS
Kim
H C
HC
Kim
J R
JR
Chang
H M
HM
Kim
J H
JH
Kim
J S
JS
Kim
T W
TW
D000328:Adult; D000368:Aged; D002985:Clinical Protocols; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008643:Mesentery; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011379:Prognosis; D012004:Rectal Neoplasms / Q000401:mortality* / Q000473:pathology; D012811:Sigmoid Neoplasms / Q000401:mortality* / Q000473:pathology; D016019:Survival Analysis