Pattern of Colon Cancer Lymph Node Metastases in Patients Undergoing Central Mesocolic Lymph Node Excision: A Systematic Review.
BACKGROUND
Extended mesocolic lymph node dissection in colon cancer surgery seems to improve oncological outcome. A possible reason might be related to metastases in the central mesocolic lymph nodes.


OBJECTIVE
The purpose of this study was to describe the pattern of mesocolic lymph node metastases, particularly in central lymph nodes, and the risk of skip, aberrant, and gastrocolic ligament metastases as the argument for performing extended lymph node dissection.


METHODS
EMBASE and PubMed were searched using the terms colon or colorectal with sentinel node, lymph node mapping, or skip node; lymph node resection colon; and complete or total and mesocolic excision.


METHODS
Studies describing the risk of metastases in central, skip, aberrant, and gastrocolic ligament lymph node metastases from colon adenocarcinomas in 10 or more patients were included. No languages were excluded.


METHODS
The risk of metastases in the central mesocolic lymph nodes was measured.


RESULTS
A total of 2052 articles were screened, of which 277 underwent full-text review. The 47 studies fulfilling the inclusion criteria were very heterogeneous, and meta-analyses were not considered appropriate. The risk of central mesocolic lymph node metastases for right-sided cancers varies between 1% and 22%. In sigmoid cancer, the risk is reported in ≤12% of the patients and is associated with advanced T stage.


CONCLUSIONS
The retrospective design and heterogeneity, in terms of definitions of lymph node location, tumor sites, stage, morphology, pathology assessment, and inclusion criteria (selection bias), of the included studies were limitations. Also, anatomic definitions were not uniform.


CONCLUSIONS
The present literature cannot give a theoretical explanation of a better oncological outcome after extended lymph node dissection. Consensus for a standardization of anatomical definitions and surgical and pathological assessments is warranted for future mapping studies.
1 Department of Surgery, Hillerød University Hospital, University of Copenhagen, Hillerød, Denmark 2 Department of Surgery, Zealand University Hospital, University of Copenhagen, Køge, Denmark 3 Department of Radiology, Hillerød University Hospital, University of Copenhagen, Hillerød, Denmark 4 Department of Internal Medicine, Gentofte University Hospital, University of Copenhagen, Hellerup, Denmark 5 Department of Surgical Gastroenterology, Rigshospitalet, University of Copenhagen, København Ø, Denmark.
Claus A
CA
Bertelsen
Anders
A
Kirkegaard-Klitbo
Mingyuan
M
Nielsen
Salvatore M G
SM
Leotta
Fukumori
F
Daisuke
Ismail
I
Gögenur
D003082:Colectomy / Q000379:methods*; D003110:Colonic Neoplasms / Q000473:pathology / Q000601:surgery; D003951:Diagnostic Errors / Q000517:prevention & control*; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods; D008198:Lymph Nodes / Q000473:pathology / Q000601:surgery; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008646:Mesocolon; D018570:Risk Assessment