Sentinel lymph node evaluation does not improve staging accuracy in colon cancer.
BACKGROUND
Lymph node involvement is an important prognostic factor in colorectal cancer. Sentinel lymph node (SLN) evaluation for assessing lymph node status in colorectal cancer remains controversial. Here we evaluated the sensitivity, predictive value, and accuracy of SLN evaluation for determining lymph node status in resectable colon cancer.


METHODS
A prospective phase 2 cohort study of SLN evaluation in colon cancer was conducted from September 1998 to April 2006. Patients underwent resection and SLN mapping with 1% isosulfan blue and (m99)Tc sulfur colloid injection. SLNs were evaluated by hematoxylin and eosin (HE) staining and, if findings were negative, by additional thin HE sections and immunohistochemical (IHC) staining for pancytokeratin and MOC31. Overall survival for patients with IHC-positive disease was evaluated by Kaplan-Meier analysis and the log rank test.


RESULTS
SLNs were identified in 119 (99%) of the 120 patients eligible for the study. Median number of SLNs identified was 4 (range, 0-13). Forty-nine patients (40%) had nodal metastases on HE. The SLN accurately identified nodal metastases in 29 (59%) of these 49 patients and was negative for metastases in 22 patients (41%). SLNs in eight patients (7%) were negative by HE but positive by IHC staining. Positive IHC status did not affect survival after a median follow-up of 33 months (P = .41).


CONCLUSIONS
The low sensitivity and high false-negative rate of SLN evaluation does not support this technique for improving the accuracy of nodal staging for patients with colon cancer. The significance of IHC-positive SLNs remains uncertain.
Lim
Sherry J
SJ
Department of Surgical Oncology, The University of Texas, M. D. Anderson Cancer Center, 1515 Holcombe Blvd., P.O. Box 301402, Houston, Texas, 77230-1402, USA.
Feig
Barry W
BW
Wang
Huamin
H
Hunt
Kelly K
KK
Rodriguez-Bigas
Miguel A
MA
Skibber
John M
JM
Ellis
Vickie
V
Cleary
Karen
K
Chang
George J
GJ
D002288:Adenocarcinoma, Mucinous / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007633:Keratins / Q000378:metabolism; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D012394:Rosaniline Dyes; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy
D012394:Rosaniline Dyes; C025484:iso-sulfan blue; D007633:Keratins