Phase I study on sentinel lymph node mapping in colon cancer: a preliminary report.
OBJECTIVE
Lymph node (LN) metastasis is one of the most significant prognostic factor in colorectal cancer. In fact, therapeutic decisions are based on LN status. However, multiple studies have reported on the limitations of the conventional pathological LN examination techniques, and therefore, the actual number of patients with LN positive colorectal cancer is probably underestimated. We assume that lymphatic tumor dissemination follows an orderly sequential route. We report here a simple and harmless coloration technique that was recently elaborated, and that allows us to identify the sentinel LN(s) (SLN) or first relay LNs in colorectal cancer patients. The main endpoint of this clinical trial is the feasibility of the technique.


METHODS
Twenty patients treated by surgery for a colic cancer were admitted in this protocol. A subserosal peritumoral injection of lymphazurin 1% was performed 10 min before completing the colic resection. A pathologist immediately examined the specimens, harvested the colored SLN, and examined them by serial cuts (200 microm) with H&E staining, followed by immunohistochemical staining (AE1-AE3 cytokeratin markers), when serial sections were classified as cancer free.


RESULTS
The preoperative identification of the SLN was impossible in at least 50 of the cases, however, SLNs were identified by the pathologist in 90% of cases. In two patients (10%) SLN was never identified. The average number of SLN was 3.9. Immunohistochemical analysis of the SLN has potentially changed the initial staging (from Dukes B to Dukes C) for 5 of the 20 patients (25%). On the other hand, there was one patient (5%) with hepatic metastasis from adenocarcinoma for whom SLN pathology was negative for metastasis (skip metastasis).


CONCLUSIONS
SLN biopsy is readily feasible with identification of SLN in at least 90% of patients with colorectal cancers. Our results indicate that 45% of patients initially staged as Dukes B had tumor cells identified in their SLN when these were subjected to our protocol. This represented a 25% upgrading rate when our complete study population is considered. However, controversy persist about the clinical significance and metastatic potential of these often very small clusters of tumor cells.
Bendavid
Yves
Y
Laboratoire de recherche et d'enseignement chirurgical, Maisonneuve-Rosemont Hospital, University of Montréal, Montréal, Québec, Canada.
Latulippe
Jean François
JF
Younan
Rami J
RJ
Leclerc
Yves E
YE
Dube
Serge
S
Heyen
Françoise
F
Morin
Michel
M
Girard
Robert
R
Bastien
Edouard
E
Ferreira
José
J
Cerino
Michel
M
Dubé
Pierre
P
D014408:Biomarkers, Tumor / Q000032:analysis; D002277:Carcinoma / Q000473:pathology*; D003110:Colonic Neoplasms / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D010347:Patient Care Planning; D011300:Preoperative Care; D012394:Rosaniline Dyes; D021701:Sentinel Lymph Node Biopsy
D014408:Biomarkers, Tumor; D012394:Rosaniline Dyes; C025484:iso-sulfan blue; D007633:Keratins