Number of Lymph Nodes in Primary Nodal Basin and a "Second Look" Protocol as Quality Indicators for Optimal Nodal Staging of Colon Cancer.
BACKGROUND
-Evaluation of 12 or more lymph nodes (LNs) is currently used as a quality indicator for adequacy of pathologic examination of colon cancer resections.


OBJECTIVE
-To evaluate the utility of a focused LN search in the immediate vicinity of the tumor and a "second look" protocol in improving LN staging in colon cancer.


METHODS
-Lymph nodes were submitted separately from the primary nodal basin (PNB) and secondary nodal basin (SNB) defined as an area less than 5 cm away and an area greater than 5 cm away from the tumor edge, respectively, in 201 consecutive resections (2010-2013). One hundred sixty-eight consecutive tumors (2006-2009) were used as a control group. A second search was performed in all cases that were N0 after the first search.


RESULTS
-In cases that were N0 after the first search, 20.9 ± 10.8 LNs were collected from the PNB, compared to 8.5 ± 9.1 from the SNB. Positive LNs were found in N+ tumors in the PNB in all cases but in only 9% (4 of 46) of SNBs (P < .001). A second search increased node count by an average of 10 additional LNs. In 5 of 114 cases (4.4%), N0 after the first search converted to N+ after a second search that yielded 1 to 4 positive LNs, all of which were in the PNB.


CONCLUSIONS
-Emphasis on the number of LNs examined from the PNB and a "second look" protocol improve nodal staging.
Mikhail
M
Lisovsky
Shannon N
SN
Schutz
Michael G
MG
Drage
Xiaoying
X
Liu
Arief A
AA
Suriawinata
From the Department of Pathology (Drs Lisovsky, Liu, and Suriawinata and Ms Schutz), Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; and the Department of Pathology (Drs Drage and Srivastava), Brigham & Women's Hospital, Boston, Massachusetts.
Amitabh
A
Srivastava
D000230:Adenocarcinoma / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000473:pathology*; D003110:Colonic Neoplasms / Q000473:pathology*; D006305:Health Status Indicators; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D010338:Pathology, Clinical / Q000379:methods; D011446:Prospective Studies