Risk factors for lymph node metastasis in submucosal invasive colorectal cancer.
BACKGROUND
Recent studies have shown a 7-15% lymph node (LN) metastasis rate in submucosal invasive colorectal cancer (SICC). Identifying risk factors for LN metastasis is crucial in selecting therapeutic modalities for SICC. We assessed the possibility of and the risk factors for LN metastasis in SICC.


METHODS
We performed a retrospective study on 168 SICC patients who underwent curative resection between June 1989 and December 2004 at Asan Medical Center. The level of submucosal invasion was classified into upper third (sm1), middle third (sm2), and lower third (sm3). The following carcinoma-related variables were assessed: tumor size, tumor location, depth of submucosal invasion, cell differentiation, lymphovascular invasion, neural invasion, and tumor cell dissociation (TCD).


RESULTS
The overall LN metastasis rate was 14.3%. Significant predictors of LN metastasis both univariately and multivariately were sm3 (p = 0.039), poorly differentiated cancer (p = 0.028), and TCD (p = 0.045). Lymphovascular invasion was a risk factor for LN metastasis in univariate analysis (p = 0.019); however, in multivariate analysis, lymphovascular invasion could not predict LN metastasis. No statistical difference was observed in the risk of LN metastasis with regard to tumor location, size, and neural invasion.


CONCLUSIONS
The depth of submucosal invasion, cell differentiation, and tumor cell dissociation were significant pathologic predictors of LN metastasis in SICC. Because SICC is associated with a considerable risk of LN metastasis, local excision may be performed carefully in SICC without adverse features.
Choi
Pyong W
PW
Department of Surgery, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, South Korea. eacechoi@hanmail.net
Yu
Chang Sik
CS
Jang
Se J
SJ
Jung
Sang H
SH
Kim
Hee C
HC
Kim
Jin C
JC
D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome