A study on distal spread of low and middle rectal cancer in mesorectum and rectal wall / 中华普通外科杂志

ABSTRACT

Objective To examine the frequency and mode of distal spread of low and middle rectal cancer in the mesorectum and rectal wall to determine the optimal distal clearance in situ. Methods Thirty-four specimens with low and middle rectal cancer were collected in the pathologic study between August 2004 and December 2005 in Cancer Center of Sun Yat-sen University,Twenty-eight specimens with low and middle rectal cancer were enrolled in the pathologic study between October 2006 and October 2007 in Shandong Provincial Hospital of Shandong University.Logistic regression wag used to analyze clinicopathoiogic factors related to distal spread of low and middle rectal cancer in the mesorectum and rectal wall. Results Two types of disial spread of the tumor were identified in rectal wallsubmucosa invasion and muscularis propda invasion.Distal spread in rectal wall was observed in 16%(10/62)of the patients.The length of distal spread in rectal wall was found from 0.5 cm to 1.0 cm.Four types of distal spread of the tumor were identified in mesorectumlymph node invasion,blood and lymphatic vessel invasion,perineural invasion,isolated neoplastic microfoci.Distal spread in mesorectum was observed in 19%(12/62)of the patients.The length of distal spread in mesorectum was found from 0.5 cm to 4.0 cm.Univariate analysis showed that serum CEA,lymph node invasion.circumferential margin involvemenl and Dukes stage were correlated with distal spread of low and middle rectal cancer in the mesorectum and rectal wall.Dukes stage was shown to be independent impact factor by multivariate analysis(Wald=8.386,P=0.004).Conclusion Dukes stage is an independent impaet factor for distal spread of low and middle rectal cancer in the mesorectum and rectal wall.Resection of 1.5 cm for distal rectal wall mandatory for a curative resection,provided that the clearance for distal mesorectum is no less than 5.0 cm.