title: Predictive histopathologic factors for lymph node metastasis in patients with nonpedunculated submucosal invasive colorectal carcinoma.
abstract: OBJECTIVE
  Risk factors for lymph node metastasis in patients with nonpedunculated submucosal invasive colorectal carcinoma remain to be characterized. This study examines the relationship between lymph node metastasis and clinicopathologic factors in nonpedunculated submucosal invasive colorectal carcinoma.
  
  
  METHODS
  The study cohort comprised 155 patients who had undergone surgical treatment for nonpedunculated submucosal invasive colorectal carcinoma. The clinicopathologic factors investigated included gender, age, tumor location, macroscopic type, tumor size, histologic type and grade, intramucosal growth pattern, lymphatic invasion, venous invasion, degree of focal dedifferentiation at the submucosal invasive front, status of the remaining muscularis mucosa, and the depth and width of submucosal invasion.
  
  
  RESULTS
  Lymph node metastases were found in 19 patients (12.3 percent). Univariate analysis showed that lymphatic invasion, focal dedifferentiation at the submucosal invasive front, status of the remaining muscularis mucosa, and depth of submucosal invasion all had a significant influence on lymph node metastasis. Multivariate analysis showed lymphatic invasion (P = 0.014) and high-grade focal dedifferentiation at the submucosal invasive front (P = 0.049) to be independent factors predicting lymph node metastasis. No lymph node metastasis was found in tumors with a depth of submucosal invasion of <1.3 mm.
  
  
  CONCLUSIONS
  Lymphatic invasion and high-grade focal dedifferentiation at the submucosal invasive front are important predictors of lymph node metastasis in patients with nonpedunculated submucosal invasive colorectal carcinoma. Depth of submucosal invasion can be used as an identifying marker for patients who do not require subsequent surgery after endoscopic resection.
authors.affiliation: Clinical Laboratory Division, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tominaga
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Nakanishi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nimura
authors.forename: Kimio
authors.initials: K
authors.lastname: Yoshimura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sakai
authors.forename: Tadakazu
authors.initials: T
authors.lastname: Shimoda
mesh_terms: D000368:Aged; D002277:Carcinoma / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D012307:Risk Factors