title: Severe tumor budding is a risk factor for lateral lymph node metastasis in early rectal cancers.
abstract: BACKGROUND
  Lateral lymph node (LLN) metastasis sometimes occurs in patients with early rectal cancer that has invaded the submucosa (SM) and muscularis propria (MP). This study aims to identify the risk factor(s) for LLN metastasis in such patients.
  
  
  METHODS
  We retrospectively analyzed 65 patients with pathological SM or MP lower rectal adenocarcinoma, for whom radical resection had been performed at a single institution.
  
  
  RESULTS
  We performed LLN dissection in 52 (80%) patients. The LLN dissection rates in the case of pathological SM and MP tumors were 65.6% and 94.4%, respectively, and the corresponding LLN metastasis rates were 6.9% and 11.1%. Severe tumor budding was found to be a risk factor for LLN metastasis (P = 0.002). Further, of six patients with LLN metastasis, four did not have coincident mesenteric lymph node metastasis.
  
  
  CONCLUSIONS
  In rectal cancer that has pathologically invaded SM and MP, LLN metastasis is not negligible. LLN dissection could lower the local recurrence rate of SM and MP rectal cancer. In case LLN dissection is not performed, patients with a high tumor budding grade should be administered adjuvant therapy.
authors.affiliation: Department of Colorectal Surgery, Seirei Hamamatsu General Hospital, Shizuoka, Japan. yoh2007@sis.seirei.or.jp
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Homma
authors.forename: Takashi
authors.initials: T
authors.lastname: Hamano
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Otsuki
authors.forename: Shinichi
authors.initials: S
authors.lastname: Shimizu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000009:adverse effects; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000473:pathology*; D012189:Retrospective Studies; D012307:Risk Factors