title: [Colorectal cancer: lymphatic metastasis and choice of operation].
abstract: OBJECTIVE
  To study lymphatic metastasis of colorectal cancer for deceding the of dissection extent of dissection.
  
  
  METHODS
  Six hundred and twenty-three lymph nodes from 74 cases of colorectal cancer were analyzed after D(3) resection. They were classified into peritumor, longitudinal spread, and upward spread groups. The metastasis rate of lymph node and its incidence were calculated.
  
  
  RESULTS
  The metastasis rate of lymph node and its incidence in the peritumor, longitudinal spread, and upward spread (N(2) and N(3)) groups were 47.2% and 38.6%, 22.8% and 18.6%, and 29.7% (20.3% and 9.4%) and 10.2% (19.0% and 5.3%), respectively. The distribution rate of metastatic lymph node was 61.2%, 17.1%, and 21.6% in the peritumor, longitudinal spread, and upward spread groups, respectively. Within 2.0 cm on the anal side of rectal cancer, the metastasis rate was 3.7%, whereas in 2.0 - 4.0 cm no metastasis was observed cancer at the lower part of the rectum demonstrated a higher lateral metastasis rate.
  
  
  CONCLUSIONS
  Colorectal cancer tends to metastasize to longitudinal and the risk of metastasis increased in the stage of pT(3) and pT(4) or low differentiation stage. Jump metastasis is also a feature. D(3) radical resection is necessary for colorectal cancer, but extended lateral lymph node needs enectomy or total mesorectal excision. No residual tumor tissue exists at the anastomosis site after low anterior resection when the excision distance is beyond 2.0 cm from the anal margin of rectal cancer.
authors.affiliation: Department of General Surgery, Shanghai Jingan District Central Hospital, Shanghai 200040.
authors.forename: Y
authors.initials: Y
authors.lastname: Gao
authors.forename: B
authors.initials: B
authors.lastname: Jiang
authors.forename: R
authors.initials: R
authors.lastname: Sun
authors.forename: M
authors.initials: M
authors.lastname: Lu
authors.forename: H
authors.initials: H
authors.lastname: Shen
authors.forename: X
authors.initials: X
authors.lastname: Tong
authors.forename: C
authors.initials: C
authors.lastname: Tu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods*; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery