title: Prognostic impact of lymph node dissection is different for male and female colon cancer patients: a propensity score analysis in a multicenter retrospective study.
abstract: OBJECTIVE
  Colon cancers in male and female patients are suggested to be oncologically different. The aim of this study is to elucidate the prognostic impact of lymph node dissection (LND) in male and female colon cancer patients.
  
  
  METHODS
  A total of 5941 stage I-III colon cancer patients who were curatively operated on during the period from 1997 to 2007 were retrospectively studied. Cancer-specific survival (CSS) was individually compared between for male and female patients treated with D3, D2, and D1 LND. Background differences of the patients were matched using propensity scores.
  
  
  RESULTS
  D3, D2, and D1 LND were performed in 3756 (63 %), 1707 (29 %), and 478 (8 %), respectively, and more extensive LND was indicated for younger patients and more advanced disease. D2 LND was significantly associated with decreased cancer-specific mortality compared to D1 LND in male patients (HR 0.54, 95 % CI 0.32-0.89, p = 0.04), but not in female patients. D3 LND did not correlate to an improved prognosis compared to D2 LND both in male and female patients.
  
  
  CONCLUSIONS
  D2 LND was associated with an improved CSS in male, but not female colon cancer patients, compared to D1 LND. This suggested that colon cancer in male and female patients might be oncologically different, and that the prognostic impact of the extent of surgical intervention for colon cancer might therefore be different between sexes.
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Soichiro
authors.initials: S
authors.lastname: Ishihara
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Otani
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Yasuda
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishikawa
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Junichiro
authors.initials: J
authors.lastname: Tanaka
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Tomomichi
authors.initials: T
authors.lastname: Kiyomatsu
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Kazushige
authors.initials: K
authors.lastname: Kawai
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hata
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Hioaki
authors.initials: H
authors.lastname: Nozawa
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Kazama
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Yamaguchi
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Sunami
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Joji
authors.initials: J
authors.lastname: Kitayama
authors.affiliation: Department of Surgical Oncology, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugihara
authors.affiliation: Department of Surgical Oncology, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. toshwatanabe@yahoo.co.jp.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000368:Aged; D003110:Colonic Neoplasms / Q000401:mortality / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods*; D008297:Male; D015999:Multivariate Analysis; D011379:Prognosis; D057216:Propensity Score; D016016:Proportional Hazards Models; D012189:Retrospective Studies
keywords: Colon cancer; Lymph node dissection; Prognosis; Surgery