title: Characteristics of recurrence after curative resection for T1 colorectal cancer: Japanese multicenter study.
abstract: BACKGROUND
  Because the rate of recurrence after curative resection for T1 colorectal cancer is low, the characteristics of recurrence remain obscure. This multicenter study attempted to clarify the characteristics of recurrence after curative resection for T1 colorectal cancer.
  
  
  METHODS
  We analyzed the associations between recurrence and various clinicopathological features in 798 patients who had undergone curative resection alone for T1 colorectal cancer at 14 hospitals between 1991 and 1996.
  
  
  RESULTS
  The rate of lymph node metastasis (LNM) in patients with T1 colorectal cancer was 10.5% (84/798), and 18 (2.3%) of the 798 patients developed recurrence during the median follow-up of 7.8 years. The recurrence rates in patients with colon cancer with and without LNM were 3.6 and 1.3%, respectively (p = 0.19). These rates in patients with cancer of the rectum were 25.0 and 1.1% (p < 0.0001). Among various parameters, histological grade (p < 0.0001), location (p = 0.025), LNM (p < 0.0001), and venous invasion (p = 0.0013) were risk factors for recurrence. Among them, LNM (p = 0.0008) and histological grade (p = 0.041) were independent risk factors for recurrence after curative resection for T1 colorectal cancer. Time to recurrence was more likely to be shorter for patients with, than without nodal involvement. In patients with an unfavorable histological grade, all recurrences developed within 1 year.
  
  
  CONCLUSIONS
  The recurrence rate after curative resection for node-negative T1 colorectal cancer was very low. The effectiveness of surveillance to detect recurrence after curative resection for T1 colorectal cancer should be validated in further studies.
authors.affiliation: Department of Surgical Oncology, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. h-kobayashi.srg2@tmd.ac.jp
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Mochizuki
authors.forename: Takayuki
authors.initials: T
authors.lastname: Morita
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kotake
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Teramoto
authors.forename: Shingo
authors.initials: S
authors.lastname: Kameoka
authors.forename: Yukio
authors.initials: Y
authors.lastname: Saito
authors.forename: Keiichi
authors.initials: K
authors.lastname: Takahashi
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hase
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Oya
authors.forename: Koutarou
authors.initials: K
authors.lastname: Maeda
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirai
authors.forename: Masao
authors.initials: M
authors.lastname: Kameyama
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shirouzu
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugihara
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000188:drug therapy / Q000556:secondary / Q000601:surgery; D016015:Logistic Models; D008175:Lung Neoplasms / Q000188:drug therapy / Q000556:secondary / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors