title: Difference in the recurrence rate between right- and left-sided colon cancer: a 17-year experience at a single institution.
abstract: OBJECTIVE
  The prognostic differences between right- and left-sided colon cancer are controversial. This study aimed to clarify the clinical difference between right- and left-sided colon cancer.
  
  
  METHODS
  We enrolled 820 patients with stage I/II/III colon cancer who underwent radical surgery with curative intent. We explored the impact of the tumor location on the postoperative disease-free survival (DFS) rate using the univariate and multivariate analyses.
  
  
  RESULTS
  Right-sided disease occurred in 399 of the 820 patients. The mean follow-up period was 55.8 ± 34.9 months. The pathological stage distribution was as follows: stage I 261 patients; stage II 283; and stage III 251. There were no significant differences in the five-year DFS of the overall populations (right 88.6%; left 89.4%; P = 0.231). The subgroup analyses demonstrated that patients with stage I right-sided colon cancer had a significantly better 5-year DFS rate than did those with left-sided disease (100 vs. 95.2%, P = 0.034). There were no significant differences in the distributions of the first recurrent sites (P = 0.559).
  
  
  CONCLUSIONS
  The tumor location may contribute to postoperative tumor recurrence. However, these effects were inconsistent across tumor stages. Our results provide a better understanding of the prognostic disparity between tumor locations; this may improve patient consent and postoperative surveillance.
authors.affiliation: Department of Surgery, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo, Japan, konosuke125@gmail.com.
authors.forename: Konosuke
authors.initials: K
authors.lastname: Moritani
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Koji
authors.initials: K
authors.lastname: Okabayashi
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ishii
authors.forename: Takashi
authors.initials: T
authors.lastname: Endo
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kitagawa
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D003110:Colonic Neoplasms / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012008:Recurrence; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors