title: Is there a sex effect in colon cancer? Disease characteristics, management, and outcomes in routine clinical practice.
abstract: BACKGROUND
  The incidence of colon cancer varies by sex. Whether women and men show differences in extent of disease, treatment, and outcomes is not well described. We used a large population-based cohort to evaluate sex differences in colon cancer.
  
  
  METHODS
  Using the Ontario Cancer Registry, all cases of colon cancer treated with surgery in Ontario during 2002-2008 were identified. Electronic records of treatment identified use of surgery and adjuvant chemotherapy. Pathology reports for a random 25% sample of all cases were obtained, and disease characteristics, treatment, and outcomes in women and men were compared. A Cox proportional hazards model was used to identify factors associated with overall (os) and cancer-specific survival (css).
  
  
  RESULTS
  The study population included 7249 patients who underwent resection of colon cancer; 49% (n= 3556) were women. Stage of disease and histologic grade did not vary by sex. Compared with men, women were more likely to have right-sided disease (55% vs. 44%,p≤ 0.001). Surgical procedure and lymph node yield did not differ by sex. Adjuvant chemotherapy was delivered to 18% of patients with stage ii and 64% of patients with stage iii disease; when adjusted for patient- and disease-related factors, use of adjuvant chemotherapy was similar for women and men [relative risk: 0.99; 95% confidence interval (ci): 0.94 to 1.03]. Adjusted analyses demonstrated that os [hazard ratio (hr): 0.80; 95% ci: 0.75 to 0.86] and css (hr: 0.82; 95% ci: 0.76 to 0.90) were superior for women compared with men.
  
  
  CONCLUSIONS
  Long-term survival after colon cancer is significantly better for women than for men, which is not explained by any substantial differences in extent of disease or treatment delivered.
authors.affiliation: Division of Cancer Care and Epidemiology, Queen's University Cancer Research Institute.
authors.forename: J S
authors.initials: JS
authors.lastname: Quirt
authors.affiliation: The departments of Oncology, Queen's University, Kingston, ON.; Surgery, Queen's University, Kingston, ON.
authors.forename: S
authors.initials: S
authors.lastname: Nanji
authors.affiliation: Division of Cancer Care and Epidemiology, Queen's University Cancer Research Institute.
authors.forename: X
authors.initials: X
authors.lastname: Wei
authors.affiliation: Medicine, Queen's University, Kingston, ON.; Public Health Sciences, Queen's University, Kingston, ON.
authors.forename: J A
authors.initials: JA
authors.lastname: Flemming
authors.affiliation: Division of Cancer Care and Epidemiology, Queen's University Cancer Research Institute; The departments of Oncology, Queen's University, Kingston, ON.; Medicine, Queen's University, Kingston, ON.; Public Health Sciences, Queen's University, Kingston, ON.
authors.forename: C M
authors.initials: CM
authors.lastname: Booth
keywords: Colon cancer; chemotherapy; outcomes; sex effects; surgery