title: Colorectal cancer in the young: trends, characteristics and outcome.
abstract: BACKGROUND
  Colorectal cancer (CRC) in young patients is associated with a poor outcome due to advanced stage at diagnosis and poor differentiation.
  
  
  OBJECTIVE
  The aim of this study is to compare clinicopathological characteristics, overall survival (OS) and disease-free survival (DFS) of young (≤40 years) and older patients with CRC.
  
  
  METHODS
  A total of 2,538 patients including 59 young patients (age ≤40 years) with CRC were identified over 20 years. The clinicopathological variables of young patients were compared with a group of consecutive older patients (n = 416) spanning both decades. Survival analysis was done using Kaplan-Meier, log-rank and Cox regression models.
  
  
  RESULTS
  The frequency in young patients increased from 1.4% to 3.0% from first to second decade (overall -2.3%, p = 0.006). There was a higher frequency of tumours with poor differentiation (43% vs. 16%, p = < 0.001), T4 stage (47% vs. 30%, p = 0.005) and vascular invasion (VI; 38% vs. 29%, p = 0.13) in younger group. There was no significant difference in OS (p = 0.116) and DFS (p = 0.261) between the two groups. Node-negative young patients had a significantly better OS (p = 0.046). Young patients with VI had significantly reduced OS (p = 0.043), whereas young patients without VI had significantly better OS (p = 0.012). Multivariate analysis showed T4 status (p = 0.001) and vascular invasion (p = 0.002) as independent prognostic factors for OS and T4 status (p = 0.004) as independent factor influencing DFS.
  
  
  CONCLUSIONS
  The frequency of CRC in young patients increased significantly. Vascular invasion is the single most important prognostic factor in young CRC. Along with vascular invasion, high proportion of T4 status in young patients increases the chances of recurrence and negates any survival advantage in young patients.
authors.affiliation: Department of Colorectal Surgery, St. George's Hospital, Blackshaw Road, London, SW17 0QT, UK.
authors.forename: Senthil
authors.initials: S
authors.lastname: Ganapathi
authors.forename: Devinder
authors.initials: D
authors.lastname: Kumar
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Katsoulas
authors.forename: David
authors.initials: D
authors.lastname: Melville
authors.forename: Shirley
authors.initials: S
authors.lastname: Hodgson
authors.forename: Caroline
authors.initials: C
authors.lastname: Finlayson
authors.forename: Robert
authors.initials: R
authors.lastname: Hagger
mesh_terms: D000328:Adult; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000628:therapy*; D003710:Demography; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D016019:Survival Analysis; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology