title: Do metastatic colorectal cancer patients who present with late relapse after curative surgery have a better survival?
abstract: BACKGROUND
  Patients who relapse after potentially curative surgery for colorectal cancer tend to relapse within 5 years. There is, however, a group of patients who relapse beyond 5 years after resection and this late relapsing group may have a different behaviour and prognosis.
  
  
  METHODS
  We analysed data from a prospective population-based registry to compare the characteristics and survival of relapsed patients with metachronous mCRC. Patients were categorised into relapse at <2, 2-5 and >5 years following their initial surgery. Univariate log-rank tests and multivariate Cox regression was performed to determine whether time to relapse (TTR) and other factors were associated with overall survival (OS).
  
  
  RESULTS
  A total of 750 metachronous mCRC patients were identified. In all, 56% relapsed ≤2 years, 32.4% at 2-5 years and 11.6% >5 years. Median survival time from the time of diagnosis of mCRC for the three groups was 17.6, 26.1 and 27.5 months, respectively. Short TTR (<2 years) was significantly associated with survival (HR=0.75, 95% confidence interval (CI)=0.60-0.93 and HR=0.73, 95% CI=0.53-1.01, respectively, for 2-5 and >5 years vs <2 years, P<0.05). However, there was no significant difference in survival between patients who relapsed at 5 years or later compared with those who relapsed between 2 and 5 years (HR=0.98, 95% CI=0.69-1.38, P=0.90).
  
  
  CONCLUSIONS
  TTR within 2 years is an independent predictor of shorter survival time for mCRC patients who experience a relapse. These data do not support the hypothesis that patients who have late relapse late (>5 years) have a 'better' biology or survival compared with patients with a TTR of 2-5 years.
authors.affiliation: Department of Medical Oncology, The Queen Elizabeth Hospital, Woodville, South Australia, Australia.
authors.forename: V T
authors.initials: VT
authors.lastname: Broadbridge
authors.forename: C S
authors.initials: CS
authors.lastname: Karapetis
authors.forename: C
authors.initials: C
authors.lastname: Beeke
authors.forename: R J
authors.initials: RJ
authors.lastname: Woodman
authors.forename: R
authors.initials: R
authors.lastname: Padbury
authors.forename: G
authors.initials: G
authors.lastname: Maddern
authors.forename: S W
authors.initials: SW
authors.lastname: Kim
authors.forename: D
authors.initials: D
authors.lastname: Roder
authors.forename: P
authors.initials: P
authors.lastname: Hakendorf
authors.forename: T J
authors.initials: TJ
authors.lastname: Price
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000401:mortality* / Q000601:surgery; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality*; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate