title: Clinicopathological features and outcome in advanced colorectal cancer patients with synchronous vs metachronous metastases.
abstract: BACKGROUND
  Synchronous metastases of colorectal cancer (CRC) are considered to be of worse prognostic value compared with metachronous metastases, but only few and conflicting data have been reported on this issue.
  
  
  METHODS
  We retrospectively investigated patient demographics, primary tumour characteristics and overall survival (OS) in 550 advanced CRC patients with metachronous vs synchronous metastases, who participated in the phase III CAIRO study. For this purpose only patients with a prior resection of the primary tumour were considered.
  
  
  RESULTS
  The clinical and pathological characteristics associated with poor prognosis that we observed more often in patients with synchronous metastases (n=280) concerned an abnormal serum lactate dehydrogenase (LDH) concentration (P=0.01), a worse WHO performance status (P=0.02), primary tumour localisation in the colon (P=0.002) and a higher T stage (P=0.0006). No significant difference in median OS was observed between patients with synchronous metastases and metachronous metastases (17.6 vs 18.5 months, respectively, P=0.24).
  
  
  CONCLUSIONS
  Despite unfavourable clinicopathological features in patients with synchronous metastases with a resected primary tumour compared to patients with metachronous metastases, no difference in the median OS was observed. Possible explanations include a (partial) chemoresistance in patients with metachronous disease because of previous adjuvant treatment, whereas differences between the two groups in screening procedures resulting in a lead time bias to diagnosis or in prognostic molecular markers remain speculative.
authors.affiliation: Department of Medical Oncology, Radboud University Nijmegen Medical Centre, P.O. Box 9101, Nijmegen 6500 HB, The Netherlands.
authors.forename: L J M
authors.initials: LJ
authors.lastname: Mekenkamp
authors.forename: M
authors.initials: M
authors.lastname: Koopman
authors.forename: S
authors.initials: S
authors.lastname: Teerenstra
authors.forename: J H J M
authors.initials: JH
authors.lastname: van Krieken
authors.forename: L
authors.initials: L
authors.lastname: Mol
authors.forename: I D
authors.initials: ID
authors.lastname: Nagtegaal
authors.forename: C J A
authors.initials: CJ
authors.lastname: Punt
mesh_terms: D000328:Adult; D000368:Aged; D017326:Clinical Trials, Phase III as Topic; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology*; D005260:Female; D006801:Humans; D006836:Hydro-Lyases / Q000097:blood; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011379:Prognosis; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D006836:Hydro-Lyases; C045581:lactate dehydratase