title: Colorectal cancer survival: An analysis of patients with metastatic disease synchronous and metachronous with the primary tumor.
abstract: BACKGROUND
  Whether metastatic colorectal cancer (mCRC) that presents synchronously with the primary lesion behaves differently from mCRC that appears metachronously to the primary disease is not clear.
  
  
  METHODS
  The South Australian Clinical Registry for mCRC collects data for patients diagnosed after February 2006. Data from 2502 patients, available on October 22, 2012, were analyzed according to stage at initial diagnosis (SAID) to compare outcomes between metachronous tumors (MTs) (stages I, II, III) and synchronous tumors (STs) (stage IV). Overall survival (OS) was calculated from the date of mCRC diagnosis.
  
  
  RESULTS
  Patients with ST had more liver-only metastases, and patients with MT had more lung-only, non-lung and non-liver, and non-lung metastases. The median time to recurrence differed significantly according to SAID: stage I, 49.3 mo (n = 29), stage II, 25.2 mo (n = 346) and stage III, 18.4 mo (n = 497). The median OS was longer for patients with MT than for those with ST (19.0 vs.14.9 mo, P = .003). For patients who received any treatment for mCRC, the OS was longer for patients with MT than for those with ST (19.2 vs. 15.3 mo, P = .005). In patients who received only chemotherapy for mCRC, the median OS was longer for patients with MT than for those with ST (15.2 vs. 9.9 mo, P < .0001). No difference in OS between the MT and ST groups for patients who did not receive treatment for mCRC (1.6 vs. 2.6 mo; P = .95).
  
  
  CONCLUSIONS
  Patients with MT have a longer OS than those with ST, independent of treatment. Classification of patients according to whether they have metachronous or synchronous presentation of mCRC is prognostic. These results may add further support for population screening with the aim to reduce de novo metastatic disease.
authors.affiliation: Department of Medical Oncology, Flinders Centre for Innovation in Cancer, Flinders Medical Centre, Bedford Park, Australia.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Department of Medical Oncology, The Queen Elizabeth Hospital Woodville, Australia; The University of Adelaide, Adelaide, Australia.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Price
authors.affiliation: Department of Surgery, Flinders Medical Centre, Bedford Park, Australia.
authors.forename: Carol
authors.initials: C
authors.lastname: Beeke
authors.affiliation: Department of Medical Oncology, Flinders Centre for Innovation in Cancer, Flinders Medical Centre, Bedford Park, Australia.
authors.forename: Kunal
authors.initials: K
authors.lastname: Jain
authors.affiliation: Department of Medical Oncology, Flinders Centre for Innovation in Cancer, Flinders Medical Centre, Bedford Park, Australia.
authors.forename: Gargi
authors.initials: G
authors.lastname: Patel
authors.affiliation: Department of Surgery, Flinders Medical Centre, Bedford Park, Australia.
authors.forename: Rob
authors.initials: R
authors.lastname: Padbury
authors.affiliation: Flinders Centre for Innovation in Cancer, Flinders University, Bedford Park, Australia.
authors.forename: Graeme P
authors.initials: GP
authors.lastname: Young
authors.affiliation: Sansom Institute for Health Research, University of South Australia, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Roder
authors.affiliation: Department of Medical Oncology, The Queen Elizabeth Hospital Woodville, Australia.
authors.forename: Amanda
authors.initials: A
authors.lastname: Townsend
authors.affiliation: Department of Medical Oncology, The Queen Elizabeth Hospital Woodville, Australia.
authors.forename: Sarwan
authors.initials: S
authors.lastname: Bishnoi
authors.affiliation: Department of Medical Oncology, Flinders Centre for Innovation in Cancer, Flinders Medical Centre, Bedford Park, Australia; Flinders Centre for Innovation in Cancer, Flinders University, Bedford Park, Australia. Electronic address: C.Karapetis@flinders.edu.au.
authors.forename: Christos S
authors.initials: CS
authors.lastname: Karapetis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy; D011379:Prognosis; D012042:Registries; D013021:South Australia / Q000453:epidemiology; D015996:Survival Rate; D055815:Young Adult
keywords: Epidemiological; Patterns of metastases; Patterns of treatment; Registry; Survival