title: A simple technique to estimate best- and worst-case survival in patients with metastatic colorectal cancer treated with chemotherapy.
abstract: BACKGROUND
  Patients with incurable cancer usually want specific information about prognosis, and clinicians' estimates are often inaccurate. Studies in breast and lung cancer have suggested that simple multiples of the median overall survival (OS) can accurately estimate the time at which 90%, 75%, 25% and 10% of patients are alive.
  
  
  METHODS
  We identified 46 phase III randomised clinical trials of chemotherapy in metastatic colorectal cancer, representing data from 29 011 patients. We extracted data on demographics, treatment and survival from 96 patient cohorts and assessed agreement with the estimated survival time points, calculated as 0.25, 0.5, 2 and 3 times the median OS.
  
  
  RESULTS
  Median OS was 16.8 months in the trials. There were 342 assessable time points. For 301 of these, the estimated survival time was within 0.75-1.33 of the actual survival time (88% agreement). The worst agreement (76%) was at the earliest (90%) level of survival.
  
  
  CONCLUSIONS
  Simple multiples of the median OS give reasonable estimates of the times at which different survival levels are reached in patients with metastatic colorectal cancer. Taken with previous studies, these findings are likely to be valid across a large range of patients. We would encourage clinicians to think of prognosis as a trajectory, and to consider quoting survival ranges instead of point estimates, in discussions with patients.
authors.affiliation: Department of Clinical Oncology, Charing Cross Hospital, Imperial College Healthcare NHS Trust, London. Electronic address: mhw@doctors.net.uk.
authors.forename: M
authors.initials: M
authors.lastname: Williams
authors.affiliation: Department of Clinical Oncology, Kent and Canterbury Hospital, Canterbury.
authors.forename: R A
authors.initials: RA
authors.lastname: Singer
authors.affiliation: Department of Clinical Oncology, The Royal Surrey County Hospital, Guildford, UK.
authors.forename: A
authors.initials: A
authors.lastname: Lerner
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000401:mortality* / Q000473:pathology; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic
chemical_list: D005472:Fluorouracil
keywords: metastatic colorectal cancer; prognosis; review; survival