title: The impact of POSSUM score on the long-term outcome of patients with rectal cancer.
abstract: OBJECTIVE
  The TMN staging system is the most important tool for predicting the long-term survival of colorectal cancer patients. However, physiological conditions and the operation may also influence survival. This study evaluated the impact of the Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (POSSUM) and the colorectal version (CR-POSSUM) on the long-term survival of patients with rectal cancer.
  
  
  METHODS
  Prospectively collected data were included of consecutive patients who underwent rectal cancer resection between 2000 and 2004. The relationship between the POSSUM and CR-POSSUM scores and the physiological components with outcomes and survivals was analysed.
  
  
  RESULTS
  The study included 343 patients (196 men, 263 open resections, 74 laparoscopic resections, six local resections) with a mean follow-up of 56.5 months. Thirty-five patients had had neoadjuvant chemoradiation and 115 had adjuvant chemotherapy. Their median POSSUM score was 34 (interquartile range 31-39) and the median CR-POSSUM score was 19 (interquartile range 18-21). The log rank test showed a significant difference (P < 0.05) in long-term survival for patients who belonged to different POSSUM score groups and POSSUM physiological score groups. Factors found on multivariate analysis to have significant association with long-term survival included TNM stage, perineural invasion, local invasion, obstruction, emergency operation, POSSUM score and POSSUM physiological score.
  
  
  CONCLUSIONS
  The mortality of patients after rectal cancer surgery can be predicted by POSSUM, P-POSSUM (a subsequent version of POSSUM) or CR-POSSUM with no significant difference between them. Both POSSUM and the POSSUM physiological score were significantly related to survival. The POSSUM score was one of the factors that independently predicted long-term survival.
authors.affiliation: Division of Colorectal Surgery, Department of Surgery, The University of Hong Kong, Hong Kong.
authors.forename: H
authors.initials: H
authors.lastname: Cheung
authors.forename: J T C
authors.initials: JT
authors.lastname: Poon
authors.forename: W-L
authors.initials: WL
authors.lastname: Law
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D015897:Comorbidity; D013505:Digestive System Surgical Procedures / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy; D011379:Prognosis; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D012720:Severity of Illness Index
keywords: POSSUM; Rectal cancer; long-term outcome