title: Ten years experience of managing the primary tumours in patients with stage IV colorectal cancers.
abstract: BACKGROUND
  Approximately 20% of patients with colorectal cancer have metastases at the time of presentation. Such patients are often offered systemic chemotherapy but debate continues as to whether these patients benefit from resection of the primary tumour. We describe our ten years experience of managing the primary tumours in patients with stage IV colorectal cancer. The aim of this study was to describe the overall survival of patients undergoing surgery in these circumstances and to determine whether any prognostic indicators could be identified.
  
  
  METHODS
  920 consecutive patients presenting with stage IV colorectal cancer disease were identified from the Leicester Colorectal Cancer database. Patients undergoing resection of the primary tumour (Resection Group) with the residual metastatic disease were compared to those patients who had not their primary tumour excised (Non-Resection Group). Various different variables in two groups were compared by using Mann-Whitney U test. Kaplan-Meier survival analysis and log-rank test were used to compare the overall survivals. Univariate analysis was performed for each group to elicit the significant prognostic factors whereas Cox regression model was used to identify the independent predictors of overall survival.
  
  
  RESULTS
  The Kaplan-Meier survival analysis of two groups showed prolonged survival for Resection Group compared to the Non-Resection Group (median; 14.5 Vs 5.83 months, p = <0.005). The multivariate analysis of different survival predicting variables, revealed the resection of the primary tumour as an independent predictor of overall survival (p < 0.001). The univariate analysis of resection group identified age at presentation, tumour site, tumour stage (pT), lymph nodal stage (pN), complete histological resection, tumour fixity, ASA grade, mode of surgery, post-operative chemotherapy and sites of metastasis as significant factors (p < 0.05) for survival prediction. When these factors were used in Cox-Regression model, only the age at presentation (p = 0.001), tumour fixity (p = 0.012) and lymph nodal involvement (p = 0.042) were independent predictors for overall survival. Treatment with post-operative chemotherapy and a smaller volume of liver metastases were associated with prolonged survival (p < 0.05).
  
  
  CONCLUSIONS
  Surgical resection of primary tumour for stage IV colorectal cancers is associated with prolonged survival for selected patients. Age at presentation, extent of liver involvement, tumour fixity and ASA grade can help to decide the patients who will benefit from surgery.
authors.affiliation: Department of Colorectal Surgery, Leicester General Hospital NHS Trust, University Hospitals of Leicester NHS Trust, Leicester, United Kingdom. mia7@leicester.ac.uk
authors.forename: Muhammad Imran
authors.initials: MI
authors.lastname: Aslam
authors.forename: Ashish
authors.initials: A
authors.lastname: Kelkar
authors.forename: David
authors.initials: D
authors.lastname: Sharpe
authors.forename: John Stuart
authors.initials: JS
authors.lastname: Jameson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome