title: Prognostic factors and the role of adjuvant chemotherapy in post-curative surgery for Dukes B and C colon cancers and survival outcomes: a Malaysian experience.
abstract: BACKGROUND
  Adjuvant chemotherapy improves survival in Dukes C colon cancers post-curative resection. However, the evidence for a role with Dukes B lesions remains unproven despite frequent use for disease characterized by poor prognostic features. In view of limited Asia-specific data, this study aimed to determine survival outcomes and identify prognostic factors in a tertiary teaching hospital in Malaysia.
  
  
  METHODS
  A total of 116 subjects who underwent curative surgery with and without adjuvant chemotherapy for Duke B and C primary colon adenocarcinomas diagnosed from 2004-2009 were recruited and data were collected retrospectively. Five-year overall survival (OS) and disease free survival (DFS) were analysed using Kaplan-Meier survival analysis and log-rank (Mantel-Cox) test. Prognostic factors were determined using Cox proportional hazards regression with both univariate and multivariate analyses.
  
  
  RESULTS
  The survival analysis demonstrated a 5-year OS of 74.0% for all patients, with 74.9% for Dukes C subjects receiving chemotherapy compared to 28.6% in those not receiving chemotherapy (p=0.001). For Dukes B disease, the 5-year survival rate was 82.6% compared to 75.0% for subjects receiving and not receiving chemotherapy, respectively (p=0.17). Independent prognostic factors identified included a CEA level more than 3.5 ng/ml (hazard ratio (HR)=4.78; p=0.008), serosal involvement (HR=3.75; p=0.028) and completion of chemotherapy (HR= 0.20; p=0.007).
  
  
  CONCLUSIONS
  In a regional context, this study supports current evidence from the West that adjuvant chemotherapy improves survival in Dukes C colon cancers post curative surgery. However, although a clear benefit has yet to be proven for Dukes B disease, our results suggest survival improvement in selected cases.
authors.affiliation: Clinical Oncology Unit, Faculty of Medicine, National University of Malaysia, Kuala Lumpur, Malaysia E-mail : iin_astrid@yahoo.co.uk.
authors.forename: Astrid Sinarti
authors.initials: AS
authors.lastname: Hassan
authors.forename: Manimalar
authors.initials: M
authors.lastname: Naicker
authors.forename: Khairul Hazdi
authors.initials: KH
authors.lastname: Yusof
authors.forename: Wan Zamaniah
authors.initials: WZ
authors.lastname: Wan Ishak
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000401:mortality* / Q000556:secondary / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives; D000069287:Capecitabine / Q000008:administration & dosage; D017024:Chemotherapy, Adjuvant; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D005500:Follow-Up Studies; D006801:Humans; D000077146:Irinotecan; D002955:Leucovorin / Q000008:administration & dosage; D008207:Lymphatic Metastasis; D008296:Malaysia; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D011184:Postoperative Period; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult
chemical_list: D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D000069287:Capecitabine; D000077146:Irinotecan; D002955:Leucovorin; D005472:Fluorouracil; D002166:Camptothecin