title: Dukes' classification as a prognostic factor in patients with squamous cell carcinoma of the thoracic esophagus undergoing combined-modality treatment.
abstract: BACKGROUND
  Several disadvantages of the TNM classification have resulted in a search for a simpler, clearer, and more reliable staging system for esophageal cancer. We evaluated Dukes' classification as a prognostic indicator in 81 patients with squamous cell carcinoma of the thoracic esophagus treated with combined-modality therapy.
  
  
  METHODS
  The pathological staging was determined according to the TNM and Dukes' classification. The cumulative survival rates were calculated using the Kaplan-Meier method. The differences in survival between the patients in particular stages of both classifications were estimated with the log-rank test.
  
  
  RESULTS
  The differences in cumulative survival rates between TNM I and TNM IIa, between TNM IIa and TNM IIb and between TNM IIb and TNM III patients were 20.2% (37.2 vs. 46.6), 27.5% (46.6 vs. 33.8) and 60.7% (33.8 vs. 13.3), respectively, and were not statistically significant (P = 0.58, P = 0.53 and P = 0.18). The cumulative survival rates for TNM III and TNM IV patients were similar (13.3 and 14.3). The difference in cumulative survival rates between Dukes' A and B patients amounted to 52.5% (54.3 vs. 25.8), which was statistically significant (P = 0.02). The difference in cumulative survival rates between Dukes' B and C patients was 41.5% (25.8 vs. 15.1), but fell short of statistical significance (P = 0.12). The cumulative survival rates for Dukes' C and D patients were similar (15.1 and 16.6).
  
  
  CONCLUSIONS
  Dukes' staging system for esophageal cancer is simpler, clearer and more accurate, and could thus be a better prognostic tool than the TNM classification.
authors.affiliation: Second Department of General Surgery, Skubiszewski Medical University, Lublin, Poland. tomskocz@yahoo.com
authors.forename: Andrzej
authors.initials: A
authors.lastname: Dabrowski
authors.forename: Tomasz
authors.initials: T
authors.lastname: Skoczylas
authors.forename: Aleksander
authors.initials: A
authors.lastname: Ciechański
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Wallner
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Zinkiewicz
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Cwik
authors.forename: Rafał
authors.initials: R
authors.lastname: Górczyński
authors.forename: A
authors.initials: A
authors.lastname: Borowski
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000145:classification / Q000175:diagnosis / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000601:surgery; D004359:Drug Therapy, Combination; D004938:Esophageal Neoplasms / Q000145:classification / Q000175:diagnosis / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D015996:Survival Rate