Dukes' classification as a prognostic factor in patients with squamous cell carcinoma of the thoracic esophagus...

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.

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.

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).

Dukes' staging system for esophageal cancer is simpler, clearer and more accurate, and could thus be a better prognostic tool than the TNM classification.