BACKGROUND.
The fifth edition of the American Joint Committee on Cancer staging manual defines new rules for classifying nasopharyngeal carcinoma. The authors tested the value of this new system by applying these rules retrospectively to their previously treated patients and comparing the results with those obtained using the fourth edition of the AJCC staging manual or the Ho staging system.
METHODS.
Information from 107 patients who had biopsy-proven squamous cell carcinoma of the nasopharynx that was treated in a constant fashion with definitive-intent radiation therapy alone at one institution provided the data base for this analysis. The extent of disease of each patient was staged according to the rules of 1) the fourth edition of the AJCC staging manual, 2) the Ho staging system, and 3) the fifth edition of the AJCC staging manual.
RESULTS.
The new system appears to be better than the two previous systems. It separated patients into cohorts of more equal size than did either of the other systems. It also correlated with outcome for the study population more appropriately than did the fourth edition of the AJCC staging manual or the Ho staging system.
CONCLUSIONS.
The fifth edition of the AJCC staging manual appears to be an improvement over the previous AJCC or Ho staging systems for the staging of nasopharyngeal carcinoma.