Background: The Chinese 1992 staging system for nasopharyngeal carcinoma (NPC) has been widely adopted in mainland China since 1992. The fifth edition of the International Union Against Cancer (UICC) TNM classification defines new rules for classifying NPC. The current study compares the two in predicting NPC prognosis.
Methods: Four hundred eleven NPC patients, most of whom had disease of undifferentiated histologic type and were treated in a constant fashion and with definitive intent with radiation therapy alone, entered this comparative study. The patients were restaged according to the rules of the fifth edition of the UICC staging manual and the Chinese 1992 staging system.
Results: In the opinion of the authors, the predictive power of the Chinese 1992 T classification was superior. Conversely, the authors felt that the UICC N classification was more reasonable. The patients were categorized more evenly by the UICC stages than by the Chinese 1992 stages. The 5-year disease specific survival rates for patients in corresponding stages of both systems were almost identical despite differences in the criteria defining T and N classifications. Statistical analysis showed that the agreement rate was 72%. There were some agreement and correlation between the two staging systems.
Conclusions: Both systems are essentially similar. Each system appears to have some subtleties that could improve the outcome prediction of the other system if the two were somehow combined. However, it appeared to the authors that the UICC system was slightly better.
Copyright 2000 American Cancer Society.