Clinical staging of oropharyngeal carcinoma: a critical evaluation of a new stage grouping proposal

BACKGROUND: An alternative to the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) stage grouping system was proposed for patients with oropharyngeal carcinoma by Hart et al. (1995) on behalf of the Dutch Head and Neck Oncology Cooperative Group. The system was created by regrouping the T, N, and M categories without redefining the categories themselves. METHODS: Data related to epidemiology, treatment, and survival from 224 previously untreated patients with oropharyngeal carcinoma were analyzed. Staging was performed according to the 1992 UICC/AJCC criteria and according to the proposed stage grouping system. Kaplan-Meier estimates of overall survival were compared for both staging systems; and in a Cox proportional hazards regression analysis, the influence of the variables age, gender, subsite and side of tumor location, histopathologic grade, form of treatment, and stage distribution (according to 1992 UICC criteria and that proposed by Hart et al.) on overall survival was determined. RESULTS: The proposed staging system showed a more balanced distribution of patients (16% in Stage I, 37% in Stage II, 14% in Stage III, and 33% in Stage IV compared with 5% in Stage I, 7% in Stage II, 21% in Stage III, and 67% in Stage IV according to UICC/AJCC 1992 staging). Furthermore, the proposed staging system showed better prognostic discrimination for overall survival (5-year survival rates according to the staging system of Hart et al. were 59% in Stage I, 31% in Stage II, 28% in Stage III, and 16% in Stage IV, vs. 61% in Stage I, 59% in Stage II, 32% in Stage III, and 24% in Stage IV according to UICC/AJCC 1992 staging). CONCLUSIONS: The results are in concordance with the results published by the Dutch Head and Neck Oncology Cooperative Group. It is possible to improve the current staging system by regrouping the T, N, and M categories. See editorial on pages 1611-2, this issue.]