Comparison of the addition of T and N integer scores with TNM stage groups in head and neck cancer

The 1987 TNM classification system modified T and N definitions for squamous cell carcinomas of the head and neck. It did not change stage groupings (I through IV). The primary purpose of clinical staging is to divide patients into prognostically meaningful groups. The 1987 changes to the TNM T and N descriptions may not have removed the previously established heterogeneity within stage groups III and IV which existed before 1987. The development of a stage grouping system called TANIS (the T And N Integer Score), which is formed by adding the integer values of the T and N classifications, is reported herein. We compared the prognostic performance of T, N, TNM stage group, and TANIS stage for radiotherapy response and survival using data from 86 patients with newly diagnosed, measurable TNM II (oral cavity), and localized TNM III‐IV squamous cell carcinomas of the head and neck, excluding nasopharynx, who were randomized to test 5‐fluorouracil‐methotrexate sequencing. The sequencing of chemotherapy was shown to make no difference to prognosis. All patients received 60 Gy of radiotherapy in 6 weeks. As compared to T, N, and the TNM stage group system, TANIS was the single best predictor for a complete response to radiotherapy (p = 0.0005). TANIS was also the single best predictor for survival from randomization (p = 5 × 10⁻⁶). With the 86 patients divided into three groups (TANIS 2 to 3, 4, and 5 to 7), TANIS provided a better prognostic discrimination than did the TNM stage grouping method (TNM II, III, and IV). TANIS is a single index that combines T and N information in a simple way which was more strongly associated with radiotherapy response and survival than the traditional TNM stage groups.