Comparative effectiveness of the revised American Joint Committee on Cancer staging system

The American Joint Committee on Cancer (AJCC) staging manual is periodically updated. This study aims to examine the staging performances in delineating stage-specific survival curves and to evaluate the reclassification of cases based on the 7th and 8th AJCC editions in Taiwan. Data were sourced from the Taiwan Cancer Registry for cases diagnosed in 2017 (7th edition) and 2018 (8th edition), each with a 2-year follow-up period. Performance was assessed using the area under the receiver operating characteristic curve and the Lorenz curve-derived Gini index, along with 2-year survival rates for evaluating patient prognoses. The 8th edition showed superior staging in 4 specific cancer types. Oropharyngeal cancer exhibited more variable 2-year survival rates across stages, and liver cancer showed a clearer decline in survival rates with advancing stages. The 8th edition also improved prognostic staging for nonsmall cell lung cancer and reclassified 26.4% of stage 4 prostate cancer patients under the 7th edition into stages 3 or 4A, showing 2-year survival rates above 90%. Our study highlights the 8th edition's refined capacity for stage-specific survival distinctions and reclassification of cases to enhance prognostication in certain cancers within Taiwan. We recommend a comprehensive evaluation when adopting a new edition or version.