title: Modified Tumor Classification With Inclusion of Tumor Characteristics Improves Discrimination and Prediction Accuracy in Oral and Hypopharyngeal Cancer Patients Who Underwent Surgery.
abstract: Several histopathological characteristics have a significant prognostic impact on recurrence and survival rates in head and neck squamous cell carcinoma (HNSCC). We conducted a retrospective study on patients with HNSCC to compare traditional pathological T (pT) classification to a new T classification system that incorporates these histopathological characteristics.Newly diagnosed patients with HNSCC (n = 349) post major surgery were identified from the cancer registry database between 2004 and 2013. The pT and new T classification systems were compared with respect to recurrence-free survival (RFS), disease-specific survival (DSS), and survival rates using the Cox proportional hazards model with adjustments. The discriminatory ability of these 2 classification systems was evaluated using the adjusted hazard ratio (HR) and Akaike information criterion (AIC) in a multivariate regression model. The prediction accuracy was assessed using Harrell's C-statistic.The new T classification, which incorporated tumor size, extent, and location with histopathological features had better discriminatory ability and monotonicity of gradients than did pT classification. The new T4 classification yielded a higher adjusted HR in RFS (HR, 4.11; 95% confidence interval [CI], 7.75-9.65) and in DSS (HR, 4.39; 95% CI, 1.6-12.03), and a lower AIC in recurrence (927 vs 969) and survival rates (791 vs 833).The new T classification system had better discriminatory ability in RFS and DSS compared with the routinely used American Joint Committee on Cancer (AJCC) pT classification system. Therefore, this new T classification system, which includes tumor size, location, extent, and histopathological features, could be used as an alternative to AJCC pT classification for patients with HNSCC.
authors.affiliation: From the Department of Otolaryngology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan (C-CL, H-CH); School of Medicine, Tzu Chi University, Hualian, Taiwan (C-CL, H-CH, Y-CS); Division of Hematology-Oncology, Department of Internal Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan (Y-CS); Department of Medical Research, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan (C-HY); Department of Radiation Oncology, Chi-Mei Medical Center, Tainan, Taiwan (C-CY); and Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan (C-CY).
authors.forename: Ching-Chih
authors.initials: CC
authors.lastname: Lee
authors.forename: Hsu-Chueh
authors.initials: HC
authors.lastname: Ho
authors.forename: Yu-Chieh
authors.initials: YC
authors.lastname: Su
authors.forename: Chia-Hui
authors.initials: CH
authors.lastname: Yu
authors.forename: Ching-Chieh
authors.initials: CC
authors.lastname: Yang
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000145:classification* / Q000473:pathology* / Q000601:surgery; D005260:Female; D006258:Head and Neck Neoplasms / Q000145:classification* / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000145:classification* / Q000473:pathology* / Q000601:surgery; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D000077195:Squamous Cell Carcinoma of Head and Neck