Incorporation of log odds of positive lymph nodes into the AJCC TNM classification improves prediction of survival in oral cancer.

Objectives To assess the prognostic performance of a new N classification that incorporates the log odds of positive lymph nodes ( LODDS) into the routinely used pathological N classification for oral squamous cell carcinoma ( OSCC) patients. Design Retrospective cohort study utilising LODDS into pN category was performed, and the AJCC TNM stage and T-New N-M stage were compared with respect to 5-year disease-specific survival ( DSS) rates. The discriminability was evaluated from the linear trend chi-square test, Akaike information criterion ( AIC) and Harrell's c-statistic. Setting Medical centrer in Taiwan. Participants A total of 463 patients received primary surgery and neck dissection between 2004 and 2013 for OSCC. Main outcome measures The discriminability for 5-year DSS rates. Results The median follow-up period was 54 months, the mean patient age was 54 ± 11 years and 428 patients (92.4%) were male. The patients with higher LODDS had worse 5-year DSS rates. Incorporation of LODDS into the prognostic model based on the seventh edition of the TNM classification significantly improved discriminative performance for 5-year DSS with a lower AIC (1883 versus 1897), and higher prediction accuracy (Harrell's c-statistic: 0.768 versus 0.764). Conclusions By utilising a merger of the LODDS and pN classifications to create a new N classification has better discriminatory and predictive ability than pathological TNM staging and could help identify high-risk patients for intense adjuvant therapy. [ABSTRACT FROM AUTHOR]