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.