Modified traditional TNM staging of pyriform sinus and hypopharyngeal and laryngeal cancer based on lymph node ratio and its clinical significance: a population-based study combined with external validation.

BACKGROUND: To evaluate the application value of a new tumor-node-metastasis lymph node ratio-modified (TLNRM) staging prediction model based on lymph node ratio (LNR) in patients with pyriform sinus and hypopharyngeal and laryngeal cancer (PHLC).

MATERIALS AND METHODS: A total of 2257 patients with pathologically diagnosed PHLC from 2004 through 2019 were collected from the SEER database for analysis. The N staging of AJCC was replaced by LNR, and we compared the differences in patient prognosis and judgment ability between the new TLNRM staging and the 8th edition TNM staging. At the same time, data from 1094 people in our hospital were included for external verification and validation.

RESULTS: We selected four cutoff points based on LNR and reclassified N staging into five groups (LNR1-5). Compared to the traditional TNM staging (8th edition), the new TLNRM staging showed a statistically significant 5-year overall survival difference. The decision curve showed that the new TLNRM staging had a higher net benefit for different decision thresholds than the traditional TNM staging system's prediction line. The smaller Akaike information criterion (AIC) and Bayesian information criterion (BIC) suggested that the new staging system had a higher sensitivity to prognosis evaluation compared to the traditional staging system. TLNRM stage III patients can benefit from radiotherapy, while TLNRM IVA and IVB patients can benefit from chemoradiotherapy. The same conclusion has been drawn from external validation data from our center.

CONCLUSIONS: Compared with the traditional 8th edition AJCC staging system, the new TLNRM staging system has advantages in predicting the staging and prognosis of PHLC patients and can independently guide postoperative chemoradiotherapy in patients.