Nodal fusion and soft tissue invasion provide incremental risk stratification in pathologically N3b classification hypopharyngeal squamous cell carcinoma.

BACKGROUND

Hypopharyngeal squamous cell carcinoma (HPSCC) patients with extranodal extension (ENE) are classified as pN3b and have the poorest prognosis. However, further risk stratification within this high-risk subgroup remains controversial.

METHODS

We retrospectively reviewed 141 HPSCC patients who underwent neck dissection and whose disease was confirmed as pN3b at our hospital between January 2012 and December 2021. The primary endpoint was disease-free survival (DFS). Survival analysis was performed using the Kaplan‒Meier method with the log-rank test for group comparisons. Multivariable analysis was conducted using Cox proportional hazards regression.

RESULTS

Compared with patients without lymph node fusion (LNF, n = 30), those with LNF (n = 111) had significantly worse overall survival (OS, P = 0.0177), DFS (P = 0.0302), and distant metastasis-free survival (DMFS, P = 0.0404). Notably, patients with both LNF and soft tissue invasion (STI, n = 17) exhibited the poorest outcomes, with a median OS of only 19 months (95% CI: 4.210-33.790). Compared with patients with LNF alone (n = 94), those with both LNF and STI had significantly shorter OS (P = 0.0385), DFS (P = 0.0032), and regional recurrence-free survival (RFS, P = 0.0143). Multivariable analysis revealed that LNF and pT classification were independent risk factors for the entire pN3b cohort, whereas STI and pT classification were independent risk factors specifically for the LNF-positive subgroup.

CONCLUSION

We identified two candidate prognostic features (LNF and STI) for pN3b HPSCC patients. These findings may assist clinicians in identifying high-risk patients and guiding more personalized treatment decisions.