Impact of neck nodal yield on immune checkpoint inhibitor outcome after recurrence in head and neck squamous cell carcinoma.

INTRODUCTION

Neck dissection and adequate lymph node yield (LNY) are important in the treatment of head and neck squamous cell carcinoma (HNSCC). Cervical lymph nodes represent the primary sites for T-cell priming; however, the impact of LNY on the efficacy of immune checkpoint inhibitors (ICIs) remains unclear.

METHODS

A total of 120 patients with HNSCC who relapsed after surgical resection and subsequently received ICIs were included. The association of LNY, neutrophil-lymphocyte ratio (NLR), and programmed death-ligand 1 (PD-L1) expression with ICI outcomes were evaluated.

RESULTS

Among 120 patients, 31 underwent unilateral, 82 bilateral, and 7 no neck dissection. The median LNY was 26 (mean, 29.9; range, 0-145). PD-L1 expression was evaluated in 80 patients, 69 of whom had combined positive score ≥ 1. The low-LNY group had a higher overall response rate to ICI than the high-LNY group (42.9% vs. 16.9%, P = 0.003). Patients with high LNY had inferior PFS (median, 1.3 vs. 5.9 months; P < 0.001) and OS (median, 9.7 vs. 21.1 months; P = 0.007) compared with those with low LNY. In multivariable analysis, high LNY and high NLR were independent predictors of poor survival, whereas PD-L1 expression was not. Among patients with PD-L1-positive tumors, those with high NLR had inferior survivals compared with those with low NLR.

CONCLUSIONS

Extensive lymphatic ablation, as reflected by high LNY, may be associated with diminished ICI efficacy in relapsed HNSCC. These findings suggest that LNY warrants further investigation as a potential biomarker for ICI outcomes in patients with post-surgical recurrent HNSCC.