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

Abstract

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.