Programmed Death Ligand-1 and Tumor Burden Score Dictate Treatment Responses in Patients with Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma.

BACKGROUND

The significance of tumor burden for survival is unknown for patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC). The purpose of our study was to evaluate the prognostic impact of programmed death ligand-1 (PD-L1) and tumor burden score (TBS) in patients with R/M HNSCC.

PATIENTS AND METHODS

R/M HNSCC patients who were treated with cisplatin, 5-fluorouracil plus cetuximab (EPF) or pembrolizumab (PPF) as first-line treatment were included in our study. PD-L1 and TBS were estimated and correlated with treatment responses. Kaplan-Meier curves were plotted for outcomes estimation.

RESULTS

A total of 252 R/M HNSCC patients were included, with 126 high tumor burden (HTB) and 126 low tumor burden (LTB) patients. Median progression-free survival (PFS) was 7.1 months in LTB and 3.9 months in HTB ( < 0.001) and median overall survival (OS) was 14.2 months in LTB and 9.2 months in HTB ( = 0.001). Patients with LTB had better PFS and OS than those with HTB independent of PD-L1 status. Subgroup analysis showed HTB patients treated with EPF had better survival than those treated with PPF, regardless of PD-L1 expression. For LTB PD-L1 positive patients, there was a longer survival with PPF than EPF, while for LTB PD-L1 negative patients, survival was similar between PPF and EPF. Multivariate analysis exhibited that tumor burden was significantly correlated with OS.

CONCLUSIONS

Tumor burden is significantly correlated with survival in patients with R/M HNSCC. PD-L1 and TBS should be taken into consideration to determine first-line treatment.