RUEY-LONG HONGYen, Chia-JuiChia-JuiYenLien, Ming-YuMing-YuLienCheng, RebeccaRebeccaChengSu, Yu-WenYu-WenSuLin, Han-NanHan-NanLinPoon, Song LingSong LingPoonChien, Chih-YenChih-YenChien2024-07-152024-07-152024-05https://scholars.lib.ntu.edu.tw/handle/123456789/719761This study explored the relationship between betel-nut chewing and programmed death-ligand 1 (PD-L1) expression in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) patients in Taiwan. A total 280 R/M HNSCC patients, predominantly male, were evaluated; 75.4 % of whom chewed betel-nut. The prevalence of PD-L1 expression (combined positive score ≥1) was 94.3 % with similar PD-L1 expression rates between betel-nut-exposed and non-exposed groups. PD-L1 prevalence did not differ in those who received prior first-or second-line systemic therapy. In summary, betel-nut exposure did not notably affect PD-L1 expression rates in R/M HNSCC patients in Taiwan.enjournal article10.1016/j.oraloncology.2024.10676038520758