5-FU	5-fluorouracil
AE	Adverse event
CI	Confidence interval
CPS	Combined positive score
CR	Complete response
CRP	C-reactive protein
CTCAE	National Cancer Institute Common Terminology Criteria for Adverse Events
DCR	Disease control rate
dMMR	Mismatch repair-deficient
DoR	Duration of response
ECOG	Eastern Cooperative Oncology Group
ESCC	Esophageal squamous cell carcinoma
FP	5-fluorouracil and cisplatin
FFPE	Formalin-fixed paraffin-embedded
HR	Hazard ratio
ICI	Immune checkpoint inhibitor
IHC	Immunohistochemistry
irAE	Immune-related adverse event
IRB	Institutional review board
IV	Intravenously
MFDS	Ministry of Food and Drug Safety
MSI	Microsatellite instability
NGS	Next-generation sequencing
NLR	Neutrophil-to-lymphocyte ratio
ORR	Objective response rate
OS	Overall survival
PCR	Polymerase chain reaction
PD-1	Programmed death-1
PD-L1	Programmed death-ligand 1
PD	Progressive disease
PFS	Progression-free survival
PLR	Platelet-to-lymphocyte ratio
PR	Partial response
RECIST 1.1	Response Evaluation Criteria in Solid Tumors version 1.1
SCC	Squamous cell carcinoma
SD	Stable disease
TMB	Tumor mutation burden
TPS	Tumor proportion score
TRAE	Treatment-related adverse event
UNL	Upper normal limit
XP	Capecitabine and cisplatin