Table 11.

Summary of findings about the role of liquid biopsy in saliva samples

Type of marker	Type of tumor	Study endpoint	Findings	Reference
sctDNA	HNSCC	Early diagnosis	sctDNA is a useful diagnostic tool for early cancer detection	Sethi 2009 [339]
sctDNA	OSSC	Disease recurrence and survival	HPV DNA presence and concentration in saliva correlated with disease recurrence and survival	Ahn 2014 [340]
sctDNA	OSSC	Prediction of treatment response	Salivary HPV DNA was predictive of treatment response	Hanna 2019 [341]
sctDNA	HNSCC	Early diagnosis and prognosis for oral cavity cancers;	Saliva ctDNA increaseS the sensitivity for diagnosis and prognosis of oropharynx, hypopharynx and larynx tumors	Wang 2015 [18]
sctDNA	NSLC	Analysis of EGFR mutation status	High concordance of EGFR mutation status between saliva and plasma	Ding 2019 [342]
mRNA	HNSCC	Early diagnosis	The expression of specific mRNAs showed a high sensitivity in early cancer detection	Li 2004; Elashoff 2012; Bu 2015; Chai 2016 [347–350]
miRNA	HNSCC	Early diagnosis and prediction of treatment response	The expression of specific miRNAs showed a high sensitivity in early cancer detection and is predictive of treatment response	Han 2018; Zahran 2015; Wu 2019; Uma 2020; Greither 2017; Ahmad 2019 [351–355]
LncRNAs; circRNAs	HNSCC	Early diagnosis and prognosis	LncRNAs and circRNAs showed a potential diagnostic and prognostic value	Tang 2013; Bahn 2014; Zhao 2018 [85, 227, 356–359]
Exosomal small RNA	Esophageal squamous cell carcinoma	Early diagnosis and prognosis	Saliva-derived exosomal small RNA signature provide diagnostic and prognostic information	Li 2022 [85, 227, 359]

LncRNA Long-non-coding RNA, mRNA messager-RNA, miRNA micro-RNA, circRNA circular RNA, NSCLC Non-Small Cell Lung Cancer, HNSCC Head and neck squamous cell carcinomas, OSSC Oropharyngeal squamous cell carcinoma