Emerging salivary biomarkers for early detection of oral squamous cell carcinoma

Table 1 Salivary biomarkers for oral cancer detection

Cytokine	Biomarker matrix	Validation methods	Biological sample	Results	P value	Ref.
IL-6	Saliva	ELISA	Control (n = 13), OSCC (n = 13)	Salivary IL-6 levels were significantly higher compared to the control group	< 0.001	Arantes et al[9], 2018
IL-8	Saliva	ELISA	Control (n = 13), OSCC (n = 13)	Salivary IL-8 levels were significantly elevated in OSCC patients compared to the control group	< 0.001	Arantes et al[9], 2018
IL-6	Saliva	ELISA	Control (n = 20), OSCC (n = 19)	Elevated levels of IL-6 were identified in the OSCC group	< 0.05	Bastías et al[32], 2024
IL-8	Saliva	ELISA	Control (n = 20), OSCC (n = 19)	High level of IL-8 was identified in the OSCC group	< 0.05	Bastías et al[32], 2024
IL-6	Saliva serum	ELISA	Control (n = 20), OSCC (n = 30)	Significant difference was encountered between the salivary and serum IL-6 levels in the OSCC group and the control one	< 0.001	Chu et al[30], 2019
IL-8	Saliva serum	ELISA	Control (n = 20), OSCC (n = 30)	Highly significant difference was noted in the IL-8 salivary and serum levels of the OSCC group compared to the control one	< 0.001	Chu et al[30], 2019
IL-6	Saliva	ELISA	Control (n = 30), OSCC (n = 30)	Increased salivary levels of IL-6 were identified in the OSCC group compared to the control one	< 0.001	Elbehi et al[24], 2020
IL-8	Saliva	ELISA	Control (n = 30), OSCC (n = 30)	Highly significant difference was identified in the IL-8 levels compared to the control one	< 0.0001	Elbehi et al[24], 2020
IL-6	Saliva	Bio-Plex multiplex	Control (n = 21), OSCC (n = 20)	IL-6 concentration was higher in the OSCC group compared to the control (T0)	0.005	Lee et al[33], 2011
IL-8	Saliva	Bio-Plex multiplex	Control (n = 21), OSCC (n = 20)	IL-8 concentration was higher in the OSCC group compared to the control one (T0)	0.004	Lee et al[33], 2011
IL-6	Saliva serum	ELISA	Control (n = 52), OSCC (n = 52)	Higher levels of IL-6 before the treatment were associated with the survival rate; higher levels were identified in patients with OSCC compared to the controls	< 0.001	Gau and Wong[31], 2007
IL-8	Saliva serum	ELISA	Control (n = 52), OSCC (n = 52)	IL-8 was identified in higher concentrations in the saliva and serum of patients with OSCC	0.01	Gau and Wong[31], 2007
IL-6	Saliva serum	Luminex assay ELISA	Control (n = 9), OSCC (n = 26)	The IL-6 level was significant higher compared to the age-matched controls	0.0002	Assad et al[34], 2020
IL-8	Saliva	Luminex assay ELISA	Control (n = 9), OSCC (n = 26)	IL-8 had a slightly higher concentration in the OSCC group compared to age-matched controls	0.1087	Assad et al[34], 2020
IL-8	Saliva	ELISA	Control (n = 60), OSCC (n = 60)	The concentration of IL-8 was significantly higher in the OSCC group compared to the control	< 0.0001	Baňasová et al[23], 2015
IL-6	Saliva	ELISA	Control (n = 25), OSCC (n = 25)	Salivary IL-6 is significantly elevated in OSCC compared to the healthy control group	< 0.001	Ajdani et al[16], 2022

The table summarizes the key findings from various studies investigating interleukin-6 and interleukin-8 as diagnostic markers for oral cancer, highlighting their validation methods, sample types, and results. IL: Interleukin; ELISA: Enzyme-linked immunosorbent assay; OSCC: Oral squamous cell carcinoma.