Plasma free amino acid profiling of esophageal cancer using high-performance liquid chromatography spectroscopy

Table 1 Concentration of plasma free amino acids in controls and esophageal squamous cell carcinoma patients

Amino acid (μmol/L)	Control	ESCC	P value
Aspartate	0.04 ± 0.03	0.06 ± 0.07	< 0.001
Glutamate	0.37 ± 0.30	0.07 ± 0.06	< 0.001
Asparagine	0.06 ± 0.04	0.05 ± 0.04	0.36
Serine	0.27 ± 0.51	0.12 ± 0.12	0.51
Glycine	0.14 ± 0.09	0.07 ± 0.03	< 0.001
Histidine	0.28 ± 0.17	0.16 ± 0.11	< 0.001
Arginine	0.09 ± 0.05	0.09 ± 0.15	0.77
Threonine	0.21 ± 0.21	0.08 ± 0.08	< 0.001
Taurine	0.26 ± 0.18	0.13 ± 0.12	< 0.001
Alanine	0.98 ± 1.06	0.19 ± 0.18	< 0.001
Proline	0.08 ± 0.06	0.06 ± 0.07	0.19
Cystine	0.01 ± 0.02	0.03 ± 0.04	0.01
Tyrosine	0.07 ± 0.06	0.06 ± 0.03	0.50
Valine	0.24 ± 0.16	0.23 ± 0.29	0.80
Methionine	0.12 ± 0.19	0.02 ± 0.01	< 0.001
Lysine	0.09 ± 0.05	0.08 ± 0.07	0.45
Isoleucine	0.29 ± 0.33	0.12 ± 0.08	< 0.001
Leucine	0.21 ± 0.16	0.12 ± 0.08	< 0.001
Phenylalanine	0.12 ± 0.07	0.07 ± 0.03	< 0.001