[Study on the difference and clinical value of serum amino acids in patients with laryngeal squamous cell carcinoma].

To detect the differences in types and levels of amino acids in the peripheral serum of patients with laryngeal squamous cell carcinoma and non-tumor patients, and explore their relationship with clinical parameters of laryngeal squamous cell carcinoma as well as their clinical value in diagnosis. High-performance liquid chromatography-tandem mass spectrometry（HPLC-MS） was employed to detect the serum amino acid contents and levels of 62 patients diagnosed with laryngeal carcinoma and 141 non-tumor patients at the First Affiliated Hospital of Jinzhou Medical University between September 2018 and February 2021. The study compared the differences in 22 non-essential and essential amino acids found in the serum between the experimental group and the control group. An ROC curve and risk scoring formula of multivariate linear logic regression model was utilized to evaluate the efficiency of serum amino acids in the early diagnosis of laryngeal carcinoma. There were significant differences in the contents of fourteen types of amino acids between the experimental and control groups, with thirteen amino acids showing higher levels in the experimental group（<0.05）. Seven of these amino acids were essential, including phenylalanine, threonine, leucine, valine, histidine, tyrosine, and citrulline. The other six amino acids were non-essential, including arginine, asparagine, cysteine, glycine, ornithine, and proline. Interestingly, the content of homocysteine in the experimental group was lower than that in the control group（=0.024）. Further analysis showed that patients with laryngeal squamous cell carcinoma in TNM stage Ⅰ and Ⅱ had higher serum methionine levels compared to those in stages Ⅲ and Ⅳ（=0.026）. In addition, the content of serum histidine was higher in patients with poorly differentiated squamous cell carcinoma compared to those with well-differentiated squamous cell carcinoma（=0.041）. The level of asparagine in the serum of patients with laryngeal squamous cell carcinoma older than 64 years old was lower than that in patients younger than 64 years old（=0.033）. The level of tryptophan in the serum of patients with a smoking history was lower than that in patients without a smoking history（=0.033）. The level of citrulline in the serum of patients with a history of alcohol consumption was higher than that in patients with no history of alcohol consumption（=0.003）. ROC curve analysis showed that out of the 14 different amino acids between the experimental and control groups, citrulline and cysteine were relatively effective as independent factors in the diagnosis of laryngeal squamous cell carcinoma, with an AUC of 0.856 and 0.850, respectively. Arginine was the most sensitive factor in the diagnosis of laryngeal squamous cell carcinoma（AUC=0.855）. However, citrulline alone had the highest specificity（0.830） in the diagnosis of laryngeal squamous cell carcinoma, and the combination of 12 amino acids significantly improved the diagnostic efficiency of laryngeal squamous cell carcinoma, with an AUC of 0.946, sensitivity of 0.887, and specificity of 0.894. A risk score formula for a multivariate logistic regression model was established based on the differential amino acid content in the serum. The risk score of laryngeal squamous cell carcinoma group was higher than that of the non-tumor group（<0.001）. The AUC of risk score in the diagnosis of laryngeal squamous cell carcinoma was 0.953 with sensitivity and specificity of 0.957 and 0.855. This study found that there are differences in the contents of 14 amino acids among which 13 amino acids were increased in serum of patients with laryngeal squamous cell carcinoma, and were associated with age, clinical stage, pathological differentiation, smoking, and drinking. Combined detection of 12 amino acids can improve the diagnostic efficiency of laryngeal squamous cell carcinoma and serve as potential markers for the auxiliary diagnosis of laryngeal squamous cell carcinoma using peripheral blood samples. Additionally, the established risk score model was found to be more effective in the diagnosis of laryngeal squamous cell carcinoma, indicating its important potential value as an auxiliary diagnostic tool.