Abstract
Objective: The plasma free amino acid profile reflects the metabolic status of the body and has been reported to change in various pathologic conditions, including liver dysfunction and various cancers. To develop a novel diagnostic marker for the early detection and clinical treatment of prostate cancer, the diagnostic performance of "AminoIndex", a multiplexed model based on the plasma free amino acid profile was investigated.
Methods: Plasma amino acid levels in prostate cancer patients and healthy controls were measured. After univariate analysis, the multiplexed model based on the plasma amino acid profile was applied in multivariate analysis to evaluate its diagnostic performance in distinguishing patients from healthy controls. The performance of "AminoIndex" in distinguishing prostate cancer patients from healthy controls was evaluated using the area under the receiver operating characteristic curves (ROC_AUC) obtained from predicted index scores.
Results: Plasma alanine, histidine, asparagine and proline were increased, whereas tryptophan was decreased in patients as compared to the healthy controls. The ROC_AUC of the "AminoIndex" in distinguishing prostate cancer patients from healthy controls was 0.74 and it was also able to detect early-stage cancer. No significant correlation was observed between "AminoIndex" and PSA.
Conclusion: "AminoIndex" could be used independently of PSA as a novel diagnostic marker for prostate cancer. Combinational diagnosis with PSA would be a promising strategy.
