Abstract Background Metabolomics offers novel insights into metabolic alterations in colorectal cancer (CRC), including changes in amino acid profiles. Several studies have reported differences between CRC patients and controls, suggesting potential diagnostic utility. Purpose To evaluate evidence on amino acid alterations in CRC and advanced precursors across biological matrices and their potential as non-invasive biomarkers. Method A comprehensive search of MEDLINE, EMBASE, and Cochrane CENTRAL identifi ed 77 studies analysing amino acids in faeces, urine, serum, plasma, tissue, and saliva. Results Few studies included advanced adenomas and none assessed advanced serrated polyps. Results were heterogeneous across matrices, except for tissue, where most amino acids were consistently upregulated in CRC. Reported diagnostic performance varied widely (AUC 0.28–0.91), with limited external validation. Conclusion Overall, amino acids show limited standalone diagnostic value but may enhance multi-metabolitepanels. Standardisation, inclusion of early lesions, and robust validation are essential for future biomarker research.
Opperman et al. (Sat,) studied this question.