Head and neck cancer remains a challenging malignancy with high recurrence rates. Metabolomics offers a window into tumor biology. This study measured serum levels of six metabolites in 19 subjects, including untreated and treated HNC patients, benign tumor patients, and healthy controls. The results revealed that tryptophan and its main metabolite kynurenine were significantly elevated in malignant cases, with tryptophan declining after therapy but kynurenine persisting high, suggesting sustained immunosuppression. Arginine was markedly increased, while its downstream product putrescine rose only in treated patients, and the arginine/putrescine ratio normalized post-treatment, indicating its utility as a treatment efficacy marker. Additionally, glutamine was depleted and glutamate elevated in active disease, reflecting glutaminolysis-driven energy reprogramming. These metabolic disturbances were not observed in benign tumors or controls. The study proposes serum tryptophan and the arginine/putrescine ratio as promising biomarkers for disease activity and therapeutic monitoring. The capillary electrophoresis method used is inexpensive and feasible, supporting wider application in clinical settings.
The work titled “Head and/or Neck Cancer Deviates the Tryptophan, Arginine and Glutamine Pathways: Applications in Diagnosis and Prognosis”, was published on Malignancy Spectrum (published on June 30, 2026).
DOI：10.15302/MSP.2026.0010