Aromatic Amino Acids as Biomarkers of Gastric Cancer
Higher levels of aromatic amino acids may indicate early stage gastric cancer, according to a research group in China.1 Gastric cancer is difficult to diagnose at the onset of the disease because symptoms are normally found at a later stage. For patients requiring treatment, time is precious, and so efforts are in place to find new methods of diagnosing gastric cancer to remove the need for a display of physical symptoms.
An endoscopy for sample collection followed by a pathological biopsy is the diagnostic method of choice for most clinicians. This is said to be highly invasive and in some cases inaccurate.
In it’s most basic definition, cancer is a collection of cancerous cells with invasive properties that disrupt the body’s normal functions. When ‘normal’ cells transform into cancerous cells, there are chemical changes within the metabolome. Researchers in China have exploited this characteristic to propose novel gastric cancer biomarkers.
Samples were taken from the gastric juice of 185 subjects; some were healthy and some had been diagnosed with either early- or late-stage gastric cancer. Liquid chromatography–mass spectrometry (LC–MS) analysis showed a higher level of aromatic amino acids, including tyrosine, phenylalanine and tryptophan in the metabolome of patients diagnosed with early stage gastric cancer compared to control subjects.
Biomarkers could potentially be used in large-scale population screening programmes to increase diagnosis rates; however, the sample size of the study and the boundaries of what is normal and what is not need to be optimized.
1. Deng et al, PLoS ONE 7(11), e49434 (2012).