The levels of organic
acids representing metabolic pathway end products are important indicators of physiological status, and may be associated with metabolic changes in
cancer. The aim of this study is to investigate the levels of organic
acids in cancerous and normal tissues from
gastric cancer patients and to confirm the role of metabolic alterations in gastric
carcinogenesis. Organic
acids in normal and cancerous tissues from forty-five patients with gastric
adenocarcinoma were investigated by gas chromatography-mass spectrometry in selected ion monitoring mode as
methoxime/tert-butyldimethylsilyl derivatives. We analysed the significant differences in the levels of organic
acids in normal and
cancer tissues and investigated the correlation of these levels in
cancer tissues with clinicopathological features. The levels of Krebs cycle components, including α-
ketoglutaric acid,
succinic acid,
fumaric acid,
malic acid and
oxaloacetic acid, were significantly increased in
cancer tissues compared to normal tissues. In addition, the levels of glycolytic products, including
pyruvic acid and
lactic acid, as well as the levels of
ketone bodies, including
3-hydroxybutyric acid, were also significantly increased in
cancer tissues compared to normal tissues. The levels of
ketone bodies in
cancer tissues with differentiated histology and in intestinal-type
cancer tissues were significantly increased. The organic
acid profiling analysis described here may be a generally useful clinical tool for understanding the complexity of metabolic events in gastric
adenocarcinoma, and organic
acids may have potential as metabolic markers for the future discovery of diagnostic and therapeutic modalities.