Serum Amino Acid Levels in Patients With Hepatocellular Carcinoma

Abstract

Serum amino acid concentrations in cirrhotic patients with and without hepatocellular carcinoma (HCC) were investigated. Elevation of serum aromatic amino acids (AAA) and methionine levels observed in cirrhotic patients without malignancy was not apparent in cirrhotic cases with HCC, and thus the ratio of branched chain amino acids (BCAA) to AAA was not so diminished in the latter cases. Development of hepatic encephalopathy in cirrhotic patients with HCC led to only a slight change in the serum aminogram characteristic of hepatic failure. In patients who underwent operations, tissue amino acid compositions of hepatocellular, gastric, and colon cancers were compared with each other and their respective surrounding epithelia. Amino acid contents in the tumor tissue were generally higher than those in the respective nontumorous parts, especially in the case of HCC. The methionine, tyrosine, and phenylalanine contents in HCC were much higher than in cirrhotic or normal liver. Serum aminograms in rats with ethionine‐induced HCC were similar to those in cirrhotic patients with HCC. Amino acid contents in HCC were higher than those in the surrounding cirrhotic liver tissue of rats. Serum and liver tyrosine and isoleucine contents rose significantly in rats 5 to 6 weeks after the initiation of a 0.25% ethionine‐containing diet. After the 20th week of the experiment, by which time well‐differentiated HCC had developed, liver tyrosine and isoleucine contents increased whereas serum isoleucine concentrations decreased. The results suggest that the serum amino acid patterns characteristic of cirrhotic patients with HCC may result from the increased consumption of amino acids by HCC. Determinations of the amino acid levels are also useful for estimating the prognosis and discovering imminent hepatic encephalopathy in cirrhotic patients with HCC.

Serum Concentration of Free Amino Acids in Dogs Suffering From Perianal Tumours

“…Taking under consideration the results from the study, prediction of tumour malignancy by assessment of sulphur-containing amino acids seems to be limited due to the fact that cysteine and cystine in serum were not evaluated. In opposition to the observations, the results of experimental studies on humans have shown that aromatic amino acid concentration increases in subjects suffering from neoplastic processes of the gastrointestinal tract, while BCAAs level decreases in such patients (13,17,31). Other data from research conducted on humans demonstrated changes in BCAAs concentration in patients with various neoplastic diseases, although total amino acid level was decreased (7,17,21).…”

“…Due to a huge contribution of protein synthesis in growing tumours, it was found that the metabolism of sulphur-containing amino acids is most significantly influenced under such conditions. Thus, serum evaluation of amino acids may be considered as a valuable method for diagnosis and treatment of patients suffering from neoplastic diseases (19,20,30,31).…”

Specific alterations in the serum amino acid profile of patients with lung cancer and head and neck cancer

“…Some studies have analyzed changes in certain amino acids in each type of tumor, in order to determine the influence of a particular tumor on the general metabolism of the patient, and occasionally to use as a diagnostic and therapeutic parameter [12][13][14][15][16][17][18] . Most of these studies, however, have included a low number of patients, with notable variations in their weight, clinical situation, tumor stage, and so on, all of which affect their reliability.…”

The management of the patient with malnutrition: from evidence to clinical practice

“…In patients with advanced chronic liver disease, BCAA concentrations are low, whereas the concentrations of aromatic amino acids (AAAs) such as phenylalanine and tyrosine are high, a low Fisher ratio (BCAAs/AAAs) has been proven to a marker of liver disease progression, while a simplified Fisher ratio (BCAAs/tyrosine) predicts albumin levels at one year. [33][34][35] Several clinical trials have suggested that BCAA supplementation improves the prognosis of cirrhotic patients, and a recent review concludes that their supplementation improves nutritional status and quality of life in patients with advanced cirrhosis, and some international guidelines already recommend their use. 36 Another review of meta-analysis recommends oral administration of BCAAs in hepatic encephalopathy, especially in combination with nonabsorbable disaccharides.…”