Leucine, isoleucine, and valine are collectively known as branched chain amino acids (BCAAs) and are often discussed in the same physiological and pathological situations. The two consecutive initial reactions of BCAA catabolism are catalyzed by the common enzymes referred to as branched chain aminotransferase (BCAT) and branched chain α-keto acid dehydrogenase (BCKDH). BCAT transfers the amino group of BCAAs to 2-ketoglutarate, which results in corresponding branched chain 2-keto acids (BCKAs) and glutamate. BCKDH performs an oxidative decarboxylation of BCKAs, which produces their coenzyme A-conjugates and NADH. BCAT2 in skeletal muscle dominantly catalyzes the transamination of BCAAs. Low BCAT activity in the liver reduces the metabolization of BCAAs, but the abundant presence of BCKDH promotes the metabolism of muscle-derived BCKAs, which leads to the production of glucose and ketone bodies. While mutations in the genes responsible for BCAA catabolism are involved in rare inherited disorders, an aberrant regulation of their enzymatic activities is associated with major metabolic disorders such as diabetes, cardiovascular disease, and cancer. Therefore, an understanding of the regulatory process of metabolic enzymes, as well as the functions of the BCAAs and their metabolites, make a significant contribution to our health.

Branched-chain amino acids (BCAAs), as essential amino acids, engage in various physiological processes, such as protein synthesis, energy supply, and cellular signaling. The liver is a crucial site for BCAA metabolism, linking the changes in BCAA homeostasis with the pathogenesis of a variety of liver diseases and their complications. Peripheral circulating BCAA levels show complex trends in different liver diseases. This review delineates the alterations of BCAAs in conditions including non-alcoholic fatty liver disease, hepatocellular carcinoma, cirrhosis, hepatic encephalopathy, hepatitis C virus infection, and acute liver failure, as well as the potential mechanisms underlying these changes. A significant amount of clinical research has utilized BCAA supplements in the treatment of patients with cirrhosis and liver cancer. However, the efficacy of BCAA supplementation in clinical practice remains uncertain and controversial due to the heterogeneity of studies. This review delves into the complicated relationship between BCAAs and liver diseases and tries to untangle what role BCAAs play in the occurrence, development, and outcomes of liver diseases.

Background: Anticancer therapies are associated with significant adverse side effects and few treatments that alleviate symptoms exist. Branched-chain amino acids (BCAAs) have been investigated as an intervention for reducing anticancer therapy side effects, although a review of the literature results has yet to be published. Aim: The current review summarizes evidence surrounding this topic and suggests both support and caution in using BCAAs as a treatment for patients receiving anticancer therapies. Methods: In this review, two literature searches were completed. Google Scholar, PubMed, EBSCOhost, and Cochrane databases were searched using the terms "branched-chain amino acids and cancer" and "BCAA and cancer." Results: Two bodies of evidence emerged: One supporting beneficial effects and the other showing adverse outcomes of BCAA supplementation in patients with cancer. Evidence of benefit was a decrease in malnourishment and unintentional weight loss during and after chemotherapy. Potential harms included the idea cancer cells may utilize BCAAs as a source of energy for growth. Conclusions: Supplementation of BCAAs in individuals with cancer should be implemented cautiously. Those who are severely malnourished due to anticancer therapy may benefit the most. BCAA supplementation may also be provided once cancer has been destroyed from the individual's body to aid with recovery.

We aimed to compare the safety of lenvatinib as first-line treatment for unresectable hepatocellular carcinoma (HCC) in patients with Child-Pugh A (CP-A) and Child-Pugh B (CP-B) and to determine the adverse events (AEs) that cause dose reduction/interruption of treatment in patients with CP-B.

Sixty-six patients with lenvatinib as a first-line treatment for HCC at Ogaki Municipal Hospital (Ogaki, Japan) between April 2018 and January 2022 were retrospectively evaluated. We analyzed the treatment duration, AEs, and reasons for dose reduction/interruption associated with lenvatinib treatment in patients with CP-A and CP-B HCC.

The CP-B group had significantly more cases of grade ≥ 2 fatigue and anorexia than the CP-A group (p  =  0.045 and p  =  0.042, respectively). Regarding AEs that caused dose reduction/interruption of treatment, the CP-A group had significantly more cases of proteinuria than the CP-B group (p  =  0.015), whereas the CP-B group had significantly more cases of hand-foot syndrome (HFS) than the CP-A group (p  =  0.013).

Patients with CP-B have greater difficulty than patients with CP-A in continuing treatment with repeated dose reductions/interruption of treatment due to intolerable grade ≥ 2 AEs (fatigue and anorexia). HFS is more likely to cause dose reduction/interruption of treatment in CP-B than in CP-A unresectable HCC.

Dietary supplementation with branched-chain amino acids (BCAA) is often used in cirrhotic patients to improve nutritional status. We wanted to explore the evidence for BCAA supplementation in chronic liver disease.

We searched MEDLINE and EMBASE for studies with BCAA supplementation with the presence of a disease-control group (placebo or no intervention) using search terms 'liver cirrhosis', 'hepatocellular carcinoma', 'branched chain amino acids' and relevant synonyms. Risk of bias was assessed using ROBINS-I and RoB 2.0 tools. Meta-analyses were performed with a random-effects model. Results were reported following EQUATOR guidelines.

Of 3378 studies screened by title and abstract, 54 were included (34 randomized controlled trials, 5 prospective case-control studies, 13 retrospective case-control studies: in total 2308 patients BCAA supplementation, 2876 disease-controls). Risk of bias was high/serious for almost all studies. According to meta-analyses, long-term (at least 6 months) BCAA supplementation in cirrhotic patients significantly improved event-free survival (p = .008; RR .61 95% CI .42-.88) and tended to improve overall survival (p = .05; RR .58 95% CI .34-1.00). Two retrospective studies suggested the beneficial effects during sorafenib for hepatocellular carcinoma. Available studies reported no beneficial effects or contradictory results of BCAA after other specific therapeutic interventions (resection or radiological interventions for hepatocellular carcinoma, liver transplantation, paracentesis or variceal ligation). No convincing beneficial effects of BCAA supplementation on liver function, nutritional status or quality of life were found. No study reported serious side effects of BCAA.

Prophylactic BCAA supplementation appears safe and might improve survival in cirrhotic patients.

Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer and presents together with cirrhosis in most cases. In addition to commonly recognized risk factors for HCC development, such as hepatitis B virus/hepatitis C virus infection, age and alcohol/tobacco consumption, there are nutritional risk factors also related to HCC development including high intake of saturated fats derived from red meat, type of cooking (generation of heterocyclic amines) and contamination of foods with aflatoxins. On the contrary, protective nutritional factors include diets rich in fiber, fruits and vegetables, n-3 polyunsaturated fatty acids and coffee. While the patient is being evaluated for staging and treatment of HCC, special attention should be paid to nutritional support, including proper nutritional assessment and therapy by a multidisciplinary team. It must be considered that these patients usually develop HCC on top of long-lasting cirrhosis, and therefore they could present with severe malnutrition. Cirrhosis-related complications should be properly addressed and considered for nutritional care. In addition to traditional methods, functional testing, phase angle and computed tomography scan derived skeletal muscle index-L3 are among the most useful tools for nutritional assessment. Nutritional therapy should be centered on providing enough energy and protein to manage the increased requirements of both cirrhosis and cancer. Supplementation with branched-chain amino acids is also recommended as it improves response to treatment, nutritional status and survival, and finally physical exercise must be encouraged and adapted to individual needs.

This review provides epidemiological and translational evidence for milk and dairy intake as critical risk factors in the pathogenesis of hepatocellular carcinoma (HCC). Large epidemiological studies in the United States and Europe identified total dairy, milk and butter intake with the exception of yogurt as independent risk factors of HCC. Enhanced activity of mechanistic target of rapamycin complex 1 (mTORC1) is a hallmark of HCC promoted by hepatitis B virus (HBV) and hepatitis C virus (HCV). mTORC1 is also activated by milk protein-induced synthesis of hepatic insulin-like growth factor 1 (IGF-1) and branched-chain amino acids (BCAAs), abundant constituents of milk proteins. Over the last decades, annual milk protein-derived BCAA intake increased 3 to 5 times in Western countries. In synergy with HBV- and HCV-induced secretion of hepatocyte-derived exosomes enriched in microRNA-21 (miR-21) and miR-155, exosomes of pasteurized milk as well deliver these oncogenic miRs to the human liver. Thus, milk exosomes operate in a comparable fashion to HBV- or HCV- induced exosomes. Milk-derived miRs synergistically enhance IGF-1-AKT-mTORC1 signaling and promote mTORC1-dependent translation, a meaningful mechanism during the postnatal growth phase, but a long-term adverse effect promoting the development of HCC. Both, dietary BCAA abundance combined with oncogenic milk exosome exposure persistently overstimulate hepatic mTORC1. Chronic alcohol consumption as well as type 2 diabetes mellitus (T2DM), two HCC-related conditions, increase BCAA plasma levels. In HCC, mTORC1 is further hyperactivated due to RAB1 mutations as well as impaired hepatic BCAA catabolism, a metabolic hallmark of T2DM. The potential HCC-preventive effect of yogurt may be caused by lactobacilli-mediated degradation of BCAAs, inhibition of branched-chain α-ketoacid dehydrogenase kinase via production of intestinal medium-chain fatty acids as well as degradation of milk exosomes including their oncogenic miRs. A restriction of total animal protein intake realized by a vegetable-based diet is recommended for the prevention of HCC.

Lenvatinib was recently approved as a novel first-line molecular targeted agent (MTA) for treating hepatocellular carcinoma (HCC). The importance of relative dose intensity (RDI) has been shown in the treatment of various types of cancers. However, RDI may not accurately reflect the treatment intensity of lenvatinib, as it is the first oral MTA where the dose is based on the patient's weight. We aimed to evaluate the utility of 2M-DBR (the delivered dose intensity/body surface area ratio at 60 days) by comparing the relationship between 2M-DBR, 2M-RDI (RDI at 60 days), and the therapeutic response. The therapeutic response to lenvatinib was evaluated in 45 patients who underwent computed tomography 8-12 weeks after treatment initiation. We also investigated the clinical factors associated with high 2M-DBR. The area under the receiver operating characteristic of 2M-DBR that predicts the response to lenvatinib was higher than that of 2M-RDI (0.8004 vs. 0.7778). Patients with high 2M-DBR achieved significantly better objective responses and disease control rates than those with low 2M-DBR (p < 0.0001 and 0.0008). Patients with high 2M-DBR experienced significantly longer progression-free survival (PFS) than those with low 2M-DBR (p = 0.0001), while there was no significant correlation between 2M-RDI levels and PFS (p = 0.2198). Patients who achieved higher levels of 2M-DBR had a significantly better modified ALBI grade (p = 0.0437), better CONUT score (p = 0.0222), and higher BTR (p = 0.0281). Multivariate analysis revealed that high 2M-DBR was the only significant factor associated with longer PFS. In conclusion, 2M-DBR could be an important factor that reflects treatment intensity and useful for predicting the response to lenvatinib against HCC, instead of 2M-RDI.

To assess the impact of obesity on cancer-related fatigue (CRF) in patients with breast cancer, through a secondary analysis of a large, longitudinal, nationwide study of breast cancer patients beginning chemotherapy.

All patients (N = 565; aged 53 ± 10.6) with breast cancer completed the multidimensional fatigue symptom inventory and the symptom inventory to measure CRF symptoms at baseline, post-chemotherapy, and 6 months post-chemotherapy. Height and weight at baseline were used to categorize subjects based on body mass index (BMI): obese (≥ 30.0 kg/m²; n = 294), overweight (25.0-29.9 kg/m²; n = 146), and normal weight (18.5-24.9 kg/m²; n = 125). Multivariate regression models evaluated the relationship of obesity level to CRF over time, controlling for age, menopausal status, race, Karnofsky Performance Status, cancer stage, radiation, and exercise status.

At baseline, the obese had significantly higher CRF symptoms than the normal weight subjects for both the Multidimensional fatigue symptom inventory (MFSI) total (obese = 11.2 vs normal weight = 6.3; p = 0.03) and Symptom Inventory (SI) (obese = 3.5 vs normal weight = 2.9; p = 0.03). Significantly higher SI fatigue scores persisted at post-chemotherapy for the obese (obese = 5.0 vs normal weight = 4.4; p = 0.02). At 6 months post-chemotherapy, the obese patients still had significantly higher SI fatigue scores (obese = 3.5 vs normal weight = 3.0; p = 0.05).

Obese patients suffered greater CRF from pre-chemotherapy through 6 months post-chemotherapy. Recommendations for weight loss or weight maintenance may impact CRF levels in obese breast cancer patients before and after chemotherapy.