The effect of dietary protein depletion on hepatic 5-fluorouracil metabolism

The role of nutrition in children with cancer

In recent years, the influence of nutrition on the health and growth of children has become increasingly important. The relevance of nutrition is even greater for children who are facing cancer. Malnutrition, within the context of undernutrition and overnutrition, may impact not only the effectiveness of treatments and outcomes, but also the quality of life for patients and their families. In this article, we review nutritional assessment methods for children with cancer, focusing on the specific characteristics of this population and analyze the efficacy of nutritional interventions, which include enteral, parenteral, and nutritional education. From our analysis, two important conclusions emerged: i) there is a need to focus our attention on the nutritional status and the body composition of oncologic children, since these factors have a relevant impact on clinical outcomes during treatment as well as after their conclusion; ii) the support of skilled clinical nutrition personnel would be extremely helpful for the global management of these patients.

Therapeutic drug monitoring for cytotoxic anticancer drugs: Principles and evidence-based practices

Cytotoxic drugs are highly efficacious and also have low therapeutic index. A great degree of caution needs to be exercised in their usage. To optimize the efficacy these drugs need to be given at maximum tolerated dose which leads to significant amount of toxicity to the patient. The fine balance between efficacy and safety is the key to the success of cytotoxic chemotherapeutics. However, it is possibly more rewarding to obtain that balance for this class drugs as the frequency of drug related toxicities are higher compared to the other therapeutic class and are potentially life threatening and may cause prolonged morbidity. Significant efforts have been invested in last three to four decades in therapeutic drug monitoring (TDM) research to understand the relationship between the drug concentration and the response achieved for therapeutic efficacy as well as drug toxicity for cytotoxic drugs. TDM evolved over this period and the evidence gathered favored its routine use for certain drugs. Since, TDM is an expensive endeavor both from economic and logistic point of view, to justify its use it is necessary to demonstrate that the implementation leads to perceivable improvement in the patient outcomes. It is indeed challenging to prove the utility of TDM in randomized controlled trials and at times may be nearly impossible to generate such data in view of the obvious findings and concern of compromising patient safety. Therefore, good quality data from well-designed observational study do add immense value to the scientific knowledge base, when they are examined in totality, despite the heterogeneity amongst them. This article compiles the summary of the evidence and the best practices for TDM for the three cytotoxic drug, busulfan, 5-FU and methotrexate. Traditional use of TDM or drug concentration data for dose modification has been witnessing a sea change and model informed precision dosing is the future of cytotoxic drug therapeutic management.

Review of nutritional status, body composition, and effects of antineoplastic drug disposition

The overall survival for children with cancer in high income countries is excellent. However, there are many disparities that may negatively affect survival, which are particularly problematic in low income countries, such as nutritional status at diagnosis and throughout therapy. Nutritional status as well as concomitant foods, supplements, and medications may play a role in overall exposure and response to chemotherapy. Emerging science around the microbiome may also play a role and should be further explored as a contributor to disease progression and therapeutic response. This article highlights some of these issues and proposes additional areas of research relevant to nutritional status and pharmacology that are needed in pediatric oncology.

Comparison of enteral nutrition with total parenteral nutrition for patients with locally advanced unresectable esophageal cancer harboring dysphagia in definitive chemoradiotherapy

BACKGROUND

The nutritional status of patients with esophageal squamous cell carcinoma (ESCC) harboring dysphagia is often poor. The efficacy and safety of enteral nutrition (EN) versus total parenteral nutrition (TPN) have not been addressed in patients with ESCC requiring nutritional support during definitive chemoradiotherapy (dCRT).

METHODS

We performed a retrospective analysis of 51 locally advanced unresectable ESCC patients with dysphagia receiving EN (n = 28) or TPN (n = 23) during dCRT between 2009 and 2016.

RESULTS

Patient characteristics in EN vs. TPN were as follows: median age (range), 67 (34 to 82) vs. 66 (57 to 83); ECOG performance status 0/1/2, 11/15/2 vs. 7/14/2; dysphagia score 2/3/4, 11/15/2 vs. 14/8/1; and primary tumor location Ce/Ut/Mt/Lt/Ae, 4/6/14/3/1 vs. 2/2/16/1/2. Median changes in serum albumin level one month after dCRT were +8.8% (-36 to 40) in EN and -12% (-64 to 29) in TPN (P = 0.00377). Weight, body mass index, and skeletal muscle area were not significantly different between the groups. Median durations of hospitalization were 50 days (18 to 72) in EN and 63 days (36 to 164) in TPN (P = 0.00302). Adverse events during dCRT in EN vs. TPN were as follows: catheter-related infection, 0 vs. 6 (27%); aspiration pneumonia, 3 (11%) vs. 2 (9%); mediastinitis, 3 (11%) vs. 1 (5%); grade ≥3 neutropenia, 6 (21%) vs. 14 (64%) (P = 0.00287); and febrile neutropenia, 0 vs. 6 (27%) (P = 0.00561).

CONCLUSIONS

EN may be advantageous for improving serum albumin level, and reducing hematological toxicity and duration of hospitalization compared with TPN during dCRT in ESCC patients.

Therapeutic Drug Monitoring in Oncology: International Association of Therapeutic Drug Monitoring and Clinical Toxicology Recommendations for 5-Fluorouracil Therapy

5-Fluorouracil (5-FU) is dosed by body surface area, a practice unable to reduce the interindividual variability in exposure. Endorsed by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT), we evaluated clinical evidence and strongly recommend TDM for the management of 5-FU therapy in patients with colorectal or head-and-neck cancer receiving common 5-FU regimens. Our systematic methodology provides a framework to evaluate published evidence in support of TDM recommendations in oncology.

Body composition and sarcopenia: The next-generation of personalized oncology and pharmacology?

Body composition has gained increasing attention in oncology in recent years due to fact that sarcopenia has been revealed to be a strong prognostic indicator for survival across multiple stages and cancer types and a predictive factor for toxicity and surgery complications. Accumulating evidence over the last decade has unraveled the "pharmacology" of sarcopenia. Lean body mass may be more relevant to define drug dosing than the "classical" body surface area or flat-fixed dosing in patients with cancer. Since sarcopenia has a major impact on patient survival and quality of life, therapeutic interventions aiming at reducing muscle loss have been developed and are being prospectively evaluated in randomized controlled trials. It is now acknowledged that this supportive care dimension of oncological management is essential to ensure the success of any anticancer treatment. The field of sarcopenia and body composition in cancer is developing quickly, with (i) the newly identified concept of sarcopenic obesity defined as a specific pathophysiological entity, (ii) unsolved issues regarding the best evaluation modalities and cut-off for definition of sarcopenia on imaging, (iii) first results from clinical trials evaluating physical activity, and (iv) emerging body-composition-tailored drug administration schemes. In this context, we propose a comprehensive review providing a panoramic approach of the clinical, pharmacological and therapeutic implications of sarcopenia and body composition in oncology.

A Multidisciplinary Review of Nutrition Considerations in the Pediatric Oncology Population: A Perspective From Children's Oncology Group

Over the past few decades, great progress has been made in the survival rates of childhood cancer. As survival rates have improved, there has been an increased focus on supportive care. Nutrition is a supportive-care modality that has been associated with improved tolerance to chemotherapy, improved survival, increased quality of life, and decreased risk of infection in children undergoing anticancer therapy. Guidelines and assessment criteria have been proposed for the nutrition management of a child with cancer; however, there is no consistent use of criteria among institutions treating children with cancer. This review will present the current evidence and standards of practice incorporating aspects of nutrition, nursing, pharmacology, and psychosocial challenges to consider in the nutrition management of a child with cancer. Recommendations for clinical practice are presented.

[Impact of cancer muscle mass loss on anticancer treatment toxicities]

Administration of targeted therapies as a flat dose and administration of chemotherapy based on body surface area do not take into account several important sources of inter-individual variation. These variations could be responsible partially for the occurrence of toxicity. Furthermore, the availability of high-resolution CT images in the record of cancer patients, from which key body composition information may be derived, allows us to study the relationship between body composition and toxicity. If many studies have highlighted this relationship, the mechanisms are not completely understood. There are some arguments for a pharmacokinetic hypothesis: low muscle mass i.e. sarcopenia, is associated with high drug plasma concentration which in turn is associated with an increase in the incidence of toxicity. The other hypothesis is that sarcopenic patients have a higher susceptibility to medical events leading to an increase in chemotherapy toxicity. This concept of frailty was widely described in studies in the elderly. This body composition analysis opened a huge area of research and many questions still need to be resolved. Defining the cut-offs values for low muscle mass is important since in most of the studies, the cut-offs values used were defined using survival studies. What could be the physiological link between cut-off values defined by survival studies and chemotherapy toxicities? Authors also used the median values, the level which predicted the occurrence of toxicity most accurately and sometimes the measure of the psoas. The final and crucial question is the capacity of reducing toxicity by body composition based dosing.

Indirect assessment of dihydropyrimidine dehydrogenase activity in cats

Use of 5-fluoropyridimine antimetabolite drugs, specifically 5-fluorouracil (5-FU), has been discouraged in cats because of adverse events including neurotoxicity and death. Causes of toxicity have never been elucidated. In humans, toxicity has been associated with ineffective metabolism secondary to deficiencies in dihydropyrimidine dehydrogenase (DPD). Direct assessment of DPD activity is challenging; determination of uracil:dihydrouracil (U:UH2 ) in plasma using high performance liquid chromatography (HPLC) has been reported as an indirect measurement. U:UH2 was measured in the plasma of 73 cats. Mean U:UH2 for all cats was 1.66 ± 0.11 (median 1.53, range 0.24-7.00). Seventeen (23%) cats had U:UH2 >2, a value associated with decreased DPD activity in humans. Spayed female cats had significantly lower U:UH2 as compared with intact females, and age and U:UH2 were weakly but significantly negatively correlated (r = -0.26). Studies correlating U:UH2 and 5-FU tolerability are required to further determine the validity and use of this test in cats.

A rapid HPLC-ESI-MS/MS method for determination of dihydrouracil/uracil ratio in plasma: evaluation of toxicity to 5-flurouracil in patients with gastrointestinal cancer

BACKGROUND

A liquid chromatography-tandem mass spectrometry method for the simultaneous quantitation of endogenous uracil (U) and dihydrouracil (UH2) was developed and tested in a Brazilian population of patients with gastrointestinal cancer previously exposed to 5-fluorouracil (5FU).

METHODS

The analytes were extracted by a liquid-liquid method using 5-clorouracil as internal standard. The separation was performed on a reversed-phase XTerra C18 column with a mobile phase composed of methanol and aqueous 0.1% ammonium hydroxide (15:85). Mass spectrometry detection was carried out using negative electrospray ionization and selected reaction monitoring. Bovine serum albumin was employed as an alternative matrix to prepare the calibration standards, aiming to avoid the measurement of physiologic U and UH2. Calibration curves were constructed over the range of 5-200 ng/mL for U and 10-500 ng/mL for UH2.

RESULTS

The mean RSD values in the intrarun precision were 6.5% and 10.0% and in the interrun precision were 7.8% and 9.0% for U and UH2, respectively. The mean accuracy values were within the range of 90%-110% for both analytes. The analytes were stable in plasma under different conditions of temperature and time. The validated method was successfully applied to determine the plasma concentrations of U and UH2 in patients with gastrointestinal cancer (n = 32) previously treated with 5FU and for whom clinical toxicity was well documented. U concentrations varied from 21.8 to 56.6 ng/mL, whereas UH2 concentrations varied from 57.7 to 271.5 ng/mL. UH2/U ratio ranged from 1.56 to 6.18.

CONCLUSIONS

The method has proved to provide a quick, reliable, and reproducible quantitation of the plasma concentrations of U and its metabolite UH2. The UH2/U ratios did not discriminate patients previously exposed to 5FU with and without severe toxicities, possibly due to the small sample. Further studies in a larger population are desirable.

Effects of caloric intake on intestinal mucosal morphology and immune cells in rats treated with 5-Fluorouracil

Anticancer drugs have been reported to damage the intestinal mucosa. We evaluated the effects of caloric intake on the mucosal morphology and immune cells in rats treated with 5-fluorouracil (5-FU). Rats were received a liquid diet plus 5-FU treatment for 8 days as follows: Low calorie group (25 kcal/day with 5-FU), Normal calorie group (50 kcal/day with 5-FU), and Control group (50 kcal/day with saline). The mucosal morphology, cell numbers and phenotypes of spleen and intraepithelial lymphocytes (IEL) were assessed. As compared with the control group, the villus heights were significantly lower in the Low calorie group, but not significantly lower in the Normal calorie group. The total cell yield from the spleen, CD4+ and CD8+ T cells decreased in the Low and Normal calorie group, but these changes were less pronounced in Normal calorie group. The total cell yield from the IEL also decreased in the Low calorie group, but not in the Normal calorie group. Our study demonstrated that sufficient caloric intake attenuated the damages in intestinal morphology and in the immune cell numbers. Clinically, nutritional support would be expected to be one approach to reducing the risk of bacterial translocation or infection induced by chemotherapy.

Anticarcinogenic activity of selenium-enriched green tea extracts in vivo

Both selenium and green tea have been shown to have potential antitumor effects. Here we have investigated the anticarcinogenic effect of the selenium-enriched green tea extract (Se-TE) in a Kunming mice model transplanted with human hepatoma cells HepG2. Mice were assigned to 8 groups consisting of 10 mice each after tumor cell inoculation. The control group received only water, whereas the remaining groups received regular green tea extract (RT), Se-TE which was produced by fertilization with selenite on tea leaves, selenite, and RT + selenite. After the mice were fed intragastrically with these agents for 8 days, tumor growth in RT-, Se-TE-, and selenite-fed mice was significantly suppressed, compared with that in control mice (P < 0.001). Supplementation with Se-TEs and selenite was able to elevate mice blood and liver Se concentrations, but did not significantly enhance selenoprotein glutathione peroxidase and other antioxidant enzyme superoxide dismutase activity in mice blood and liver. These results suggest that the antitumor function of Se-TEs may be attributed to the oxidative stress induced by selenium and green tea components in a suitable selenium supplementation pathway.

Monitoring fluoropyrimidine metabolism in solid tumors with in vivo (19)F magnetic resonance spectroscopy

(19)Fluorine magnetic resonance spectroscopy ((19)F MRS) offers unique possibilities for monitoring the pharmacokinetics of fluoropyrimidines in vivo in tumors and normal tissue in a non-invasive way, both in animals and in patients. This method may therefore be useful for predicting response to fluoropyrimidine-based therapy with or without the effects of modulating agents, and this may be of value for the individualization of anticancer therapy and the strategic development of new anticancer drugs. (19)F MRS has been very valuable in elucidating the basic aspects of fluoropyrimidine metabolism, especially in animal studies. Studies in humans have indicated its clinical potential, but widespread application has been hampered by the relatively low detection sensitivity of the method. The recent introduction of clinical MR scanners with magnetic fields above 1.5 T may stimulate increased clinical use of (19)F MRS.

Pharmacokinetic changes in drugs during protein-calorie malnutrition: correlation between drug metabolism and hepatic microsomal cytochrome p450 isozymes

The rats with protein-calorie malnutrition (PCM, 5% casein diet for a period of 4-week) were reported to exhibit 60 and 80% suppression in the hepatic microsomal cytochrome P450 (CYP) 1A2 and CYP2C11 levels, respectively, and 40-50% decreases in CYP2E1 and CYP3A1/2 levels compared to control (23% casein diet for a period of 4-week) based on Western blot analysis. In addition, Northern blot analysis showed that CYP1A2, CYP2E1, CYP2C11, and CYP3A1/2 mRNAs decreased in the state of PCM as well. Hence, pharmacokinetic changes of the drugs in rats with PCM [especially the area under the plasma concentration-time curve from time zero to time infinity (AUC) changes of metabolite(s)] reported from literatures were tried to explain in terms of CYP isozyme changes in the rats. Otherwise, the time-averaged nonrenal clearance (CL NR) of parent drug was compared. Pharmacokinetic changes of the drugs in other types of malnutritional state, such as kwashiorkor and marasmus, in both human and animal models were also compared. The drugs reviewed are as follows: diuretics, antibiotics, anticancer agents, antiepileptics, antiarrythmics, analgesics, xanthines, antimalarials, and miscellaneous.

Evaluation of dihydropyrimidine dehydrogenase activity in South-west Asian, Kenyan and Ghanaian populations

AIMS

Dihydropyrimidine dehydrogenase (DPD) reduces endogenous pyrimidines and therapeutic analogues such as the anticancer agent 5-fluorouracil (5FU). Among Caucasian populations DPD activity is highly variable and subject to polymorphic regulation. To evaluate interethnic influence, DPD activity was assessed in South-west Asian, Kenyan and Ghanaian populations.

METHODS

DPD activity was determined in peripheral mononuclear cells using[14C]-5-fluorouracil and h.p.l.c. analysis.

RESULTS

A high degree of variation in DPD activity was observed within each population (range CV = 34-48%). Median DPD activity also varied between these populations. South-west Asian and Kenyan subjects exhibited almost identical median values (192 and 193.5 pmol min(-1) mg(-1), respectively), which were similar to Caucasians (median 215 pmol min(-1) mg(-1). A significantly lower median DPD activity (119 pmol min(-1) mg(-1)) was observed in the Ghanaian population.

CONCLUSIONS

The similarity in DPD activity between Caucasian, Kenyan and South-west Asian populations suggests that the incidence of 5FU-related toxicity may be comparable in these groups. The pharmacokinetic implications of lower activity amongst Ghanaians needs to be evaluated.

Characterization of dihydropyrimidine dehydrogenase on immunohistochemistry in colon carcinoma, and correlation between immunohistochemical score and protein level or messenger RNA expression

BACKGROUND

Dihydropyrimidine dehydrogenase (DPD) is the first enzyme that metabolizes 5-fluorouracil (5-FU). Until now, enzymatic activity or mRNA expression of DPD has been investigated. However, there are no papers on immunohistochemical evaluation of DPD. We investigated DPD staining on immunohistochemistry, and examined the relationship among immunohistochemical score, protein level and mRNA expression of DPD.

MATERIALS AND METHODS

Forty-seven resected colon cancer specimens, four colon cancer cell lines, two xenografts by colon cancer cell lines, and human mononuclear cells were used. Immunohistochemistry was performed using DPD monoclonal antibody. Protein levels were determined by Western blot analysis. And mRNA levels were calculated by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

DPD was strongly expressed in the cytoplasm of cancer cells, and in the cytoplasm of macrophage and plasma cells. The immunohistochemical score was more correlated with protein levels (P = 0.0054) than mRNA expression (P = 0.9028).

CONCLUSIONS

We investigated the characterization of DPD immunohistochemically, and showed that immunohistochemical expression of DPD can be used to predict the sensitivity of colorectal carcinomas to 5-FU.

Impact of nutrition on pharmacokinetics of anti-neoplastic agents

It has been estimated that approximately 80% of the world's pediatric population lives in countries with limited resources, and that 43% of these children are malnourished. In children with cancer, malnutrition may antedate the diagnosis or be a result of aggressive chemotherapeutic regimens. Studies have shown that children with cancer and malnutrition have a less favorable prognosis, a higher risk of early relapse, and tolerate chemotherapy poorly when compared with children with normal nutritional status. Improvements in nutritional status may improve tolerance to chemotherapy. An understanding of the mechanisms responsible for the effects of malnutrition on drug disposition and pharmacodynamic response is important, especially for anti-neoplastic agents, which have a narrow therapeutic index and may be associated with potentially severe or life-threatening side-effects. Several factors related to malnutrition have been suggested to alter drug disposition. Diminished protein "status" in malnourished children results in lower amounts of plasma proteins, increasing the concentration of free drug available to exert its cytotoxic effect. Severely malnourished individuals also exhibit decreased oxidative metabolism and reduced glomerular filtration rate (GFR), potentially increasing concentrations of parent drug or active metabolites. Malnourished children receiving chemotherapy for the treatment of an underlying malignancy may need specifically "tailored" protocols to achieve therapeutic response while minimizing adverse acute and long-term side effects. The role of specific interventions, such as correction of nutritional status or pharmacokinetic drug monitoring, should be evaluated in this context.

Autoregulation of 5-fluorouracil metabolism

5-Fluorouracil (5-FU) is a commonly used anticancer agent for the treatment of gastrointestinal, head and neck, and breast tumours. This study determined the influence of 5-FU on dihydropyrimidine dehydrogenase (DPD) activity, the enzyme responsible for its in vivo degradation. DPD activity was measured in mononuclear cells obtained prior to and after the administration of 5-FU in 20 patients with colorectal cancer. Following the results from the human studies, DPD activity was measured in Sprague-Dawley rat liver up to 72 h after administration of 5-FU 200 mg/kg as a single injection. Total liver P450 content and the production of testosterone metabolites (indicative of CYP3A activity) were also analysed to determine the specificity of 5-FU-associated alteration in rat liver metabolism. Human mononuclear cell DPD activity decreased by a median of 38.7% following the administration of 5-FU (P = 0.001). 5-FU-induced alterations in rat liver DPD were also observed, with the lowest activity occurring 48 h after injection (50% of control activity; P = 0.009). Rat liver DPD activity returned to near control values by 72 h postinjection. Rat liver total P450 content and CYP3A activity were not significantly different in 5-FU treated or control tissues. Thus, 5-FU demonstrates autoregulation of its metabolism through inhibition of DPD activity. Although this inhibition appears to be specific for DPD, the mechanism for enzyme inhibition is not clear. These findings may aid in the design of 5-FU treatment regimens and provide the basis for further studies into the regulation of DPD.

Incorporation of 5-fluorouracil into hepatoma and normal tissue RNA at protein depletion in the rat

BACKGROUND AND OBJECTIVES

5-fluorouracil (5-FU) exerts its effects mainly by its incorporation into RNA and inhibition of DNA synthesis. Its toxicity may therefore be estimated by measuring its incorporation into RNA. Protein malnutrition has been considered to increase the toxicity of 5-FU.

METHODS

Rats with a hepatoma implanted into the liver were fed on either a 25% or a 0% casein diet for 1 week. On the last day, they were infused via the hepatic artery with a therapeutic dose of 3H-5-FU. Its incorporation into RNA was measured in hepatoma and several normal tissues.

RESULTS

Protein deprivation increased the incorporation of 5-FU into liver and intestinal RNA. Incorporation into hepatoma RNA did not increase significantly, but the ratio, liver/hepatoma RNA incorporation, remained unchanged.

CONCLUSIONS

Protein deprivation might increase the toxicity of 5-FU on liver and intestine.