Cancer chemotherapy in infants and children

Doxorubicin-Induced Gut Toxicity in Piglets Fed Bovine Milk and Colostrum

OBJECTIVE

Chemotherapy-induced intestinal toxicity is a common adverse effect of cancer treatment. We hypothesized that a milk diet containing bovine colostrum (BC) would reduce intestinal toxicity in doxorubicin-treated piglets.

METHODS

"Study 1" investigated intestinal parameters 9 days after a single dose of doxorubicin (1 × 75 mg/m) in piglets fed bovine milk enriched with whey protein (BM). In "study 2," responses to doxorubicin treatment were investigated in piglets receiving either 7 BC feedings per day (Only-BC, n = 13), 4 BC feedings (High-BC, n = 13), 2 BC feedings (Low-BC, n = 14), or no BC (only BM, n = 13).

RESULTS

Doxorubicin treatment induced clinical signs of intestinal toxicity with diarrhea and weight loss, relative to controls (P < 0.05). White blood cells, hexose absorptive function, plasma citrulline, weights of intestine, colon, and spleen were reduced, whereas gut permeability and plasma C-reactive protein levels were increased (all P < 0.05). Limited or no effects were observed for digestive enzymes, proinflammatory cytokines, or tight-junction proteins in the intestine. Increasing BC supplementation to doxorubicin-treated piglets (study 2) had no consistent effects on plasma C-reactive protein and citrulline levels, intestinal morphology, digestive enzymes, permeability, or proinflammatory cytokines. Only-BC pigs, however, had lower diarrhea severity toward the end of the experiment (P < 0.05 vs BM) and across the BC groups, intestinal toxicity was reduced (P < 0.01).

CONCLUSIONS

Doxorubicin-treated piglets are relevant for studying chemotherapy-induced gut toxicity. Colostrum supplementation had limited effects on doxorubicin-induced toxicity in milk-fed piglets suggesting that colostrum and a bovine milk diet enriched with whey protein provided similar protection of the developing intestine from chemotherapy-induced toxicity.

Milk diets influence doxorubicin-induced intestinal toxicity in piglets

Chemotherapy-induced gastrointestinal (GI) toxicity is a common adverse effect of cancer treatment. We used preweaned piglets as models to test our hypothesis that the immunomodulatory and GI trophic effects of bovine colostrum would reduce the severity of GI complications associated with doxorubicin (DOX) treatment. Five-day-old pigs were administered DOX (1 × 100 mg/m(2)) or an equivalent volume of saline (SAL) and either fed formula (DOX-Form, n = 9, or SAL-Form, n = 7) or bovine colostrum (DOX-Colos, n = 9, or SAL-Colos, n = 7). Pigs were euthanized 5 days after initiation of chemotherapy to assess markers of small intestinal function and inflammation. All DOX-treated animals developed diarrhea, growth deficits, and leukopenia. However, the intestines of DOX-Colos pigs had lower intestinal permeability, longer intestinal villi with higher activities of brush border enzymes, and lower tissue IL-8 levels compared with DOX-Form (all P < 0.05). DOX-Form pigs, but not DOX-Colos pigs, had significantly higher plasma C-reactive protein, compared with SAL-Form. Plasma citrulline was not affected by DOX treatment or diet. Thus a single dose of DOX induces intestinal toxicity in preweaned pigs and may lead to a systemic inflammatory response. The toxicity is affected by type of enteral nutrition with more pronounced GI toxicity when formula is fed compared with bovine colostrum. The results indicate that bovine colostrum may be a beneficial supplementary diet for children subjected to chemotherapy and subsequent intestinal toxicity.

Regimen-specific effects of RNA-modified chimeric antigen receptor T cells in mice with advanced leukemia

Cytotoxic T lymphocytes modified with chimeric antigen receptors (CARs) for adoptive immunotherapy of hematologic malignancies have demonstrated activity in early phase clinical trials. While T cells bearing stably expressed CARs are efficacious and have potential long-term persistence, temporary expression of a CAR via RNA electroporation is also potentially efficacious in preclinical models. Temporary CAR expression using RNA presents a method of testing CARs clinically with additional safety where there may be concerns about possible chronic "on-target, off-tumor" toxic effects, as the degradation of RNA ensures complete removal of the CAR over time without relying on suicide induction systems. CD19-directed RNA CAR T cells were tested in vivo for efficacy and comparison to lentiviral vector (LV)-generated stable CAR T cells. We tested the hypothesis that multiple infusions of RNA CAR T cells preceded by lymphodepleting chemotherapy could mediate improved survival and sustained antitumor responses in a robust leukemia xenograft model. The saturation strategy using rationally designed multiple infusions of RNA CARs based on multiple model iterations approached the efficacy of a stable LV expression method. Two-color imaging revealed that relapse was a locoregional phenomenon in both the temporary and the stable expression models. In marked contrast to stably expressed CARs with retroviral or LV technology, the efficacy of RNA CARs appears independent of the costimulatory signaling endodomains likely because they more influence proliferation and persistence rather than short-term efficacy. The efficacy of the RNA CAR infusions may approach that of stably expressed CARs, offer theoretically safer initial clinical testing in addition to suicide systems, and allow for rapid and effective iterative preclinical modeling for the testing of new targets.

Pharmacokinetic and pharmacogenetic determinants and considerations in chemotherapy selection and dosing in infants

INTRODUCTION

There is a lack of high-quality data regarding optimal chemotherapy dosage regimens among infants. Dosing regimens for chemotherapy during the first year of life are commonly based on empiric recommendations extrapolated from older children; however, balancing efficacy and toxicity is critical as severe adverse drug reactions may lead to treatment failure or reduced adherence to needed medications.

AREAS COVERED

This review describes pharmacokinetic and pharmacogenetic considerations when administering chemotherapeutic agents to infants. Examples of commonly used agents are provided with practical recommendations for dosing adjustments.

EXPERT OPINION

Optimal chemotherapy for children and infants in particular has lagged behind the remarkable progress in cancer treatment and it is clear that far more basic and clinical research are needed with respect to the mechanistic basis of age-dependent differences in pharmacokinetic parameters. More recent studies which have combined pharmacokinetic data with clinical toxicity and outcome data have resulted in a number of more evidence-based guidelines at least for the initial chemotherapy dosing; however, at present, the dosing of chemotherapy drugs in neonates and infants remains largely empiric.

The effect of chemotherapy on the growing skeleton

With the increasing use of high dose (poly)chemotherapy schedules in the treatment of childhood cancer it is particularly important to know the adverse effects of these treatments. Growth is a complex mechanism affected not only by chemotherapy but also by the malignancy itself as well as nutritional status, the use of corticosteroids and (cranial) radiation. In vitro and animal studies are often the most useful in determining the effect of a single chemotherapeutic agent on the growing skeleton. In vitro studies have shown doxorubicin, actinomycin D and cisplatin to have a direct effect on growth plate chondrocytes that in animals results in decreased growth and final height. Clinical studies with multiagent chemotherapy have demonstrated that antimetabolites decrease bone growth and final height. Childhood cancer survivors are at risk of a reduced bone mineral density, mainly due to methotrexate, ifosfamide and corticosteroids. This reduced bone mineral density persists into adult life and may increase bone fracture risk at an older age.

The effects of impaired liver function on the elimination of antineoplastic agents

OBJECTIVE

To critically review available data on the disposition of cancer chemotherapy in patients with hepatic dysfunction, and to derive at dose recommendation.

DATA SOURCES

All published studies in English.

STUDY SELECTION

Both human and animal studies.

DATA SYNTHESIS

The available studies were sequentially qualitatively described and critically discussed.

CONCLUSIONS

The liver is responsible for the metabolism and elimination of many anticancer agents. Their accumulation during hepatic insufficiency may expose the patient to increased risk of drug toxicity. A variety of clinical methods have been described to estimate the need to decrease doxorubicin dose according to degree of hepatic failure to avoid serious toxicity. In some studies prospective ascertainment of clinical indices such as hepatic enzymes and bilirubin was successful in preventing doxorubicin-induced hepatotoxicity. Liver dysfunction has a major impact on cyclophosphamide pharmacokinetics. However, because such impairment leads to less production of the active aldophosphamide, fewer adverse effects were observed in hepatically impaired patients. Vinca alkaloids are extensively metabolized by the liver and excreted in the bile. Systemic exposure to these drugs is inversely correlated to the degree of hepatic failure measured by serum alkaline phosphatase. Although hepatic metabolism is a major route of elimination of fluorouracil, the kidney also plays an important role in its elimination. It has been suggested to reduce its dose in cirrhotic patients. Available pharmacokinetic data and their clinical implications are also discussed for azathioprine, mercaptopurine, etoposide, epirubicin, amsacrine, cytarabine, and other less-studied drugs. Recommendations for dose adjustments are presented and discussed.

The survivors of childhood solid tumors

With the improvement in cancer therapy in recent years, the number of cancer survivors is rapidly increasing. Potential late medical and psychosocial sequelae of cancer therapy are reviewed. A practical guide for the primary health care giver is provided.

Pharmacologic considerations in the treatment of acute lymphoblastic leukemia

Great strides have been made in the chemotherapy of childhood ALL over the past three decades. Principles and concepts learned from early successes in treating this disease subsequently have been applied to the treatment of other pediatric cancers and adult malignancies. Because of the prominent role of chemotherapy in the treatment of ALL, a clear understanding of the clinical pharmacology of the antileukemic drugs is essential. This article reviews issues relating to the clinical pharmacology of the anticancer drugs that are commonly used in the treatment of acute lymphoblastic leukemia.