Retrospective evaluation and prediction of clearance and toxicity of high dose methotrexate in childhood acute lymphoblastic leukemia patients

To find the predictors of High Dose Methotrexate toxicities in childhood Acute Lymphoblastic Leukemia Patients. This study included 198 Childhood Acute Lymphoblastic Leukemia patients (303 infusions) who were treated with High Dose Methotrexate. Methotrexate levels at different time point were measured by modified enzyme multiplied immunoassay technique assay. The correlation between Methotrexate levels and toxicity was evaluated by Receiver Operating Characteristic curve. When the Methotrexate level at 42 h was lower than 0.76 µmol/L, the sensitivity for predicting thorough clearance at 66 h was 90.78%. When the Methotrexate level at 42 h was higher than1.5 µmol/L, the sensitivity for predicting delayed clearance was 82.17%. When the Methotrexate level at 66 h was higher than 0.5 µmol/L, the sensitivity for predicting Methotrexate toxicity was 89.09%. When the Methotrexate level at 66 h was lower than 0.1 µmol/L, the sensitivity for predicting Methotrexate nontoxicity was 92.73%. The Methotrexate level at 42 h could be predictor for delayed clearance. The Methotrexate level at 66 h could be predictor for toxicity.

Modified FLOX as first-line chemotherapy for metastatic colorectal cancer patients in the public health system in Brazil: Effectiveness and cost-utility analysis.

Incorporation of new drugs for treatment of metastatic colorectal cancer (mCRC) has led to a clear improvement in overall patient survival, the added cost of treatment, however, is a major concern worldwide. The cost-effectiveness of using a modified FLOX (mFLOX) regimen for treating mCRC patients was delineated. In this study, 82 consecutive mCRC patients were treated with leucovorin (LV) at 20 mg/m2 in combination with weekly bolus of 5-fluorouracil (5-FU) (500 mg/m2) for 6 consecutive weeks and oxaliplatin (85 mg/m2) at weeks 1, 3 and 5, every 8 weeks. Overall survival (OS) and toxicity were evaluated. A Markov Model with a 2-year time horizon and 2-week cycles was developed, comparing mFLOX and mFOLFOX6 in a Brazilian environment. Health outcomes were measured in quality-ajusted life years (QALYs). The median overall period of survival was 19 months, while the estimated 1-year survival was 75%. Response by RECIST was assessed in 33 patients. Partial response was observed in 39.4% of patients, while 36.3% were stable. The mFLOX regimen cost was BRL 9,000, while the mFOLFOX6 BRL 22,000 (1 EUR=2.29 BRL), leading to an incremental costed of BRL 13,000, considering a 20-week period of first-line therapy. The incremental effect of the mFOLFOX was of 0,117 QALY. The incremental cost-effectiveness ratio of mFOLFOX6 was of BRL 110,344/QALY. The sensitivity analysis detected no differences in the outcome measures. In conclusion, the mFLOX is an active regimen in mCRC patients, possibly providing a cost-effective option in public health systems.

A comparison of vitamin A and leucovorin for the prevention of methotrexate-induced micronuclei production in rat bone marrow

INTRODUCTION: Methotrexate, a folate antagonist, is a mainstay treatment for childhood acute lymphoblastic leukemia. It is also widely used in a low dose formulation to treat patients with rheumatoid arthritis. In rats, methotrexate is known to induce micronuclei formation, leading to genetic damage, while vitamin A is known to protect against such methotrexate-induced genetic damage. Leucovorin (folinic acid) is generally administered with methotrexate to decrease methotrexate-induced toxicity. OBJECTIVES: We aimed to determine whether vitamin A and leucovorin differed in their capacity to prevent formation of methotrexate-induced micronuclei in rat bone marrow erythrocytes. The present study also aimed to evaluate the effect of combined treatment with vitamin A and leucovorin on the formation of methotrexate-induced micronuclei. METHODS: Male and female Wistar rats (n=8) were injected with 20 mg/kg methotrexate (single i.p. dose). The control group received an equal volume of distilled water. The third and fourth groups of rats received vitamin A (5000 IU daily dose for 4 successive days) and leucovorin (0.5 mg/kg i.p. dose for 4 successive days), respectively. The fifth and sixth groups of rats received a combination of vitamin A and a single dose of methotrexate and a combination of leucovorin and methotrexate, respectively. The last group of rats received a combination of leucovorin, vitamin A and single dose of methotrexate. Samples were collected at 24 hours after the last dose of the treatment into 5 percent bovine albumin. Smears were obtained and stained with May-Grunwald and Giemsa. One thousand polychromatic erythrocytes were counted per animal for the presence of micronuclei and the percentage of polychromatic erythrocyte was determined. RESULTS: Comparison of methotrexate-treated rats with the control group showed a significant increase in the percentage of cells with micronuclei and a significant decrease polychromatic...