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Biomedical subjects

P J Moe

Publications and source records attributed to P J Moe.

At least 19 recordsLinked to original sources

Superior treatment results in females with high-risk acute lymphoblastic leukemia in childhood.

In this population-based study, 808 children aged 1-15 years from Denmark, Finland, Iceland, Norway and Sweden, were diagnosed between July 1981 and June 1986 as suffering from non-B-cell acute lymphoblastic leukemia (ALL). The total population was 4.5 million children. Remission was achieved in 770/808 of the patients (95%). No sex difference in the remission rate was observed. The event free survival (EFS) at 102 months was 0.47 for males and 0.62 for females (p less than 0.001). There was no difference in EFS between males and females with standard-risk (0.58 and 0.60) or intermediate-risk (0.47 and 0.60) ALL, respectively. The EFS for females with high-risk ALL (0.68) was superior to that of males with high-risk ALL (0.31). Cox multivariant analysis showed that white blood cell count, sex, age and thrombocyte count were significant prognostic factors in all children. The intensified treatment according to the prognostic factors used in this study led to equal EFS for females with ALL from all risk groups. Males with high-risk ALL, however, did not benefit from the intensified treatment.

Age Factors

Cerebrospinal fluid exchange after intrathecal methotrexate overdose. A report of two cases.

Two patients aged 11 and four years, were accidentally given a 10-fold overdose of intrathecal methotrexate while being treated for malignant disease. Neither patient developed any signs of neurotoxicity and exchange of lumbar cerebro-spinal fluid was started 3 and 5 h later, respectively. In one of the patients, who received 120 mg of methotrexate intrathecally, 31% of the given dose was recovered during 2 h of cerebrospinal fluid exchange that was started 3 h after the accidental overdosage. No sequelae were observed in any of the patients. Cerebrospinal fluid exchange is safe and can be recommended in all cases of intrathecal methotrexate overdosage. Ventriculo-cisternal perfusion is not necessary in cases of a 10-fold overdose if the patient has no signs of acute neurotoxicity.

Cerebrospinal Fluid

Reproduction following treatment for childhood leukemia: a population-based prospective cohort study of fertility and offspring.

Of all children diagnosed with leukemia in Denmark, Finland, Iceland, Norway, and Sweden, 981 had discontinued therapy before 1985 and had been followed up annually after cessation of therapy. Progeny was registered and fertility evaluated among survivors who passed age 18 years without a relapse (n = 299). By April 1989, 48 offspring were registered, one of whom had congenital anomalies. This was no more than expected from the incidence of birth defects in the general population. No childhood malignancies or genetic diseases have so far been diagnosed in the progeny. In the study group, none of the 19 female and 8 male survivors of myeloid leukemias had become parents, and only 4 fathers were reported among the 131 male survivors of acute lymphoblastic leukemia (ALL). However, 23 of the 149 females treated for ALL had delivered 41 children. Fertility was measured as cumulative rates of first birth by maternal age. In a Cox regression analysis, cases who had received prophylactic radiation of the central nervous system (CNS) had a lower first birth rate than those without radiation (rate ratio 0.39, 95% CI 0.15-1.00), indicating that doses of 18-24 Gy to the brain may possibly be a risk factor. By using the Norwegian birth cohort of 1966 as a control group, matching the median year of birth for the study subjects, the group of female ALL survivors as a whole was as likely as the general female population to have given birth up to the age of 23. The first generation of females successfully treated for childhood ALL seems to have a nearly normal reproductive pattern during young adulthood, without increased risk of congenital anomalies in the offspring. However, cranial radiation as CNS prophylaxis may possibly impair subsequent reproduction.

Adolescent

How much is too much? Folinic acid rescue dose in children with acute lymphoblastic leukaemia.

The effect of folinic acid rescue dose on the event-free survival of 71 children with acute lymphoblastic leukaemia was examined in a retrospective clinical study. All patients, diagnosed between 1 January 1980 and 1 January 1989, were treated according to the Norwegian Pilot protocol which included eight courses of high dose (6-8 g/m2/24 h intravenous infusion) methotrexate. Following the infusion, a uniform dose of 75 mg (at 36 h after the beginning of the drug infusion) and 15 mg (at 39-106 h) folinic acid rescue was administered to all patients, at predetermined intervals. The uniformity of the rescue dose resulted in distribution of dosages in the range of 38-140 mg/m2 and 7.5-28 mg/m2 for the different periods, respectively, when the dose was recalculated on the basis of the body surface area of the individual patients. The event-free survival of children receiving less or more than 15 mg/m2 (75 mg/m2) rescue dose was compared. Although no significant difference was found, a tendency was observed for a lower risk of relapse in patients receiving less folinic acid. No major methotrexate-related toxicity was observed in the group of patients receiving the lower dose of rescue. These observations suggest that the reduction of folinic acid rescue dose below the generally accepted 12-15 mg/m2 dose may increase the efficacy of high-dose methotrexate therapy while still remaining safe in preventing treatment-related toxicity. Prospective, randomised clinical trials are needed to examine the role of rescue as a determinant of effective exposure to methotrexate in patients receiving high-dose methotrexate treatment.

Adolescent

Second malignant neoplasms in patients treated for childhood leukemia. A population-based cohort study from the Nordic countries. The Nordic Society of Pediatric Oncology and Hematology (NOPHO).

Among a cohort of 981 children who were followed up 4.3-26.5 years after cessation of antileukemic therapy, eight patients in remission of acute lymphoblastic leukemia (ALL) developed a distinctively new malignant disease. The second malignant neoplasms (SMN) included brain tumors, basal cell carcinomas, thyroid cancer, leiomyosarcoma and finally rhabdomyosarcoma in a patient who also had suffered from Hodgkin's disease while still on antileukemic treatment. Cranial radiation had been given to 58.4% of the patients in the study group, which consisted of 895 ALL patients who had completed various chemotherapy protocols. With one exception, the SMN appeared after 7.5-16.5 years at a location previously exposed to radiotherapy (RT). The estimated cumulative risk of SMN appearing within 20 years after diagnosis was 2.9%, and the corresponding risk for cases with RT was 8.1% compared to 0.3% for those without (p = 0.05). In a Cox regression analysis, the incidence rate ratio of SMN between patients with and without RT was 6.7 (95% CI = 0.8, 57.7). Based on age-, year- and sex-specific cancer incidence figures for Norway, the overall standardized incidence rate ratio (SIR) of SMN after treatment for ALL was 5.9 (95% CI = 2.2, 12.9). The number of brain tumors among patients who had received cranial radiation was nearly 27 times greater than expected, whereas no such tumors were seen after chemotherapy. Individuals treated for childhood ALL are at increased risk of a new malignancy, and this seems mainly to be associated with previous irradiation.

Antineoplastic Combined Chemotherapy Protocols

Comparative study on the pharmacokinetics of 7-hydroxy-methotrexate after administration of methotrexate in the dose range of 0.5-33.6 g/m2 to children with acute lymphoblastic leukemia.

Concentrations of 7-hydroxy-methotrexate (7-OH-MTX) were determined in serum samples obtained after 266 infusions of methotrexate administered to 58 children with acute lymphoblastic leukemia. The dose of methotrexate (MTX) was in the range of 0.5-33.6 g/m2. Pharmacokinetic parameters (metabolic index, drug/metabolite ratio, half-life) of 7-OH-MTX and their relationship to the kinetics of methotrexate were analyzed. A great variability was observed in the extent and time-course of the metabolite formation. The concentration of the metabolite was higher than that of the parent compound at any examined time after the end of the 24 hours' infusion. The increase of 7-OH-MTX levels at the end of the methotrexate infusion was found to be proportionate to the increase of the dose of MTX. Males had significantly higher metabolite levels than did females (P less than 0.01) in the dose range of 0.5-8.0 g/m2. The age of the patients also significantly influenced the rate of the metabolite formation. The serial number of the treatment courses did not have effect on the metabolism of MTX. Dose dependency of the elimination half-life of the metabolite was found. Although a tendency was observed that patients in continuous complete remission had higher metabolite levels than those who relapsed, the difference was not significant. Further studies are needed to determine the clinical importance of 7-OH-MT.

Adolescent

7-Hydroxymethotrexate concentrations in serum and cerebrospinal fluid of children with acute lymphoblastic leukemia.

Concentrations of methotrexate (MTX) and 7-hydroxymethotrexate (7-OH-MTX) were determined by HPLC in the serum and cerebrospinal fluid (CSF) of 29 children with acute lymphoblastic leukemia. CSF and serum samples were obtained at the end of 104 infusions of MTX given in a dose range of 0.5-8.0 g/m2. Concentrations, distribution ratios in serum and CSF for MTX and 7-OH-MTX, and the metabolic index were analyzed with regard to the MTX dose, age and clinical state of the patients. A wide inter-patient (2- to 12-fold) but narrower (1.1- to 3.5-fold) intra-patient variability of the concentrations was observed. A dose-proportional increase in the metabolite concentration was found in serum. On the other hand, the elevation of the level of metabolite in CSF was less than proportional to the dose. The CSF/serum distribution data suggest the existence of a saturable carrier system for MTX and 7-OH-MTX between serum and CSF that has lower affinity for 7-OH-MTX. No correlation was found between concentrations of MTX and 7-OH-MTX in the serum of patients receiving the same dose of MTX. No significant difference was observed in the values for metabolic index between relapsed patients and those who were in continuous complete remission. A significant correlation was found between age and metabolic index: the younger the patient, the higher the metabolite concentration measured in serum.

Aging

Recommendation for collection of venous blood from children, with special reference to production reference values.

Reference values should be produced under standardized conditions. To enable comparison it is desirable to use the same procedure also in other clinical situations. A procedure for the collection of venous blood from children with special reference to production of reference values is recommended. It deals with five items: preparation of the child before specimen collection, preparation of the blood collection site, equipment for specimen collection, the specimen collection itself, and handling and storage of the specimen. Alternative methods are described since no single method is suitable for all paediatric age groups. The problem of adhering to a proposed procedure during routine clinical work is also commented upon. The recommendation has been produced as a joint effort of the Scandinavian Committee on Reference Values and a working group set up by the National Paediatric Societies in the Nordic countries.

Adolescent

Treatment of refractory aplastic anemia with plasmapheresis: report of a case in childhood with review of the literature.

Treatment of aplastic anemia may raise considerable problems in some patients. This report concerns a boy whose illness started at 11 years of age. At first admission laboratory data were: hemoglobin 7.5 g/l, and counts of leucocytes, neutrophils and platelets were 2.3, 0.6, and 8 x 10(9)/l, respectively. His bone marrow was hypoplastic with sparse erythropoiesis. The patient did not respond to traditional medical treatment. Serum contained a high concentration of erythropoietin but no antibodies against erythropoietin. The patient's serum did neither alone, nor supported with recombinant erythropoietin, stimulate erythropoiesis in a bioassay, suggesting that some factor(s) inhibiting erythropoietic activity was present. Based on this hypothesis, plasma exchange was performed. After 26 weeks of plasmapheresis the hematological parameters were normalized. We conclude that plasmapheresis might be an alternative in treatment of resistant aplastic anemia. Further diagnostic tools to identify patients who might benefit from such a treatment are required.

Anabolic Agents

Rescue after intermediate and high-dose methotrexate: background, rationale, and current practice.

Pharmacologic rescue methods used in combination with intermediate and high-dose methotrexate therapy are reviewed, with special emphasis on rescue with nucleosides and folinic acid. The mechanism of action, pharmacokinetics, and clinical applications of the rescue agents are described in detail in view of the literature and also of the own findings of the authors. In spite of the promising results of the in vitro studies and in vivo experiments in animal models, the clinical value of thymidine as a rescue agent remains to be determined. Currently, the only indication to use thymidine instead of folinic acid following high-dose methotrexate is to prevent toxicity related to extremely high methotrexate levels in patients with delayed elimination of methotrexate. In spite of the widespread application of folinic acid rescue, the exact mechanism of its action is not fully understood. The rescue dose and schedule in the majority of clinical protocols is empirical, and the start of the rescue administration is too early, allowing less than 36 to 42 hours of exposure to methotrexate. Clinical and laboratory findings indicate that while the early start of FA administration is unnecessary for protecting normal cells, it is potentially dangerous in terms of reduction of the antitumor effect of methotrexate. Our findings suggest that less than the most widely used 12-15 mg/m2 per dose rescue may be sufficient in preventing methotrexate related toxicity in patients with normal elimination of the drug. In addition, reducing the dose of the rescue may be beneficial to achieve better therapeutic results with high-dose methotrexate. Due to methodological problems, the pharmacokinetics of folinic acid rescue has not been excessively studied in humans. Recent data indicate that the pharmacokinetics of folinic acid in children is characterized by great intra- and interpatient variability. The effect of food on the bioavailability of folinic acid has not yet been studied, though it is most frequently administered orally. The introduction of the pure l-stereoisomer of the rescue agent in the clinical practice may eliminate potential interactions with the d-isomer, and may also simplify the introduction of therapeutic drug monitoring for folinic acid as well. This could lead to more rational clinical use of folinic acid as a rescue agent following intermediate and high-dose methotrexate therapy.

Cell Survival

Late relapses after treatment for acute lymphoblastic leukemia in childhood: a population-based study from the Nordic countries.

Seven late relapses of acute lymphoblastic leukemia occurring 5.5 to 12.3 years after cessation of therapy are reported in 986 patients who had discontinued treatment for leukemia acquired before the age of 15. The study covers patients from the five Nordic countries. Of the 434 patients with ALL who had passed 5 years of follow-up without recurrence, seven have subsequently relapsed so far; an estimated cumulative proportion of 6.9% within the 10 years. In addition, we report a girl 15.9 years old at diagnosis who relapsed 7.3 years after cessation of therapy. These findings confirm that "cure" of acute lymphoblastic leukemia treated in the 1970s cannot be considered definite, even 5 years after discontinuation of therapy.

Adolescent

A population-based study of children with standard risk acute lymphoblastic leukemia in the five Nordic countries. A follow-up of 230 patients.

Two hundred and thirty children with standard risk acute lymphoblastic leukemia (ALL) were diagnosed during a period of 3 years from July 1, 1981 to June 30, 1984 in the five Nordic countries. Criteria for standard risk ALL were age above 2.0 and below 10 years, WBC less than or equal to 20 x 10(9)/l, no evidence of CNS-involvement, mediastinal mass or T- or B-cell leukemia. The children were treated without prophylactic CNS irradiation, the majority (200 patients) according to two treatment programs. Follow-up of the entire group after a minimum of 30 months showed 64% of the children living in complete continuous remission with a probability of event-free survival of 0.60. The treatment results are not entirely satisfactory and intensification of therapy is required. A subgroup of patients with WBC between 10 and 20 x 10(9)/l and with adverse prognosis was identified, justifying a change of the present criteria for risk grouping.

Adolescent