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Biomedical subjects

A T Meadows

Publications and source records attributed to A T Meadows.

At least 55 records · Page 3Linked to original sources
PubMed1994

Disseminated nonlymphoblastic lymphoma of childhood: a Childrens Cancer Group study, CCG-552.

PURPOSE: To assess the efficacy of a chemotherapy-only regimen in pediatric patients with disseminated non-lymphoblastic lymphoma and acute B-cell leukemia (B-ALL). PATIENTS AND METHODS: Sixty-eight eligible patients with previously untreated disseminated non-lymphoblastic lymphoma were enrolled on a Childrens Cancer Group study. Therapy included cycles of chemotherapy, systemic and intrathecal (IT), ever 3 weeks for a total maximal duration of 57 weeks. Fifty-five patients had small non-cleaved cell lymphoma (SNCCL) and 13 had diffuse large cell lymphoma (DLCL). Forty-seven were stage III, six were stage IV, and 15 had B-ALL; 13 had central nervous system (CNS) involvement. RESULTS: Four year event-free survival (EFS) was 53% (SE +/- 12%). Stage III SNCCL patients with LDH < 500 IU/L achieved an improved EFS compared to other SNCCL patients (86% vs. 42% 4 year EFS, P = .072). The primary site of failure for advanced stage SNCCL patients was the CNS. All Ki-1-positive DLCL patients relapsed. Patterns of failure, time to relapse, and outcome following relapse differed between SNCCL and DLCL patients. CONCLUSIONS: Advanced stage SNCCL requires better CNS-directed chemotherapy to reduce the CNS failure rate; however, the achievement of durable disease-free survival in four of 11 patients with CNS disease without use of cranial irradiation suggests merit for further evaluation of chemotherapy-only strategies. DLCL patients do not need intensive CNS-directed chemotherapy.

Adolescent↗
PubMed1994

Maternal diet and risk of astrocytic glioma in children: a report from the Childrens Cancer Group (United States and Canada)

N-nitroso compounds and their precursors, nitrites and nitrates, have been hypothesized as risk factors, and vitamins C and E, which inhibit N-nitroso formation, as protective factors for brain tumors. A case-control study of maternal diet during pregnancy and risk of astrocytoma, the most common childhood brain tumor, was conducted by the Childrens Cancer Group. The study included 155 cases under age six at diagnosis and the same number of matched controls selected by random-digit dialing. A trend was observed for consumption of cured meats, which contain preformed nitrosamines (a class of N-nitroso compounds) and their precursors (adjusted odds ratio [OR] for highest quartile of intake relative to lowest = 1.7, P trend = 0.10). However, no strong trends were observed for nitrosamine (OR = 0.8, P = 0.60); nitrite (OR = 1.3, P = 0.54); nitrate (OR = 0.7, P = 0.43); vitamin C (OR = 0.7, P = 0.37); or vitamin E (OR = 0.7, P = 0.48). Iron supplements were associated with a significant decrease in risk (OR = 0.5, 95 percent confidence interval = 0.3-0.8). The effect of several dietary factors differed by income level, making interpretation of the results difficult. Future research should investigate the effect of dietary components not assessed in this study, as these may explain the disparate effects by income level. The results of this study provide limited support for the nitrosamine hypothesis.

Astrocytoma↗
PubMed1993

Relation between maternal diet and subsequent primitive neuroectodermal brain tumors in young children.

BACKGROUND: It has been hypothesized that a high dietary intake of nitrosamines and their precursors, nitrites and nitrates, is a risk factor for brain tumors. Vitamins C and E inhibit the formation of nitrosamines and thus may be protective. METHODS: We conducted a case-control study of maternal diet and the risk of primitive neuroectodermal tumors of the brain in children. The case patients were under the age of six years at diagnosis in 1986 to 1989. The controls were selected by random-digit telephone dialing and were matched for age and race to 166 case patients. Telephone interviews with the mothers included questions on the frequency of consumption of alcohol, vitamin and mineral supplements, and 53 foods during pregnancy. RESULTS: Significant protective trends were observed for vegetables (odds ratio for the highest quartile group for intake relative to the lowest, 0.37; P for trend = 0.005), fruits and fruit juices (odds ratio, 0.28; P = 0.003), vitamin A (odds ratio, 0.59; P = 0.03), vitamin C (odds ratio, 0.42; P = 0.009), nitrate (odds ratio, 0.44; P = 0.002), and folate (odds ratio, 0.38; P = 0.005). A nonsignificant trend of increasing risk was observed for nitrosamine (odds ratio, 1.65; P = 0.15). The use of iron (odds ratio, 0.43; P = 0.004), calcium (odds ratio, 0.42; P = 0.05), and vitamin C (odds ratio, 0.35; P = 0.04) supplements at any time during the pregnancy and the use of multivitamins during the first six weeks (odds ratio, 0.56; P = 0.02) were associated with decreased risk. In multivariate analyses, folate, early multivitamin use, and iron supplements generally remained protective. CONCLUSIONS: These results do not support the hypothesis that nitrosamines have a role in the development of primitive neuroectodermal tumors in young children, but they do suggest that certain other aspects of maternal diet can influence the risk.

Astrocytoma↗
PubMed1993

Family history of cancer and seizures in young children with brain tumors: a report from the Childrens Cancer Group (United States and Canada).

The occurrence of cancer and neurological disorders in first- and second-degree relatives of children in the United States and Canada diagnosed with brain tumor before age six was investigated. A pair-matched case-control study with 155 astrocytoma and 166 primitive neuroectodermal tumor (PNET) cases was performed. Cases were identified through the Childrens Cancer Group. Controls were selected by random-digit dialing and matched to cases on age, race, and telephone area code and exchange. Childhood cancers were more common in PNET relatives compared with the general population (standardized incidence ratio [SIR] = 2.5, 95 percent confidence interval [CI] 1.1-4.8, P = 0.02) and with control relatives (odds ratio [OR] = 3.0, CI = 0.5-30, P = 0.29). For astrocytoma, nonsignificant excesses of brain tumor, leukemia/lymphoma, and childhood cancer occurred among case relatives compared with control relatives, but not compared with the general population. Astrocytoma cases were significantly more likely than controls to have a relative with seizures (OR = 2.5, CI = 1.2-4.9, P = 0.009), especially childhood seizures (OR = 3.4, CI = 1.2-12, P = 0.02), epilepsy (OR = 3.0, CI = 0.9-13, P = 0.08), and febrile convulsions (OR = 4.5, CI = 0.9-43, P = 0.07). A family history of stroke was not a risk factor for either type of brain tumor. These results suggest that some childhood brain tumors may result from a genetic susceptibility and that some risk factors may affect childhood astrocytoma and PNET differently.

Adult↗
PubMed1993

Long-term follow-up of patients treated with COMP or LSA2L2 therapy for childhood non-Hodgkin's lymphoma: a report of CCG-551 from the Childrens Cancer Group.

PURPOSE: We analyzed the long-term results of a Childrens Cancer Group (CCG) randomized study comparing cyclophosphamide, vincristine, methotrexate, and prednisone (COMP) versus LSA2L2 as treatment for childhood non-Hodgkin's lymphoma. The initial results were previously reported (N Engl J Med 308:559, 1983). PATIENTS AND METHODS: A total of 429 patients are reported here, 68 with localized disease and 361 with disseminated disease. The distribution of disseminated-disease patients by histologic type was 164 lymphoblastic, 60 large-cell, and 137 undifferentiated lymphomas. Median follow-up duration of surviving patients is 8 years. RESULTS: Event-free survival (EFS) of patients with localized disease was 84% at 5 years. No differences were seen between the two treatment regimens. Results for patients with disseminated disease was dependent on histologic subtype: patients with lymphoblastic lymphoma did better when treated with LSA2L2 (5-year EFS of 64% v 35% for COMP); COMP produced better results for patients with undifferentiated lymphoma (5-year EFS of 50% v 29% for LSA2L2). Results for large-cell lymphoma patients were similar (5-year EFS of 52% for COMP v 43% for LSA2L2). Five percent of patients died of treatment-related complications while on therapy (primarily infections). Only four deaths without progression have been observed off-therapy (two from restrictive lung disease, one from an acute asthma attack, one from colon cancer). Patient survival rates after recurrence were poor. CONCLUSION: Treatment success can be expected in 84% of pediatric patients with localized non-Hodgkin's lymphoma. For patients with disseminated disease, treatment success can be expected in 64% of those with lymphoblastic and 50% of those with undifferentiated or large-cell disease. To date, late adverse events are rare.

Adolescent↗
PubMed1993

Influence of radiation on growth in pediatric patients.

Although radiation therapy plays a central role in the treatment of many pediatric malignancies, serious consequences may result from its use. Among these is the growth arrest that may result either directly or indirectly from radiation treatments. In this article, the relationship between radiation therapy and growth in children is discussed in detail, including the pathologic and physical basis, and preventative and therapeutic measures.

Bone and Bones↗
PubMed1993

Sequential development of Wilms tumor, T-cell acute lymphoblastic leukemia, medulloblastoma and myeloid leukemia in a child with type 1 neurofibromatosis: a clinical and cytogenetic case report.

In her 8 1/2 years of life, a girl with neurofibromatosis type 1 (NF1) developed four sequential primary malignant neoplasms: Wilms tumor, T-cell acute lymphoblastic leukemia, medulloblastoma and acute myeloid leukemia. The last three tumors were characterized by chromosomal abnormalities non-randomly associated with that particular disease. There was no evidence of germline p53 mutation or of mutation of p53 in the last two tumors. We hypothesize that an unusual mutation of the NF1 gene in this child promoted growth in tissues where the normal or mutated NF-1 gene product is usually silent or growth inhibitory.

Bone Marrow↗
PubMed1992

Electrocardiographic changes and arrhythmias after cancer therapy in children and young adults.

Transient electrocardiographic changes and arrhythmias are known to be acute manifestations of cardiotoxicity secondary to cancer therapy with anthracyclines or cardiac irradiation. However, despite the known risk of late cardiac dysfunction in survivors of childhood cancer therapy, the risk of clinically important electrocardiographic abnormalities and arrhythmias after treatment is unknown. Standard 12-lead and 24-hour ambulatory electrocardiograms were recorded in 73 patients who received anthracyclines alone, 24 who received cardiac irradiation alone, and 27 who received both anthracyclines and cardiac irradiation. The mean age of the patients was 15 years. Mean cumulative anthracycline dose was 282 mg/m2 in patients who received anthracyclines alone and 244 mg/m2 in patients who received both anthracyclines and cardiac irradiation. Analysis of the 12-lead and 24-hour electrocardiograms demonstrated increased frequency of QTc prolongation, supraventricular premature complexes, supraventricular tachycardia, ventricular premature complexes, couplets and ventricular tachycardia (all p less than 0.001) when compared with an age-matched healthy population. Most patients had abnormalities limited to single supraventricular or ventricular premature complexes; however, potentially serious ventricular ectopy, including ventricular pairs and ventricular tachycardia, were noted in patients with cumulative doses greater than 200 mg/m2. Electrocardiographic abnormalities and arrhythmias are not limited to the acute phase of treatment with anthracyclines and cardiac irradiation. Survivors of childhood malignancy who received anthracyclines or cardiac irradiation, or both, probably should undergo ambulatory electrocardiographic monitoring as part of their follow-up to detect potentially life-threatening arrhythmias.

Adolescent↗
PubMed1992

Parental occupation and childhood astrocytoma: results of a case-control study.

Parental occupations were investigated as possible risk factors for astrocytoma, the most frequently occurring brain tumor in children. A case-control study of 163 pairs was performed. Cases under 15 years of age at diagnosis in 1980-1986 were identified through the tumor registries of eight hospitals in Pennsylvania, New Jersey, and Delaware. Controls were selected by random-digit dialing and were matched to cases on age, race, and telephone area code. Occupations before the child's conception, during the pregnancy, and after the child's birth were studied separately. We did not observe any strong associations. Significantly more fathers of cases were electrical or electronic repairmen, a subgroup of an occupational category previously associated with increased risk. An excess of case mothers employed as nurses was observed, which was significant for mothers of children diagnosed before 5 years of age. Elevated although not significant odds ratios were observed for some white collar and professional occupations in case parents; for paternal exposure to paint and paternal occupation in the paper and pulp mill industry, both in the period after the child's birth; and for maternal occupation as a hairdresser. The lack of strong associations may have resulted from low statistical power for some job groupings. Our study, unlike previous studies, focused on a single type of brain tumor: childhood astrocytoma. Thus our results suggest that some parental occupations associated with childhood brain tumors in previous studies may not be risk factors for childhood astrocytoma.

Adolescent↗
PubMed1992

Whole-brain irradiation and decline in intelligence: the influence of dose and age on IQ score.

PURPOSE: Decline in intelligence can occur after whole-brain cranial irradiation for childhood malignancy. The purpose of this analysis was to estimate better the impact of dose and age at time of irradiation on IQ decline. PATIENTS AND METHODS: A total of 48 children were studied. We combined two previously reported studies that included 15 patients with pediatric acute lymphocytic leukemia (ALL) and 18 pediatric patients with medulloblastoma/posterior fossa primitive neural ectodermal tumors (PNETs) in whom serial IQ tests were administered. Another 15 patients (nine ALL and six PNET) were studied subsequent to these reports. This experience included ALL patients who were treated with whole-brain irradiation at doses of 18 Gy (n = 9) and 24 Gy (n = 15), and PNET patients who were treated with 18 Gy (n = 5), 22 to 24 Gy (n = 2), and 32 to 40 Gy (n = 17). Multiple regression models were constructed to estimate expected IQ score after treatment based on initial IQ score, age at treatment, and dose of whole-brain irradiation. RESULTS: Using a multiple linear regression model to correct for initial IQ and age at treatment, patients who received a dose of 36 Gy to the whole brain were estimated to score 8.2 points less on IQ testing than those with 24 Gy (95% confidence interval [CI], 1.8 to 14.6) and 12.3 points less than those who received 18 Gy (95% CI, 2.7 to 21.7). Older age at the time of irradiation resulted in less decline in subsequent IQ score. The predicted IQ decline is 11.9 points less in a 10-year-old patient than in a 3-year-old patient (95% CI, 4.2 to 19.6) for equivalent doses of irradiation. The model to predict IQ accounts for half the total variation in IQ score. There was no significant difference between the coefficients that reflected IQ decrease from radiation dose between subgroups who had ALL versus those with PNET. CONCLUSIONS: One can forecast final IQ score based on the initial IQ score, dose of irradiation, and age at time of irradiation. Our findings should aid in the selection of appropriate therapy when whole-brain irradiation is needed.

Adolescent↗
PubMed1992

Late effects of early childhood cancer therapy.

The late effects of cancer treatment in children diagnosed early in life (under 2 years of age) may be compared to those in children who were over 2 years at the time of diagnosis. Such areas as growth and development (e.g., intellectual and sexual), vital organ function and risk for second cancer are of particular interest. This report reviews late occurring morbidity which was studied in approximately 400 survivors of childhood cancer, 93 of whom were under 2 years of age at diagnosis. The most commonly reported late effect was musculoskeletal in radiation treated patients. More severe cognitive deficits were seen among both age groups cranially irradiated for leukaemia prophylaxis with 24 Gy compared to 18 Gy. Second cancers developed equally between the two age groups. Predisposing factors and/or prior therapy may produce second cancers. There are inherent problems in assessing the outcomes of very young children treated for cancer. Improved survival has only been evident during the last 15 years, a period too short to appreciate many of the end points of interest in adult life. Such patients require a necessarily long follow-up period but this will prove informative in the future as more institutions initiate procedures for extended surveillance.

Antineoplastic Agents↗
PubMed1992

Osteosarcoma as a second malignant neoplasm in children.

Nine patients who had an osteosarcoma that had developed as a second malignant neoplasm in a previously irradiated site were managed at a major center for the treatment of tumors in children. The doses of radiation had averaged 4144 centigray (range, 2300 to 8000 centigray) and chemotherapy had been administered, when appropriate, for the primary malignant lesion (Ewing sarcoma, malignant fibrous histiocytoma, Hodgkin lymphoma, neuroblastoma, neurofibrosarcoma, rhabdomyosarcoma, and Wilms tumor). The interval between the initial treatment and the diagnosis of the secondary sarcoma averaged ten years and one month (range, five years and ten months to twenty-one years and nine months). Three patients were alive, two of them with active disease, at the time of writing. The other six had died within three years (average, fifteen months) after the second diagnosis. The prevalence of secondary osteosarcoma is increasing as the survival of children who have a malignant lesion increases. Plans for tumor therapy should take into account the risk of this complication, which is usually fatal.

Adolescent↗
PubMed1991

Second neoplasms after acute lymphoblastic leukemia in childhood.

BACKGROUND: Effective forms of treatment for acute lymphoblastic leukemia (ALL) in childhood now result in survival rates above 70 percent at five years, but the treatments are potentially carcinogenic. To determine the magnitude of this risk and identify possible risk factors for the development of second neoplasms, we studied a large cohort of children treated for ALL. METHODS AND RESULTS. We undertook a retrospective cohort study of 9720 children who had been given a diagnosis of ALL between June 1972 and August 1988 and had been treated according to the therapeutic protocols of the Children's Cancer Study Group. The median follow-up was 4.7 years (range, 2 months to 16 years). We found that 43 second neoplasms occurred among the children in the cohort, including 24 neoplasms of the central nervous system, 10 new leukemias and lymphomas, and 9 other neoplasms. This represented a 7-fold excess of all cancers and a 22-fold excess of neoplasms of the central nervous system. The estimated cumulative proportion of children in whom a second neoplasm developed was 2.53 percent 15 years after diagnosis (95 percent confidence limits, 1.74 percent and 3.38 percent). An even higher risk, particularly of central nervous system tumors, was evident in children five years of age or less at the time of the diagnosis of ALL (P = 0.012). All central nervous system neoplasms developed in children who had previously undergone irradiation. There was no association with exposure to cyclophosphamide or anthracyclines. CONCLUSIONS: There is a substantial excess of second neoplasms, especially of the central nervous system, among children treated for ALL. Children five years old or younger and those receiving radiation are at higher risk, especially for second tumors arising in the central nervous system.

Central Nervous System Neoplasms↗