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Biomedical subjects

W H Meyer

Publications and source records attributed to W H Meyer.

At least 19 recordsLinked to original sources
PubMed1992

Improved prognosis of children with osteosarcoma metastatic to the lung(s) at the time of diagnosis.

BACKGROUND: A poor outcome is traditionally ascribed to osteosarcoma metastatic to the lungs, but data have been unavailable regarding the outcome of such patients after systematic treatment on clinical trials. METHODS: The clinical course and outcome of 31 patients who had osteosarcoma metastatic to the lungs diagnosed between 1962 and 1990 at St. Jude Children's Research Hospital were reviewed to determine whether the use of increasingly aggressive multimodality therapy has improved their outcome. The patients were grouped by treatment eras, based on major changes in therapy (i.e., single-agent or two-agent era, 1962-1972; standard multiagent era, 1972-1982; and intensive multiagent era, 1982-1990). RESULTS: With increasingly intensive chemotherapy, more aggressive efforts to resect metastatic disease, and earlier detection of pulmonary metastases by computed tomography, the survival of these patients has improved significantly over the 28-year study period. Those treated since 1982 have a 50% estimated probability of survival at 3 years, whereas there were no survivors at 3 years in the two earlier eras. Survival for the former group reached a plateau of 30% at 4 years. CONCLUSIONS: The use of aggressive multimodality therapy, coupled with modern pediatric imaging techniques to detect pulmonary disease, has improved the traditionally dismal outlook in pediatric patients with osteosarcoma and synchronous pulmonary metastases.

Adolescent↗
PubMed1992

Use of GM-CSF in children after high-dose chemotherapy.

The toxicity and efficacy of recombinant human granulocyte-macrophage colony-stimulating factor (rhuGM-CSF) is established in adults, but limited information is available on its use in children. The profound myelotoxicity induced by cisplatin (40 mg/m2 daily x 5) and etoposide (150 mg/m2 daily x 3) provides a model to test the clinical value of recombinant human granulocyte-macrophage colony-stimulating factor in pediatric cancer patients; myelosuppression occurred (absolute neutrophil count [ANC] < 500/microL) during 99 of 118 (84%) courses given to 44 children with refractory solid tumors. Fifty-nine courses (50%) resulted in hospitalizations for fever. Subsequently, rhuGM-CSF was added to this treatment regimen to: (i) determine the dose-limiting toxicity of this agent in children; and (ii) to determine whether it can decrease the duration and severity of neurtropenia and attendant complications. Here we summarize and update our experience with this glycoprotein in children with relapsed solid tumors.

Adolescent↗
PubMed1992

Assessment of osteosarcoma response to preoperative chemotherapy using dynamic FLASH gadolinium-DTPA-enhanced magnetic resonance mapping.

RATIONALE AND OBJECTIVES: To improve the accuracy of magnetic resonance imaging (MRI) in evaluating the response of osteosarcomas to preoperative chemotherapy, the authors developed a technique of mapping tumor necrosis and viability by quantitating slope values of gadolinium-DTPA (Gd-DTPA) uptake on dynamic fast low-angle shot (FLASH) images. METHODS: Dynamic contrast-enhanced FLASH imaging of a single representative plane was performed on six osteosarcomas. Tumors were mapped by dividing resultant images into contiguous regions of interest and deriving slopes representing percentage increase in signal intensity (SI) per minute over the baseline for each region. The results were compared with estimations of viable tumor volume on subtracted Gd-DTPA-enhanced T1-weighted images and histologic maps of necrotic and viable tumor. RESULTS: Dynamic FLASH estimations of percent tumor necrosis using a critical slope value of 45% per minute correctly predicted histologic response to chemotherapy in all six patients. Comparison of dynamic FLASH and histologic maps showed a high degree of correlation. Static enhanced T1-weighted images overestimated the amount of residual viable tumor. CONCLUSIONS: Dynamic FLASH Gd-DTPA-enhanced mapping is a potentially useful noninvasive method of quantitating tumor response to chemotherapy.

Adolescent↗
PubMed1992

Ifosfamide plus etoposide in newly diagnosed Ewing's sarcoma of bone.

PURPOSE: We assessed the activity of ifosfamide plus etoposide against newly diagnosed Ewing's sarcoma of bone by administering this drug pair before standard induction therapy (the upfront window approach). PATIENTS AND METHODS: Twenty-six children and adolescents with newly diagnosed, previously untreated Ewing's sarcoma of bone were enrolled onto this pilot study (EW-87). Eighteen were at a higher risk of treatment failure, with a primary tumor size of more than 8 cm or metastases at diagnosis. Window therapy with ifosfamide (1.6 g/m2/d with mesna uroprotection) and etoposide (100 mg/m2/d) was given in three 5-day cycles at 21-day intervals. Responses were evaluated clinically and radiologically. Subsequent induction therapy comprised three cycles of cyclophosphamide and doxorubicin. Radiation therapy was the primary local control modality; surgery was limited to biopsy or resection of expendable bones. After the local control phase, alternating courses of vincristine plus dactinomycin, ifosfamide plus etoposide, and cyclophosphamide plus doxorubicin were given as maintenance therapy. RESULTS: There were four complete responses and 21 partial responses to ifosfamide/etoposide window therapy (overall response rate 96%; 95% confidence interval [CI], 80% to 99%). Disease progression was observed in four patients during the cyclophosphamide/doxorubicin phase. Chemotherapy was well tolerated; only 16% (20 of 125) of all ifosfamide/etoposide window and maintenance cycles resulted in hospitalization for fever and neutropenia. Two patients developed chemotherapy-induced cystitis. CONCLUSIONS: The combination of ifosfamide and etoposide is highly active against previously untreated Ewing's sarcoma and generally is well tolerated. The ultimate impact of these two agents on outcome will be determined in randomized multicenter studies.

Adolescent↗
PubMed1991

Ewing's sarcoma: local tumor control and patterns of failure following limited-volume radiation therapy.

Sixty children with localized osseous Ewing's sarcoma were treated between 1978 and 1988 with induction chemotherapy (cyclophosphamide, adriamycin), irradiation and/or surgery, and 10 months of maintenance chemotherapy (cyclophosphamide, adriamycin, dactinomycin, vincristine). Following induction chemotherapy, 43 patients received primary radiation therapy to limited radiation volumes defined by post-chemotherapy residual soft tissue tumor extension and initial osseous tumor extent. Irradiation was defined as low dose at 30-36 Gy (median 35 Gy) for 31 cases with objective response to induction chemotherapy and high dose at 50-60 Gy (median 50.4 Gy) for 12 patients with poor response to induction chemotherapy or with tumors greater than or equal to 8 cm. Overall event-free survival at 5 years is 59% and local tumor control is 68%. Initial failures have been local (12), simultaneous local and distant failures (7), and distant (6). In the surgical resection group, 14 patients had complete resection without radiation therapy, and 3 patients had microscopic residual plus 35-41 Gy; 100% local control has been maintained. In 43 patients with primary radiation therapy group, local tumor control is 58% (p = .004). Despite limited radiation volume, 18/19 local failures occurred centrally within the bone, well within the radiation volume. Imaging response to induction chemotherapy predicted local tumor control in the radiation therapy group: 62% with complete response/partial response versus 17% with no response/progressive disease (p less than 0.01). Local tumor control related strongly to primary tumor size in the radiation therapy group; among 31 cases receiving 35 Gy, local tumor control is 90% for lesions less than 8 cm versus 52% for tumors greater than or equal to 8 cm (p = .054). The central pattern of local failure in this experience suggests the effectiveness of limited radiation volume. The overall local tumor control rate following the tested dose level of 35 Gy appears to be inadequate, although results in selected cases with tumors less than 8 cm in greatest tumor dimension indicate potential efficacy in a yet limited experience.

Adolescent↗
PubMed1991

Osteosarcoma. Clinical features and evolving surgical and chemotherapeutic strategies.

Osteosarcoma is the most common neoplasm of bone in children and adolescents. The first effective therapy became available in the early 1970s, and although controversy existed for several years regarding the relative value of aggressive multiagent chemotherapy, presently about 60% of patients with resectable primary tumors and no metastases at diagnosis will be cured. New imaging methods, including computerized tomography, magnetic resonance imaging, and radionuclide techniques, that are sensitive to changes in local tumor perfusion have improved the ability to define the extent of tumor and the response to chemotherapy, and to plan surgery. Although amputation historically has been the primary method for local tumor control, newer surgical techniques and endoprosthetic devices, coupled with effective preoperative chemotherapy, have offered less radical surgery for 50% to 80% of patients with osteosarcoma. New therapeutic agents, including ifosfamide and the immunosuppressive drug, muramyl tripeptide phosphatidylethanolamine, hold promise for improvement in the cure rate of osteosarcoma.

Adolescent↗
PubMed1991

Lower prevalence of the debrisoquin oxidative poor metabolizer phenotype in American black versus white subjects.

Our objective was to determine whether there are differences in debrisoquin hydroxylase (P450IID6) activity between American black subjects and white subjects. Phenotype was assigned in a group of 586 unrelated white and black children with use of dextromethorphan as the substrate probe. Restriction fragment length polymorphism analysis of genomic deoxyribonucleic acid (DNA) was performed in a subset of subjects by use of a full length complementary DNA for P450IID6. Thirty-seven of 480 (7.7%) white children were poor metabolizers compared with 2 of 106 (1.9%) black children (p = 0.03). Among 41 white subjects and 18 black subjects, there were significant differences (p less than 0.05) in two XbaI DNA restriction fragments; the 44 kb fragment was more common and the 29 kb fragment was less common in black versus white extensive metabolizers. There is a lower prevalence of the debrisoquin poor metabolizer phenotype among American black persons, which could have implications for efficacy or toxicity of drugs metabolized by this enzyme, as well as for racial differences in the prevalence of diseases associated with the debrisoquin oxidative phenotype.

Black People↗
PubMed1991

Metastatic small cell tumor of bone with 'true' rosettes and glial fibrillary acidic protein positivity.

A 15-year-old black girl was admitted to St. Jude Children's Research Hospital with a lytic lesion involving the right fourth metacarpal bone with a solitary metastasis to the ipsilateral axillary lymph node. Histologic examination of both the primary lesion and metastasis revealed a primitive small round cell lesion. Abundant rosettes with central lumina were present in the metastasis. Immunohistochemical stains performed on sections of the metastasis were strongly positive for glial fibrillary acidic protein (GFAP) and negative for neuron-specific enolase (NSE), S-100 protein, and Leu-7. Electron microscopic examination of the metastasis revealed lumen formation with apical microvilli and juxtaluminal junctional complexes. This tumor exhibits features that are suggestive, but not definitive, of primitive ependymal differentiation and further expands the morphologic and immunophenotypic range of small round cell tumors of bone.

Adolescent↗
PubMed1991

Phase I study of flavone acetic acid (NSC 347512, LM975) in patients with pediatric malignant solid tumors.

To evaluate the anticancer agent flavone acetic acid (FAA), we conducted a Phase I trial involving 17 pediatric patients with various malignant solid tumors. Dosages investigated included 5,120 and 6,144 mg/m2 given as 3-hour intravenous infusions; and 10,000, 12,500, 15,000, and 17,500 mg/m2 delivered in a 24-hour constant infusion with alkalinization. Grade 2 or worse toxicity was minimal, with 2 patients having nausea/vomiting, 2 having diarrhea, 1 becoming hypertensive, 1 becoming hypotensive, and 2 having myalgia. Three patients who received a 17,500 mg/m2 dose had no toxicity. Disease was stabilized for a brief period in 2 patients--1 with brain stem glioma and 1 with astrocytoma. The FAA pharmacokinetics varied with an average (SD) terminal half-life of 27.9 hr (18.7), clearance of 2.04 L/hr/m2 (0.37), and steady-state volume of 19.9 L/m2 (10.6). This study was discontinued because FAA caused no significant toxicity or therapeutic responses at doses 2.5 gm/m2 greater than had been tolerated by adults.

Adolescent↗
PubMed1991

Changing pattern of pulmonary metastases with adjuvant chemotherapy in patients with osteosarcoma: results from the multiinstitutional osteosarcoma study.

The multiinstitutional osteosarcoma study (MIOS), a randomized trial of adjuvant therapy for osteosarcoma with a concurrent control group, registered 113 patients from June 1982 to August 1984. Preliminary analysis of the study indicated a significant event-free survival advantage favoring immediate adjuvant chemotherapy, (P less than .001). For patients treated with surgery alone or with surgery and adjuvant chemotherapy, the lungs were involved in more than 80% of the relapses. Patients relapsing after surgery alone tended to relapse earlier (P less than .01), had more pulmonary nodules (P less than .01), and had more frequent bilateral pulmonary involvement (P less than .01) than those treated with immediate postsurgical adjuvant chemotherapy. However, patients relapsing after treatment with surgery alone experienced a significantly longer interval to further disease progression (P less than .01) and improved survival after relapse (P = .01) when compared with patients who relapsed after treatment with immediate adjuvant chemotherapy. The only factor predictive of survival after relapse was if the patient could be made surgically disease-free after initial relapse (P = .03).

Antineoplastic Agents↗
PubMed1991

Ifosfamide, Fanconi's syndrome, and rickets.

Three of 218 children treated with ifosfamide plus the uroprotectant mesna, in single- or combination-agent protocols, have developed Fanconi's renal syndrome, all of whom were in a subgroup of 86 children who had also received cisplatin or carboplatin therapy. Patients receiving ifosfamide who have received prior cisplatin (or carboplatin) are at significantly higher risk of developing Fanconi's syndrome than are those who have received no prior nephrotoxic therapy (P = .04). The role of prior nephrotoxic therapy, including cisplatin and its derivatives, and the total dose of ifosfamide should be considered in the assessment of this rare but serious and apparently irreversible side effect.

Adolescent↗
PubMed1991

Adjuvant chemotherapy of high-grade osteosarcoma of the extremity. Updated results of the Multi-Institutional Osteosarcoma Study.

The Multi-Institutional Osteosarcoma Study (MIOS) was designed to determine whether intensive multiagent adjuvant chemotherapy improves the outcome of patients with nonmetastatic high-grade osteosarcoma of the extremity as compared with concurrent controls. After definitive surgery of the primary tumor, patients were randomly assigned to immediate adjuvant chemotherapy or to observation without adjuvant treatment. Updated results of this trial indicate that the projected six-year event-free survival for the control group is 11% compared to 61% for the chemotherapy group (p less than 0.001). Similar results were observed in patients who declined randomization but who were followed according to the treatment arms of the protocol. When randomized and nonrandomized patients are pooled according to assigned treatment, a survival advantage favoring those patients treated with immediate adjuvant chemotherapy is apparent. An analysis of prognostic factors among patients receiving immediate adjuvant chemotherapy reveals that elevation of the serum lactic dehydrogenase at diagnosis is the factor most predictive of adverse outcome. Location of the primary site in the tibia confers a favorable prognosis. The authors conclude that the natural history of high-grade osteosarcoma of the extremity has not changed over the past two decades. The administration of immediate adjuvant chemotherapy has a significant favorable impact on event-free survival and should be recommended for all such patients.

Adult↗
PubMed1991

Recent developments in genetic mechanisms, assessment, and treatment of osteosarcomas.

Osteosarcoma is the most common malignant bone tumor in children and adolescents. The tumor, which is composed of malignant spindle cells that produce osteoid, typically occurs in the diaphyseal region of long bones; about half of all osteosarcomas arise in the distal femur or proximal tibia. Clinically detectable metastases are present in about 20% of patients at diagnosis, and most patients have subclinical metastases. Effective therapy with complete surgical resection of tumor and intensive multiagent chemotherapy results in the cure of over 50% of patients with osteosarcoma. Recent developments of importance include an improved understanding of the importance of the p53 gene in the pathogenesis of osteosarcoma, the description of preclinical models, the development of improved imaging techniques for determining tumor extent and responsiveness to chemotherapy, and refinements in therapy.

Adolescent↗
PubMed1990

Development and characterization of pediatric osteosarcoma xenografts.

Of 33 surgical specimens of osteosarcoma obtained from 24 patients, eight were established as transplantable tumor lines in immune-deprived CBA/CaJ inbred mice. Each line retained the histological characteristics of the corresponding primary tumor and produced human lactate dehydrogenase isozymes. Volume doubling times, which ranged from a mean of 12.3 +/- 5.6 to 39.3 +/- 9.8 days, were stable for individual lines over multiple passages. Flow cytometric analysis indicated similar cellular DNA content values in the primary human tumors and established xenograft lines; the presence of two separate stem lines, as in the original tumors, was observed in the laboratory models. Comparison of two methods of immune deprivation indicated that thymectomy, whole-body irradiation, and bone marrow reconstitution was associated with a higher rate of successful engraftment than was thymectomy, 1-beta-D-arabinofuranosylcytosine treatment, and whole-body irradiation. Bone marrow-reconstituted mice also showed less variability in tumor volume doubling time. We conclude that osteosarcoma can be heterotransplanted into bone marrow-reconstituted mice with a relatively high success rate and that the xenografts retain features characteristic of the tumors of origin. The availability of these models should prove useful in the development of new therapeutic regimens and in understanding the biology of osteosarcoma.

Animals↗
PubMed1990

Sarcomas (other than Ewing's) of flat bones in children and adolescents. A clinicopathologic study.

The clinicopathologic features and response to therapy of 28 patients with non-Ewing's flat bone sarcoma treated at St. Jude Children's Research Hospital, Memphis, Tennessee, over a 25-year period were reviewed. Twenty-two patients had osteosarcoma, four malignant fibrous histiocytoma, one chondrosarcoma, and one fibrosarcoma. Ages at diagnosis ranged from 3 to 24 years (median, 15 years). Primary sites were craniofacial bones in ten patients, pelvis eight, scapula four, ribs two, metatarsal bones two, clavicle one, and vertebra one. All primary tumors were associated with soft tissue extension; none of the patients had metastatic disease at presentation. Six cases represented second malignancies that arose 5 to 16 years after irradiation for an unrelated tumor. Complete excision was possible in ten patients, eight of whom received postoperative chemotherapy. Five of these patients remain free of disease 1.8+ to 13+ years (median, 8.1 years) from diagnosis. Prolonged remissions after adjuvant chemotherapy were achieved in only two of 18 patients after incomplete surgical resection or biopsy. The median survival time in this group was 1 year (range, 0.2-7.7+ years). The remaining 16 patients had progressive local disease, but only two developed concurrent metastases. Thus, complete surgical resection appears to maximize disease-free survival in patients with non-Ewing's flat bone sarcoma. For the large percentage of patients in whom total resection is not possible, because of soft tissue extension and local invasion of bulky tumors, preoperative chemotherapy may increase the likelihood of complete excision and improve long-term survival.

Adolescent↗
PubMed1990

A second nonrandom translocation, der(16)t(1;16)(q21;q13), in Ewing sarcoma and peripheral neuroectodermal tumor.

The majority of Ewing sarcomas and peripheral neuroectodermal tumors (PNET) that have been karyotyped contain a specific translocation, t(11;22)(q23;q11). We report here a second nonrandom translocation, der(16)t(1;16)(q21;q13), in 2 of 20 cases of Ewing sarcoma (seven previously unreported) and 2 of 7 cases of PNET (all previously unreported). All cases with this translocation also contained the t(11;22). Comparison of C-banding patterns in tumor and peripheral lymphocyte karyotypes in one case indicated that the likely breakpoints were 1q21 and 16q13. The presence of this translocation in cell lines will enable further investigation of the molecular events important in the pathogenesis of Ewing sarcoma and PNET.

Adolescent↗
PubMed1990

Ifosfamide neurotoxicity is related to previous cisplatin treatment for pediatric solid tumors.

Neurotoxicity developed in 22 of 97 children and adolescents with malignant solid tumors treated within a phase II ifosfamide protocol. The occurrence of neurotoxicity was related to previous cumulative dosages of cisplatin. One third of the patients who had received more than 600 mg/m2 of cisplatin developed this complication. The relative risk increased 3.2-fold with previous cisplatin dosages above 301 to 600 mg/m2, and 4.1-fold with dosages of 601 to 1,340 mg/m2. The increased risk of neurotoxicity in patients who had received more than 600 mg/m2 of cisplatin may be related to either a decreased clearance of ifosfamide itself or of the drug's active metabolites.

Adolescent↗