PubMed Health⌕ Search

Biomedical subjects

P K Duffner

Publications and source records attributed to P K Duffner.

At least 19 recordsLinked to original sources
PubMed1998

Second malignancies in young children with primary brain tumors following treatment with prolonged postoperative chemotherapy and delayed irradiation: a Pediatric Oncology Group study.

Between 1986 and 1990, the Pediatric Oncology Group conducted a study in which 198 children younger than 3 years of age with malignant brain tumors were treated with prolonged postoperative chemotherapy in an effort to delay irradiation and reduce long-term neurotoxicity. Children younger than 2 years of age received 24 months of chemotherapy followed by irradiation, and those between 2 and 3 years of age received 12 months of chemotherapy plus irradiation. Chemotherapy was given in 28-day cycles (AAB, AAB), with cycle A = vincristine (0.065 mg/kg) intravenously on days 1 and 8 and cyclophosphamide (65 mg/kg) intravenously on day 1, and cycle B = cisplatinum (4 mg/kg) intravenously on day 1 and etoposide (6.5 mg/kg) intravenously on days 3 and 4. Five of the 198 children developed second malignancies, with a cumulative risk at 8 years of 11.3% (95% confidence interval [CI], 0-39%). Four of the five second malignancies occurred in children younger than 2 years of age at diagnosis, with a cumulative risk at 8 years of 18.9% (CI, 0-70%). Initial diagnoses were choroid plexus carcinoma (2 children), ependymoma (1 child), desmoplastic infantile ganglioglioma (2 children), and medulloblastoma (1 child). Duration from diagnosis of initial tumor to second malignancy was 33, 35, 57, 66, and 92 months. Three children younger than 2 years of age developed lymphoproliferative disease, that is, myelodysplastic syndrome (2 children), both with monosomy 7 deletions, and acute myelogenous leukemia (1 child), after 24 to 26 cycles of chemotherapy, including 8 cycles of etoposide. Two of 3 received craniospinal irradiation (2,560/3,840 cGy) and (3,520/5,320 cGy). Time to second malignancy was 7 years 8 months, 4 years 9 months, and 2 years 9 months. Two children developed solid tumors, at 5 years 6 months and 2 years 11 months, respectively, after initiation of treatment. A sarcoma developed after 26 cycles of chemotherapy and no irradiation, and a meningioma developed after 12 cycles of chemotherapy and local craniospinal irradiation. Potential causative factors for this high rate of secondary malignancies include prolonged use of alkylating agents and etoposide with or without irradiation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Clinical and neuroradiologic findings in infants with intracranial ependymomas. Pediatric Oncology Group.

Typical clinical characteristics, neuroradiologic findings, and initial neuroradiologic studies were reviewed for 40 patients <3 years of age with intracranial ependymomas, who were treated in the Pediatric Oncology Group (prolonged postoperative chemotherapy and delayed radiation for children <3 years of age with malignant brain tumors). The study included 16 females and 24 males, aged 3 to 35 months, who were diagnosed and registered in the study between 1986 and 1990. Commonly, patients presented with vomiting (70%), ataxia (53%), headache (28%), lethargy (28%), increased head circumference (23%), and irritability (23%). Duration of symptoms before diagnosis ranged from 1 day to 11 months. Thirty-five tumors (88%) were infratentorial; average tumor size was 4.3 (+/-1.4) x 4.2 (+/-1.7) x 4.1 (+/-1.8) cm at presentation. Noncontrast CT scans were performed on 23 patients; 13 (57%) were isodense to surrounding brain tissue and 13 (57%) were calcified. Contrast CT scans of 29 patients revealed that 28 (97%) were enhanced. Of the 15 T1-weighted MRI scans, 10 (67%) demonstrated low-signal intensity tumors, and 15 (94%) of the 16 T2-weighted scans revealed high-signal tumors. Forty-three percent of the tumors were cystic. Blood was observed within only 2 tumors and peritumoral edema was uncommon. Twenty-five percent of the ependymomas extended out to involve the dura, and 97% of the infratentorial tumors showed characteristic plasticity. Hydrocephalus was present in 34 (85%) children.

Brain Neoplasms↗
PubMed1998

Atypical teratoid/rhabdoid tumor of the central nervous system: a highly malignant tumor of infancy and childhood frequently mistaken for medulloblastoma: a Pediatric Oncology Group study.

Fifty-five patients with atypical teratoid/rhabdoid tumors of the central nervous system were studied to define the clinical and pathologic features of this newly described neoplasm. The lesion occurred primarily in children younger than 2 (mean age at diagnosis, 17 months). The neoplasms were located in the posterior fossa (36 patients) and the supratentorial compartment (17 patients) or were multifocal in both compartments (2 patients) at presentation. Histologically, the tumors were composed of small cells and large, pale cells in a jumbled architectural arrangement. The small cell component resembled medulloblastoma and occasionally had cords of cells in a mucinous background, simulating chordoma. The cytoplasm of the larger cells was conspicuous with a somewhat "rhabdoid" appearance, although rhabdoid features were not always prominent. Epithelioid features in the form of poorly formed glands or Flexner-Wintersteiner rosettes were noted in a minority of lesions. The neoplasms showed striking polyphenotypic immunoreactivity, including that for vimentin, glial fibrillary acidic protein, epithelial membrane antigen, cytokeratins, synaptophysin, chromogranin, and smooth muscle actin. Using a probe for chromosome 22, seven of eight scorable cases showed a solitary signal by fluorescence in situ hybridization (FISH) consistent with monosomy 22. The eighth scorable case showed three signals by fluorescence in situ hybridization and had a translocation involving chromosome 22 reported by conventional cytogenetics. In contrast to patients with medulloblastoma, the neoplasm with which these lesions are often confused, the outcome of the patients was uniformly poor. The mean postoperative survival of patients with atypical teratoid/rhabdoid tumors was only 11 months. Local recurrence, seeding of the cerebrospinal fluid pathways, or both, were common terminal events. This study underscores the distinctive clinical, histopathologic, immunohistochemical, and cytogenetic character of this unusually aggressive tumor.

Brain Neoplasms↗
PubMed1998

Prognostic factors in infants and very young children with intracranial ependymomas.

The Pediatric Oncology Group (1986-1990) conducted a study in which 48 children <3 years of age with intracranial ependymomas were treated with prolonged postoperative chemotherapy (CT) and delayed RT. Thirty-one children, 0-23 months of age at diagnosis (Gp A) received 2 years of CT followed by RT; while 17 children, 24-36 months of age at diagnosis (Gp B) received CT for 1 year followed by radiation. One-year survivals were 87% (Gp A) and 94% (Gp B) and 2-year survivals were 67% (Gp A) and 82% (Gp B). In subsequent years a significant divergence in survivals according to age has been noted (p = 0.04). Five-year survivals were 25.7% (Gp A) vs. 63.3% (Gp B). The curves began to diverge 1 year following diagnosis. Other than age, the only significant prognostic factor was degree of surgical resection: 5-year survivals were 66% (total resection) vs. 25% (subtotal resection). Neither the presence of metastases, degree of anaplasia nor the degree of surgical resection varied significantly according to age at diagnosis. The most likely reason for the difference in survivals between the two age groups relates to the timing of radiation following CT, i.e., 1-year delay in children 24-36 months of age compared to a 2-year delay in children 0-23 months of age. An alternative but less likely hypothesis is that ependymomas in the younger children have a more aggressive biology. In contrast, survivals in the 24- to 36-month group are much better than previous reports in the literature suggesting that prolonged postoperative CT may allow both a delay in CRT as well as provide improved survivals. Based on these results, future treatment trials should emphasize maximal surgical resection and a delay in radiation of no more than 1 year.

Age Distribution↗
PubMed1996

Response of recurrent medulloblastoma to low-dose oral etoposide.

PURPOSE: The outcome for patients with recurrent medulloblastoma has historically been poor, with most patients dying of disseminated disease. Here, we report on seven patients with recurrent medulloblastoma, most heavily pretreated with a variety of chemotherapeutic agents, including parenteral etoposide (VP-16), who showed responses to the administration of repeated courses of low-dose oral VP-16. PATIENTS AND METHODS: Seven patients age 4 to 16 years were treated with VP-16 after neuroradiographic and clinical evidence of tumor progression. Six had received prior irradiation. All seven had been pretreated with a variety of chemotherapeutic agents and schedules, including parenteral VP-16. VP-16 was administered orally as repeated 21-day courses at 50 mg/m2/d with a 7-day interval between courses. Evaluation consisted of neuroradiographic and clinical examination after completion of every two courses of therapy. Complete blood cell counts were performed weekly. RESULTS: The major toxicity of oral VP-16 was hematologic, with two patients requiring platelet transfusions due to thrombocytopenia and two requiring RBC transfusions. All seven patients developed treatment-related neutropenia. Two patients were supported with granulocyte colony-stimulating factor (G-CSF) between courses. One patient developed infectious epididymitis after course 2 and required intravenous antibiotics; this illness was complicated by Clostridium difficile colitis. There was one episode of fever associated with neutropenia. There were no treatment-related deaths. Of seven patients assessed, six have demonstrated partial responses (PRs) and the remaining patient had stable disease (SD). CONCLUSION: This report demonstrates the activity of oral VP-16 in the treatment of a small cohort of pretreated patients with recurrent medulloblastoma. This form of administration of oral VP-16 was well tolerated and produced modest toxicity.

Administration, Oral↗
PubMed1995

Lack of efficacy of postoperative chemotherapy and delayed radiation in very young children with pineoblastoma. Pediatric Oncology Group.

Eleven infants with pineoblastomas were treated with prolonged postoperative chemotherapy in an attempt to delay radiation and reduce neurotoxicity. These infants were part of the Pediatric Oncology Group infant brain tumor study but the outcome of infants with pineoblastomas was not previously reported. Ages ranged from 1 month to 35 months, with eight of 11 < or = 12 months at diagnosis. Four had + cytology and three had + myelograms at diagnosis. The majority had partial surgical resection (25-75% reduction in tumor) and 10 had shunts. Chemotherapy consisted of two 28-day cycles of cyclophosphamide plus vincristine, followed by one 28-day cycle of cisplatin plus etoposide. Craniospinal radiation was planned following completion of either 2 years of chemotherapy (children less than 24 months at diagnosis) or following one year (children 24-36 months at diagnosis). Neuroimaging results following two cycles of cyclophosphamide and vincristine were one partial response, five stable disease, and five progressive disease. There were no responders in the leptomeninges. All children ultimately failed chemotherapy (2 months-11 months). Nine failed in the primary site. Of those eight children in whom a metastatic workup was performed at time of progression, all had evidence of leptomeningeal disease. Six received radiation following failure on chemotherapy. All failed either in the primary site, leptomeninges or extraneurally (peritoneal cavity). All children died. Survival following diagnosis ranged from 4 months to 13 months. This chemotherapy regimen was neither effective in controlling tumor in the primary site nor in treating or preventing leptomeningeal spread.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Postoperative chemotherapy and delayed radiation in infants and very young children with choroid plexus carcinomas. The Pediatric Oncology Group.

Eight infants with choroid plexus carcinomas were treated with surgery, prolonged postoperative chemotherapy and delayed radiation. The results suggest that some infants with choroid plexus carcinomas can be successfully treated with multimodality therapy, even allowing children with less than a gross total resection to have prolonged disease-free intervals.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Etiologies of central diabetes insipidus in children.

The last major review of the etiologies of central diabetes insipidus in children was performed a quarter century ago, prior to the development of modern neuroimaging techniques. We retrospectively reviewed the records of children with central diabetes insipidus identified at Children's Hospital of Buffalo from 1979 to 1992. Of the 35 patients identified, 27 were males and 8 were females. Their ages ranged from 3 weeks to 20 years. Nineteen children had brain tumors, 7 had cerebral malformations, 3 had central nervous system infections, 1 had traumatic brain injury, and 5 were considered idiopathic. Patients with brain death were excluded from the review. Thirty-one of 35 patients developed diabetes insipidus in conjunction with other endocrinopathies. Brain tumor and its treatment account for the most common cause. Cranial magnetic resonance imaging has improved the identification of structural lesions and the understanding of the pathophysiology of central diabetes insipidus.

Adolescent↗
PubMed1994

Desmoplastic infantile gangliogliomas: an approach to therapy.

Desmoplastic infantile gangliogliomas are massive cystic tumors, typically occurring in the cerebral hemispheres of infants. They are remarkable pathologically for a prominent desmoplasia and, in some cases, for a cellular mitotically active component that can be readily interpreted as a malignant neoplasm. Four children less than 1 year of age were diagnosed with desmoplastic infantile gangliogliomas in the Pediatric Oncology Group infant brain tumor study (Protocol number 8633). All had been diagnosed by their respective institutions as having malignant tumors, i.e., Grade III astrocytoma, malignant meningioma, leptomeningeal fibrosarcoma, and gliosarcoma. All had increased intracranial pressure, and two had seizures. The tumors were extremely large, with one measuring 12 x 9 x 9 cm. None had evidence of metastatic disease. One patient had a gross total resection, and the other three had debulking procedures. All four children were treated with chemotherapy (cyclophosphamide, vincristine, cisplatinum, etoposide) for periods ranging from 12 to 24 months. Of those with postoperative measurable disease, one child had a complete response, one a partial response, and one had stable disease at the conclusion of chemotherapy. No child received radiation therapy. All children are alive with progression-free survivals after diagnosis of more than 36, 42, 48, and 60 months, respectively. Although desmoplastic infantile gangliomas are rare, recognition of this tumor type is essential because, despite their massive size and pathologically malignant appearance, they may have a relatively benign clinical course. If total surgical resection can be achieved, further therapy may not be indicated. In those patients in whom residual disease is present, chemotherapy appears to be an effective form of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Postoperative chemotherapy and delayed radiation in children less than three years of age with malignant brain tumors.

BACKGROUND: Among patients with malignant brain tumors, infants and very young children have the worst prognosis and the most severe treatment-related neurotoxic effects. Therefore, in 1986, the Pediatric Oncology Group began a study in which postoperative chemotherapy was given in order to permit a delay in the delivery of radiation to the developing brain. METHODS: Children under 36 months of age with biopsy-proved malignant brain tumors were treated postoperatively with two 28-day cycles of cyclophosphamide plus vincristine, followed by one 28-day cycle of cisplatin plus etoposide. This sequence was repeated until the disease progressed or for two years in 132 children 24 months of age at diagnosis and for one year in 66 children 24 to 36 months of age at diagnosis. After this, the patients received radiation therapy. The response to the first two cycles of chemotherapy was measured in 102 patients with residual postoperative disease. RESULTS: The first two cycles of cyclophosphamide and vincristine produced complete or partial responses in 39 percent of the 102 patients who could be evaluated. The response rates were highest among patients with medulloblastomas, malignant gliomas, or ependymomas. Patients with brain-stem gliomas or embryonal tumors (primitive neuroectodermal tumors) had little or no response. The progression-free survival rate was 41 percent at one year for children who were 24 to 36 months old at diagnosis and 39 percent at two years for those under 24 months of age at diagnosis. Multivariate analysis identified embryonal tumors as a significant adverse prognostic feature (relative risk, 2.2; 95 percent confidence interval, 1.4 to 3.4) and complete resection as a favorable feature (relative risk, 0.33; 95 percent confidence interval, 0.20 to 0.54). Complete responses to chemotherapy were associated with a progression-free survival rate approaching that achieved with gross total resection. A comparison of cognitive evaluations obtained at base line and after one year of chemotherapy revealed no evidence of deterioration in cognitive function. CONCLUSIONS: Chemotherapy appears to be an effective primary postoperative treatment for many malignant brain tumors in young children. Disease control for one or two years in a large minority of patients permitted a delay in the delivery of radiation and, on the basis of preliminary results, a reduction in neurotoxicity. For patients who had undergone total surgical resection or who had a complete response to chemotherapy, the results are sufficiently encouraging to suggest that radiation therapy may not be needed in this subgroup of children after at least one year of chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Changes in the approach to central nervous system tumors in childhood.

Current approaches to children with brain tumors are in a state of evolution. Currently, 50% of children with all types of brain tumors may be expected to survive 5 years. Therefore, the goals of neuro-oncology have broadened to include improved survival and improved quality of life. This article reviews changes in therapy that have altered survival as well as changes in therapy as a consequence of increasing recognition of complications and toxicity of treatment.

Brain↗
PubMed1991

Optic pathway tumors.

Overall, the majority of patients with optic pathway tumors will have stable disease regardless if they are radiated or receive chemotherapy. This is a very indolent tumor system and, for the most part, not a threat to life. Because of this, issues regarding appropriate therapeutic approaches have yet to be resolved. Most agree that in patients with progressive visual loss and tumor limited to the orbit, surgery can be associated with a cure. The downside is the loss of vision associated with surgical extirpation. Radiation rather than surgery has been the mainstay of treatment for intracranial tumors of the optic pathway. To eliminate side effects associated with radiotherapy in the young child, chemotherapy may be the more considered choice. However, on escape of control, i.e., conversion of stable disease to progressive disease, radiotherapy should be considered.

Child↗
PubMed1991

The long-term effects of central nervous system therapy on children with brain tumors.

Survivals of children with brain tumors have increased over the past 20 years owing to advances in surgery, radiation, and, most recently, chemotherapy. Unfortunately, central nervous system therapy, particularly radiation, may be associated with the development of dementia and learning disabilities, leukoencephalopathy, endocrinopathies, and oncogenesis. Recognition of these long-term effects of therapy is important as some are amenable to treatment and others may be prevented by modification of current treatment regimens.

Brain↗
PubMed1989

Treatment of CNS neoplasms in childhood by the Pediatric Oncology Group.

The incidence of brain tumors in children under 15 years of age in the United States is 2.4/100,000. Based upon a US population of approximately 60 million black and white children, there are only 1,200-1,500 newly diagnosed causes of CNS neoplasia diagnosed in children each year in the US. These relatively small numbers, the large geographic dispersion, and the multitude of histologic types, make it unlikely that all but a few medical centers can develop a large experience with this diverse group of tumors. The Brain Tumor Committee (BTC) of the Pediatric Oncology Group was formed, in part, to address this problem. Each of the four goals of the BTC will be addressed separately. A justification for the rationale for each goal is given, following which there is a discussion of how each goal is being met.

Antineoplastic Agents↗
PubMed1989

The significance of MRI abnormalities in children with neurofibromatosis.

We prospectively evaluated 47 children with neurofibromatosis to determine whether the previously reported high signals on magnetic resonance imaging (MRI) (prolonged T2) correlated with CT, brainstem auditory evoked responses (BAER), EEG, clinical examinations, cognitive abilities, or seizure disorder. Thirty percent of children had a history of seizures and 70% had either learning disabilities or mental retardation. Overall, 74% had an abnormal MRI examination. Sixty-two percent had high signals (prolonged T2) on T2-weighted images. Abnormal signals were located primarily in the basal ganglia, brainstem, and cerebellum. Twenty-five percent of patients had abnormal EEGs, 28% had abnormal CTs, and 27% had abnormal BAER examinations. The abnormal signals on MRI did not consistently relate to findings on CT, BAER, EEG, school placement, or clinical examination. The abnormal signals presumably reflect areas of abnormal brain parenchyma, either hamartomas, heterotopias, or local areas of brain dysplasia.

Adolescent↗
PubMed1988

Prospective intellectual testing in children with brain tumors.

Sixteen children with brain tumors received prospective intellectual evaluations with a follow-up of 2 to 5 years. All patients were treated with surgery and radiation and 5 received chemotherapy. Most of the children remained within the normal range of intelligence, but intelligence quotient (IQ) scores declined over time. Learning disabilities were present in 15 of 16 children after radiation, and 11 required special educational services. Risk factors associated with decline in IQ appear to be young age at time of radiation and adjuvant chemotherapy.

Brain Neoplasms↗
PubMed1988

Isolated optic nerve gliomas in children with and without neurofibromatosis.

With the advent of noninvasive neuroimaging of the orbits and brain, many asymptomatic patients with intraorbital optic gliomas have been identified. These children, predominantly with neurofibromatosis, present a therapeutic quandary to the treating physician. There is no consensus regarding either the natural history of intraorbital optic gliomas or the approach treatment. This paper reviews the literature on the treatment of 227 children with intraorbital optic gliomas with surgery, radiation or 'watchful waiting'. Based on this review, an approach to the management of children with intraorbital optic gliomas with and without neurofibromatosis is suggested.

Child↗