Lucy B. Rorke

Treatment of Children With Medulloblastomas With Reduced-Dose Craniospinal Radiation Therapy and Adjuvant Chemotherapy: A Children's Cancer Group Study

PURPOSE Medulloblastoma is the most common malignant brain tumor of childhood. After treatment with surgery and radiation therapy, approximately 60% of children with medulloblastoma are alive and free of progressive disease 5 years after diagnosis, but many have significant neurocognitive sequelae. This study was undertaken to determine the feasibility and efficacy of treating children with nondisseminated medulloblastoma with reduced-dose craniospinal radiotherapy plus adjuvant chemotherapy. PATIENTS AND METHODS Over a 3-year period, 65 children between 3 and 10 years of age with nondisseminated medulloblastoma were treated with postoperative, reduced-dose craniospinal radiation therapy (23.4 Gy) and 55.8 Gy of local radiation therapy. Adjuvant vincristine chemotherapy was administered during radiotherapy, and lomustine, vincristine, and cisplatin chemotherapy was administered during and after radiation. RESULTS Progression-free survival was 86% +/- 4% at 3 years and 79% +/- 7% at 5 years. Sites of relapse for the 14 patients who developed progressive disease included the local tumor site alone in two patients, local tumor site and disseminated disease in nine, and nonprimary sites in three. Brainstem involvement did not adversely affect outcome. Therapy was relatively well tolerated; however, the dose of cisplatin had to be modified in more than 50% of patients before the completion of treatment. One child died of pneumonitis and sepsis during treatment. CONCLUSION These overall survival rates compare favorably to those obtained in studies using full-dose radiation therapy alone or radiation therapy plus chemotherapy. The results suggest that reduced-dose craniospinal radiation therapy and adjuvant chemotherapy during and after radiation is a feasible approach for children with nondisseminated medulloblastoma.

The cerebellar medulloblastoma and its relationship to primitive neuroectodermal tumors.

A simple classification system for central nervous system neoplasms occurring primarily in infancy and childhood and largely composed of undifferentiated neuroepithelial cells is proposed. Classification is based upon appearance of the tumor as determined by light microscopy, immunocytochemical techniques, and ultrastructural features without consideration for site of origin. This classification is based on the concept that neoplastic transformation of primitive neuroepithelial cells in subependymal zones at all levels of the central nervous system or pineal body may develop into tumors largely composed of similar cells. It therefore seems appropriate to call these neoplasms primitive neuroectodermal tumors and to use descriptive terms to indicate the direction of cellular differentiation, when it has occurred. Proposed terminology for the five subtypes of undifferentiated neuroepithelial round cell tumors is as follows: 1) Primitive neuroectodermal tumor, not otherwise specified (PNET, NOS), 2) PNET with glial differentiation, 3) PNET with ependymal differentiation, 4) PNET with neuronal differentiation, and 5) PNET with multi- or bipotential differentiation. If the tumor is located in the cerebellum, medulloblastoma may be added in parentheses; if in the pineal body, pineal parenchymal neoplasm may be added.

Central Nervous System Atypical Teratoid/Rhabdoid Tumor: Results of Therapy in Children Enrolled in a Registry

PURPOSE Atypical teratoid/rhabdoid tumor (AT/RT) of the CNS is an extremely rare and aggressive tumor of early childhood. The poor outcome with conventional infant brain tumor therapy has resulted in a lack of clear treatment guidelines. A registry has been established to create an outcomes database and to facilitate biology studies for this tumor. MATERIALS AND METHODS A standardized data sheet was provided to treating physicians listing the reports that were to be sent to the registry for abstraction. Follow-up information was sought twice yearly. RESULTS Information was complete for 42 patients. Median age at diagnosis was 24 months. Nine patients (21%) had disseminated disease at diagnosis. Sixteen tumors were infratentorial; 26 were supratentorial. Twenty patients (48%) received a primary complete resection. Primary therapy included chemotherapy in all patients, radiotherapy in 13 patients (31%), stem-cell rescue in 13 patients (31%), and intrathecal chemotherapy in 16 patients (38%). Recurrent or progressive disease was reported in nine and 19 patients, respectively. Twenty-seven patients (64%) are dead of disease (3 to 62 months from diagnosis) and one patient died of toxicity. Fourteen patients (33%) show no evidence of disease (9.5 to 96 months from diagnosis). The median survival is 16.75 months and the median event-free survival is 10 months. CONCLUSION Aggressive therapy has prolonged the natural history in a subset of children. Prospective multi-institutional and national clinical trials designed specifically for AT/RT are needed. Enrollment onto the AT/RT registry should be continued.

Immunohistochemical analysis of hSNF5/INI1 in pediatric CNS neoplasms.

Atypical teratoid/rhabdoid tumor (AT/RT) may be misdiagnosed as primitive neuroectodermal tumor/medulloblastoma (PNET) and occasionally as other tumors. Molecular genetic analysis of AT/RT demonstrates deletion and mutation of the hSNF5/INI1 gene in most cases, with decreased or absent expression at the RNA or protein level. Immunohistochemistry with an antibody to INI1 was performed to determine whether this would be a sensitive and specific means of assessing INI1 loss in pediatric brain tumors. Fifty-three tumors consisting of 20 AT/RTs, 10 PNETs, and 23 other central nervous system tumors were examined. No nuclear staining was found in all 20 AT/RTs. Most other central nervous system tumors demonstrated nuclear staining. Eight cases in which classification as AT/RT or PNET was difficult were also examined. Seven cases had no chromosome 22 deletion or INI1 mutation; INI1 antibody showed nuclear staining in these cases. One case was a recurrent tumor with features consistent with an AT/RT. INI1 immunostaining was negative in this case, and a mutation in INI1 was subsequently identified. Immunohistochemical staining with an INI1 antibody correlates with molecular findings in AT/RT and may be useful in confirming the histologic diagnosis. INI1 immunostaining may have particular utility in the analysis of tumors with indeterminate histologic features or atypical immunophenotypic profiles.

Revision of the world health organization classification of brain tumors for childhood brain tumors

A classification for childhood brain tumors based upon revision of nomenclature of all brain tumors published by the World health Organization (WHO) in 1979 is proposed. Applicability of the WHO classification scheme was tested in a combined study of the clinical and pathologic features of approximately 3300 brain tumors in children. It was found to be adequate for many of the neoplasms but unsuitable for a significant proportion, including a number of complex cerebral tumors for which there was no appropriate name. Nomenclature of poorly differentiated or densely cellular neuroepithelial tumors was simplified to reflect the current state of knowledge of neuroembryology and neuro‐oncology, although the Committee members recognized that such a proposal would likely perpetuate the longstanding and continuing controversy relative to the nature and origin of these neoplasms. Cancer 56: 1869‐1886, 1985.

Magnetic resonance scans should replace biopsies for the diagnosis of diffuse brain stem gliomas: a report from the Children's Cancer Group.

Childrens Cancer Group Protocol CCG-9882 was designed to determine the effectiveness of hyperfractionated radiation for the treatment of children and young adults with brain stem gliomas. The study opened for the accrual of patients on September 21, 1988, and was closed on June 30, 1991. The first 54 children in the study were treated with irradiation doses of 100 cGy given twice daily to a total dosage of 7200 cGy. The next 66 children were treated with a similar daily regimens to a total of 7800 cGy. Tumors were diagnosed by clinical and radiographic criteria. Decisions about the need for surgery were left to the discretion of the treating neurosurgeon; tissue diagnosis did not alter the therapy in patients with diffuse infiltrating tumors. We reviewed the neuroradiology and neurosurgery reports as well as the pathological specimens of children entered on the study. By magnetic resonance (MR) imaging criteria, tumors involved the majority of the brain stem in 76% of cases; only three patients had tumors localized to the midbrain or medulla. Operations were performed on 56 of 120 patients (47%). Cerebrospinal fluid shunts were inserted in 27 (23%) of the children; insertion of a shunt was the only operation in 11, and a shunt was inserted in conjunction with a tumor operation in 16. Tumor operations were performed in 45 (38%) of the patients; 24 had stereotactic biopsies, and 21 had craniotomies. Of the 21 patients who had craniotomies, only biopsies were performed in 11; partial tumor resections were performed in 5 patients and subtotal resection in 5.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Medulloblastoma Resections on Outcome in Children: A Report from the Children's Cancer Group

We reviewed the data of children with high-stage primitive neuroectodermal tumors (medulloblastomas) who were treated on Childrens Cancer Group-921 protocol to evaluate the correlation between tumor resection and prognosis. Patients enrolled in the study had either tumors that were operatively categorized to be Chang tumor stage 3b or 4, postoperative residual tumors > 1.5 cm2, or evidence of tumor dissemination (Chang metastasis Stages [M Stages] 1-4) at diagnosis. Resections were analyzed in two ways, as follows: 1) by the extent of resection (percent of the tumor that was removed), as estimated by the treating neurosurgeon; and 2) by the extent of residual tumor (how much of the tumor was left), as estimated from postoperative scans. Two hundred and three children were enrolled in the study with institutional diagnoses of primitive neuroectodermal tumors-medulloblastomas; diagnoses were confirmed by central neuropathological review in 188 patients. Progression-free survival (PFS) at 5 years was 54% (standard error, 5%). As in previous Childrens Cancer Group studies, age and M stage correlated with survival; PFS was significantly lower in children 1.5 to 3.0 years old at diagnosis and in those with any evidence of tumor dissemination (M Stage 1-4). On univariate analysis, neither extent of resection nor extent of residual tumor correlated with PFS. However, adjusting for other factors, extent of residual tumor was important; PFS was 20% (standard error, 14%) better at 5 years in children with no dissemination (M Stage 0) who had < 1.5 cm2 of residual tumor (P = 0.065) and was 24% (standard error, 14%) better at 5 years in children > 3 years old with no tumor dissemination (M Stage 0) and with < 1.5 cm2 residual tumor (P = 0.033). On the basis of our observations, we conclude that extent of tumor resection, as estimated by the neurosurgeon, does not correlate with outcome but that extent of residual tumor does correlate with prognosis in certain children (those who are > 3 years old, with no tumor dissemination). In contrast to age and M stage, the major factors associated with outcome, residual tumor is an important variable in outcome, one that neurosurgeons can control.

Central nervous system atypical teratoid/rhabdoid tumors of infancy and childhood

SummaryClinical and morphological features of an apparently unique, biologically aggressive central nervous system tumor in 32 infants and children are presented. This neoplasm is formed wholly or partly by rhabdoid cells, areas resembling typical primitive neuroectodermal tumor, and, less frequently, malignant mesenchymal and/ or epithelial tissue. The tumor has been named atypical teratoid/rhabdoid tumor (ATT/RhT) and is regarded as a unique class of primary central nervous system (CNS) tumors. It occurs most commonly in infants less than two years of age, has often metastasized throughout the CNS at presentation, does not respond to therapy and causes death less than a year after diagnosis. These tumors may occur in any CNS site but almost 60% are located in the cerebellum. The most common chromosomal abnormality involves chromosome 22.

Survival of infants with primitive neuroectodermal tumors or malignant ependymomas of the CNS treated with eight drugs in 1 day: a report from the Childrens Cancer Group.

PURPOSE Very young children with CNS primitive neuroectodermal tumors (PNETs) and ependymomas have a poor prognosis and commonly have impairment of growth and cognitive abilities, in part resulting from radiotherapy. Thus, an intensive chemotherapeutic regimen was used to treat children less than 18 months of age at diagnosis. PATIENTS AND METHODS Children were treated on a Childrens Cancer Group (CCG) protocol with an eight-drug chemotherapeutic regimen (vincristine, carmustine, procarbazine, hydroxyurea, cisplatin, cytarabine, prednisone, and cyclophosphamide) following surgery and postoperative staging. Delayed or reduced-volume radiotherapy was to be administered to all patients, but, in fact, was omitted in most cases. RESULTS On central review of pathology, 82 children had diagnosis concordant with study entry criteria. Of these, 46 (56%) had posterior fossa (PF) PNET, eight (10%) had pineal PNET, 11 (12%) had nonpineal supratentorial PNET, 15 (18%) had ependymoma, and two had rhabdoid tumors. Fifty percent of tumor resections were complete, as verified by postoperative computed tomographic (CT) scan, and 23% of patients had metastatic disease at the time of diagnosis. Objective tumor response was documented following two cycles of chemotherapy in 28% of assessable patients. Toxicity of chemotherapy was primarily hematopoietic. Five children died of chemotherapy-related complications. Radiotherapy was administered to only nine patients before tumor progression. The 3-year progression-free survival (PFS) rates for PF PNET, pineal PNET, supratentorial nonpineal PNET, and ependymoma are 22% (SE = 6%), 0%, 55% (16%), and 26% (11%), respectively. The 3-year PFS rate for those children without metastatic disease was 29% (6%), as compared with 11% (6%) for those with metastatic disease. The only independent predictors of PFS were metastasis stage and location of the tumor within the pineal region. The median time to progression was 6 months. Twenty-four children completed the chemotherapeutic regimen without tumor progression; 19 are event-free survivors more than 2 years from diagnosis, only three of whom received radiation therapy. CONCLUSION While overall survival in this group of very young patients is poor, a subset of children who have received only chemotherapy as adjuvant treatment remain free from tumor recurrence.

Medulloblastoma: Clinical and biologic aspects

Medulloblastoma is the most common childhood primary CNS tumor, and treatment approaches have evolved over the past three decades. The biologic underpinnings of medulloblastoma are not fully characterized, but recent work has identified new, important directions for research. Stratification of patients with medulloblastoma into risk groups is the backbone of most ongoing therapeutic studies. Patients are usually characterized as being either average risk or poor risk, although an intermediate risk group may exist. Standard treatment for older children with medulloblastoma consists of radiation and, for most, chemotherapy. Children with nondisseminated disease at the time of diagnosis have been reported to have as high as an 80% five-year disease-free survival rate after treatment with reduced dose (2340 cGy) craniospinal irradiation, local boost radiation therapy (5500 cGy), and chemotherapy, given during and after radiation therapy. Preradiation chemotherapy has yet to be shown to be of benefit for children with medulloblastoma. Children with disseminated disease are a highly problematic subgroup of patients to treat. A variety of new approaches are being studied, most of which are intensifying chemotherapy either prior to or after radiation. Long-term survivors of medulloblastoma are at significant risk for permanent endocrinologic, cognitive, and psychological sequelae. Infants and very young children with medulloblastoma remain a difficult therapeutic challenge because they have the most virulent form of the disease and are at highest risk for treatment-related sequelae.