Phase I topotecan preparative regimen for high-risk neuroblastoma, high-grade glioma, and refractory/recurrent pediatric solid tumors.

We evaluated the toxicity and maximum tolerated dose of topotecan in a novel myeloablative regimen as treatment for high-risk pediatric tumors. Patients received an assigned topotecan dosage in combination with fixed doses of carboplatin and thiotepa, followed by autologous hematopoietic stem cells infusion. Topotecan dose was escalated in cohorts of four patients until the maximum tolerated dose of topotecan was defined or until accrual of 30 patients. Pharmacokinetics of topotecan were examined, and event-free survival was estimated. We describe preliminary results following treatment of 25 pediatric patients with high-risk solid tumors.

Surveillance imaging in children with medulloblastoma (posterior fossa PNET).

BACKGROUND: The use of surveillance imaging in children with medulloblastoma has been criticised. The aim of this study was to determine what proportion of relapses are detected by surveillance and whether these are found at a relatively favourable stage. METHODS: This study was a retrospective review of the medical charts and imaging studies of 89 patients treated at a single children's cancer centre. Relapse was defined as evidence of an increase in volume of residual tumour of greater than 25% or the presence of metastases, or new onset of positive CSF cytology. Relapse was termed symptomatic if it was diagnosed by tests performed because of new symptoms that occurred in the interval between surveillance examinations. Asymptomatic relapse was diagnosed solely on the basis of surveillance imaging. Survival time to relapse was calculated from the date of the first surgical procedure. RESULTS: Surveillance imaging detected 17 (71%) of the 24 relapses that occurred later than 6 months after diagnosis. All seven patients who presented with symptoms between scans have died, with a median survival from relapse of 5 months. Median survival from relapse in the patients detected by surveillance was 44 months, and four remain alive at 44-75 months. The patients detected by surveillance tended to have less advanced disease, which was more amenable to salvage therapy. CONCLUSION: This type of study cannot prove that surveillance imaging improves survival in children with medulloblastoma because of the effects of lead time and length biases. Despite this, surveillance does appear to be effective in detecting potentially curable medulloblastoma relapses and should be offered to all patients.

Treatment of progressive or recurrent pediatric malignant supratentorial brain tumors with herpes simplex virus thymidine kinase gene vector-producer cells followed by intravenous ganciclovir administration.

OBJECT: The outcome for children with recurrent malignant brain tumors is poor. The majority of patients die of progressive disease within months of relapse, and other therapeutic options are needed. The goal of this Phase I study was to evaluate the safety of in vivo suicide gene therapy in 12 children with recurrent, malignant, supratentorial brain tumors. METHODS: After optimal repeated tumor resection, multiple injections of murine vector-producing cells shedding murine replication-defective retroviral vectors coding the herpes simplex virus thymidine kinase type 1 (HSV-Tk1) gene were made into the rim of the resection cavity. Fourteen days after the vector-producing cells were injected, ganciclovir was administered for 14 days. The retroviral vector that was used only integrated and expressed HSV-Tk1 in proliferating cells, which are killed after a series of metabolic events lead to cell death. The median age of the patients was 11 years (range 2-15 years). Treated brain tumors included seven malignant gliomas, two ependyminomas, and three primitive neuroectodermal tumors. The patients were treated with one of three escalating dose concentrations of vector-producer cells. Four transient central nervous system adverse effects were considered possibly related to the vector-producing cells. In no child did permanent neurological worsening or ventricular irritation develop, and tests for replication-competent retroviruses yielded negative findings. CONCLUSIONS: This Phase I study demonstrates that in vivo gene therapy in which a replication-defective retroviral vector in murine vector-producing cells is delivered by brain injections can be performed with satisfactory safety in a select group of children with localized supratentorial brain tumors.

Treatment of high-risk neuroblastoma with intensive chemotherapy, radiotherapy, autologous bone marrow transplantation, and 13-cis-retinoic acid. Children's Cancer Group.

BACKGROUND: Children with high-risk neuroblastoma have a poor outcome. In this study, we assessed whether myeloablative therapy in conjunction with transplantation of autologous bone marrow improved event-free survival as compared with chemotherapy alone, and whether subsequent treatment with 13-cis-retinoic acid (isotretinoin) further improves event-free survival. METHODS: All patients were treated with the same initial regimen of chemotherapy, and those without disease progression were then randomly assigned to receive continued treatment with myeloablative chemotherapy, total-body irradiation, and transplantation of autologous bone marrow purged of neuroblastoma cells or to receive three cycles of intensive chemotherapy alone. All patients who completed cytotoxic therapy without disease progression were then randomly assigned to receive no further therapy or treatment with 13-cis-retinoic acid for six months. RESULTS: The mean (+/-SE) event-free survival rate three years after the first randomization was significantly better among the 189 patients who were assigned to undergo transplantation than among the 190 patients assigned to receive continuation chemotherapy (34+/-4 percent vs. 22+/-4 percent, P=0.034). The event-free survival rate three years after the second randomization was significantly better among the 130 patients who were assigned to receive 13-cis-retinoic acid than among the 128 patients assigned to receive no further therapy (46+/-6 percent vs. 29+/-5 percent, P=0.027). CONCLUSIONS: Treatment with myeloablative therapy and autologous bone marrow transplantation improved event-free survival among children with high-risk neuroblastoma. In addition, treatment with 13-cis-retinoic acid was beneficial for patients without progressive disease when it was administered after chemotherapy or transplantation.

Double-alkylator non-total-body irradiation regimen with autologous hematopoietic stem-cell transplantation in pediatric solid tumors.

PURPOSE: To determine the maximum-tolerated dose (MTD) of cyclophosphamide (CTX) when administered with fixed doses of carboplatin, etoposide, and melphalan (CEM) followed by autologous hematopoietic stem-cell transplantation (HSCT) in children with recurrent or high-risk solid tumors as a consolidation chemotherapy, and to make preliminary observations on efficacy. PATIENTS AND METHODS: Twenty-seven patients with solid tumors between the ages of 2 and 21 years were enrolled. Twenty of 27 had recurrent disease, whereas seven were treated in first remission. Nine were treated with melphalan 50 mg/m2/d for 4 days, carboplatin 300 mg/m2/d for 4 days as a continuous infusion (CI), and etoposide 200 mg/m2/d for 4 days as a CI (level I). CTX 750 mg/m2/d for 4 days was added to this regimen for the next 18 patients (level II). Seven of nine patients at level I and four of 18 at level II received bone marrow (BM) only, while two of nine at level I and 14 of 18 at level II received BM plus peripheral-blood stem cells (PBSC). RESULTS: The median time to reach an absolute neutrophil count (ANC) greater than 500/microl was 12.5 and 10 days for patients who received BM only and BM plus PBSC, respectively. Three cases of grade 3 mucositis, one Candida sepsis, and two transient hypoxemias were the main nonfatal toxicities. No toxic mortality was observed among level I patients. Three of 18 (16%) level II patients, all in second CR, died of transplant-related complications. Median follow-up is 29 months. Nine died of progressive disease (one second malignancy), six relapsed and are alive with disease, and nine are in continuous CR. Among the 15 PNET/Ewing's sarcoma patients, seven are in continuous CR (three of nine in second CR/VGPR, four of six in first CR/VGPR). CONCLUSION: The addition of CTX 3 g/m2 to CEM followed by autologous HSCT as a consolidation therapy resulted in 16% toxic mortality in children with recurrent or high-risk solid tumors. Further CTX dose escalation was aborted. No common nonhematologic toxicity was identified. The event-free survival (EFS) of 66% +/- 19% at 3 years for patients with metastatic PNET/Ewing's sarcoma in first remission is encouraging. However, this is based on only six patients. Both level I and II need further exploration in high-risk pediatric solid tumors in first remission.

Chemotherapy without irradiation--a novel approach for newly diagnosed CNS germ cell tumors: results of an international cooperative trial. The First International Central Nervous System Germ Cell Tumor Study.

PURPOSE: Radiation therapy for CNS germ cell tumors (GCT) is commonly associated with neurologic sequelae. We designed a therapeutic trial to determine whether irradiation could be avoided. PATIENTS AND METHODS: Patients received four cycles of carboplatin, etoposide, and bleomycin. Those with a complete response (CR) received two further cycles; others received two cycles intensified by cyclophosphamide. RESULTS: Seventy-one patients were enrolled (45 with germinoma and 26 with nongerminomatous GCT [NGGCT]). Sixty-eight were assessable for response. Thirty-nine of 68 (57%) achieved a CR within four cycles. Of 29 patients with less than a CR, 16 achieved CR with intensified chemotherapy or second surgery. Overall, 55 of 71 (78%) achieved a CR without irradiation. The CR rate was 84% for germinomas and 78% for NGGCT. With a median follow-up duration of 31 months, 28 of 71 patients were alive without relapse or progression. Thirty-five showed tumor recurrence (n = 28) or progression (n = 7) at a median of 13 months. Twenty-six of 28 patients (93%) who recurred following remission underwent successful salvage therapy. Pathology was the only variable predictive of survival. The probability of surviving 2 years was .84 for germinoma patients and .62 for NGGCT. Seven of 71 patients died of toxicity associated with study chemotherapy. CONCLUSION: Forty-one percent of surviving patients and 50% of all patients were treated successfully with chemotherapy only without irradiation. Chemotherapy-only regimens for CNS GCT, although encouraging, should continue to be used only in the setting of formal clinical trials.

Chemotherapy plus local treatment in the management of intraocular retinoblastoma.

OBJECTIVE: To describe platinum-based chemotherapy combined with local treatment modalities as an alternative to external beam radiotherapy for intraocular retinoblastoma. DESIGN: Platinum levels were measured by atomic absorption analysis in the tumors of 2 patients with retinoblastoma given carboplatin 5 or 2.5 hours before enucleation. Platinum levels in heated vs nonheated Greene melanoma tumors in rabbits were compared. A retrospective review of 172 affected eyes in 136 consecutive patients treated for retinoblastoma between January 1990 and December 1995 was performed. From 1990 to 1992, all treatable eyes initially received systemic carboplatin, 560 mg/m2, followed by 15 to 30 minutes of continuous diode laser hyperthermia (thermochemotherapy). Since 1992, larger tumors were treated initially with 3 monthly cycles of carboplatin, etoposide, and vincristine sulfate to reduce tumor volume (chemoreduction) followed by sequential aggressive local therapy (SALT) during examinations under anesthesia every 2 to 3 weeks. OUTCOME MEASURE: Treatment success was defined as eradication of tumor without enucleation or external beam radiotherapy. RESULTS: Significant therapeutic platinum levels were measured in the human tumors 2.5 and 5 hours after carboplatin administration. Increasing the temperature by 9 degrees C for 15 minutes doubled platinum levels in the rabbit model. Of the 38 eyes with Reese-Ellsworth group 1 through 5b tumors that were treated primarily with thermochemotherapy, all 24 eyes with group 1 and 2 tumors were treated successfully and two of the 4 eyes with group 3 tumors and all 10 eyes with group 5b tumors were treated unsuccessfully. Chemoreduction plus SALT was the primary treatment in 35 eyes and was successful in all 10 eyes with group 1 through 4 tumors and unsuccessful in all 7 eyes with extensive subretinal seeding and all 18 eyes with group 5b tumors with vitreous seeding. Seventy patients received carboplatin or carboplatin, vincristine, and etoposide, with myelosuppression, occasionally associated with bacteremia, being the main side effect. Transfusions were required in 15% of patients. Radiation retinopathy occurred in all 6 eyes treated with iodine 125 plaques. CONCLUSIONS: Thermochemotherapy is successful primary treatment for Reese-Ellsworth group 1 and 2 retinoblastomas. For larger tumors in the absence of vitreous or extensive subretinal seeding, 3 cycles of chemoreduction followed by SALT eradicates residual viable tumor. Chemoreduction plus SALT was not successful in eyes with diffuse vitreous or extensive subretinal seeding. Prior chemotherapy increases the risk for radiation retinopathy following 125I plaque therapy. External beam radiotherapy can safely be avoided in the primary treatment of Reese-Ellsworth groups 1 through 4 nondispersed retinoblastoma.

Esthesioneuroblastoma in the pediatric age-group: the role of chemotherapy and autologous bone marrow transplantation.

Esthesioneuroblastoma, a malignant neoplasm arising from olfactory epithelium, is unusual in the pediatric age-group. Management has traditionally involved surgery and radiotherapy, alone or in combination, with chemotherapy reserved for recurrent or high grade disease. We report a single institution experience utilizing chemotherapy and radiotherapy as the initial treatment and successful control of the primary tumor in two patients. In one patient, neck dissection and high dose chemotherapy combined with autologous bone marrow transplantation were used as successful salvage therapy of neck metastasis. Both patients are alive and disease free with a mean follow-up of 56 months. These results support the role of chemotherapy in the treatment of esthesioneuroblastoma and suggest that chemotherapy be used as part of the initial combined modality treatment plan.

Pharmacokinetic studies of 13-cis-retinoic acid in pediatric patients with neuroblastoma following bone marrow transplantation.

A phase I clinical trial of 13-cis-retinoic acid (cis-RA) was undertaken to determine the maximally tolerated dose (MTD) and pharmacokinetics (PK) of cis-RA following bone marrow transplantation (BMT) in children with high-risk neuroblastoma. Mean peak serum levels of cis-RA in 31 pediatric patients ranged from 4.9 to 8.9 microM following doses of 100-200 mg/m2 per day, divided into two doses every 12 h administered orally. The PK of cis-RA obeyed a single-compartment model following first-order absorption in the majority of patients. A linear increase in the mean peak serum levels and area under the time-concentration curve (AUC) with increasing dose was observed. The average half-lives of absorption and elimination were 1.0 and 5.8 h, respectively. At the MTD of 160 mg/m2 per day, the mean cis-RA peak serum concentration was 7.2 +/- 5.3 microM. AUC values were not altered significantly during a 2-week course of treatment or over a long period of multiple courses. Levels of trans-retinoic acid, a metabolite of cis-RA, remained low but were similar on days 1 and 14, whereas the 4-oxo-13-cis-RA metabolite had increased in 64% of patients by day 14. Peak serum cis-RA concentrations correlated with clinical toxicity as grade 3 to 4 toxicity was seen in 44% of patient-courses (8/18) with peak serum levels > 10 microM, but only 13% (12/96) with peak serum levels < 10 microM. These results show that cis-RA given at 160 mg/m2 to children achieved serum concentrations known to be effective against neuroblastoma in vitro, and the PK for cis-RA differs from that reported for trans-retinoic acid in children.

Phase I trial of 13-cis-retinoic acid in children with neuroblastoma following bone marrow transplantation.

PURPOSE: Treatment of neuroblastoma cell lines with 13-cis-retinoic acid (cis-RA) can cause sustained inhibition of proliferation. Since cis-RA has demonstrated clinical responses in neuroblastoma patients, it may be effective in preventing relapse after cytotoxic therapy. This phase I trial was designed to determine the maximal-tolerated dosage (MTD), toxicities, and pharmacokinetics of cis-RA administered on an intermittent schedule in children with neuroblastoma following bone marrow transplantation (BMT). PATIENTS AND METHODS: Fifty-one assessable patients, 2 to 12 years of age, were treated with oral cis-RA administered in two equally divided doses daily for 2 weeks, followed by a 2-week rest period, for up to 12 courses. The dose was escalated from 100 to 200 mg/m2/d until dose-limiting toxicity (DLT) was observed. A single intrapatient dose escalation was permitted. RESULTS: The MTD of cis-RA was 160 mg/m2/d. Dose-limiting toxicities in six of nine patients at 200 mg/m2/d included hypercalcemia (n = 3), rash (n = 2), and anemia/thrombocytopenia/emesis/rash (n = 1). All toxicities resolved after cis-RA was discontinued. Three complete responses were observed in marrow metastases. Serum levels of 7.4 +/- 3.0 mumol/L (peak) and 4.0 +/- 2.8 mumol/L (trough) at the MTD were maintained during 14 days of therapy. The DLT correlated with serum levels > or = 10 mumol/L. CONCLUSION: The MTD of cis-RA given on this intermittent schedule was 160 mg/m2/d. Serum levels known to be effective against neuroblastoma in vitro were achieved at this dose. The DLT included hypercalcemia, and may be predicted by serum cis-RA levels. Monitoring of serum calcium and cis-RA levels is indicated in future trials.

Bone abnormalities detected with skeletal scintigraphy after bone marrow harvest in patients with childhood neuroblastoma.

PURPOSE: To illustrate abnormalities detected with radionuclide skeletal scintigraphy, computed tomography (CT), and radiography after bone marrow harvest in patients who are candidates for autologous bone marrow transplantation (ABMT) in treatment of neuroblastoma. MATERIALS AND METHODS: Twenty-four patients with neuroblastoma underwent ABMT and evaluation with conventional skeletal scintigraphy. Findings of abnormality on bone scans were correlated whenever possible with findings from CT and plain radiography. RESULTS: Skeletal scintigraphy revealed 36 sites of increased activity in the sacroiliac region, iliac crest, or both caused by bone marrow harvest in the 24 patients. In 10 patients, follow-up bone scans showed complete disappearance of abnormal activity at 18 sites. CONCLUSION: The harvesting of marrow for ABMT caused iatrogenic abnormalities on bone scans. It is important that these be recognized so that they will not be confused with progressive or new metastases.

Hypercalcemia: a dose-limiting toxicity associated with 13-cis-retinoic acid.

PURPOSE: 13-cis-Retinoic acid (cis-RA) has efficacy in the treatment and prevention of certain malignancies. In vitro effects against neuroblastoma include induction of differentiation, inhibition of proliferation, and decreased N-myc expression. We hypothesized that cis-RA may be effective against minimal residual disease in neuroblastoma patients. A phase I trial to determine the maximal tolerated dosage and toxicity of cis-RA in pediatric patients with neuroblastoma after bone marrow transplantation was initiated. PATIENTS AND METHODS: Forty-nine pediatric patients (status post-bone marrow transplant for neuroblastoma) were treated for 14 days with oral cis-RA in escalating doses from 100 to 200 mg/m2/day followed by a 14-day rest period for up to 12 months. RESULTS: In three of 39 patients (7.7%) evaluable for calcium levels, hypercalcemia (12.6-18.7 mg/dl) was the dose-limiting toxicity. Grade 1-3 hypercalcemia occurred in nine of 39 patients (23%). The overall incidence of hypercalcemia was 31% (12 of 39). Only one patient was symptomatic due to the hypercalcemia, with arthralgias and myalgias. The hypercalcemia resolved with temporary discontinuation of the drug and a 25% dose reduction for subsequent courses. CONCLUSIONS: Hypercalcemia is a novel dose-limiting toxicity for cis-RA. Patients receiving high doses of cis-RA should have monitoring of serum calcium levels.

Escalating dose of continuous infusion combination chemotherapy for refractory neuroblastoma.

PURPOSE: This trial was undertaken to determine if a continuous infusion format with increased dose-intensity had antitumor activity with tolerable toxicity in patients with advanced neuroblastoma. PATIENTS AND METHODS: Forty heavily pretreated patients with refractory or progressive neuroblastoma received continuous infusion doxorubicin, cisplatin, and etoposide along with bolus ifosfamide in a dose-escalation format. A total of 79 courses of chemotherapy were administered at five different dose levels. RESULTS: Fifteen of 35 assessable patients (43%) achieved either a partial response (PR) or complete response (CR), including five patients with a CR, three with a very good PR (VGPR), and seven with a PR. Hematologic toxicity was severe, but reversible, and other toxicities, although significant, were tolerable and much less than that accepted in a bone marrow transplantation (BMT) setting. CONCLUSION: This investigation illustrates that response is possible even in an extremely poor-prognosis group of patients, and it suggests that such a regimen may be effective if given before disease progression occurs.

Expression of interleukin-4 receptors on early human B-lineage cells.

Interleukin-4 (IL-4) regulates multiple stages of the antigen-dependent phase of B-cell development. However, its precise role in regulating B lymphopoiesis in bone marrow is not as well defined. We examined whether surface IgM- normal and leukemic human B-cell precursors (BCP) expressed IL-4 receptors using biotinylated IL-4. Constitutive expression of IL-4 receptors was detected on both normal and leukemic BCP. A higher percentage of normal BCP (82% +/- 15%) expressed IL-4 receptors compared with leukemic BCP (44% +/- 8%). Using mean fluorescent intensity as an indicator of receptor level on the IL-4 receptor positive cells, normal (91 +/- 41) and leukemic (44 +/- 37) BCP expressed comparable numbers of receptors. IL-4 induced the expression of CD23 on 30% of the leukemic BCP cases examined. IL-4 induced CD23 on surface IgM+ fetal bone marrow lymphoid cells but not on the surface IgM- normal BCP, despite the presence of detectable receptors on the surface IgM- cells. IL-4 did not stimulate proliferation of normal BCP, nor could it enhance the effect of recombinant IL-7 or low molecular weight B-cell growth factor. However, IL-4 increased the expression of surface IgM and surface Ig kappa on in vitro differentiated pre-B cells. Our collective results identify no role for IL-4 in the proliferation of normal or leukemic BCP, but identify a role in the enhancement of surface Ig expression during pre-B to B-cell differentiation.

Ontogeny of normal human B-cell and T-cell precursors and its relation to leukemogenesis.

The concept that a pluripotent stem cell exists and has the capacity eventually to give rise to mature B and T cells is uncontestable. However, the precise developmental relationship between pluripotent stem cells and the earliest stages of B-cell and T-cell development are still obscure. Patterns of gene expression are being identified that characterize normal B-cell and T-cell precursors, and the regulatory variables that influence self-renewal and differentiation of these cells. These are important studies because childhood lymphoblastic leukemia almost always manifests a cellular phenotype consonant with an immature lymphoid cell. A comprehensive understanding of the etiology of acute lymphoblastic leukemia will likely be hastened by a more thorough understanding of normal lymphopoiesis. This knowledge will complement the large data base that currently characterizes lymphoblastic leukemia in children.

Differentiation of normal human pre-B cells in vitro.

The differentiation of surface Ig- pre-B cells into surface Ig+ B cells is a critical transition in mammalian B cell ontogeny. Elucidation of the growth factor requirements and differentiative potential of human pre-B cells has been hampered by the absence of a reproducible culture system that supports differentiation. Fluorescence-activated cell sorting and magnetic bead depletion were used to purify fetal bone marrow CD10+/surface mu- cells, which contain 60-70% cytoplasmic mu+ pre-B cells. CD10+/surface mu- cells cultured for 2 d were observed to differentiate into surface mu+ cells. Analysis by Southern blotting provided direct evidence that rearrangement of kappa light chain genes occurs in culture, and flow cytometric analysis revealed the appearance of surface Ig+ B cells expressing mu/kappa or mu/lambda. Unexpectedly, the kappa/lambda ratio in differentiated cells was the inverse of what is normally observed in adult peripheral blood. Differentiation occurs in the absence of exogenous growth factors or cytokines, suggesting that a stimulus-independent differentiative inertia might characterize pre-B cells in vivo. Future use of this model will facilitate our understanding of normal and abnormal human pre-B cell differentiation.

The clinical spectrum of infections with viridans streptococci in bone marrow transplant patients.

A retrospective review of 832 bone marrow transplant patients was performed to determine the clinical spectrum and risk factors for viridans streptococci infections. The incidence of viridans streptococci cultured from the blood and/or cerebrospinal fluid was 15% (123/832), occurring within 15 days of bone marrow transplant in 78% of patients, usually during profound neutropenia. Strep. mitis was the most frequent isolate (47%). Only 27% (33/123) of patients were symptomatic beyond fever, usually with neurologic, pulmonary, and/or cardiovascular manifestations. Ten (8%) of 123 culture positive patients developed a fulminant cardiorespiratory collapse, with a 60% mortality. One additional death occurred due to cerebritis. However, a time dependent covariate analysis found no significant difference in overall mortality (p = 0.30) or duration of hospitalization (p = 0.50) in patients with or without viridans streptococci infections. A multivariate analysis revealed that age less than 18 years (RR = 1.5, p = 0.04) and a primary diagnosis of acute lymphocytic leukemia (RR = 1.5, p = 0.07) were independent and significant risk factors for viridans streptococci infections. Sex, conditioning regimen, donor type, in vitro bone marrow treatment, and acute graft-versus-host disease were not significant. Viridans streptococci should be recognized as pathogens in bone marrow transplant patients which require appropriate antibiotics and aggressive supportive therapy.