Myeloablative therapy and unpurged autologous bone marrow transplantation for poor-prognosis neuroblastoma: report of 34 cases

Naxitamab Combined with Granulocyte-Macrophage Colony-Stimulating Factor as Consolidation for High-Risk Neuroblastoma Patients in First Complete Remission under Compassionate Use-Updated Outcome Report

Naxitamab is an anti-GD2 antibody approved for the treatment of relapsed/refractory HR-NB. We report the survival, safety, and relapse pattern of a unique set of HR-NB patients consolidated with naxitamab after having achieved first CR. Eighty-two patients were treated with 5 cycles of GM-CSF for 5 days at 250 μg/m²/day (-4 to 0), followed by GM-CSF for 5 days at 500 μg/m²/day (1-5) and naxitamab at 3 mg/kg/day (1, 3, 5), on an outpatient basis. All patients but one were older than 18 months at diagnosis and had stage M; 21 (25.6%) pts had MYCN-amplified (A) NB; and 12 (14.6%) detectable MRD in the BM. Eleven (13.4%) pts had received high-dose chemotherapy and ASCT and 26 (31.7%) radiotherapy before immunotherapy. With a median follow-up of 37.4 months, 31 (37.8%) pts have relapsed. The pattern of relapse was predominantly (77.4%) an isolated organ. Five-year EFS and OS were 57.9% (71.4% for MYCN A) 95% CI = (47.2, 70.9%); and 78.6% (81% for MYCN A) 95% CI = (68.7%, 89.8%), respectively. EFS showed significant differences for patients having received ASCT (p = 0.037) and pre-immunotherapy MRD (p = 0.0011). Cox models showed only MRD as a predictor of EFS. In conclusion, consolidation with naxitamab resulted in reassuring survival rates for HR-NB patients after end-induction CR.

Autologous Stem-Cell Transplantation for High-Risk Neuroblastoma: Historical and Critical Review

Simple Summary

The original idea that providing higher doses of cytotoxic agents will result in higher rates of tumor cell killing was proposed in the 1980s. Preclinical data supported clinical testing. Advancements in bone marrow and peripheral stem-cell support technologies during the 1980s and 1990s allowed for clinical developments that permitted testing the higher dose hypothesis in oncology patients. The results of almost 20 years of clinical trials proved the linear relationship between dosing and clinical outcome to be mostly inaccurate. As a consequence, the adult oncology field abandoned high-dose chemotherapy strategies by the turn of the 21st century. Neuroblastoma is the only pediatric extracranial solid tumor where high-dose chemotherapy has remained part of the standard management for high-risk cases. This systematic review aims to understand the historical reason for such an exception and analyzes data challenging the benefit of high-dose chemotherapy and autologous stem-cell transplants in the era of anti-GD2 immunotherapy.

Abstract

Curing high-risk neuroblastoma (HR-NB) is a challenging endeavor, which involves the optimal application of several therapeutic modalities. Treatment intensity for cancer became highly appealing in the 1990s. Investigative trials assumed that tumor response correlated with the dosage or intensity of drug(s) administered, and that this response would translate into improved survival. It was postulated that, if myelotoxicity could be reversed by stem-cell rescue, cure might be possible by increasing the dose intensity of treatment. The principle supported autologous stem-cell transplant (ASCT) strategies. High-dose therapy transformed clinical practice, legislation, and public health policy, and it drove a two-decade period of entrepreneurial oncology. However, today, no ASCT strategies remain for any solid tumor indication in adults. As with most solid malignancies, higher dosing of cytotoxic agents has not resulted in a clear benefit in survival for HR-NB patients, whereas the long-term toxicity has been well defined. Fortunately, novel approaches such as anti-GD2 immunotherapy have demonstrated a significant survival benefit with a much less adverse impact on the patient’s wellbeing. On the basis of extensive experience, persisting with administering myeloablative chemotherapy as the standard to treat children with HR-NB is not consistent with the overall aim in pediatric oncology of curing with as little toxicity as possible.

Immunotherapy approaches targeting neuroblastoma

PURPOSE OF REVIEW

In the era of immune-oncology, a breakthrough in the field of pediatric solid tumor research has been the demonstration that immunotherapy for patients with high-risk neuroblastoma improves the event-free and overall survival. Immunotherapeutic approaches including a monoclonal antibody targeting the cell surface glycosphingolipid disialoganglioside and cytokines successfully eliminate minimal residual disease.

RECENT FINDINGS

Since this seminal discovery, clinical trials evaluating immunotherapy in combination with chemotherapy and cellular therapies have begun to demonstrate effectiveness in treatment of bulky disease. Broader knowledge has also been gained regarding immunotherapy-limiting side-effects. Furthermore, biologic studies in actively treated patients have contributed to our growing understanding of the underlying immunologic processes and mechanisms of tumor response and immune evasion.

SUMMARY

The example of neuroblastoma is beginning to demonstrate that various immunotherapies combined with more conventional anticancer treatments can be synergistic. These advancements pose new challenges to both clinical researchers and medical provider and herald a new era in pediatric cancer therapy.

Silencing of Y-box binding protein-1 by RNA interference inhibits proliferation, invasion, and metastasis, and enhances sensitivity to cisplatin through NF-κB signaling pathway in human neuroblastoma SH-SY5Y cells

Y-box binding protein-1 (YB-1), a member of Y-box protein family binding DNA and RNA, has been proposed as a novel marker in multiple malignant tumors and found to be associated with tumor malignancy. Neuroblastoma is an embryonal tumor arising from neuroblast cells of the autonomic nervous system, which is the most common cancer diagnosed in infants. It has been reported that YB-1 is highly expressing in various human tumors including nasopharynx, thyroid, lung, breast, colon, ovary, and prostate cancers. This study aimed to investigate the functional role of YB-1 in neuroblastoma by silencing YB-1 using RNA interference (shRNA) in neuroblastoma SH-SY5Y cells. We found that silencing of YB-1 decreased the proliferation, migration, and invasion of SH-SY5Y cells. At molecular level, inhibition of YB-1 decreased the expression level of PCNA as well as MMP-2 in neuroblastoma SH-SY5Y cells. Also, we discovered that YB-1 silencing sensitized SH-SY5Y cells to cisplatin and promoted the apoptosis induced by cisplatin due to down-regulation of multidrug resistance (MDR) 1 protein via NF-κB signaling pathway. Therefore, we consider that targeting YB-1 is promising for neuroblastoma treatment and for overcoming its cisplatin resistance in the development of new neuroblastoma therapeutic strategies.

Neuroblastoma (Peripheral neuroblastic tumours)

Peripheral neuroblastic tumours (PNTs), a family of tumours arising in the embryonal remnants of the sympathetic nervous system, account for 7-10% of all tumours in children. In two-thirds of cases, PNTs originate in the adrenal glands or the retroperitoneal ganglia. At least one third present metastases at onset, with bone and bone marrow being the most frequent metastatic sites. Disease extension, MYCN oncogene status and age are the most relevant prognostic factors, and their influence on outcome have been considered in the design of the recent treatment protocols. Consequently, the probability of cure has increased significantly in the last two decades. In children with localised operable disease, surgical resection alone is usually a sufficient treatment, with 3-year event-free survival (EFS) being greater than 85%. For locally advanced disease, primary chemotherapy followed by surgery and/or radiotherapy yields an EFS of around 75%. The greatest problem is posed by children with metastatic disease or amplified MYCN gene, who continue to do badly despite intensive treatments. Ongoing trials are exploring the efficacy of new drugs and novel immunological approaches in order to save a greater number of these patients.

A Phase I New Approaches to Neuroblastoma Therapy Study of Buthionine Sulfoximine and Melphalan With Autologous Stem Cells for Recurrent/Refractory High-Risk Neuroblastoma

BACKGROUND

Myeloablative therapy for high-risk neuroblastoma commonly includes melphalan. Increased cellular glutathione (GSH) can mediate melphalan resistance. Buthionine sulfoximine (BSO), a GSH synthesis inhibitor, enhances melphalan activity against neuroblastoma cell lines, providing the rationale for a Phase 1 trial of BSO-melphalan.

PROCEDURES

Patients with recurrent/resistant high-risk neuroblastoma received BSO (3 gram/m(2) bolus, then 24 grams/m(2) /day infusion days -4 to -2), with escalating doses of intravenous melphalan (20-125 mg/m(2) ) days -3 and -2, and autologous stem cells day 0 using 3 + 3 dose escalation.

RESULTS

Among 28 patients evaluable for dose escalation, one dose-limiting toxicity occurred at 20 mg/m(2) melphalan (grade 3 aspartate aminotransferase/alanine aminotransferase) and one at 80 mg/m(2) (streptococcal bacteremia, grade 4 hypotension/pulmonary/hypocalcemia) without sequelae. Among 25 patients evaluable for response, there was one partial response (PR) and two mixed responses (MRs) among eight patients with prior melphalan exposure; one PR and three MRs among 16 patients without prior melphalan; one stable disease with unknown melphalan history. Melphalan pharmacokinetics with BSO were similar to reports for melphalan alone. Melphalan Cmax for most patients was below the 10 μM concentration that showed neuroblastoma preclinical activity with BSO.

CONCLUSIONS

BSO (75 gram/m(2) ) with melphalan (125 mg/m(2) ) is tolerable with stem cell support and active in recurrent/refractory neuroblastoma. Further dose escalation is feasible and may increase responses.

Autologous and allogeneic cellular therapies for high-risk pediatric solid tumors

Since the 1950s, the overall survival of children with cancer has gone from almost zero to approaching 80%. Although there have been notable successes in treating solid tumors such as Wilms tumor, some childhood solid tumors have continued to elude effective therapy. With the use of megatherapy techniques such as tandem transplantation, dose escalation has been pushed to the edge of dose-limiting toxicities, and any further improvements in event-free survival will have to be achieved through novel therapeutic approaches. This article reviews the status of autologous and allogeneic hematopoietic stem cell transplantation (HSCT) for many pediatric solid tumor types. Most of the clinical experience in transplant for pediatric solid tumors is in the autologous setting, so some general principles of autologous HSCT are reviewed. The article then examines HSCT for diseases such as Hodgkin disease, Ewing sarcoma, and neuroblastoma, and the future of cell-based therapies by considering some experimental approaches to cell therapies.

Outcomes of the POG 9340/9341/9342 trials for children with high-risk neuroblastoma: a report from the Children's Oncology Group

BACKGROUND

From 1993 to 1995, the Pediatric Oncology Group (POG) enrolled patients with high-risk neuroblastoma on three sequential, conjoined studies: a phase II induction window (9340), followed by intensive multiagent induction chemotherapy (9341), and subsequent myeloablative therapy with autologous stem cell rescue (9342). We report here the outcomes of patients treated on these studies.

PATIENTS AND METHODS

Patients were between 1 and 21 years old with high-risk neuroblastoma. Phase II window therapy consisted of two courses of either paclitaxel, topotecan, or cyclophosphamide with topotecan. Induction therapy consisted of at least five cycles of intensive chemotherapy, followed by myeloablative therapy with purged autologous stem cell reinfusion. Patient responses, treatment toxicities, and overall and event-free survival rates were calculated.

RESULTS

Eighty-four percent of patients responded to induction chemotherapy, with 39% achieving complete response. Toxicities were primarily hematologic. The 7-year EFS and OS rates for all eligible patients on POG 9341 were 23 +/- 4% and 28 +/- 4%, respectively. The 7-year EFS and OS rates for patients treated on POG 9342 were 27 +/- 6% and 29 +/- 6%, respectively.

CONCLUSIONS

These studies were the first attempt by POG to use autologous stem cell transplantation for neuroblastoma treatment in a cooperative group setting. Toxicities and outcomes were comparable to contemporary cooperative group studies. The phase II induction window had no detectable effect on outcomes. New strategies are needed to improve survival for this devastating disease.

Long-term adverse effects on dentition in children with poor-risk neuroblastoma treated with high-dose chemotherapy and autologous stem cell transplantation with or without total body irradiation

Chemo- and radiotherapy may have injurious effects on developing teeth. In this long-term follow-up study among poor-risk neuroblastoma (NBL) survivors our aims were: (1) to assess both the type and extent of the side-effects of the anticancer treatment on tooth development; and (2) to develop an index for expressing total damage to the permanent dentition. We studied the dental development from panoramic radiographs (PRG) of 18 long-term survivors treated under the age of 6 years with high-dose (HD) chemotherapy and autologous stem cell transplantation (ASCT) for poor-risk NBL. The myeloablative therapy was either HD chemotherapy and fractionated total body irradiation (TBI) of 10-12 Gy (TBI group, n = 10) or HD chemotherapy only (non-TBI group, n = 8). A defect index (DeI) was developed to describe the damage to the permanent dentition. The DeI was also tested in 18 healthy adolescents. All NBL patients had disturbances in dental development including short roots, arrested root development, microdontia and tooth aplasia. After TBI, 9/10 patients had very severe root defects, in contrast to none in the non-TBI group. All children in the TBI group had 2-12 (mean 6.6) missing permanent teeth, while 2/5 in the non-TBI group (3/8 excluded due to young age) had two and four missing permanent teeth, respectively. Microdontia was found at equal frequency in both groups. The mean value of the DeI was 70.0 (range 28-117) in the TBI group, 15.2 (range 4-34) in the non-TBI group (P<0.001, Mann-Whitney U test) and 1.8 (range 0-15) in healthy adolescents. Disturbances in dental development may compromise occlusal function in poor-risk NBL patients after ASCT, especially when TBI is included in the conditioning regimen. Long-term dental follow-up and rehabilitation is required.

Is autologous bone marrow transplant (ABMT) and high-dose chemotherapy an approach that can rescue some children with advanced cancer disease?

The object was to determine the role ABMT in children with advanced cancer Those included had failed to respond to conventional treatment with 4 different ablative chemotherapy regimens. Bone marrow stem cells were identified with CD34. Cellular viability was determined after the bone marrow extraction and before the infusion. Fifteen patients were included, whose ages ranged from 1 to 13 years old with a median of 7. Six had acute leukemia, 6 with primitive neuroectodermic tumors, and 3 with other tumors. The median disease-free survival for the whole group was of 2 months, range of 1 to 29 months and SD of 10.1. A total of 6 children are alive (40%) and without evidence of tumor activity from 1 to 29 months. The disease-free survival rate for these group was of 19.1 months, with an SD of 7.9 months.

Improved survival of children with advanced neuroblastoma treated by intensified therapy including myeloablative chemotherapy with stem cell transplantation: a retrospective analysis from the Tohoku Neuroblastoma Study Group

In the hospitals of the Tohoku Neuroblastoma Study Group (TNBSG), treatment for children with advanced neuroblastoma (NB) was intensified in the mid-1990's with the introduction of myeloablative therapy (MT) with stem cell transplantation (SCT) including the use of autologous peripheral blood stem cells (PBSC) and bone marrow transplantation (BMT). In this report, we examined whether the intensified therapy improved the outcome of children with advanced NB (age> 12 months) who were diagnosed between 1991 and 1997. Patients were 36 children (23 boys and 13 girls) with an average age of 3.4 years (range; 1 to 14 years). Six of them had stage III disease, and the other 30 had stage IV. They were treated initially with induction chemotherapy, surgery, and post-operative chemoradiotherapy, after which 17 of them continued further chemotherapy and the other 19 received MT/SCT (18 with PBSCT and 1 with BMT). Progression-free survival (PFS) rate at seven years from diagnosis was 43.5% for all patients, 66.7% for stage III patients and 38.2% for stage IV patients. The difference between stage III and IV patients was not significant. Among the 30 patients with stage IV disease, PFS at seven years was significantly higher in the 19 patients who received MT/SCT (55.6%) than in the 11 patients who did not receive it (12.5%). There was no difference in clinical and biological risk factors between these two groups, except for the proportion of patients with favorable response to initial therapy (36% and 80% for patients without and with MT/SCT, respectively). Furthermore, the proportion of patients with N-myc amplification was significantly higher in patients with progressive disease (PD) after MT/SCT than in those in CR after MT/SCT. The results of this retrospective study of children with advanced NB suggest that therapy intensification involving MT/SCT might result in lengthened survival time for patients with stage IV disease, and that post-transplant PD remains a risk for patients with high levels of N-myc amplification.

Hyperfractionated low-dose radiotherapy for high-risk neuroblastoma after intensive chemotherapy and surgery

PURPOSE

To assess prognostic factors for local control in high-risk neuroblastoma patients treated with hyperfractionated 21-Gy total dose to consolidate remission achieved by dose-intensive chemotherapy and surgery.

PATIENTS AND METHODS

Patients with high-risk neuroblastoma in first remission received local radiotherapy (RT) totaling 21 Gy in twice-daily 1.5-Gy fractions. RT to the primary site followed dose-intensive chemotherapy and tumor resection; the target field encompassed the extent of tumor at diagnosis, plus 3-cm margins and regional lymph nodes. RT to distant sites followed radiologic evidence of response. Local failure was correlated with clinical factors (including other consolidative treatments) and biologic findings.

RESULTS

Of 99 consecutively irradiated patients followed for a median of 21.1 months from RT, 10 relapsed in or at margins of RT fields at 1 to 27 months (median, 14 months). At 36 months after RT, the probability of primary-site failure was 10.1% +/- 5.3%. No primary-site relapses occurred among the 23 patients whose tumors were excised at diagnosis, but there were three such relapses among the seven patients who were irradiated with evidence of residual disease in the primary site. Four of 18 patients with MYCN-amplified disease and serum lactate dehydrogenase greater than 1,500 U/L had local failures (23.4% +/- 10.7% risk at 18 months). Acute radiotoxicities were insignificant, but three of 35 patients followed for > or = 36 months had short stature from decreased growth of irradiated vertebra.

CONCLUSION

Hyperfractionated 21-Gy RT is well tolerated and, together with dose-intensive chemotherapy and surgery, may help in local control of high-risk neuroblastoma. Extending the RT field to definitively encompass regional nodal groups may improve results. Visible residual disease may warrant higher RT dosing. Patients with biologically unfavorable disease may be at increased risk for local failure. RT to the primary site may not be necessary when tumors are excised at diagnosis.

In vivo cytoreduction studies and cell sorting--enhanced tumor-cell detection in high-risk neuroblastoma patients: implications for leukapheresis strategies

PURPOSE

To improve autologous leukapheresis strategies in high-risk neuroblastoma (NB) patients with extensive bone marrow involvement at diagnosis.

PATIENTS AND METHODS

Anti-G(D2) immunocytochemistry (sensitivity, 1 in 10(5) to 10(6) leukocytes) was used to evaluate blood and bone marrow disease at diagnosis and during the recovery phase of the first six chemotherapy cycles in 57 patients with stage 4 NB and bone marrow disease at diagnosis. A total of 42 leukapheresis samples from the same patients were evaluated with immunocytology, and in 24 of these patients, an anti-G(D2) immunomagnetic enrichment step was used to enhance tumor-cell detection.

RESULTS

Tumor cytoreduction was much faster in blood compared with bone marrow (3.2 logs after the first cycle and 2.1 logs after the first two cycles, respectively). Bone marrow disease was often detectable throughout induction, with a trend to plateau after the fourth cycle. By direct anti-G(D2) immunocytology, a positive leukapheresis sample was obtained in 7% of patients after either the fifth or sixth cycle; when NB cell immunomagnetic enrichment was applied, 25% of patients had a positive leukapheresis sample (sensitivity, 1 in 10(7) to 10(8) leukocytes).

CONCLUSION

Standard chemotherapy seems to deliver most of its in vivo purging effect within the first four cycles. In patients with overt marrow disease at diagnosis, postponing hematopoietic stem-cell collection beyond this point may not be justified. Tumor-cell clearance in blood seems to be quite rapid, and earlier collections via peripheral-blood leukapheresis might be feasible. Immunomagnetically enhanced NB cell detection can be highly sensitive and can indicate whether ex vivo purging should be considered.

LMCE3 treatment strategy: results in 99 consecutively diagnosed stage 4 neuroblastomas in children older than 1 year at diagnosis

PURPOSE

To tailor postinduction therapy for stage 4 neuroblastoma in children who are older than 1 year at diagnosis according to status after induction.

PATIENTS AND METHODS

From March 1987 to December 1992, 99 patients who were consecutively admitted were included in the Lyon-Marseille-Curie East of France (LMCE)3 strategy. After induction with the French Society of Pediatric Oncology NB87 regimen and surgery, patients who were in complete remission immediately proceeded to consolidation therapy with vincristine, melphalan, and fractionated total-body irradiation (VMT). All other patients underwent a postinduction strategy before VMT, either an additional megatherapy regimen or further chemotherapy with etoposide/carboplatin.

RESULTS

The progression-free survival (PFS) is 29% at 7 years from diagnosis, which compares favorably with that of a similar cohort of 72 patients previously reported by our group (LMCE1; PFS of 20% at 5 years and 8% at 14 years, P =.004). In the multivariate analysis, only age younger than 3 years at diagnosis (P =.0085) and achievement of complete or very good partial remission after NB87 and surgery (P =.00024) remained significant. The PFS of the 87 patients who were included in the postinduction strategy was significantly better than that of the comparable 62 patients on the LMCE1 study (32% v 11% at 7 years; P =.005).

CONCLUSION

The progressive improvements in the LMCE results over the last 10 years suggest that improvements in supportive care measures and increases in each component of this strategy (induction, postinduction, consolidation) may all contribute to increased survival rates.

Intensification of therapy using hematopoietic stem-cell support for high-risk neuroblastoma

The use of new strategies for dose intensification using peripheral blood stem cell or autologous purged bone marrow rescue has raised expectations for cure in advanced neuroblastoma, although conflicting reports exist regarding the efficacy of these approaches. Using risk groups based on both biological and clinical staging, the Children's Cancer Group and the Pediatric Oncology Group have agreed upon common prognostic criteria for treatment stratification. We summarize below the prognostic classification and treatment approaches that have improved the overall outcome for children with advanced neuroblastoma. Intensive induction therapy, myeloablative therapy, hematopoietic stem cell purging, and post-transplant therapy for minimal residual disease all have an important role in the treatment. Possible future improvements may incorporate more tumor-specific therapy with targeted radiotherapy, monoclonal antibodies, tumor vaccines, and differentiating agents.

High-dose therapy with stem cell rescue for pediatric solid tumors: rationale and results

Metastatic and recurrent pediatric solid tumors usually respond to chemotherapy but are likely to recur. Because of steep dose-response relationships, HDT requiring hematopoietic rescue may improve outcome. This strategy has recently been shown to be effective for metastatic neuroblastoma. Metastatic Ewing's sarcoma appears to be a closely analogous situation, and promising phase II studies suggest that a definitive trial of efficacy would be appropriate. Phase I or II trials remain appropriate and are needed to define further the efficacy of HDT for most other poor prognosis pediatric solid tumors.

Intensive chemotherapy in children with stage IV neuroblastoma

A retrospective analysis of effectiveness of sequential chemotherapy with cyclophosphamide, doxorubicin, cisplatin and etoposide in children with stage IV neuroblastoma was undertaken. Study group included 17 children of mores than one year old with median age of 3 years (range 18 months to 7 years). Fourteen were males and three females. Sites of primary tumor were abdomen in 12 patients, pelvis in 3, paravertebral in 1 and unknown in 1. Metastatic sites included bone marrow (88%), bone (82%), orbit (29.4%) and lymph node (11.7%). One patient had brain parenchymal disease and another had cerebrospinal fluid positivity for malignant cells. Fifteen of the 17 patients had major response with chemotherapy (complete response in two and partial response in 13). Ten of the 15 patients completed four courses of chemotherapy and five patients progressed while on chemotherapy and died. Only two of the ten patients, who had four courses chemotherapy are alive after 2 years. Hence the 2-year survival in this series is 11.7%. There was no toxic death in this study.

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.

Current aspects of biology, risk assessment, and treatment of neuroblastoma

Neuroblastoma is one of the most intensely studied solid malignancies that affect the pediatric age groups; its clinical presentation, treatment strategies and ultimate prognosis vary greatly. The biologic and genetic character of each tumor has an important impact on disease behavior, and clinical staging now incorporates these factors to generate an overall therapy plan. The clinical presentation of neuroblastoma is related to primary tumor location, production of metabolically active substances, and the presence of metastatic disease. There are also prognostically important associated syndromes including opsoclonus-myoclonus, Horner's syndrome, neurofibromatosis, and a variety of other neurocristopathies. The histologic features of the tumor are of prognostic significance and are utilized in treatment stratification. The International Neuroblastoma Staging System (INSS) has unified classic clinical staging. Features at diagnosis and those determined by initial operation are combined with biologic prognostic factors to achieve risk group assignment for virtually all patients. There are groups of children in which limited therapy is curative and intermediate-risk situations where standard multimodality treatment provides favorable outcomes. Unfortunately, there are many patients with high-risk disease that require intensive strategies, but success is still limited. It is in these most resistant patients that innovative approaches are being undertaken and novel strategies are being investigated.

Immunotherapy with low-dose recombinant interleukin 2 after high-dose chemotherapy and autologous stem cell transplantation in neuroblastoma

The purpose of this study was to evaluate in a phase I-II trial whether low doses of recombinant human interleukin 2 (rHuIL-2) over a prolonged period of time are safe and effective in eradicating or controlling minimal residual disease in children with neuroblastoma given high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT). From January 1992 to July 1996, 17 consecutive patients, with either stage IV or relapsed neuroblastoma, were enrolled. Patients received rHuIL-2 after a median time interval (min-max) of 105 days (56-153) after HDCT and ASCT. The protocol consisted of 2 'priming' courses of rHuIL-2 at escalating doses administered intravenously at 72-h intervals, followed by 'maintenance' with 11 monthly and six bimonthly boosting 5-day courses administered subcutaneously on an outpatient basis. At April 1997, 7 out of the 17 patients had completed the treatment schedule, four had discontinued treatment because of toxicity and four because of relapse; the remaining two patients are still on treatment, having completed 15 courses. Expansion of T lymphocytes, together with an increase in both natural killer cells and in activated T lymphocytes was evidenced. After a median (min-max) follow-up time of 30 (16-64) months, 12 out of 17 patients are alive and well. Two patients relapsed and died 14 and 35 months after transplant. Three patients are alive after having relapsed at 41, 21 and 13 months. The actuarial 2-year event-free survival and overall survival are 67% and 92% respectively. Intermittent administration of low doses of rHuIL-2 given for a long period of time is well tolerated and seems capable of controlling minimal residual disease after HDCT and ASCT in children with high-risk neuroblastoma.

High-sensitivity immunocytologic analysis of neuroblastoma cells in paired blood and marrow samples

High-sensitivity immunocytochemistry was used to evaluate the relative frequency of neuroblastoma cells in bone marrow and peripheral blood in patients with neuroblastoma (NB). A total of 51 concomitant paired blood and marrow samples (102 total) from 35 patients with NB (age 4 months-31 years; stage 29 stage IV, 4 stage III, 2 stage IVS; 14 at diagnosis, 18 in relapse, 12 during treatment, and 7 off-therapy) were analyzed. Cytospins containing up to 10(6) cells each were prepared using the mononuclear cell (MNC) fraction. For immunocytologic staining, a primary mouse monoclonal anti-GD2 antibody (3F8), a secondary antimouse biotinylated antibody, and a streptavidin-alkaline phosphatase complex were used. A minimum of two cytospins containing a mean of 1.4 x 10(6) total MNCs was analyzed in addition to a negative and a positive control. No circulating tumor cells were detected when the concomitant marrow samples were negative or had <10 positive cells per 106 MNC (23 of 51 samples). Of the 18 marrow samples positive at 10-10,000 cells per 106 MNC, 6 had detectable NB cells in the corresponding blood sample, whereas for marrow samples with >10,000 NB cells per 10(6) MNC (1%), the concomitant blood sample was positive for 9 of the 10. When both marrow and blood samples were positive (15 BM-PB pairs), NB cell frequency was significantly lower in blood, with a mean difference of 2.14 logs (median 2.22, range -0.16-4.8, standard error 0.38). In patients with NB, circulating tumor cell frequencies seem to be substantially lower than in concomitant marrow samples, with a mean difference of >2 logs.

Stage IV neuroblastoma in patients over 1 year of age at diagnosis: consolidation of poor responders with combined busulfan, cyclophosphamide and melphalan followed by in vitro mafosfamide-purged autologous bone marrow transplantation

In an attempt to improve the poor prognosis of poor responders with stage IV neuroblastoma, a new combined high-dose chemotherapy conditioning regimen was tested. Event-free and overall survival, as well as the incidence of complications, were analysed. Twenty-five children aged 12-146 months at diagnosis entered this study. All were in complete remission (CR) at the time of high-dose chemotherapy. Two or three different protocols had been necessary for them to achieve a CR. High-dose chemotherapy consisted of a combination of busulfan (600 mg/m2), cyclophosphamide (4400 mg/m2) and melphalan (140 mg/m2). It was followed by autologous bone marrow transplantation (ABMT). The bone marrow graft was purged in vitro with mafosfamide. The probability of event-free survival (EFS) at 5 years post-ABMT was 34%, compared to < 8% in a historical series. Toxicity was severe but manageable and 2 complication-related deaths were observed. Veno-occlusive disease was the most frequent extrahaematopoietic complication encountered, but its outcome was always favourable. By using a very intensive conditioning regimen consisting of a combination of three alkylating agents, the EFS of poor responders with metastatic neuroblastoma was improved and similar to that of good responders. When compared with a previously published similar series of patients, the improvement in survival appears probably related to intensification of the conditioning regimen.

Neuroblastoma in adults and adolescents: an indolent course with poor survival

BACKGROUND

Neuroblastoma rarely occurs in adults, and less than 10% of cases occur in patients older than 10 years. It has been suggested that the behavior of this disease may be different in older patients than in young children. The purpose of this study was to investigate the presentation, biologic features, and outcome of adolescent and adult patients with neuroblastoma to define differences from childhood neuroblastoma.

METHODS

Medical record and pathology reviews were conducted for 16 patients age 13 years or older (13-33 years) at diagnosis who presented with neuroblastoma at the University of California-San Francisco (UCSF) during the period 1968-1995 (patients with intracerebral tumors, esthesioneuroblastoma, or ganglioneuroma were excluded). Six of these patients received their original diagnosis at UCSF, and the others were referred after diagnosis. The survival for the same period for all neuroblastoma patients ages 13-18 years (n = 38) registered in the Children's Cancer Group (CCG) was compared with the survival for those ages 1-13 years (n = 1912). Three of the UCSF patients were enrolled in CCG studies.

RESULTS

Biologic characteristics observed in adolescents and adults differed from those observed in younger patients. In the UCSF population, only 6 of 15 tested patients age 13 or older had elevated urinary catecholamines, and 0 of 6 tested patients had MYCN amplification. There were two patients with Stage I disease, three with Stage II, two with Stage III, and nine with Stage IV. Primary sites were adrenal, pelvic, and retroperitoneal in four cases each; mediastinal in two cases; and paraspinal in two cases. Metastases in nine patients at diagnosis were observed in bone in five; in bone marrow in four; in lymph nodes in three; in the liver in two; and in the pleura, breast, and dura in one patient each. 131I-metaiodobenzylguanidine uptake was observed in 9 of 11 patients. Initial treatment included surgery for 13 of 16 patients, chemotherapy for 10 of 16, radiation therapy for 7 of 16, and autologous bone marrow transplantation for 1 of 16. Relapses occurred in 15 of 16 patients and death in 13 of 16, with overall survival 30% 5 years after diagnosis. Only 1 patient currently remains free of clinical disease 24 months after diagnosis. Several of these patients had long courses from diagnosis to death, with multiple recurrences and/or chronic, persistent disease. In the CCG data base, 76% of patients ages 13-18 years had metastatic disease at diagnosis. In this group, only 1 of 32 had MYCN amplification. The actuarial survival of all CCG patients ages 13-18 years was 7% at 5 years and 4% at 10 years, whereas that for patients ages 1-13 years was 30% at 5 years and 23% at 10 years.

CONCLUSIONS

Neuroblastoma in adolescents and adults has different biologic characteristics and a longer course than in children; nevertheless, ultimately the outcome is poor regardless of stage. A much more aggressive or innovative therapeutic approach is needed for these patients.

Secondary central nervous system metastases in children with neuroblastoma

Cerebral and meningeal involvement in patients with primary extracranial neuroblastoma (NB) is unusual although it is generally present in disseminated disease. The intensification of chemotherapy that has prolonged survival in these children has changed the pattern of relapse presentation, as occurs with isolated central nervous system (CNS) disease. We report 4 patients with secondary CNS metastases. Three infants of 16, 14, and 10 months of age, diagnosed with primary abdominal NB stage 4, presented neuromeningeal metastases during maintenance chemotherapy with seizures and cranial hypertension as the first manifestation. Another 8-year-old patient diagnosed with NB stage 3 presented local relapse with later neuromeningeal metastases. All died in the following 3 months. The possibility of CNS relapse in patients with NB should be considered when neurological symptoms and signs appear. These new relapse forms overshadow the prognosis of these children.

Primary hypothyroidism as a consequence of 131-I-metaiodobenzylguanidine treatment for children with neuroblastoma

BACKGROUND

131-I-metaiodobenzylguanidine is a radioiodinated compound selectively concentrated by cells of neuroectodermal origin, including neuroblastoma cells, for this reason it may represent a promising treatment modality for neuroblastoma in childhood. Although a potential side effect of 131-I-MIBG administration is thyroid dysfunction, relatively few data are reported about this issue.

METHODS

A series of 14 long term surviving patients with neuroblastoma who had been treated with 131-I-MIBG courses ranging from 2.5 to 5.5 gigabecquerels after surgical and conventional pharmacologic therapy is reported.

RESULTS

Twelve patients developed primary hypothyroidism that was clinically overt in 8 patients and compensated in 4 patients within 6-12 months of completion of 131-I-MIBG administration. Only in two patients was thyroid function spared. Significant correlations between the cumulative dose of 131-I-MIBG and the degree of thyroid failure were not found.

CONCLUSIONS

Primary hypothyroidism appears to be a common side effect in children with neuroblastoma treated with 131-I-MIBG. This finding suggests that methods to preserve thyroid function other than oral administration of iodide should be sought.

Patterns of failure following total body irradiation and bone marrow transplantation with or without a radiotherapy boost for advanced neuroblastoma

PURPOSE

To evaluate the patterns of failure and outcome of patients undergoing high-dose chemotherapy, total body irradiation (TBI), and bone marrow transplantation (BMT) for advanced/relapsed pediatric neuroblastoma, with emphasis on the impact of a radiotherapy boost to primary and metastatic sites.

METHODS AND MATERIALS

Between May 1986 and June 1993, 26 patients with advanced neuroblastoma underwent high-dose chemotherapy and TBI followed by BMT at our institution. The majority of patients were over the age of 2 years (73%) and were Stage IV at diagnosis (81%). Multiple metastatic sites were involved including bone (17), bone marrow (15), distant nodes (11), liver (5), lung (4) and brain (1). Twenty patients (77%) received cyclophosphamide (50 mg/kg x 4 days) and TBI as consolidation therapy. TBI was delivered to a total dose of 12 Gy given in 2 Gy twice daily (b.i.d.) fractions over the 3 days preceding bone marrow infusion. A local radiotherapy boost of 8-24 Gy was given to 13 out of 26 patients (50%) to the primary and/or metastatic sites immediately prior to or following induction chemotherapy according to physician judgement. Sites not amenable to a radiotherapy boost included the bone marrow, diffuse/bilateral lung involvement, and multiple bone metastases (> four sites).

RESULTS

The actuarial overall survival of the 26 patients was 40.4% at 3 and 5 years, with a progression-free survival at 5 years of 38.5%. Six patients died of transplant-related toxicity (23%). The use of cyclophosphamide as high-dose consolidation chemotherapy was significantly better than other multidrug regimens used in terms of overall survival (p < 0.0001) and progression-free survival (p = 0.0004). The presence of liver involvement prior to BMT was a significant adverse prognostic factor by multivariate analysis. Of the 20 patients surviving the transplant, 10 (50%) underwent a local radiotherapy boost. The patterns of failure were as follows: 3 out of 10 "boost" patients failed overall, none in previous (old) sites of disease only, 1 in new sites only, and 2 in old and new sites; 6 out of 10 "no boost" patients failed overall, 4 in old sites only, none in new sites only, and 2 in old and new sites. There was a trend toward improved 5-year progression-free survival in patients surviving the transplant that received a boost (68% vs. 33%, p = 0.24). A failure analysis was also performed for each of the 59 initially involved sites, of which the majority (64%) were amenable to a radiotherapy boost. Overall, there is a trend toward less failure in sites amenable to a radiotherapy boost that were irradiated (1 out of 10) vs. those not irradiated (6 out of 28). Failure in the liver occurred in three out of four of the patients with liver involvement that did not receive boost radiotherapy, whereas all seven patients with distant nodal involvement were controlled without a boost. Long-term sequelae include learning difficulties (2), cataract formation (1), and hearing loss (2). Sequelae attributable to a radiotherapy boost occurred in only one patient who received whole brain radiotherapy and developed a cataract and learning difficulties.

CONCLUSION

We have found an actuarial 5-year survival rate of 40.4% for patients with advanced neuroblastoma treated with BMT, which compares favorably with results of other published series. Disease recurrence following BMT was most common in previous sites of disease. The majority (64%) of these sites were amenable to a radiotherapy boost. An analysis of failure suggests that a low-dose radiotherapy boost improves control of these sites.

Cost analysis of immunomagnetic marrow purging for neuroblastoma: in-house purging versus submission to purging centers

High-dose chemoradiotherapy in conjunction with autologous bone marrow transplantation has been used in the treatment of advanced stage neuroblastoma. Because of frequent marrow involvement, marrow purging methods, such as the immunomagnetic technique, have been developed. Current cost constraints force institutions to consider in-house purging versus submission of marrow to purging centers. Our analysis demonstrates that 15 procedures per year are needed to justify an up-front investment in equipment and supplies with a break-even period of 5 years. This number is also required to keep technical proficiency current without frequent retraining of personnel. The analysis includes start-up costs for institutions without a bone marrow processing laboratory, as well as for institutions already processing marrow or peripheral blood stem cells. For institutions performing fewer procedures per year, submission of marrow to purging centers is more cost effective than in-housing purging.

Role of myeloablative therapy in improved outcome for high risk neuroblastoma: review of recent Children's Cancer Group results

The use of new strategies for dose intensification using peripheral blood stem cell or autologous purged bone marrow rescue has raised expectations for cure in advanced neuroblastoma, although conflicting reports exist regarding the efficacy of these approaches. Using risk groups based on both biological and clinical staging, the Children's Cancer Group (CCG) has conducted a series of pilot studies to test new induction, consolidation and myeloablative regimens to attempt to improve outcome. We summarise below the outcome and prognostic factor analysis for the pilot chemotherapy trial, CCG-(CCG-321P2), and the use of high dose myeloablative chemoradiotherapy with allogeneic (CCG-321P1) or autologous purged bone marrow rescue (CCG-321P3) for high risk neuroblastoma patients who were progression-free at the end of induction chemotherapy. After autologous bone marrow transplantation (ABMT), progression-free survival (PFS) at 4 years was 38% (median follow-up 4 years). Prognostic factors for relapse after ABMT included pre-BMT disease status, bone marrow tumour content at harvest, extent of primary resection at diagnosis, and time to ABMT. MYCN amplification, age, stage, and pre-BMT myeloablative regimen were not significant. Allogeneic BMT did not have a better outcome than ABMT. In a retrospective, non-randomised comparison of ABMT and chemotherapy, there was a significant difference in PFS for stage IV patients. High risk subgroups possibly benefiting from ABMT could be identified, including those with tumour MYCN amplification, over 2 years at diagnosis, and those not in complete remission at the end of induction. A randomised prospective trial comparing myeloablative therapy with ABMT to continuous infusion consolidation chemotherapy is currently underway in CCG to determine the relative benefit.

Bone marrow transplantation for high risk neuroblastoma at the Children's Hospital of Philadelphia: an update

A bone marrow transplant (BMT) protocol including surgical excision, local and total body irradiation, and high dose multiagent chemotherapy based on melphalan and bone marrow rescue has been in effect for children with high risk or relapsed neuroblastoma at the Children's Hospital of Philadelphia since 1979. The initial results were reported in 1984 [August et al.: J Clin Oncol 2:609-616, 1984]. This report updates the initial results and those that followed changes in the original conditioning regimen. Forty-two patients were treated between may 1979 and November 1987, and included 27 whose disease had relapsed and 15 who received BMT as part of primary treatment. Allogeneic marrow was given to 12 and autologous marrow to 30; in 7 of these 30, the marrow was purged with monoclonal antibodies and magnetic beads. The 4-year actuarial survival rate is 29%. Ten patients died of early treatment-related complications, 18 died of progressive disease, and 2 died of late complications (1 AIDS and 1 acute myelogenous leukemia). Censoring the two late complications the actuarial 4-year relapse-free survival rate becomes 32%. The longest interval after BMT to relapse was 20 months. There was no significant difference in the survival for patients transplanted following relapse or in first remission. The better survival for patients rescued with autologous marrow (30%) is not statistically significantly different from the result with allogeneic marrow (17%).

Clonal analysis of peripheral blood lymphocytes from three patients with advanced neuroblastoma receiving recombinant interleukin-2 and interferon alpha

In this study we have investigated, at the population and the clonal levels, the immunophenotypes and the non-specific cytotoxic functions of peripheral blood lymphocytes from three stage IV neuroblastoma patients receiving treatment with recombinant interleukin-2 (IL-2) and interferon alpha (IFN alpha). Both IL-2 alone and the combination of IL-2 and IFN alpha caused an in vivo expansion of CD56+, CD3- NK cells most of which expressed the p75 molecule, i.e. the beta chain of the IL-2 receptor. Peripheral blood mononuclear cells (PBMC), drawn after treatment, displayed an increased NK activity, but no lymphokine-activated killer (LAK) activity. However, the subsequent in vitro culture of PBMC with high-dose IL-2 induced the generation of a potent LAK activity, which was mediated by an expanded population of CD3+, CD8+ T cells. Finally lymphocytes that had been isolated after cytokine therapy were cloned, in the presence of low-dose phytohemagglutin, immediately or following culture with IL-2. Clones derived from LAK cells expanded in vitro had predominantly a CD3+, CD8+ immunophenotype, whereas those raised from freshly separated lymphocytes were either CD3+, CD4+ or CD3+, CD8+ in equal proportions. Most of the above clones were poorly or not at all cytolytic against NK-sensitive or NK-resistant targets. In contrast, the few NK clones obtained (CD3-, CD56+) lysed all targets with high efficiency.

High-dose chemotherapy with autologous bone marrow rescue in advanced stage IV neuroblastoma

In order to better evaluate the role of bone marrow purging procedures in the treatment of stage IV neuroblastoma, two similar groups of patients, prospectively treated during the same period at Léon Bérard Center, Lyon, France, and at Giannina Gaslini Institute, Genova, Italy, were reviewed. 18 children were treated in Lyon with a protocol including induction chemotherapy, surgery and a single course of high-dose chemotherapy followed by purged autologous bone marrow rescue. 21 patients were treated in Genoa with a very similar protocol which did not include purging procedures. Progression-free survival at 6 years was 12% (95% confidence interval 0-24%), without any difference between the two series of patients. The only prognostic factor for long-term survival was the persistence (or not) of bone lesions and the presence of metastatic disease (bone or bone marrow) at graft. The small numbers in the two groups and the very poor outcome make it difficult to conclude on the efficacy of purging.

Does in vitro bone marrow purging improve the outcome after autologous bone marrow transplantation?

High-dose therapy with bone marrow rescue is now regarded as an effective treatment for a variety of malignancies. In an attempt to circumvent the scarcity of HLA-matched donors, autologous marrow has been successfully used as the source of cells for hematopoietic reconstitution. There has been considerable controversy as to whether any malignant cells present in the graft could contribute to relapse of disease post-transplant. In this paper we review clinical results obtained by using autologous transplantation and present evidence on how ex vivo tumor purging may contribute to the outcome.