Robert C. Seeger

Treatment of High-Risk Neuroblastoma with Intensive Chemotherapy, Radiotherapy, Autologous Bone Marrow Transplantation, and 13-cis-Retinoic Acid

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.

International criteria for diagnosis, staging, and response to treatment in patients with neuroblastoma.

Neuroblastoma is one of the most common tumors in childhood. However, it often has been difficult to compare clinical and laboratory studies of this disease due to a lack of uniform criteria for diagnosis, staging, and response. An international group of conferees addressed each of these issues and reached a consensus. Specific criteria for making a diagnosis of neuroblastoma are defined. A new neuroblastoma staging system is proposed that takes into account the most important elements of current but incompatible systems. Finally, criteria for response to treatment are standardized. The criteria proposed herein represent an international consensus of essentially every major pediatric oncology group or organization in the United States, Europe, and Japan. The staging system should be referred to as the International Neuroblastoma Staging System, and the response criteria as the International Neuroblastoma Response Criteria. Implementation of these criteria will greatly facilitate the comparison of clinical and laboratory studies by different groups and countries. Furthermore, these criteria should serve as a foundation on which future modifications or improvements can be based.

Effects of retinoic acid (RA) on the growth and phenotypic expression of several human neuroblastoma cell lines

It has been shown that retinoic acid (RA) can promote morphologic differentiation and inhibit the growth of a human neuroblastoma cell line, LA-N-1. The present study tests the histological generality of these phenomena by determining the effects of RA on seven other human neuroblastoma cell lines. Results show that RA strongly inhibited anchorage-dependent growth and induced morphologic alterations in six of seven of the cell lines. These alternations included morphologic differentiation as evidenced by formation of neurite extensions in four of the lines, cellular enlargement and vacuolization in one culture, and formation of large, flattened epithelial or fibroblastic-like cells in another culture. Although one cell line was relatively insensitive to the effects of RA in monolayer culture, all seven were strongly inhibited by RA in soft agar assays. Cellular RA-binding proteins were detected in 2/2 lines tested. These findings suggest that, as a histological group, human neuroblastoma cells are extremely sensitive to RA-induced growth inhibition and morphological alterations generally associated with reduced expression of the malignant phenotype of this type of cancer.

Evidence for an Age Cutoff Greater Than 365 Days for Neuroblastoma Risk Group Stratification in the Children's Oncology Group

PURPOSE In the Childrens Oncology Group, risk group assignment for neuroblastoma is critical for therapeutic decisions, and patients are stratified by International Neuroblastoma Staging System stage, MYCN status, ploidy, Shimada histopathology, and diagnosis age. Age less than 365 days has been associated with favorable outcome, but recent studies suggest that older age cutoff may improve prognostic precision. METHODS To identify the optimal age cutoff, we retrospectively analyzed data from the Pediatric Oncology Group biology study 9047 and Childrens Cancer Group studies 321p1-p4, 3881, 3891, and B973 on 3,666 patients (1986 to 2001) with documented ages and follow-up data. Twenty-seven separate analyses, one for each different age cutoff (adjusting for MYCN and stage), tested age influence on outcome. The cutoff that maximized outcome difference between younger and older patients was selected. RESULTS Thirty-seven percent of patients were younger than 365 days, and 64% were > or = 365 days old (4-year event-free survival [EFS] rate +/- SE: 83% +/- 1% [n = 1,339] and 45% +/- 1% [n = 2,327], respectively; P < .0001). Graphical analyses revealed the continuous nature of the prognostic contribution of age to outcome. The optimal 460-day cutoff we selected maximized the outcome difference between younger and older patients. Forty-three percent were younger than 460 days, and 57% were > or = 460 days old (4-year EFS rate +/- SE: 82% +/- 1% [n = 1,589] and 42% +/- 1% [n = 2,077], respectively; P < .0001). Using a 460-day cutoff (assuming stage 4, MYCN-amplified patients remain high-risk), 5% of patients (365 to 460 days: 4-year EFS 92% +/- 3%; n = 135) fell into a lower risk group. CONCLUSION The prognostic contribution of age to outcome is continuous in nature. Within clinically relevant risk stratification, statistical support exists for an age cutoff of 460 days.

Prognostic Value of Immunocytologic Detection of Bone Marrow Metastases in Neuroblastoma

BACKGROUND Morphologic evaluation of bone marrow for neuroblastoma cells is a routine and important component of clinical staging. Specific immunostaining of malignant cells with monoclonal antibodies should be more sensitive, however, and may improve the detection of metastases and provide additional prognostic information. METHODS We looked for tumor cells in bone marrow from 197 patients with newly diagnosed neuroblastoma, using immunoperoxidase staining with monoclonal antibodies (immunocytologic analysis) and examination of smears and specimens obtained by trephine biopsy (conventional analysis). RESULTS Routine smears and trephine-biopsy specimens were positive for tumor cells in 46 percent of the patients, whereas 67 percent were positive on immunocytologic analysis (P less than 0.0001). Immunocytologic analysis detected bone marrow metastases in 34 percent of patients considered to have only localized or regional disease (Stage I, II, or III). It also identified tumor cells that were not detected by conventional analysis in patients with widespread disease (Stage IV or IVS). Tumor content, as determined by immunocytologic analysis, predicted clinical outcome in relation to the age of the patient at diagnosis. Patients with Stage II or III disease diagnosed after one year of age who did not have occult marrow metastases did well, whereas those with metastases did poorly (P = 0.006). Patients in whom Stage IV disease was diagnosed before they were one year of age did well if bone marrow metastases were few or absent, but had poor survival if the marrow contained more than 0.02 percent tumor cells (P = 0.03). CONCLUSIONS Immunocytologic analysis of bone marrow aspirates is more sensitive than conventional analysis in detecting tumor cells and provides prognostic information. The relations among marrow metastases, age at diagnosis, and clinical outcome illustrate the biologic heterogeneity of neuroblastoma.

High levels of p19/nm23 protein in neuroblastoma are associated with advanced stage disease and with N-myc gene amplification.

The gene encoding a novel protein designated nm23-H1, which was recently identified as identical to the A subunit of nucleotide diphosphate kinase from human erythrocytes, has been proposed to play a role in tumor metastasis suppression. We report that untreated neuroblastoma tumors contain a cellular polypeptide (Mr = 19,000) designated p19, identified in two-dimensional electrophoretic gels, which occurs at significantly higher levels (P = 0.0001) in primary tumors containing amplified N-myc gene. The partial amino acid sequence obtained for p19 is identical to the sequence of the human nm23-H1 protein. An antibody to the A subunit of erythrocyte nucleotide diphosphate kinase reacted exclusively with p19. In this study, significantly higher levels of p19/nm23 occurred in primary neuroblastoma tumors from patients with advanced stages (III and IV) relative to tumors from patients with limited stages (I and II) of the disease. Even among patients with a single copy of the N-myc gene, tumors from patients with stages III and IV had statistically significantly higher levels of p19/nm23 than tumors from patients with stages I and II. Our findings indicate that, in contrast to a proposed role for nm23-H1 as a tumor metastasis suppressor, increased p19/nm23 protein in neuroblastoma is correlated with features of the disease that are associated with aggressive tumors. Therefore, nm23-H1 may have distinct if not opposite roles in different tumors.

Successful treatment of stage III neuroblastoma based on prospective biologic staging: a Children's Cancer Group study.

PURPOSE To identify a biologically favorable and unfavorable subset of patients with Evans stage III neuroblastoma and to determine whether treatment stratification would improve the event-free survival (EFS) for high-risk patients and maintain excellent EFS for the lower-risk patients. PATIENTS AND METHODS Risk stratification was performed by age, MYCN gene copy number, Shimada histopathologic classification, and serum ferritin level. Lower-risk patients were treated on the less intensive Childrens Cancer Group (CCG)-3881, whereas high-risk patients were treated on CCG-3891, which included more intensive multimodality therapy and, in some cases, autologous bone marrow transplantation (ABMT). RESULTS Of 228 Evans stage III patients entered onto the study, 92% also met the definition of International Neuroblastoma Staging System (INSS) stage 3. One hundred forty-three patients met the lower-risk criteria, which included 89 patients less than 1 year of age and 54 patients 1 year of age or greater, and favorable biology, whereas 85 patients were 1 year of age or greater and biologically unfavorable. Biologically unfavorable patients 1 year of age or greater who underwent gross surgical resection had improved survival, whereas the outcome of infants or biologically favorable older patients did not change according to resection. The EFS rate at 4 years was 100% for the patients with favorable biology of any age, 90% for those less than 1 year of age but with at least one unfavorable characteristic, and 54% for Evans stage III patients 1 year of age or greater with unfavorable biology. Age, ferritin level, MYCN copy number, Shimada histopathology, primary site, and intraspinal extension were significant univariate prognostic factors for all patients, but only MYCN copy number and age were independent factors in multivariate analyses. CONCLUSION The excellent survival of the biologically favorable group and the historically improved EFS of the biologically unfavorable group suggest that biologic staging should be used to define the prognosis and treatment of stage III neuroblastoma.

Consolidation chemoradiotherapy and autologous bone marrow transplantation versus continued chemotherapy for metastatic neuroblastoma: a report of two concurrent Children's Cancer Group studies.

PURPOSE To compare event-free survival (EFS) for patients with stage IV neuroblastoma who were treated with induction chemotherapy followed by additional courses of the same chemotherapy or by intensive chemoradiotherapy and autologous bone marrow transplantation (ABMT). METHODS Two hundred seven children who were diagnosed with stage IV neuroblastoma after 1 year of age were given five to seven courses of induction chemotherapy consisting of cisplatin, etoposide, doxorubicin, and cyclophosphamide (CCC-321-P2). This chemotherapy was continued for 13 total courses for some patients, whereas intensive chemoradiotherapy with ABMT was given to others (CCG-321-P3). The decision to continue chemotherapy versus to consolidate with chemoradiotherapy was not randomized but was made by parents and physicians. Marrow used for ABMT was purged ex vivo and was free of immunocytologically detectable neuroblastoma cells. RESULTS One hundred fifty-nine of 207 patients (77%) remained event-free during induction therapy. Of these, 67 received chemoradiotherapy/ABMT (CCG-321-P3) and 74 continued chemotherapy (CCG-321-P2). Using Cox regression analysis, the relative risk (RR) of an event after chemoradiotherapy/ABMT was estimated to be 58% of that for patients who continued chemotherapy (P = .01). Similarly, Kaplan-Meier analysis estimated EFS at four years for the chemoradiotherapy/ABMT and chemotherapy groups to be 40% and 19% respectively (P = .019). Subgroups appearing to benefit from chemoradiotherapy/ABMT were those with only a partial tumor response to induction chemotherapy (RR = 0.43; P = .008; EFS, 29% v 6%) and those whose tumors had amplification of the N-myc gene (RR = 0.26; P = .112; EFS, 67% v 0%). CONCLUSION Consolidation with intensive, myeloablative chemoradiotherapy followed by purged ABMT may be more effective than continuing chemotherapy for patients with stage IV neuroblastoma.

Excellent outcome of stage II neuroblastoma is independent of residual disease and radiation therapy.

The optimal management for patients with stage II neuroblastoma has not yet been established. In order to determine the impact of adding chemotherapy and/or radiation therapy to surgery, we reviewed by questionnaire 156 patients with stage II neuroblastoma treated by 28 Childrens Cancer Study Group (CCSG) institutions from 1978 to 1985. Survival and progression-free survival (PFS) were analyzed by life-table methods with respect to age at diagnosis, site and size of primary tumor, spinal cord involvement, extent of initial resection, and treatment in addition to surgery. The overall 5-year survival was 96%; the PFS was 90%, similar to previous CCSG studies. Age at diagnosis had a small impact on PFS, with 92% PFS for patients less than 2 years of age at diagnosis, and 84% for those greater than 2 (P = .10). The only site with an adverse outcome was the head and neck (n = 11), with a PFS of 68% compared with 93% for the remaining sites (P = .02). Size of primary and intraspinal extension of primary did not affect PFS. The extent of resection and subsequent treatment with radiation therapy and/or chemotherapy did not affect the PFS. The outcome for 75 patients treated with surgery alone (6-year PFS, 89%) was not significantly different from that of 66 patients receiving radiation therapy (6-year PFS, 94%). There was no significant difference between 40 patients with gross or microscopic residual disease treated with surgery alone (PFS, 92%) and 59 patients with residual disease who also received radiation (PFS, 90%). Five of seven patients who progressed after surgery alone have been salvaged with further therapy and are now free of disease. One survives with disease, so that the 6-year survival is 98% for those treated initially with surgery alone, compared with 95% for those receiving radiation therapy and/or chemotherapy. These data suggest that surgery alone, even if complete resection is not achieved, is sufficient initial therapy for stage II neuroblastoma. The data also identify another stage of neuroblastoma, in addition to stage IV-S, for which almost all patients have a favorable prognosis because their tumor may be biologically limited in growth.

Loss of Heterozygosity at 1p36 Independently Predicts for Disease Progression But Not Decreased Overall Survival Probability in Neuroblastoma Patients: A Children’s Cancer Group Study

PURPOSE To determine the independent prognostic significance of 1p36 loss of heterozygosity (LOH) in a representative group of neuroblastoma patients. PATIENTS AND METHODS Diagnostic tumor specimens from 238 patients registered onto the most recent Childrens Cancer Group phase III clinical trials were assayed for LOH with 13 microsatellite polymorphic markers spanning chromosome band 1p36. Allelic status at 1p36 was correlated with other prognostic variables and disease outcome. RESULTS LOH at 1p36 was detected in 83 (35%) of 238 neuroblastomas. There was a correlation of 1p36 LOH with age at diagnosis greater than 1 year (P = .026), metastatic disease (P<.001), elevated serum ferritin level (P<.001), unfavorable histopathology (P<.001), and MYCN oncogene amplification (P<.001). LOH at 1p36 was associated with decreased event-free survival (EFS) and overall survival (OS) probabilities (P<.0001). For the 180 cases with single-copy MYCN, 1p36 LOH status was highly correlated with decreased EFS (P = .0002) but not OS (P = .1212). Entering 1p36 LOH into a multivariate regression model suggested a trend toward an independent association with decreased EFS (P = .0558) but not with decreased OS (P = .3687). Furthermore, allelic status at 1p36 was the only prognostic variable that was significantly associated with decreased EFS in low-risk neuroblastoma patients (P = .0148). CONCLUSION LOH at 1p36 is independently associated with decreased EFS, but not OS, in neuroblastoma patients. Determination of 1p36 allelic status may be useful for predicting which neuroblastoma patients with otherwise favorable clinical and biologic features are more likely to have disease progression.