Results of Induction Chemotherapy in Children Older Than 1 Year With a Stage 4 Neuroblastoma Treated With the NB 97 French Society of Pediat
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▲還散笫雖悝◎
the Pediatrics Department, Statistics Department, Institut Gustave Roussy, Villejuif Cedex
Pediatrics Department, Institut Curie, Paris
Nuclear Medicine Department, Institut Claudius Regaud
Onco-hematology Unit, CHU Purpan, Toulouse
Onco-hematology Department, CHU Pellegrin, Bordeaux
Pediatrics Department, Centre Leon Berard, Lyon
Pediatric Oncology Unit, CHU La Timone, Marseille
Pediatric Oncology Unit, CHU, Grenoble
Pediatric Oncology Unit, Hopital St Charles, Montpellier
Pediatric Oncology Unit, CHR, Hopital d'Enfants Brabois, Vandoeuvre, France
ABSTRACT
PATIENTS AND METHODS: From 1998 to 1999, 47 consecutive children were treated according to N7 protocol. Children received cyclophosphamide 140 mg/kg, doxorubicin 75 mg/m2, and vincristine 0.066 mg/kg (CAV) in cycles 1, 2, 4, and 6, and cisplatinum 200 mg/m2 and etoposide 600 mg/m2 (P/VP) in cycles 3, 5, and 7. The International Neuroblastoma Staging system was used with an emphasis on skeletal evaluation by 123-iodine-metaiodobenzylguanidine (MIBG) scintigraphy. A phase II study evaluating the metastasis complete response rate after induction chemotherapy was conducted in patients who had positive metastatic sites on MIBG scans at diagnosis.
RESULTS: Forty-six patients were assessable for toxicity. Hematologic toxicity was the main toxicity observed. Neutropenia was more frequent after CAV than after P/VP (P < .001). A higher rate of thrombocytopenia was observed after P/VP (P = .03). Forty patients with positive MIBG were assessable for metastatic response, and complete regression of metastases was achieved in 17 patients (ie, 43%; 95% CI, 27% to 59%). Of all 47 patients, 21 achieved complete metastatic response.
CONCLUSION: The N7 induction chemotherapy protocol was feasible in a multicentric setting. The observed metastasis complete response rate was similar to that obtained in our previous studies and significantly lower than that published in a previous series using the same regimen. In our hands, escalating doses of cyclophosphamide and prolonging conventional chemotherapy with the same drugs failed to improve the metastasis complete response rate.
INTRODUCTION
The French Society of Pediatric Oncology (SFOP) Neuroblastoma Study Group designed the NB 97 protocol aimed at improving the survival of children with stage 4 neuroblastoma. The primary goal of the study was to reproduce the excellent results published by the investigators at the Memorial Sloan-Kettering Cancer Center. This protocol combines the induction chemotherapy regimen in the N7 protocol followed by surgical excision of the primary tumor and consolidation with busulfan-melphalan with stem-cell transplantation (SCT) in patients who achieve a complete response of metastases or a partial response with fewer than three metastatic sites on metaiodobenzylguanidine scan of metastases. We report here the response of metastatic disease and the toxicity of the N7 induction regimen in 47 consecutive, previously untreated patients with stage 4 neuroblastoma who were older than 1 year.
PATIENTS AND METHODS
Evaluation of Disease Extent at Diagnosis
The primary tumor was evaluated by computed tomography or magnetic resonance imaging; the size of the lesion was measured in three dimensions.
Disease extension was assessed by 123-iodine-metaiodobenzylguanidine (MIBG) scintigraphy. Technetium-99m bone scans were performed in all patients with no MIBG uptake in the primary tumor. Biologic markers (vanillylmandelic acid, homovanillic acid, dopamine) were determined in all patients. Two biopsy specimens and at least four aspirates, performed in iliac bones, were obtained for morphologic evaluation of bone marrow. Diagnosis and staging were performed according to the revised International Neuroblastoma Diagnosis and Staging Criteria.7 NMYC amplification was evaluated according to published criteria.8
Treatment
The NB 97 protocol comprised seven courses of chemotherapy according to the N7 protocol (Table 2), with 21-day intervals between courses that were dependent on hematologic recovery as evidenced by a neutrophil count exceeding 0.5 x 109/L and a platelet count of 100 x 109/L. Courses 1, 2, 4, and 6 consisted of cyclophosphamide, doxorubicin, and vincristine (CAV). Cyclophosphamide (70 mg/kg/d) was infused over 6 hours in 250 mL of normal saline on days 1 and 2 (ie, 140 mg/kg per course), in conjunction with hydration (2,500 mL/m2/d) using D5 normal saline (1/3) with potassium chloride 2 g/L, magnesium sulfate 2 g/L, and calcium gluconate 2 g/L. Mesna was routinely used at a dose of 85 mg/kg/d in a continuous intravenous (IV) infusion. Furosemide was only administered if diuresis was inadequate. Doxorubicin (75 mg/m2) and vincristine (0.066 mg/kg with a maximal 2-mg dose per course) were administered in a continuous IV infusion for 72 hours, as of day 1. Courses 3, 5, and 7 consisted of cisplatin and etoposide (P/VP) with 2-hour IV infusions of etoposide (200 mg/m2/d) on days 1 to 3 (ie, 600 mg/m2 per course), and 1-hour IV infusions of cisplatinum (50 mg/m2/d) on days 1 to 4 (ie, 200 mg/m2/course).
Surgical resection of the tumor was performed after evaluation of response at both primary and metastatic sites after the seventh course of induction chemotherapy if a sufficient response of metastatic disease was obtained.
Consolidation with high-dose chemotherapy followed by peripheral SCT was performed in patients achieving a CR of metastases or with a partial remission of MIBG spots with not more than three persisting spots. The conditioning regimen was a combination of busulfan (600 mg/m2) and melphalan (140 mg/m2).3 Radiation therapy was delivered to the primary tumor site when MYCN amplification had been identified in the tumor cells. The results of this consolidation treatment will be reported elsewhere.
Supportive Care
Granulocyte colony-stimulating factor (G-CSF; Filgrastim; Amgen, Neuilly sur Seine Cedex, France) at a dose of 5 米g/kg/d was recommended after each course. When performed, it was started the day after the end of chemotherapy, and stopped when the neutrophil count was greater than 500/mm3. It was administered subcutaneously in outpatients, and IV when patients were hospitalized.
Platelets were transfused to maintain a platelet count above 20 x 109/L or to control bleeding. RBCs were transfused when the hemoglobin level was below 7 g/dL. All blood products were irradiated. All patients received trimethoprim-sulfamethoxazole as prophylaxis against Pneumocystis carinii.
Evaluation of Tumor Response
Tumor response of primary tumor and metastases was evaluated after the third and seventh courses of the induction therapy with the tools used at diagnosis.
As response of metastatic lesions evaluated by MIBG scintigraphy was the main end point of the phase II study, the quality of these images and their interpretation were critical. MIBG scintigraphy had to be performed according to the published recommendation. A blind review of all MIBG scans was performed by a panel of six experts, in order to evaluate the quality of the scans and tumor response. The scoring system used in this study had been previously validated to evaluate response in multicentric studies.9 Briefly, the body was divided into seven sectors for osteomedullary lesions (skull, face, chest, spine, pelvis, legs, and arms). In each region, the lesions were scored as follows for extension of metastases: the segmental score was graded as 0, no site per segment; 1, one site per segment; 2, more than one site per segment. Intensity of the uptake was not taken into account. Soft tissues metastases were not evaluated with this scoring system.
A CR of metastases was defined as the disappearance of all metastatic spots on MIBG scans associated with the disappearance of cytologic and histologic bone marrow involvement. Technetium-99m bone scans were obtained in all patients who had negative MIBG scans.
Evaluation of Toxicity
The evaluation of toxicity included a physical examination; CBCs; and serum creatinine, liver enzyme, and bilirubin determinations. Complete clinical and biologic analyses were required before each course. Echocardiography and glomerular filtration rate determination were performed periodically. Audiometry was used to evaluate hearing loss according to Brock's grading.10 Toxicity was graded according to WHO criteria.11
Statistical Methods
This protocol was designed as a phase II study since the main objective was to reproduce the metastasis response rate obtained after the N6 induction therapy.5 All study patients were treated with the same protocol and evaluated with the same tools, particularly the MIBG scan for the evaluation of response of metastases. Thus, only patients with a positive MIBG scan at diagnosis were included in this study.
According to the previously defined criteria, the expected metastases CR rate after the N6 induction chemotherapy regimen was 21 of 24 (82.5%; 95% CI, 68% to 95%).
A multistage procedure was used for this phase II study (three stages). The lowest stage below which treatment had to be considered insufficiently effective was the lowest limit of the 95% CI for the N6 data (ie, 70%). The highest success rate beyond which the study was to be stopped and the treatment considered effective was fixed at 80%. Forty-five patients (15 patients for each stage) had to be included in the phase II study to answer the question, with {alpha} and errors of 5% and 10%, respectively.
RESULTS
The median duration of induction chemotherapy from day 1 of the first course to day 1 of the seventh course was 140 days (range, 121 to 188 days). The median interval between day 1 of the first course and day 1 of the fifth course was 90 days (range, 77 to 130 days), when the theoretical interval was 84 days. Nineteen patients received their fifth course with a delay greater than 10%. As presented in Table 3, hematologic toxicity was severe.
Neutropenia occurred more often after CAV courses than after P/VP courses (97% and 65%, respectively; P < .001). Conversely, a higher rate of thrombocytopenia (< 20 x 109/L) occurred after P/VP courses when compared with CAV courses (87% v 78%; P = .03). G-CSF was administered after 56% and 83% of CAV and P/VP courses, respectively. Blood product needs were high since at least one RBC transfusion and one platelet transfusion was administered after 86% and 64% of CAV courses and 69% and 78% of P/VP courses, respectively. Hematological toxicity did not worsen with time. Fever was observed after 70% and 23% of CAV and P/VP courses, respectively (P < .001). All but one documented infections were observed in neutropenic patients in 15% and 5% of CAV and P-VP courses, respectively (P = .002). The first CAV course was the least tolerated course since 90% of the patients were febrile and 28% of these patients had a documented infection.
Extrahematologic toxicity was mainly gastrointestinal. Severe vomiting was more frequent after the P/VP courses, whereas mucositis occurred more often after the CAV courses and was severe (> grade 3) in 8%. Thirty-four patients (74%) received parenteral nutrition at least once for a median duration of 17 days (range, 3 to 104 days) because of anorexia or vomiting. Grade 1 hematuria was observed five times (3.7%), always after the fifth course, and resolved easily. The unique case of hemorrhagic cystitis required bladder catheterization and irrigation, and the severity of the condition led to the cessation of induction chemotherapy. One child developed a lysis syndrome with severe metabolite disorders and acute respiratory distress syndrome after the first course of CAV. He was admitted to the intensive care unit for a few days, during which symptoms resolved with symptomatic treatment, and chemotherapy was resumed as planned by the protocol. Hearing loss was evaluated in 21 patients. Grade 1, 2, and 3 toxicity was documented in six, one, and one patient, respectively. This evaluation was performed early, however, and hearing could worsen with time. The only case of neurologic toxicity was a paralytic ileus observed after the first course of CAV and resolved with symptomatic treatment. No toxicity-related deaths occurred during induction chemotherapy.
Tumor Response
After the central review by experts, 40 of 47 patients were considered to have metastatic spots on initial MIBG scan and to be assessable in the phase II study. Six patients had a negative MIBG scintigraphy; among them, two had been previously considered as positive, and one patient had poor-quality MIBG scans. Thirty-eight of these 40 patients had initial bone marrow involvement. Progression of metastatic disease was documented in one patient. During the time of evaluation, 17 of 40 patients had a complete remission of metastases, 15 had persistent metastases on MIBG scan with a negative bone marrow evaluation, and eight had metastases both on MIBG scan and on bone marrow evaluation. Bone marrow status and MIBG osteomedullary scores of these 40 patients at diagnosis and at the end of induction therapy are presented in Table 4Go. Patient 15's skull and face MIBG images are shown in Figure 1. It emphasizes the sensitivity of the MIBG scans in evaluating the status of the disease, which was particularly difficult to define in this patient.
Among the seven patients with negative (six patients) or noninterpretable (one patient) MIBG scintigraphy, four had a CR, and three had a partial response of metastases. These three patients were considered to have a partial response to induction chemotherapy according to INSS criteria. Six out of them had initial bone marrow involvement that disappeared after induction chemotherapy (Table 5).
Among the 47 patients, 44 had an initial bone marrow involvement, and 36 of them (82%) had a negative bone marrow evaluation after induction chemotherapy. All patients who had CR of skeletal and bone marrow metastases had no persisting soft tissue metastasis after induction chemotherapy. The response rate was not statistically different according to the induction chemotherapy duration, even taking into account only the first five courses (P = .76). At the end of induction chemotherapy, 37 of 47 patients were considered to have a disease response sufficient to have a surgical excision of the tumor and a consolidation with busulfan and melphalan.
DISCUSSION
This prompted the SFOP Neuroblastoma Study Group to evaluate the metastasis response rate after the seven courses of the N7 protocol. A metastasis CR rate evaluated on MIBG scans was the main end point of this phase II study in patients with a positive MIBG scan at diagnosis, since MIBG is the most sensitive tool for the evaluation of response of metastases.15 Concomitant extensive bone marrow assessment was performed to confirm CR of metastases. Extensive bone marrow evaluation and MIBG scintigraphy have recently been reported as "prerequisites for accurate determination of disease status."15 The scoring system used in this study had been previously validated to evaluate response in multicentric studies.9 It is very close to that used in the study published by Matthay et al,16 correlating the early metastatic response on MIBG scintigraphy with overall response and event-free survival in metastatic neuroblastoma. The only difference was the inclusion of soft tissues metastases in the scoring system used by Matthay et al. The central review of the MIBG scans by a panel of six experts guarantees the quality of interpretation. The metastasis CR rate of 43%, (95% CI, 27% to 59%) is significantly lower than that published with the N6 protocol. Indeed, the upper limit of the CI is lower than the 68% lower limit of the N6 response CI. Patient characteristics in our study were similar to those in the N6 protocol and did not account for such a difference in the metastasis response rate. In the present study, MIBG scan was performed with MIBG, whereas iodine-131-metaiodobenzylguanidine was used to evaluate the 24 patients treated according to the N6 protocol. The greater sensitivity of MIBG may account for the different response rate observed in the present study.15-17 Furthermore, we have also demonstrated that the N7 induction regimen was feasible in a multicentric study, since protocol violations were observed in only two patients, and dose-intensity was respected, with a median time from day 1 of course 1 to day 1 of course 7, of 140 days (range, 121 to 188 days) in our patients, compared with 152 days (range, 130 to 188 days) in the study of Kushner et al, which means that dose intensity was respected in these patients. Surgical excision of the primary tumor was performed after the fourth course in patients of the N6 protocol, whereas it was performed after the end of the induction chemotherapy in the NB 97 protocol. Thus, initial dose intensity may have been greater in N6 cohort. However, the response rate was not statistically different according to the induction chemotherapy duration, even taking into account only the first five courses (P = .76).
Finally, in our hands, the results obtained with this induction regimen were similar to those previously observed after the four courses in NB 87,13 using the same work-up for the evaluation of metastases. In that large series of 192 unselected patients, with shorter (four courses), less intensive chemotherapy, a 39% CR rate was observed for metastases. Whereas bone marrow CR was significantly better under NB 97 protocol (82%) than under NB 87 (66%; P = .04), skeletal MIBG response was not different: 43% and 38% in NB 97 and NB 87, respectively (P = .73). Alkylating agents, including cyclophosphamide, are effective against neuroblastoma.18 Moreover, a log-linear dose response has been demonstrated in tumor cells in vitro.19 In a retrospective analysis on the treatment of stage 4 neuroblastoma, Cheung et al demonstrated that the dose intensity was a strong predictor of clinical response, median survival and PFS.20 We previously reported that high-dose cyclophosphamide (6 g/m2/course) combined with standard-dose etoposide (250 mg/m2 per course) could be effective in 36% of patients with refractory neuroblastoma who had previously received lower doses of the same drugs.21 However, the early administration of high-dose cyclophosphamide (6 g/m2; CADE) instead of alternating cyclophosphamide-adriamycin-vincristine (CADO) with etoposide or cisplatinum failed to improve the metastasis response rate (34%) in the NB 92 protocol (Hartmann, personal communication, 1996). Thus, neither increased cyclophosphamide doses like those administered in NB 92 nor both higher cyclophosphamide doses and prolonging induction chemotherapy with the same drugs were found to improve the rate of response of metastatic lesions. However, prolonging induction with different drugs may help improve the CR rate. Indeed, we observed a 43% response rate in patients with refractory stage 4 neuroblastoma by adding carboplatin-etoposide even after induction therapy including cisplatinum.22 New drugs such CPT 11 have been proven effective against neuroblastoma in vitro and in animal models.23-26 If their efficacy is confirmed by ongoing phase I/II studies, these drugs should be introduced in first-line regimens for high-risk neuroblastoma patients and could potentially improve the response rate via a different cytotoxic mechanism. The other way to increase survival of these patients is to improve the efficacy of drugs contained in high-dose chemotherapy regimen and to improve minimal residual disease treatment. Retinoic acid has been demonstrated to improve survival of high-risk patients1 and various strategies combining retinoc acid and monoclonal antibodies are currently evaluated in Europe and the United States. Complications due to toxicity caused by this induction regimen were manageable, and no toxicity-related death occurred. As described in the N6 and N7 protocols, grade 4 myelosuppression occurred very frequently with substantial blood product transfusion requirements.5 As previously observed with the NB 87 protocol13 and in other studies,27 a strikingly high incidence of infectious and extra-hematological complications were observed after the first course of chemotherapy. These complications may be due to the poor clinical status of these children at diagnosis and the heavy tumor burden. In our experience, a significant decrease was observed in the duration of neutropenia after each course of CAV when G-CSF was administered, whereas such benefits were not so clear cut after CADO.28 Similar findings were demonstrated by the analysis of 58 patients treated according to N6 and N7 protocols.12 The use of G-CSF accelerated absolute neutrophil count recovery but did not reduce the incidence of febrile episodes and had a minimal impact on infection rates. However, the prolonged thrombocytopenia previously observed with the use of G-CSF was not observed in the present study. Most patients received parenteral nutrition because of erratic food consumption and a poor clinical status. Although doses were higher in the N7 protocol, extra-hematological toxicity was similar to that observed in NB 87. Although only one patient experienced severe hearing loss, a longer follow-up is warranted to better evaluate the incidence and severity of ototoxicity.
In conclusion, the acute toxicity induced by this intensive and prolonged induction regimen in the N7 protocol was manageable in this multicentric study. However, this protocol failed to improve the metastasis complete response rate in patients over one year of age with stage 4 neuroblastoma. Nevertheless, a longer follow-up is needed to evaluate the survival of these patients who subsequently received high-dose chemotherapy with busulfan-melphalan and SCT. This study highlights the need for common tools and standard terminology to evaluate the response of metastases in order to compare the efficacy of different therapeutic approaches.
Authors' Disclosures of Potential Conflicts of Interest
Acknowledgment
We thank P. Boutard, A. Deville, V. Gandemer, O. Lejars, G. Leverger, P. Lutz, F. Mechinaud, M. Munzer, B. Pautard, E. Plouvier, N. Sirvent, V. Edeline, F. Giammarile, J. Lumbroso, S. Siles, and M. Wioland; Lorna Saint Ange, and Severine Faure.
NOTES
Supported by a grant from Amgen, Neuilly sur Seine Cedex, France.
Authors' disclosures of potential conflicts of interest are found at the end of this article.
REFERENCES
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7. Brodeur GM, Pritchard J, Berthold F, et al: Revisions of the international criteria for neuroblastoma diagnosis, staging, and response to treatment. J Clin Oncol 11:1466每1477, 1993
8. Ambros IM, Benard J, Boavida M, et al: Quality assessment of genetic markers used for therapy stratification. J Clin Oncol 21:2077每2084, 2003
9. Frappaz D, Bonneu A, Chauvot P, et al: Metaiodobenzylguanidine assessment of metastatic neuroblastoma: Observer dependency and chemosensitivity evaluation〞The SFOP Group. Med Pediatr Oncol 34:237每241, 2000
10. Brock PR, Bellman SC, Yeomans EC, et al: Cisplatin ototoxicity in children: A practical grading system. Med Pediatr Oncol 19:295每300, 1991
11. World Health Organization.WHO Handbook for Reporting Results of Cancer Treatment. Geneva, Switzerland, World Health Organization, 1979
12. Kushner BH, Heller G, Kramer K, et al: Granulocyte-colony stimulating factor and multiple cycles of strongly myelosuppressive alkylator-based combination chemotherapy in children with neuroblastoma. Cancer 89:2122每2130, 2000
13. Coze C, Hartmann O, Michon J, et al: NB87 induction protocol for stage 4 neuroblastoma in children over 1 year of age: A report from the French Society of Pediatric Oncology. J Clin Oncol 15:3433每3440, 1997
14. Hartmann O, Valteau-Couanet D, Benhamou E, et al: 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. Eur J Cancer 33:2126每2129, 1997
15. Kushner BH, Yeh SD, Kramer K, et al: Impact of metaiodobenzylguanidine scintigraphy on assessing response of high-risk neuroblastoma to dose-intensive induction chemotherapy. J Clin Oncol 21:1082每1086, 2003
16. Matthay KK, Edeline V, Lumbroso J, et al: Correlation of early metastatic response by 123I-metaiodobenzylguanidine scintigraphy with overall response and event-free survival in stage IV neuroblastoma. J Clin Oncol 21:2486每2491, 2003
17. Shapiro B, Gross MD: Radiochemistry, biochemistry, and kinetics of 131I-metaiodobenzylguanidine (MIBG) and 123I-MIBG: Clinical implications of the use of 123I-MIBG. Med Pediatr Oncol 15:170每177, 1987
18. Carli M, Green AA, Hayes FA, et al: Therapeutic efficacy of single drugs for childhood neuroblastoma. Amsterdam, the Netherlands, Ecerpta Medica, 1982
19. Frei E III, Teicher BA, Holden SA, et al: Preclinical studies and clinical correlation of the effect of alkylating dose. Cancer Res 48:6417每6423, 1988
20. Cheung NK, Heller G, Kushner BH, et al: Stage IV neuroblastoma more than 1 year of age at diagnosis: Major response to chemotherapy and survival durations correlated strongly with dose intensity. Prog Clin Biol Res 366:567每573, 1991
21. Meresse V, Vassal G, Michon J, et al: Combined continuous infusion etoposide with high-dose cyclophosphamide for refractory neuroblastoma: A phase II study from the Societe Francaise d'Oncologie Pediatrique. J Clin Oncol 11:630每637, 1993
22. Frappaz D, Michon J, Hartmann O, et al: Etoposide and carboplatin in neuroblastoma: A French Society of Pediatric Oncology phase II study. J Clin Oncol 10:1592每1601, 1992
23. Furman WL, Stewart CF, Poquette CA, et al: Direct translation of a protracted irinotecan schedule from a xenograft model to a phase I trial in children. J Clin Oncol 17:1815每1824, 1999
24. Vassal G, Terrier-Lacombe MJ, Bissery MC, et al: Therapeutic activity of CPT-11, a DNA-topoisomerase I inhibitor, against peripheral primitive neuroectodermal tumour and neuroblastoma xenografts. Br J Cancer 74:537每545, 1996
25. Vassal G, Pondarre C, Cappelli C, et al: DNA-topoisomerase I: A new target for the treatment of neuroblastoma. Eur J Cancer 33:2011每2015, 1997
26. Vassal G, Pondarre C, Boland I, et al: Preclinical development of camptothecin derivatives and clinical trials in pediatric oncology. Biochimie 80:271每280, 1998
27. De Bernardi B, Carli M, Casale F, et al: Standard-dose and high-dose peptichemio and cisplatin in children with disseminated poor-risk neuroblastoma: Two studies by the Italian Cooperative Group for Neuroblastoma. J Clin Oncol 10:1870每1878, 1992
28. Michon JM, Hartmann O, Bouffet E, et al: An open-label, multicentre, randomised phase 2 study of recombinant human granulocyte colony-stimulating factor (filgrastim) as an adjunct to combination chemotherapy in paediatric patients with metastatic neuroblastoma. Eur J Cancer 34:1063每1069, 1998(Dominique Valteau-Couanet)
Pediatrics Department, Institut Curie, Paris
Nuclear Medicine Department, Institut Claudius Regaud
Onco-hematology Unit, CHU Purpan, Toulouse
Onco-hematology Department, CHU Pellegrin, Bordeaux
Pediatrics Department, Centre Leon Berard, Lyon
Pediatric Oncology Unit, CHU La Timone, Marseille
Pediatric Oncology Unit, CHU, Grenoble
Pediatric Oncology Unit, Hopital St Charles, Montpellier
Pediatric Oncology Unit, CHR, Hopital d'Enfants Brabois, Vandoeuvre, France
ABSTRACT
PATIENTS AND METHODS: From 1998 to 1999, 47 consecutive children were treated according to N7 protocol. Children received cyclophosphamide 140 mg/kg, doxorubicin 75 mg/m2, and vincristine 0.066 mg/kg (CAV) in cycles 1, 2, 4, and 6, and cisplatinum 200 mg/m2 and etoposide 600 mg/m2 (P/VP) in cycles 3, 5, and 7. The International Neuroblastoma Staging system was used with an emphasis on skeletal evaluation by 123-iodine-metaiodobenzylguanidine (MIBG) scintigraphy. A phase II study evaluating the metastasis complete response rate after induction chemotherapy was conducted in patients who had positive metastatic sites on MIBG scans at diagnosis.
RESULTS: Forty-six patients were assessable for toxicity. Hematologic toxicity was the main toxicity observed. Neutropenia was more frequent after CAV than after P/VP (P < .001). A higher rate of thrombocytopenia was observed after P/VP (P = .03). Forty patients with positive MIBG were assessable for metastatic response, and complete regression of metastases was achieved in 17 patients (ie, 43%; 95% CI, 27% to 59%). Of all 47 patients, 21 achieved complete metastatic response.
CONCLUSION: The N7 induction chemotherapy protocol was feasible in a multicentric setting. The observed metastasis complete response rate was similar to that obtained in our previous studies and significantly lower than that published in a previous series using the same regimen. In our hands, escalating doses of cyclophosphamide and prolonging conventional chemotherapy with the same drugs failed to improve the metastasis complete response rate.
INTRODUCTION
The French Society of Pediatric Oncology (SFOP) Neuroblastoma Study Group designed the NB 97 protocol aimed at improving the survival of children with stage 4 neuroblastoma. The primary goal of the study was to reproduce the excellent results published by the investigators at the Memorial Sloan-Kettering Cancer Center. This protocol combines the induction chemotherapy regimen in the N7 protocol followed by surgical excision of the primary tumor and consolidation with busulfan-melphalan with stem-cell transplantation (SCT) in patients who achieve a complete response of metastases or a partial response with fewer than three metastatic sites on metaiodobenzylguanidine scan of metastases. We report here the response of metastatic disease and the toxicity of the N7 induction regimen in 47 consecutive, previously untreated patients with stage 4 neuroblastoma who were older than 1 year.
PATIENTS AND METHODS
Evaluation of Disease Extent at Diagnosis
The primary tumor was evaluated by computed tomography or magnetic resonance imaging; the size of the lesion was measured in three dimensions.
Disease extension was assessed by 123-iodine-metaiodobenzylguanidine (MIBG) scintigraphy. Technetium-99m bone scans were performed in all patients with no MIBG uptake in the primary tumor. Biologic markers (vanillylmandelic acid, homovanillic acid, dopamine) were determined in all patients. Two biopsy specimens and at least four aspirates, performed in iliac bones, were obtained for morphologic evaluation of bone marrow. Diagnosis and staging were performed according to the revised International Neuroblastoma Diagnosis and Staging Criteria.7 NMYC amplification was evaluated according to published criteria.8
Treatment
The NB 97 protocol comprised seven courses of chemotherapy according to the N7 protocol (Table 2), with 21-day intervals between courses that were dependent on hematologic recovery as evidenced by a neutrophil count exceeding 0.5 x 109/L and a platelet count of 100 x 109/L. Courses 1, 2, 4, and 6 consisted of cyclophosphamide, doxorubicin, and vincristine (CAV). Cyclophosphamide (70 mg/kg/d) was infused over 6 hours in 250 mL of normal saline on days 1 and 2 (ie, 140 mg/kg per course), in conjunction with hydration (2,500 mL/m2/d) using D5 normal saline (1/3) with potassium chloride 2 g/L, magnesium sulfate 2 g/L, and calcium gluconate 2 g/L. Mesna was routinely used at a dose of 85 mg/kg/d in a continuous intravenous (IV) infusion. Furosemide was only administered if diuresis was inadequate. Doxorubicin (75 mg/m2) and vincristine (0.066 mg/kg with a maximal 2-mg dose per course) were administered in a continuous IV infusion for 72 hours, as of day 1. Courses 3, 5, and 7 consisted of cisplatin and etoposide (P/VP) with 2-hour IV infusions of etoposide (200 mg/m2/d) on days 1 to 3 (ie, 600 mg/m2 per course), and 1-hour IV infusions of cisplatinum (50 mg/m2/d) on days 1 to 4 (ie, 200 mg/m2/course).
Surgical resection of the tumor was performed after evaluation of response at both primary and metastatic sites after the seventh course of induction chemotherapy if a sufficient response of metastatic disease was obtained.
Consolidation with high-dose chemotherapy followed by peripheral SCT was performed in patients achieving a CR of metastases or with a partial remission of MIBG spots with not more than three persisting spots. The conditioning regimen was a combination of busulfan (600 mg/m2) and melphalan (140 mg/m2).3 Radiation therapy was delivered to the primary tumor site when MYCN amplification had been identified in the tumor cells. The results of this consolidation treatment will be reported elsewhere.
Supportive Care
Granulocyte colony-stimulating factor (G-CSF; Filgrastim; Amgen, Neuilly sur Seine Cedex, France) at a dose of 5 米g/kg/d was recommended after each course. When performed, it was started the day after the end of chemotherapy, and stopped when the neutrophil count was greater than 500/mm3. It was administered subcutaneously in outpatients, and IV when patients were hospitalized.
Platelets were transfused to maintain a platelet count above 20 x 109/L or to control bleeding. RBCs were transfused when the hemoglobin level was below 7 g/dL. All blood products were irradiated. All patients received trimethoprim-sulfamethoxazole as prophylaxis against Pneumocystis carinii.
Evaluation of Tumor Response
Tumor response of primary tumor and metastases was evaluated after the third and seventh courses of the induction therapy with the tools used at diagnosis.
As response of metastatic lesions evaluated by MIBG scintigraphy was the main end point of the phase II study, the quality of these images and their interpretation were critical. MIBG scintigraphy had to be performed according to the published recommendation. A blind review of all MIBG scans was performed by a panel of six experts, in order to evaluate the quality of the scans and tumor response. The scoring system used in this study had been previously validated to evaluate response in multicentric studies.9 Briefly, the body was divided into seven sectors for osteomedullary lesions (skull, face, chest, spine, pelvis, legs, and arms). In each region, the lesions were scored as follows for extension of metastases: the segmental score was graded as 0, no site per segment; 1, one site per segment; 2, more than one site per segment. Intensity of the uptake was not taken into account. Soft tissues metastases were not evaluated with this scoring system.
A CR of metastases was defined as the disappearance of all metastatic spots on MIBG scans associated with the disappearance of cytologic and histologic bone marrow involvement. Technetium-99m bone scans were obtained in all patients who had negative MIBG scans.
Evaluation of Toxicity
The evaluation of toxicity included a physical examination; CBCs; and serum creatinine, liver enzyme, and bilirubin determinations. Complete clinical and biologic analyses were required before each course. Echocardiography and glomerular filtration rate determination were performed periodically. Audiometry was used to evaluate hearing loss according to Brock's grading.10 Toxicity was graded according to WHO criteria.11
Statistical Methods
This protocol was designed as a phase II study since the main objective was to reproduce the metastasis response rate obtained after the N6 induction therapy.5 All study patients were treated with the same protocol and evaluated with the same tools, particularly the MIBG scan for the evaluation of response of metastases. Thus, only patients with a positive MIBG scan at diagnosis were included in this study.
According to the previously defined criteria, the expected metastases CR rate after the N6 induction chemotherapy regimen was 21 of 24 (82.5%; 95% CI, 68% to 95%).
A multistage procedure was used for this phase II study (three stages). The lowest stage below which treatment had to be considered insufficiently effective was the lowest limit of the 95% CI for the N6 data (ie, 70%). The highest success rate beyond which the study was to be stopped and the treatment considered effective was fixed at 80%. Forty-five patients (15 patients for each stage) had to be included in the phase II study to answer the question, with {alpha} and errors of 5% and 10%, respectively.
RESULTS
The median duration of induction chemotherapy from day 1 of the first course to day 1 of the seventh course was 140 days (range, 121 to 188 days). The median interval between day 1 of the first course and day 1 of the fifth course was 90 days (range, 77 to 130 days), when the theoretical interval was 84 days. Nineteen patients received their fifth course with a delay greater than 10%. As presented in Table 3, hematologic toxicity was severe.
Neutropenia occurred more often after CAV courses than after P/VP courses (97% and 65%, respectively; P < .001). Conversely, a higher rate of thrombocytopenia (< 20 x 109/L) occurred after P/VP courses when compared with CAV courses (87% v 78%; P = .03). G-CSF was administered after 56% and 83% of CAV and P/VP courses, respectively. Blood product needs were high since at least one RBC transfusion and one platelet transfusion was administered after 86% and 64% of CAV courses and 69% and 78% of P/VP courses, respectively. Hematological toxicity did not worsen with time. Fever was observed after 70% and 23% of CAV and P/VP courses, respectively (P < .001). All but one documented infections were observed in neutropenic patients in 15% and 5% of CAV and P-VP courses, respectively (P = .002). The first CAV course was the least tolerated course since 90% of the patients were febrile and 28% of these patients had a documented infection.
Extrahematologic toxicity was mainly gastrointestinal. Severe vomiting was more frequent after the P/VP courses, whereas mucositis occurred more often after the CAV courses and was severe (> grade 3) in 8%. Thirty-four patients (74%) received parenteral nutrition at least once for a median duration of 17 days (range, 3 to 104 days) because of anorexia or vomiting. Grade 1 hematuria was observed five times (3.7%), always after the fifth course, and resolved easily. The unique case of hemorrhagic cystitis required bladder catheterization and irrigation, and the severity of the condition led to the cessation of induction chemotherapy. One child developed a lysis syndrome with severe metabolite disorders and acute respiratory distress syndrome after the first course of CAV. He was admitted to the intensive care unit for a few days, during which symptoms resolved with symptomatic treatment, and chemotherapy was resumed as planned by the protocol. Hearing loss was evaluated in 21 patients. Grade 1, 2, and 3 toxicity was documented in six, one, and one patient, respectively. This evaluation was performed early, however, and hearing could worsen with time. The only case of neurologic toxicity was a paralytic ileus observed after the first course of CAV and resolved with symptomatic treatment. No toxicity-related deaths occurred during induction chemotherapy.
Tumor Response
After the central review by experts, 40 of 47 patients were considered to have metastatic spots on initial MIBG scan and to be assessable in the phase II study. Six patients had a negative MIBG scintigraphy; among them, two had been previously considered as positive, and one patient had poor-quality MIBG scans. Thirty-eight of these 40 patients had initial bone marrow involvement. Progression of metastatic disease was documented in one patient. During the time of evaluation, 17 of 40 patients had a complete remission of metastases, 15 had persistent metastases on MIBG scan with a negative bone marrow evaluation, and eight had metastases both on MIBG scan and on bone marrow evaluation. Bone marrow status and MIBG osteomedullary scores of these 40 patients at diagnosis and at the end of induction therapy are presented in Table 4Go. Patient 15's skull and face MIBG images are shown in Figure 1. It emphasizes the sensitivity of the MIBG scans in evaluating the status of the disease, which was particularly difficult to define in this patient.
Among the seven patients with negative (six patients) or noninterpretable (one patient) MIBG scintigraphy, four had a CR, and three had a partial response of metastases. These three patients were considered to have a partial response to induction chemotherapy according to INSS criteria. Six out of them had initial bone marrow involvement that disappeared after induction chemotherapy (Table 5).
Among the 47 patients, 44 had an initial bone marrow involvement, and 36 of them (82%) had a negative bone marrow evaluation after induction chemotherapy. All patients who had CR of skeletal and bone marrow metastases had no persisting soft tissue metastasis after induction chemotherapy. The response rate was not statistically different according to the induction chemotherapy duration, even taking into account only the first five courses (P = .76). At the end of induction chemotherapy, 37 of 47 patients were considered to have a disease response sufficient to have a surgical excision of the tumor and a consolidation with busulfan and melphalan.
DISCUSSION
This prompted the SFOP Neuroblastoma Study Group to evaluate the metastasis response rate after the seven courses of the N7 protocol. A metastasis CR rate evaluated on MIBG scans was the main end point of this phase II study in patients with a positive MIBG scan at diagnosis, since MIBG is the most sensitive tool for the evaluation of response of metastases.15 Concomitant extensive bone marrow assessment was performed to confirm CR of metastases. Extensive bone marrow evaluation and MIBG scintigraphy have recently been reported as "prerequisites for accurate determination of disease status."15 The scoring system used in this study had been previously validated to evaluate response in multicentric studies.9 It is very close to that used in the study published by Matthay et al,16 correlating the early metastatic response on MIBG scintigraphy with overall response and event-free survival in metastatic neuroblastoma. The only difference was the inclusion of soft tissues metastases in the scoring system used by Matthay et al. The central review of the MIBG scans by a panel of six experts guarantees the quality of interpretation. The metastasis CR rate of 43%, (95% CI, 27% to 59%) is significantly lower than that published with the N6 protocol. Indeed, the upper limit of the CI is lower than the 68% lower limit of the N6 response CI. Patient characteristics in our study were similar to those in the N6 protocol and did not account for such a difference in the metastasis response rate. In the present study, MIBG scan was performed with MIBG, whereas iodine-131-metaiodobenzylguanidine was used to evaluate the 24 patients treated according to the N6 protocol. The greater sensitivity of MIBG may account for the different response rate observed in the present study.15-17 Furthermore, we have also demonstrated that the N7 induction regimen was feasible in a multicentric study, since protocol violations were observed in only two patients, and dose-intensity was respected, with a median time from day 1 of course 1 to day 1 of course 7, of 140 days (range, 121 to 188 days) in our patients, compared with 152 days (range, 130 to 188 days) in the study of Kushner et al, which means that dose intensity was respected in these patients. Surgical excision of the primary tumor was performed after the fourth course in patients of the N6 protocol, whereas it was performed after the end of the induction chemotherapy in the NB 97 protocol. Thus, initial dose intensity may have been greater in N6 cohort. However, the response rate was not statistically different according to the induction chemotherapy duration, even taking into account only the first five courses (P = .76).
Finally, in our hands, the results obtained with this induction regimen were similar to those previously observed after the four courses in NB 87,13 using the same work-up for the evaluation of metastases. In that large series of 192 unselected patients, with shorter (four courses), less intensive chemotherapy, a 39% CR rate was observed for metastases. Whereas bone marrow CR was significantly better under NB 97 protocol (82%) than under NB 87 (66%; P = .04), skeletal MIBG response was not different: 43% and 38% in NB 97 and NB 87, respectively (P = .73). Alkylating agents, including cyclophosphamide, are effective against neuroblastoma.18 Moreover, a log-linear dose response has been demonstrated in tumor cells in vitro.19 In a retrospective analysis on the treatment of stage 4 neuroblastoma, Cheung et al demonstrated that the dose intensity was a strong predictor of clinical response, median survival and PFS.20 We previously reported that high-dose cyclophosphamide (6 g/m2/course) combined with standard-dose etoposide (250 mg/m2 per course) could be effective in 36% of patients with refractory neuroblastoma who had previously received lower doses of the same drugs.21 However, the early administration of high-dose cyclophosphamide (6 g/m2; CADE) instead of alternating cyclophosphamide-adriamycin-vincristine (CADO) with etoposide or cisplatinum failed to improve the metastasis response rate (34%) in the NB 92 protocol (Hartmann, personal communication, 1996). Thus, neither increased cyclophosphamide doses like those administered in NB 92 nor both higher cyclophosphamide doses and prolonging induction chemotherapy with the same drugs were found to improve the rate of response of metastatic lesions. However, prolonging induction with different drugs may help improve the CR rate. Indeed, we observed a 43% response rate in patients with refractory stage 4 neuroblastoma by adding carboplatin-etoposide even after induction therapy including cisplatinum.22 New drugs such CPT 11 have been proven effective against neuroblastoma in vitro and in animal models.23-26 If their efficacy is confirmed by ongoing phase I/II studies, these drugs should be introduced in first-line regimens for high-risk neuroblastoma patients and could potentially improve the response rate via a different cytotoxic mechanism. The other way to increase survival of these patients is to improve the efficacy of drugs contained in high-dose chemotherapy regimen and to improve minimal residual disease treatment. Retinoic acid has been demonstrated to improve survival of high-risk patients1 and various strategies combining retinoc acid and monoclonal antibodies are currently evaluated in Europe and the United States. Complications due to toxicity caused by this induction regimen were manageable, and no toxicity-related death occurred. As described in the N6 and N7 protocols, grade 4 myelosuppression occurred very frequently with substantial blood product transfusion requirements.5 As previously observed with the NB 87 protocol13 and in other studies,27 a strikingly high incidence of infectious and extra-hematological complications were observed after the first course of chemotherapy. These complications may be due to the poor clinical status of these children at diagnosis and the heavy tumor burden. In our experience, a significant decrease was observed in the duration of neutropenia after each course of CAV when G-CSF was administered, whereas such benefits were not so clear cut after CADO.28 Similar findings were demonstrated by the analysis of 58 patients treated according to N6 and N7 protocols.12 The use of G-CSF accelerated absolute neutrophil count recovery but did not reduce the incidence of febrile episodes and had a minimal impact on infection rates. However, the prolonged thrombocytopenia previously observed with the use of G-CSF was not observed in the present study. Most patients received parenteral nutrition because of erratic food consumption and a poor clinical status. Although doses were higher in the N7 protocol, extra-hematological toxicity was similar to that observed in NB 87. Although only one patient experienced severe hearing loss, a longer follow-up is warranted to better evaluate the incidence and severity of ototoxicity.
In conclusion, the acute toxicity induced by this intensive and prolonged induction regimen in the N7 protocol was manageable in this multicentric study. However, this protocol failed to improve the metastasis complete response rate in patients over one year of age with stage 4 neuroblastoma. Nevertheless, a longer follow-up is needed to evaluate the survival of these patients who subsequently received high-dose chemotherapy with busulfan-melphalan and SCT. This study highlights the need for common tools and standard terminology to evaluate the response of metastases in order to compare the efficacy of different therapeutic approaches.
Authors' Disclosures of Potential Conflicts of Interest
Acknowledgment
We thank P. Boutard, A. Deville, V. Gandemer, O. Lejars, G. Leverger, P. Lutz, F. Mechinaud, M. Munzer, B. Pautard, E. Plouvier, N. Sirvent, V. Edeline, F. Giammarile, J. Lumbroso, S. Siles, and M. Wioland; Lorna Saint Ange, and Severine Faure.
NOTES
Supported by a grant from Amgen, Neuilly sur Seine Cedex, France.
Authors' disclosures of potential conflicts of interest are found at the end of this article.
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