Retrospective analysis of peripheral blood stem cell transplantation for the treatment of high-risk neuroblastoma

Survival Benefit of Myeloablative Therapy with Autologous Stem Cell Transplantation in High-Risk Neuroblastoma: A Systematic Literature Review

BACKGROUND

Multimodal treatment of newly diagnosed high-risk neuroblastoma (HRNB) includes induction chemotherapy, consolidation with myeloablative therapy (MAT) and autologous stem cell transplantation (ASCT), followed by anti-disialoganglioside 2 (GD2) immunotherapy, as recommended by the Children's Oncology Group (COG) and the Society of Paediatric Oncology European Neuroblastoma (SIOPEN). Some centres proposed an alternative approach with induction chemotherapy followed by anti-GD2 immunotherapy, without MAT+ASCT.

OBJECTIVE

The aim of this systematic literature review was to compare survival outcomes in patients with HRNB treated with or without MAT+ASCT and with or without subsequent anti-GD2 immunotherapy.

PATIENTS AND METHODS

The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE via PubMed and EMBASE databases were systematically searched for randomised controlled trials (RCT) and observational comparative studies in patients with HRNB using search terms for 'neuroblastoma' and ('myeloablative therapy' OR 'stem cell transplantation'). Reporting of at least one survival outcome [event-free survival (EFS), progression-free survival, relapse-free survival and/or overall survival (OS)] was required for inclusion. Outcomes from RCTs were synthesized in meta-analysis, while meta-analysis of non-RCTs was not planned owing to expected heterogeneity.

RESULTS

Literature searches produced 2587 results with 41 publications reporting 34 comparative studies included in the review. Of these, 7 publications reported 4 RCTs, and 34 publications reported 30 non-RCT studies. Studies differed with respect to included populations, induction regimen, response to induction, additional treatments and transplantation procedures. Subsequent treatments of relapse were rarely reported and could not be compared. In the meta-analysis, EFS was in favour of MAT+ASCT over conventional chemotherapy or no further treatment [hazard ratio (HR) = 0.78, 95% confidence interval (CI) 0.67-0.91, p = 0.001] with a trend favouring MAT+ASCT for OS (HR = 0.86, 95% CI 0.73-1.00, p = 0.05). Tandem MAT+ASCT was found to improve EFS compared with the single procedure, with improvement in both EFS and OS in patients treated with anti-GD2 therapy. Non-RCT comparative studies were broadly consistent with evidence from the RCTs; however, not all reported survival benefits of MAT+ASCT (single or tandem). Limited comparative evidence on treatment without MAT+ASCT in patients treated with anti-GD2 immunotherapy suggests an increased risk of relapse. In relapsed patients, MAT+ASCT appears to improve OS, but evidence remains scarce.

CONCLUSIONS

Survival benefits in patients treated with MAT+ASCT confirm that the procedure should remain an integral part of multimodal therapy. In patients treated with anti-GD2 immunotherapy, limited evidence suggests that omitting MAT+ASCT is associated with an increased risk of relapse, and therefore, a change in clinical practice can currently not be recommended. Evidence suggests the use of tandem MAT+ASCT compared with the single procedure, with greater benefits observed in patients treated with anti-GD2 immunotherapy. Limited evidence also suggests improved survival following MAT+ASCT in relapsed patients, which needs to be viewed in light of emerging chemoimmunotherapy in this setting.

Factors Impacting Time to Engraftment in Patients With High-risk Neuroblastoma Following Autologous Stem Cell Transplant

BACKGROUND

Despite advances in supportive measures, myeloablative chemotherapy with stem cell rescue remains limited by toxicity and treatment-related mortality. The purpose of this study was to identify factors influencing the rate of hematopoietic recovery following autologous stem cell transplant in high-risk neuroblastoma.

PROCEDURE

We retrospectively studied 54 patients with high-risk neuroblastoma who received a single autologous stem cell transplant between 2006 and 2016. Race, sex, conditioning regimen, chemotherapy delays and bone marrow involvement were analyzed using Kaplan-Meier Log-Rank test while the amount of cells infused, age, and length of hospital stay were analyzed using univariate Cox Proportional Hazards Regression.

RESULTS

The conditioning regimen administered was significant (P=0.016) for time to engraftment of neutrophils, with busulfan/melphalan (Bu/Mel) at 16.6 days, and carboplatin/etoposide/melphalan at 12.1 days. A delay of chemotherapy during induction (n=24) was significant (P<0.001) for time to platelet engraftment of >75,000/µL. Female patients had a longer time to engraftment (P=0.029).

CONCLUSION

Patients receiving Bu/Mel as a conditioning regimen, patients who had a delay in induction chemotherapy and patients of female sex were found to be significant for delayed engraftment of neutrophils, platelets, and hemoglobin, respectively, in patients with high-risk neuroblastoma undergoing autologous stem cell transplant. Knowing these factors may lead to new expectations and possible interventions to decrease the morbidity and mortality of treatment and recovery.

Survival of high-risk pediatric neuroblastoma patients in a developing country

Little information is available about survival of high-risk pediatric neuroblastoma patients in developing countries. We aimed to assess survival among high-risk pediatric neuroblastoma patients in La Plata, Argentina. Individuals eligible for our cohort were aged <20 yr when diagnosed with high-risk neuroblastoma and received cancer-directed therapy including stem cell transplantation at Hospital de Niños Sor Maria Ludovica between February 1999 and February 2015. We estimated overall survival probabilities using an extended Kaplan-Meier approach. Our study population comprised 39 high-risk neuroblastoma patients, of whom 39% were aged >4 yr at diagnosis, 54% were male, and 62% had adrenal neuroblastoma. We observed 18 deaths, and the median survival time of our study population was 1.7 yr. The five-yr overall survival probability was 24% (95% CL: 10%, 41%). In contrast, five-yr survival of high-risk neuroblastoma patients ranges between 23% and 76% in developed countries. Survival among high-risk neuroblastoma patients is generally poor regardless of geographic location, but our results illustrate dramatically worse survival for patients in a developing country. We speculate that the observed survival differences could be attenuated or eliminated with improvements in treatment and supportive care, but addressing these issues will require creative solutions because of resource limitations.

Epidemiological and clinical characteristics of neuroblastoma in southern iran

BACKGROUND

Neuroblastoma is the third most common malignancy in children with a very heterogeneous feature. In this study, the epidemiological and clinical characteristics of children with neuroblastoma treated in a referral oncology hospital in Shiraz, Southern Iran, were investigated.

MATERIAL AND METHOD

In this historical cohort study, the medical files of 36 children under 18 years old with neuroblastoma were reviewed, who were admitted to Amir Oncology Hospital in Shiraz, Iran from 2006 to 2013. Overall survival and event free survival (EFS) curves were demonstrated by Kaplan Meier methods. Also the effects of demographic and clinical characteristics of the patients on survival were evaluated by Cox regression model.

RESULTS

The median age of diagnosis was 30 months (age range: from 4 to144 months), with M/F ratio of 63.9%. Over 70% of the patients had stage 4 of neuroblastoma at their initial presentations. Adrenal gland comprised 72.2% of the primary tumor site. The most common presenting symptoms were gastrointestinal and constitutional symptoms. The mean overall survival and EFS were 30.75 and 20.56 months, respectively. Among the different variables analyzed, only liver metastasis had an adverse effect on EFS (p=0.025 Hazard ratios 2.83, CI: 1.14-7.02).

CONCLUSION

This study revealed that the majority of children suffering from neuroblastoma in our center are high stage with disseminated disease at the time of detection. It also warns us about an urgent necessity for holding a re-educational program for general practitioners and pediatricians to review the warning signs of common pediatric cancers such as neuroblastoma.

Analysis of pediatric autologous PBSC apheresis and transplant: age is a major factor affecting post-transplant toxicity

BACKGROUND

High-dose chemotherapy followed by autologous hematopoietic cell transplantation (HCT) is used in many therapeutic protocols for pediatric intra- and extra-cranial solid tumors. HCT can be curative, but is associated with significant toxicity.

PROCEDURE

Between January 2001 and June 2009, 92 solid tumor patients (age 6 months to 27 years) underwent 94 autologous apheresis procedures at Children's National Medical Center. Out of that group, 71 patients, who underwent 162 autologous HCT, were analyzed for transplant outcomes. Multiple variable modeling was used to identify independent variables related to transplant toxicity outcome measures, such as bacteremia, intensive care admission, and death. Other outcome measures (time to pre-apheresis peripheral blood CD34+ count, product yield, and time to engraftment) were also analyzed. Independent variables included patient-specific variables (age, weight, tumor type, chemotherapy administered, and primary vs. relapsed disease) and harvest or transplant-related variables (total white blood cell and CD34+ cell counts prior to transplant, and quantity of total nucleated cells and CD34+ cells infused during transplant).

RESULTS

Transplant toxicity was significantly greater in younger patients (P = 0.001) and in neuroblastoma patients (P = 0.003). The time to neutrophil engraftment, controlling for weight, age, and chemotherapy, was positively related to absolute CD34+ cells/kg infused (P = 0.01). The time to CD34+ recovery pre-apheresis was affected by patient diagnosis (P = 0.05).

CONCLUSIONS

Younger patients had increased transplant toxicity, with infants <1 year of age at highest risk for fever, bacteremia, admission to intensive care, and death. Infants would likely benefit from hospitalization after autologous HCT until neutrophil recovery.

Retroviral gene therapy for X-linked chronic granulomatous disease: results from phase I/II trial

X-linked chronic granulomatous disease (CGD) is an inherited immunodeficiency caused by a defect in the gp91(phox) gene. In an effort to treat X-CGD, we investigated the safety and efficacy of gene therapy using a retroviral vector, MT-gp91. Two X-CGD patients received autologous CD34(+) cells transduced with MT-gp91 after a conditioning regimen consisting of fludarabine and busulfan. The level of gene-marked cells was highest at day 21 (8.3 and 11.7% in peripheral blood cells) but decreased to 0.08 and 0.5%, respectively, 3 years after gene transfer. The level of functionally corrected cells, as determined by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase assay, reached a peak at day 17 (6.5% patient 1 (P1) and 14.3% patient 2 (P2) of total granulocytes) and declined to 0.05% (P1) and 0.21% (P2), 3 years later. Some retroviral vectors were found to have integrated within or close to the proto-oncogenes MDS1-EVI1, PRDM16, and CCND2; however, no abnormal cell expansion or related hematological malignancy was observed. Overall, the gene transfer procedure did not produce any serious adverse effects and was able to convert a significant fraction of blood cells to biologically functional cells, albeit for a short period of time.