Long-term follow-up of high-risk neuroblastoma survivors treated with high-dose chemotherapy and stem cell transplantation rescue

Impact of risk-based therapy on late morbidity and mortality in neuroblastoma survivors: a report from the Childhood Cancer Survivor Study

BACKGROUND

Early efforts at risk-adapted therapy for neuroblastoma are predicted to result in differential late effects; the magnitude of these differences has not been well described.

METHODS

Late mortality, subsequent malignant neoplasms (SMNs), and severe/life-threatening chronic health conditions (CHCs), graded according to CTCAE v4.03, were assessed among 5-year Childhood Cancer Survivor Study (CCSS) survivors of neuroblastoma diagnosed 1987-1999. Using age, stage at diagnosis, and treatment, survivors were classified into risk groups (low [n = 425]; intermediate [n = 252]; high [n = 245]). Standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) of SMNs were compared with matched population controls. Cox regression models estimated hazard ratios (HRs) and 95% confidence intervals for CHC compared with 1029 CCSS siblings.

RESULTS

Among survivors (49.8% male; median age = 21 years, range = 7-42; median follow-up = 19.3 years, range = 5-29.9), 80% with low-risk disease were treated with surgery alone, whereas 79.1% with high-risk disease received surgery, radiation, chemotherapy ± autologous stem cell transplant (ASCT). All-cause mortality was elevated across risk groups (SMRhigh = 27.7 [21.4-35.8]; SMRintermediate = 3.3 [1.7-6.5]; SMRlow = 2.8 [1.7-4.8]). SMN risk was increased among high- and intermediate-risk survivors (SIRhigh = 28.0 [18.5-42.3]; SIRintermediate = 3.7 [1.2-11.3]) but did not differ from the US population for survivors of low-risk disease. Compared with siblings, survivors had an increased risk of grade 3-5 CHCs, particularly among those with high-risk disease (HRhigh = 16.1 [11.2-23.2]; HRintermediate = 6.3 [3.8-10.5]; HRlow = 1.8 [1.1-3.1]).

CONCLUSION

Survivors of high-risk disease treated in the early days of risk stratification carry a markedly elevated burden of late recurrence, SMN, and organ-related multimorbidity, whereas survivors of low/intermediate-risk disease have a modest risk of late adverse outcomes.

International recommendations for screening and preventative practices for long-term survivors of transplantation and cellular therapy: a 2023 update

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the volume of HCT performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long-term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pre-, peri- and post-transplant exposures and other underlying risk-factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and updated in 2012. To review contemporary literature and update the recommendations while considering the changing practice of HCT and cellular therapy, an international group of experts was again convened. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed but cGVHD management is not covered in detail. These guidelines emphasize special needs of patients with distinct underlying HCT indications or comorbidities (e.g., hemoglobinopathies, older adults) but do not replace more detailed group, disease, or condition specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings.

International Recommendations for Screening and Preventative Practices for Long-Term Survivors of Transplantation and Cellular Therapy: A 2023 Update

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the number of HCTs performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pretransplantation, peritransplantation, and post-transplantation exposures and other underlying risk factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and then updated in 2012. An international group of experts was convened to review the contemporary literature and update the recommendations while considering the changing practices of HCT and cellular therapy. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed, but cGVHD management is not covered in detail. These guidelines emphasize the special needs of patients with distinct underlying HCT indications or comorbidities (eg, hemoglobinopathies, older adults) but do not replace more detailed group-, disease-, or condition-specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings.

Post-treatment sperm cryopreservation practices in childhood and young adult cancer survivors

RESEARCH QUESTION

What are current practices of post-treatment fertility preservation in male childhood cancer survivors (CCS) who have not benefitted from pre-therapeutic fertility preservation in France and other European countries?

DESIGN

A survey was conducted of all fertility preservation centres in France (n = 30) and European fertility specialists (n = 9) in five European countries. Eight clinical cases and 40 questions were included to assess the effect of age at diagnosis, type of treatment (alkylating-agents, orchidectomy, testicular radiotherapy) and sperm parameters on the probability of a post-treatment fertility preservation proposal. Demographic characteristics of the responding practitioner were also collected.

RESULTS

Post-treatment sperm cryopreservation was proposed by 100% of fertility specialists in cases of severe oligoasthenoteratozoospermia, 77-88% in cases of moderate oligoasthenoteratozoospermia and in 65-77% in cases of sperm motility and vitality impairment. In cases of normal sperm parameters, 27-54% of fertility specialists would propose post-treatment sperm cryopreservation. These results did not differ significantly according to the type of treatment received or to responder-related factors. Practices of European specialists were also guided by sperm parameter results; 44-67% of specialists responding that they would propose sperm cryopreservation in cases of moderate to severe sperm parameter alterations.

CONCLUSION

Post-treatment semen analysis could be widely proposed to CCS who have not benefitted from pre-therapeutic fertility preservation. Post-treatment fertility preservation could be proposed in cases of persistent moderate to severe sperm parameter alterations. Guidelines would be important to homogenize practices and to encourage oncologists to refer CCS for fertility assessments.

Global Impact of Monoclonal Antibodies (mAbs) in Children: A Focus on Anti-GD2

Monoclonal antibodies (mAbs), as the name implies, are clonal antibodies that bind to the same antigen. mAbs are broadly used as diagnostic or therapeutic tools for neoplasms, autoimmune diseases, allergic conditions, and infections. Although most mAbs are approved for treating adult cancers, few are applicable to childhood malignancies, limited mostly to hematological cancers. As for solid tumors, only anti-disialoganglioside (GD2) mAbs are approved specifically for neuroblastoma. Inequities of drug access have continued, affecting most therapeutic mAbs globally. To understand these challenges, a deeper dive into the complex transition from basic research to the clinic, or between marketing and regulatory agencies, is timely. This review focuses on current mAbs approved or under investigation in pediatric cancer, with special attention on solid tumors and anti-GD2 mAbs, and the hurdles that limit their broad global access. Beyond understanding the mechanisms of drug resistance, the continual discovery of next generation drugs safer for children and easier to administer, the discovery of predictive biomarkers to avoid futility should ease the acceptance by patient, health care professionals and regulatory agencies, in order to expand clinical utility. With a better integration into the multimodal treatment for each disease, protocols that align with the regional clinical practice should also improve acceptance and cost-effectiveness. Communication and collaboration between academic institutions, pharmaceutical companies, and regulatory agencies should help to ensure accessible, affordable, and sustainable health care for all.

Day -1 CD34+ Cells and Platelet Count Predict the Number of Apheresis in Poor-Mobilizer Patients Rescued by Plerixafor

Plerixafor is widely used as up-front treatment with G-CSF to enhance peripheral blood hematopoietic stem cell output in patients failing previous mobilizations. Less frequently, plerixafor is used to rescue an unsatisfactory mobilization following chemotherapy (CT) and G-CSF. This study investigates if pre-collection factors affect the CD34+ cell harvest in chemotherapy and G-CSF mobilizations rescued by plerixafor. Clinical and hematological data relative to patients, mobilization, and apheresis products were retrospectively examined. The outcome was completing a target cell dose ≥ 2 × 10⁶ CD34+ cells/kg at first apheresis. The effect exerted on the outcome by patient- and disease-related factors was investigated by univariate and multivariate logistic regression analysis. The analysis included data from 42 patients affected by hematological (39 patients) and non-hematological malignancies (three patients). Twenty-nine patients (69%) attained the target cell dose at first apheresis. Twelve out of the remaining 13 patients received an additional plerixafor administration, and all accomplished the transplant dose at a second apheresis procedure. Day -1 CD34+ PB count (OR1.46, 95% CI 1.1-1.9, p = 0.008) and platelet count (OR1.0, 95% CI 1.0-1.0, p = 0.033) predicted the achievement of the target dose at first apheresis, independently of pre-mobilization CT, radiation therapy, and disease status at mobilization. At ROC curve analysis, the best cut-off value predicting the successful collection at first apheresis was 7.5/µL for Day -1 CD34+ cell count (AUC 0.830, 0.69 sensitivity, and 0.92 specificity) and 75 × 10⁹/L for Day -1 platelet count (AUC = 0.736, 0.65 sensitivity and 0.85 specificity). In conclusion, on-demand plerixafor rescue allows a successful stem cell collection, irrespectively of disease type and status, prior CT lines, and radiation exposure. Pre-apheresis CD34+ cells and platelet count predict the need for one or two aphereses.

Curative islet and hematopoietic cell transplantation in diabetic mice without toxic bone marrow conditioning

Mixed hematopoietic chimerism can promote immune tolerance of donor-matched transplanted tissues, like pancreatic islets. However, adoption of this strategy is limited by the toxicity of standard treatments that enable donor hematopoietic cell engraftment. Here, we address these concerns with a non-myeloablative conditioning regimen that enables hematopoietic chimerism and allograft tolerance across fully mismatched major histocompatibility complex (MHC) barriers. Treatment with an αCD117 antibody, targeting c-Kit, administered with T cell-depleting antibodies and low-dose radiation permits durable multi-lineage chimerism in immunocompetent mice following hematopoietic cell transplant. In diabetic mice, co-transplantation of donor-matched islets and hematopoietic cells durably corrects diabetes without chronic immunosuppression and no appreciable evidence of graft-versus-host disease (GVHD). Donor-derived thymic antigen-presenting cells and host-derived peripheral regulatory T cells are likely mediators of allotolerance. These findings provide the foundation for safer bone marrow conditioning and cell transplantation regimens to establish hematopoietic chimerism and islet allograft tolerance.

Treatment outcomes of high-dose chemotherapy plus stem cell rescue in high-risk neuroblastoma patients in Thailand

BACKGROUND

In 2013, the Thai Pediatric Oncology Group (ThaiPOG) introduced a national protocol in which high-dose chemotherapy plus stem cell rescue is performed without immunotherapy.

METHODS

This study aimed to elucidate the outcomes of high-risk neuroblastoma (HR-NB) patients treated with the ThaiPOG protocol. This retrospective cohort review included 48 patients (30 males, 18 females) with a median age of 3 years (range, 8 months to 18 years) who were treated at 5 ThaiPOG treatment centers in Thailand in 2000-2018.

RESULTS

Eight of the 48 patients showed MYCN amplification. Twenty-three patients (48%) received 131I-meta-iodobenzylguanidine prior to high-dose chemotherapy and stem cell rescue. The majority of patients achieved a complete or very good response prior to consolidation treatment. The 5-year overall survival (OS) and event-free survival (EFS) rates were 45.1% and 40.4%, respectively. Patients aged >2 years had a nonsignificantly higher mortality risk (hazard ratio [HR], 2.66; 95% confidence interval [CI], 0.92-7.68; P=0.07). The MYCN amplification group had lower OS and EFS rates than the MYCN nonamplification group, but the difference was not statistically significant (45% OS and 37.5% EFS vs. 33.3% OS and 16.6% EFS; P=0.67 and P=0.67, respectively). Cis-retinoic acid treatment for 12 months was a strong prognostic factor that could reduce mortality rates among HR-NB patients (HR, 0.27; 95% CI, 0.09-0.785; P=0.01).

CONCLUSION

High-dose chemotherapy plus stem cell rescue followed by cis-retinoic acid for 12 months was well tolerated and could improve the survival rates of patients with HR-NB.

Efficacy of post-induction therapy for high-risk neuroblastoma patients with end-induction residual disease

BACKGROUND

High-risk neuroblastoma patients with end-induction residual disease commonly receive post-induction therapy in an effort to increase survival by improving the response before autologous stem cell transplantation (ASCT). The authors conducted a multicenter, retrospective study to investigate the efficacy of this approach.

METHODS

Patients diagnosed between 2008 and 2018 without progressive disease with a partial response or worse at end-induction were stratified according to the post-induction treatment: 1) no additional therapy before ASCT (cohort 1), 2) post-induction "bridge" therapy before ASCT (cohort 2), and 3) post-induction therapy without ASCT (cohort 3). χ2 tests were used to compare patient characteristics. Three-year event-free survival (EFS) and overall survival (OS) were estimated by the Kaplan-Meier method and survival curves were compared by log-rank test.

RESULTS

The study cohort consisted of 201 patients: cohort 1 (n = 123), cohort 2 (n = 51), and cohort 3 (n = 27). Although the end-induction response was better for cohort 1 than cohorts 2 and 3, the outcomes for cohorts 1 and 2 were not significantly different (P = .77 for EFS and P = .85 for OS). Inferior outcomes were observed for cohort 3 (P < .001 for EFS and P = .06 for OS). Among patients with end-induction stable metastatic disease, 3-year EFS was significantly improved for cohort 2 versus cohort 1 (P = .04). Cohort 3 patients with a complete response at metastatic sites after post-induction therapy had significantly better 3-year EFS than those with residual metastatic disease (P = .01).

CONCLUSIONS

Prospective studies to confirm the benefits of bridge treatment and the prognostic significance of metastatic response observed in this study are warranted.

Thyroid function after diagnostic 123I-metaiodobenzylguanidine in children with neuroblastic tumors

BACKGROUND

Metaiodobenzylguanidine (MIBG) labeled with radioisotopes can be used for diagnostics ¹²³I^-) and treatment (¹³¹I^-) in patients with neuroblastic tumors. Thyroid dysfunction has been reported in 52% of neuroblastoma (NBL) survivors after ¹³¹I-MIBG, despite thyroid protection. Diagnostic ¹²³I-MIBG is not considered to be hazardous for thyroid function; however, this has never been investigated. Therefore, the aim of this study was to evaluate the prevalence of thyroid dysfunction in survivors of a neuroblastic tumor who received diagnostic ¹²³I-MIBG only.

METHODS

Thyroid function and uptake of ¹²³I^- in the thyroid gland after ¹²³I-MIBG administrations were evaluated in 48 neuroblastic tumor survivors who had not been treated with ¹³¹I-MIBG. All patients had received thyroid prophylaxis consisting of potassium iodide or a combination of potassium iodide, thiamazole and thyroxine during exposure to ¹²³I-MIBG.

RESULTS

After a median follow-up of 6.6 years, thyroid function was normal in 46 of 48 survivors (95.8%). Two survivors [prevalence 4.2% (95% CI 1.2-14.0)] had mild thyroid dysfunction. In 29.2% of the patients and 11.1% of images ¹²³I^- uptake was visible in the thyroid. In 1 patient with thyroid dysfunction, weak uptake of ¹²³I^- was seen on 1 of 10 images.

CONCLUSIONS

The prevalence of thyroid dysfunction does not seem to be increased in patients with neuroblastic tumors who received ¹²³I-MIBG combined with thyroid protection. Randomized controlled trials are required to investigate whether administration of ¹²³I-MIBG without thyroid protection is harmful to the thyroid gland.

Late effects in survivors of high-risk neuroblastoma following stem cell transplant with and without total body irradiation

BACKGROUND

Neuroblastoma is the most common extracranial solid tumor in children. Those with high-risk disease are treated with multimodal therapy, including high-dose chemotherapy, stem cell transplant, radiation, and immunotherapy that have led to multiple long-term complications in survivors. In the late 1990s, consolidation therapy involved myeloablative conditioning including total body irradiation (TBI) with autologous stem cell rescue. Recognizing the significant long-term toxicities of exposure to TBI, more contemporary treatment protocols have removed this from conditioning regimens. This study examines an expanded cohort of 48 high-risk neuroblastoma patients to identify differences in the late effect profiles for those treated with TBI and those treated without TBI.

PROCEDURE

Data on the study cohort were collected from clinic charts, provider documentation in the electronic medical record of visits to survivorship clinic, including all subspecialists, and ancillary reports of laboratory and diagnostic tests done as part of risk-based screening at each visit.

RESULTS

All 48 survivors of BMT for high-risk neuroblastoma had numerous late effects of therapy, with 73% having between five and 10 late effects. TBI impacted some late effects significantly, including growth hormone deficiency (GHD), bone outcomes, and cataracts.

CONCLUSION

Although high-risk neuroblastoma survivors treated with TBI have significant late effects, those treated without TBI also continue to have significant morbidity related to high-dose chemotherapy and local radiation. A multidisciplinary care team assists in providing comprehensive care to those survivors who are at highest risk for significant late effects.