Long-Term Sequelae in Survivors of High-Risk Neuroblastoma: Insights from the Children’s Oncology Group Study

Introduction

High-risk neuroblastoma is an aggressive pediatric cancer that poses significant treatment challenges but also results in substantial long-term health consequences for survivors. Advances in multimodal therapy, including chemotherapy, stem cell transplant (SCT), and immunotherapy, have improved survival rates. However, these intensive therapies have been associated with late effects that can impact quality of life for decades post-treatment.

The recent multicentre, cross-sectional cohort study conducted by the Children’s Oncology Group (COG), titled ‘Late effects after high-risk neuroblastoma (LEAHRN)’, aims to characterize the prevalence and risk factors of such late effects in survivors treated with modern regimens. This article critically examines their methodology, key findings, and implications for clinical practice.

Study Background and Rationale

Despite increased survival, survivors of high-risk neuroblastoma often face sequelae including hearing loss, growth failure, and lung impairment. Understanding the relationship between specific treatments and late effects is crucial for designing tailored follow-up and intervention strategies. Nevertheless, data on long-term outcomes with contemporary therapeutic protocols remain limited, underscoring the importance of this study.

Study Design and Population

This multicentre, cross-sectional cohort study involved 88 hospitals across North America, Australia, and New Zealand. Eligible participants were diagnosed with high-risk neuroblastoma on or after January 1, 2000; aged between 5 and 50 years at enrollment; alive at least five years post-diagnosis; and proficient in English, French, or Spanish. Exclusion criteria included active relapse within two years of enrollment.

Participants underwent comprehensive evaluations including audiometry, pulmonary testing, echocardiography, and laboratory assessments. Treatment exposures were abstracted from clinical records. Importantly, the study utilized a robust statistical approach, employing multivariable logistic regression to explore associations between treatment modalities and late effects.

Major Findings

The study enrolled 375 survivors out of 890 eligible individuals, with a median age at diagnosis of 2.5 years and a median follow-up duration of nine years. The cohort reflects diverse treatment histories, with all participants receiving chemotherapy, most undergoing stem cell transplants, and a significant subset receiving anti-GD2 immunotherapy.

Notably, the prevalence of late effects was high:
– Moderate-to-severe hearing loss was observed in 72% of those tested (236 of 327).
– Growth failure affected approximately 24% (87 of 360).
– Underweight status was identified in 51% (190 of 373).
– Restrictive lung disease was present in 8% of those evaluated (17 of 207), with some cases classified as moderate or severe.

The study identified a clear association between the type of stem cell transplant and late effects:
– Participants receiving tandem SCT had higher odds of growth failure (OR 3.4, 95% CI 1.6–7.2) compared to single SCT.
– Similarly, they exhibited increased risk of restrictive lung disease (OR 4.5, 95% CI 1.1–18.3).

Interestingly, neither conditioning regimen (busulfan-melphalan vs carboplatin-etoposide-melphalan) nor anti-GD2 therapy was linked to increased risks of the examined late effects. Longer follow-up duration correlated with greater prevalence, emphasizing progressive accumulation of late effects over time.

Implications for Clinical Practice

These findings underscore the significant burden of late effects among survivors of modern high-risk neuroblastoma therapy. The association between tandem SCT and more severe late effects suggests that treatment intensification may require concurrent intensified survivorship monitoring, especially for growth and pulmonary function. Importantly, the lack of association between some contemporary therapies and late effects offers reassurance but warrants ongoing surveillance.

Furthermore, the data advocate for the development of anticipatory guidance and tailored interventions—such as audiologic support, endocrine management, and pulmonary rehabilitation—to mitigate long-term morbidity. Routine long-term follow-up should be integrated into survivorship care plans, with particular attention to those who received tandem SCT.

Limitations and Future Directions

While comprehensive, the study’s cross-sectional design limits causal inferences and may underestimate the true incidence of late effects that develop or progress over time. The cohort’s diversity in treatment exposures and follow-up durations, although strengths, also pose challenges for individualized risk stratification.

Further longitudinal studies are needed to elucidate causal pathways, evaluate the impact of newer therapies such as targeted immunotherapies, and refine surveillance strategies. Additionally, integrating patient-reported outcomes and quality-of-life measures will enrich understanding of the real-world burden of late effects.

Conclusion

The LEAHRN study provides vital insight into the substantial late effects faced by survivors of high-risk neuroblastoma treated with contemporary regimens. Recognizing the treatment-related risks enables clinicians to implement personalized monitoring strategies, optimize long-term health, and inform future therapeutic approaches to reduce late morbidity in this vulnerable population.