Assessment of pulmonary outcomes, exercise capacity, and longitudinal changes in lung function in pediatric survivors of high-risk neuroblastoma

Assessing Pulmonary Function in Children and Adolescents After Cancer Treatment: Protocol for a Multicenter Cohort Study (Swiss Childhood Cancer Survivor Study FollowUp-Pulmo)

BACKGROUND

Childhood cancer survivors (CCS) are at risk of pulmonary dysfunction due to cancer treatments, but evidence on prevalence and risk factors remains limited. Most previous studies had small sample sizes or retrospective study designs, little information about treatments, or a lack of standardization of pulmonary function tests (PFTs) or limited their investigation to certain PFTs. Since spirometry mainly assesses the large airways but cancer therapy also affects peripheral airways, additional functional tests are needed. The nitrogen multiple breath washout test (N2MBW) is sensitive to peripheral airway damage in other patient populations, but its benefit in CCS is unknown. Therefore, comprehensive and standardized evaluation of pulmonary function after cancer treatment in childhood, using different PFTs that include N2MBW, is needed to address these knowledge gaps and provide insights into possible early stages of pulmonary dysfunction.

OBJECTIVE

In the Swiss Childhood Cancer Survivor Study (SCCSS) FollowUp-Pulmo, we will comprehensively assess lung function in children and adolescents after treatment for cancer to identify risk factors for pulmonary dysfunction, assess the ability of N2MBW to detect pulmonary dysfunction compared to other PFTs, and investigate the association of functional outcomes from PFTs with self-reported respiratory symptoms.

METHODS

SCCSS FollowUp-Pulmo is a prospective multicenter longitudinal cohort study embedded in routine clinical care that enrolls CCS aged 6-20 years for whom at least 1 year has passed since a childhood cancer diagnosis, who have completed treatment, and who attend regular pediatric oncological follow-up care. Inclusion criteria comprise any of the following: systemic anticancer treatment (chemotherapy, immunotherapy, or targeted agents), thoracic surgery, thoracic radiotherapy, or hematopoietic stem cell transplantation (HSCT). CCS undergo a standardized pulmonary assessment, including spirometry, body plethysmography, diffusing capacity of the lung for carbon monoxide (DLCO), and N2MBW, and complete a questionnaire on respiratory symptoms and lifestyle. Data from previous and subsequent routine care PFTs will be included in this study.

RESULTS

Recruitment started in June 2022 at the University Children's Hospital Bern, Switzerland. Subsequently, patient recruitment expanded to the University Children's Hospitals in Basel and Geneva, Switzerland. By October 2024, we had invited 220 patients, of which 201 have already participated in this study, resulting in a response rate of 91%. Their median age at the time of the study was 14 years (IQR 10-17), and the median time since diagnosis was 7 years (IQR 4-10). The study will continuously enroll new CCS.

CONCLUSIONS

This study will contribute to a comprehensive understanding of pulmonary function in CCS and assess related risk factors, as well as the utility of N2MBW compared to other PFTs. The results will assist in the development of more targeted screening and risk-stratified follow-up care.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04732273; https://clinicaltrials.gov/study/NCT04732273.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/69743.

Cyclophosphamide is not associated with clinically relevant late pulmonary dysfunction in Dutch survivors of childhood cancer - The DCCSS-LATER 2 PULM sub-study

BACKGROUND

Treatment for childhood cancer may increase the risk of long-term pulmonary complications and dysfunction. Pulmonary surveillance is recommended after established pulmonary toxic exposures, including bleomycin, busulfan, carmustine (BCNU), lomustine (CCNU), radiotherapy to a field exposing the lungs, and pulmonary surgery. However, the role of cyclophosphamide as a pulmonary toxic agent is debated.

AIM

To establish whether cyclophosphamide is associated with late pulmonary dysfunction among survivors of childhood cancer.

METHODS

In this multicenter Dutch Childhood Cancer Survivor Study (DCCSS)-LATER 2 PULM sub-study, we included 828 survivors with a median follow-up of 26.6 years, treated with cyclophosphamide and/or established pulmonary toxic treatment, or neither. Pulmonary function tests were used to measure the primary outcomes of diffusion impairment (diffusing capacity for carbon monoxide (DLCO) z-score), restriction (total lung capacity (TLC) z-score), and obstruction (forced expiratory volume in the first second/forced vital capacity (FEV1/FVC) z-score). Secondary outcomes comprised chronic cough, recurrent respiratory tract infections, shortness of breath, and supplemental oxygen need.

RESULTS

Diffusion and restrictive abnormalities were highly prevalent among those treated with established pulmonary toxic treatment, with cyclophosphamide (41.0 % and 50.4 %, respectively) and without (34.3 % and 41.9 %, respectively), and occurred less frequently in survivors treated with cyclophosphamide only (12.9 % and 7.3 %, respectively) or in survivor controls (9.9 % and 12.4 %, respectively). In multivariable analyses, cyclophosphamide did not have a clinically relevant effect on the primary or secondary outcomes.

CONCLUSIONS

This study suggests that cyclophosphamide is not associated with clinically relevant pulmonary dysfunction in long-term childhood cancer survivors.

Recommendations for surveillance of pulmonary dysfunction among childhood, adolescent, and young adult cancer survivors: a report from the International Late Effects of Childhood Cancer Guideline Harmonization Group

Childhood, adolescent, and young adult (CAYA) cancer survivors are at risk of pulmonary dysfunction. Current follow-up care guidelines are discordant. Therefore, the International Late Effects of Childhood Cancer Guideline Harmonization Group established and convened a panel of 33 experts to develop evidence-based surveillance guidelines. We critically reviewed available evidence regarding risk factors for pulmonary dysfunction, types of pulmonary function testing, and timings of surveillance, then we formulated our recommendations. We recommend that CAYA cancer survivors and healthcare providers are aware of reduced pulmonary function risks and pay vigilant attention to potential symptoms of pulmonary dysfunction, especially among survivors treated with allogeneic haematopoietic stem cell transplantation, thoracic radiotherapy, and thoracic surgery. Based on existing limited evidence and current lack of interventions, our panel recommends pulmonary function testing only for symptomatic survivors. Since scarce existing evidence informs our recommendation, we highlight the need for prospective collaborative studies to address pulmonary function knowledge gaps among CAYA cancer survivors.

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.

Longitudinal lung function in childhood cancer survivors after hematopoietic stem cell transplantation

Longitudinal data on pulmonary function after pediatric allogeneic or autologous hematopoietic stem cell transplantation (HSCT) are rare. We examined pulmonary function and associated risk factors in 5-year childhood cancer survivors (CCSs) longitudinally. We included 74 CCSs diagnosed between 1976 and 2010, treated with HSCT, and with at least two pulmonary function tests performed during follow-up. Median follow-up was 9 years (range 6-13). We described pulmonary function as z-scores for lung volumes (forced vital capacity [FVC], residual volume [RV], total lung capacity [TLC]), flows (forced expiratory volume in 1 s [FEV1], maximal mid-expiratory flow [MMEF]), and diffusion capacity for carbon monoxide (DLCO) and assessed associations with potential risk factors using multivariable regression analysis. The median z-scores for FEV1, FVC, and TLC were below the expected throughout the follow-up period. This was not the case for RV, MMEF and DLCO. Female gender, radiotherapy to the chest, and relapse were associated with lower z-scores of FEV1, FVC, MMEF, RV or DLCO. Childhood cancer survivors after HSCT are at risk of pulmonary dysfunction. The complex and multifactorial etiology of pulmonary dysfunction emphasizes the need for longitudinal prospective studies to better characterize the course and causes of pulmonary function impairment in CCSs.

Exploring pulmonary function and physical function in childhood cancer: A systematic review

BACKGROUND

Children with cancer experience pulmonary and physical function side effects from the cancer itself and the medical interventions. This systematic review examines the known relationship between pulmonary function and physical function in childhood cancer and identifies gaps in the literature.

METHODS

A search of Ovid Medline, CINAHL (EbscoHost) and Embase to identify literature from 2009 to March 2020.

RESULTS

Fifty-seven studies met inclusion criteria. Thirty-seven studies reported impaired pulmonary function. Incidence of pulmonary dysfunction ranged from 45.5 % to 84.1 %. Eighteen studies reported impaired physical function. Three studies investigated the relationship between pulmonary function and physical function. No studies explored inspiratory muscle strength.

CONCLUSION

Pulmonary function and physical function are related and frequently impaired in children during and after cancer treatment. A literature gap was found in diaphragm function and its relationship with physical function. Future studies should focus on interventions that target the pulmonary mechanisms impacting physical function.