Cardiovascular and Pulmonary Challenges After Treatment of Childhood Cancer

Acute and Late Pulmonary Effects After Radiation Therapy in Childhood Cancer Survivors: A PENTEC Comprehensive Review

OBJECTIVES

The Pediatric Normal Tissue Effects in the Clinic (PENTEC) pulmonary task force reviewed dosimetric and clinical factors associated with radiation therapy (RT)-associated pulmonary toxicity in children.

METHODS

Comprehensive search of PubMed (1965-2020) was conducted to assess available evidence and predictive models of RT-induced lung injury in pediatric cancer patients (<21 years old). Lung dose for radiation pneumonitis (RP) was obtained from dose-volume histogram (DVH) data. RP grade was obtained from standard criteria. Clinical pulmonary outcomes were evaluated using pulmonary function tests (PFTs), clinical assessment, and questionnaires.

RESULTS

More than 2,400 abstracts were identified; 460 articles had detailed treatment and toxicity data; and 11 articles with both detailed DVH and toxicity data were formally reviewed. Pooled cohorts treated during 1999 to 2016 included 277 and 507 patients age 0.04 to 22.7 years who were evaluable for acute and late RP analysis, respectively. After partial lung RT, there were 0.4% acute and 2.8% late grade 2, 0.4% acute and 0.8% late grade 3, and no grade 4 to 5 RP. RP risk after partial thoracic RT with mean lung dose (MLD) <14 Gy and total lung V20Gy <30% is low. Clinical and self-reported pulmonary outcomes data included 8,628 patients treated during 1970 to 2013, age 0 to 21.9 years. At a median 2.9- to 21.9-year follow-up, patients were often asymptomatic; abnormal PFTs were common and severity correlated with lung dose. At ≥10-year follow-up, multi-institutional studies suggested associations between total or ipsilateral lung doses >10 Gy and pulmonary complications and deaths. After whole lung irradiation (WLI), pulmonary toxicity is higher; no dose response relationship was identified. Bleomycin and other chemotherapeutics at current dose regimens do not contribute substantially to adverse pulmonary outcomes after partial lung irradiation but increase risk with WLI.

CONCLUSIONS

After partial lung RT, acute pulmonary toxicity is uncommon; grade 2 to 3 RP incidences are <1%. Late toxicities, including subclinical/asymptomatic impaired pulmonary function, are more common (<4%). Incidence and severity appear to increase over time. Upon review of available literature, there appears to be low risk of pulmonary complications in children with MLD < 14 Gy and V20Gy <30% using standard fractionated RT to partial lung volumes. A lack of robust data limit guidance on lung dose/volume constraints, highlighting the need for additional work to define factors associated with RT-induced lung injury.

Childhood cancer survivors: current challenges

Rates of childhood cancer survival in developed countries have risen to over 80-85 %. In consequence, the population of childhood cancer survivors (CCS) has grown considerably. Nevertheless, CCS present a high morbidity and mortality due to cancer or its treatment, with an increased risk of premature mortality, second primary tumors and late side effects, both physical and psychosocial, all of which decrease the quality of life. Long-term follow-up (LTFU) of CCS is recommended to prevent, detect and treat those health problems. Despite the advances achieved, the management of CCS is still not optimal. Among the areas for improvement discussed in this manuscript are: (1) Quantifying the real burden of morbimortality, by implementing new frequency measures (mean cumulative count and cumulative burden), to obtain more accurate assessments, and using simulation models, to determine individual risks; (2) Assessing the impact of risk factors for late side effects, related to the patient, tumor type, treatments, lifestyle, comorbidities, genetics and ageing; (3) Considering the impact of the international harmonisation of long-term follow-up guidelines, to generate homogeneous, evidence-based recommendations and an individualized LTFU and, (4) Challenges to LTFU implementation, considering models of care adapted to patient risk and needs, with special attention to the transition to adult-care follow-up. Finally, we comment on the situation of CCS in Spain and consider future prospects for improving the health and quality of life of this population.

Long-Term Complications after Allogeneic Hematopoietic Stem Cell Transplantation with Treosulfan- or Busulfan-Based Conditioning in Pediatric Patients with Acute Leukemia or Myelodysplastic Syndrome: Results of an Associazione Italiana Ematologia Oncologia Pediatrica Retrospective Study

Patients undergoing hematopoietic stem cell transplantation (HSCT) for hematologic malignancies during childhood have an increased risk of developing long-term sequelae that are in part attributable to the conditioning regimen. The present study aimed to assess the occurrence of long-term toxicities in a population of children who underwent HSCT for hematologic malignancies using either treosulfan or busulfan in the conditioning regimen. The cumulative incidences of growth impairment, altered gonadal function, altered thyroid function, cataracts, secondary malignant neoplasia, and altered pulmonary function were evaluated retrospectively by univariable and multivariable analyses in a population of 521 pediatric patients with acute leukemias or myelodysplastic syndromes treated in 20 Italian transplant centers affiliated with the Associazione Italiana Ematologia ed Oncologia Pediatrica (AIEOP). The median duration of follow-up for the entire study population was 7.1 years (range, 1 to 16 years). Overall, a larger proportion of patients given busulfan developed long-term toxicities compared to patients treated with treosulfan (34% versus 20%; P = .01). In univariable analysis, gonadal toxicity developed in 10% of patients who received treosulfan (95% confidence interval [CI], 3% to 15%), compared with 38% (95% CI, 24% to 39%) of busulfan-treated patients (P = .02), and this finding was confirmed by multivariable analysis (relative risk, .51; 95% CI, .34 to .76; P = .0009). We did not find any statistically significant associations between the occurrence of other long-term toxicities and the use of either busulfan or treosulfan. This study provides evidence that the use of treosulfan is correlated with a reduced incidence of gonadal toxicity in children undergoing HSCT for hematologic malignancies.

Long-term outcomes of pulmonary embolism in children and adolescents

ABSTRACT

Knowledge regarding the long-term consequences of pulmonary embolism (PE) in children is limited. This cohort study describes the long-term outcomes of PE in children who were followed-up at a single-center institution using a local protocol that included clinical evaluation, chest imaging, echocardiography, pulmonary function tests, and cardiopulmonary exercise tests at follow-up, starting 3 to 6 months after acute PE. Children objectively diagnosed with PE at age 0 to 18 years, who had ≥6 months of follow-up were included. Study outcomes consisted of PE resolution, PE recurrence, death, and functional outcomes (dyspnea, impaired pulmonary or cardiac function, impaired aerobic capacity, and post-PE syndrome). The frequency of outcomes was compared between patients with/without underlying conditions. In total, 150 patients were included; median age at PE was 16 years (25th-75th percentile, 14-17 years); 61% had underlying conditions. PE did not resolve in 29%, recurrence happened in 9%, and death in 5%. One-third of patients had at least 1 documented abnormal functional finding at follow-up (ventilatory impairments, 31%; impaired aerobic capacity, 31%; dyspnea, 26%; and abnormal diffusing capacity of the lungs to carbon monoxide, 22%). Most abnormalities were transient. When alternative explanations for the impairments were considered, the frequency of post-PE syndrome was lower, ranging between 0.7% and 8.5%. Patients with underlying conditions had significantly higher recurrence, more pulmonary function and ventilatory impairments, and poorer exercise capacity. Exercise intolerance was, in turn, most frequently because of deconditioning than to respiratory or cardiac limitation, highlighting the importance of physical activity promotion in children with PE.

Effects of postoperative radiotherapy on cardiovascular-pulmonary disease mortality in patients with stage IIIA-N2 resected NSCLC: analysis of the SEER database

Background

The role of postoperative radiotherapy (PORT) in cardiovascular-pulmonary disease mortality in patients with stage IIIA-N2 resected non-small cell lung cancer (NSCLC) remains uncertain. The purpose of this population-based analysis was to explore the effect of PORT on cardiovascular-pulmonary disease mortality in these patients.

Methods

Patients aged ≥ 18 years with stage IIIA-N2 resected NSCLC were identified in the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015 and were grouped according to the use of PORT. Propensity score matching (PSM) was used to account for differences in baseline characteristics between the Non-PORT and PORT groups. The cumulative risk for cardiovascular-pulmonary disease death was estimated using the cumulative incidence curve. Competing risk regression was used to run univariate and multivariate analyses to evaluate risk factors.

Results

A total of 3981 patients were included in the study population. Among them, 1446 patients received PORT, and 2535 did not. A total of 1380 patients remained in each group after PSM, and the baseline characteristics were not significantly different between the two groups. The cumulative incidence of cardiovascular-pulmonary mortality was 10.93% in the Non-PORT group compared with 9.85% in the PORT group. There was no significant difference in the cumulative risk between the two groups (HR 1.07, 95% CI 0.77–1.48, p = 0.703). Multivariate analysis indicated that PORT had no significant impact on increased risk, with an HR of 1.18 (p = 0.377).

Conclusions

No significant differences between the PORT and Non-PORT groups were found in cardiovascular-pulmonary-specific modalities in this study. Further studies are required to validate these results. This study highlights the importance of long-term surveillance for NSCLC patients.