The impact of local control in the treatment of type II/III pleuropulmonary blastoma. Experience of the Cooperative Weichteilsarkom Studiengruppe (CWS)

Patient Characteristics, Treatment, and Survival in Pleuropulmonary Blastoma: An Analysis from the National Cancer Database

Pleuropulmonary blastoma (PPB) is a rare childhood tumor originating from the lung or pleura, typically treated with surgery, chemotherapy (CTx), and/or radiation therapy (RTx). This study aimed to assess patient and tumor features, treatment methods, and survival rates in PPB. We retrospectively analyzed PPB patients under 18 from 2004 to 2019, using the National Cancer Database (NCDB). We assessed 5-year overall survival (OS) rates based on disease presentation and treatment regimens, using Kaplan-Meier curves and Cox proportional regression. Among 144 cases identified, 45.9% were female, with a median age of 2 years (interquartile range 1-3). In all, 62.5% of tumors originated from the lung, and 10.4% from the pleura. Moreover, 6.9% were bilateral, and the median tumor size was 8.9 cm, with 4.2% presenting with metastases. The 5-year OS rate was 79.6%, with no significant change over time (2004-2009, 77.6%; 2010-2014, 90.8%; 2015-2019, OS 75.3%; p = 0.08). In all, 5.6% received CTx alone, 31.3% surgery alone, 45.8% surgery/CTx, and 17.4% surgery/CTx/RTx. The OS rates were comparable between the surgery/CTx/RTx (80.0%) and surgery/CTx (76.5%) groups (adjusted Hazard Ratio, 1.72; 95% CI, 0.57-5.19; p = 0.34). Therefore, due to the unchanged survival rates over time, further prospective multicenter studies are needed to determine the optimal multimodal treatment regimens for this rare pediatric tumor.

Outcomes for Children With Type II and Type III Pleuropulmonary Blastoma Following Chemotherapy: A Report From the International PPB/DICER1 Registry

PURPOSE

Pleuropulmonary blastoma (PPB) is the most common primary lung neoplasm of infancy and early childhood. Type II and type III PPB have historically been associated with a poor prognosis.

METHODS

Patients with known or suspected PPB were enrolled in the International PPB/DICER1 Registry. Medical records were abstracted with follow-up ascertained annually. All PPB diagnoses were confirmed by central pathology review. Beginning in 2007, the IVADo regimen (ifosfamide, vincristine, actinomycin-D, and doxorubicin) was recommended as a potential treatment regimen for children with type II and type III PPB. This regimen was compared with a historical control cohort.

RESULTS

From 1987 to 2021, 314 children with centrally confirmed type II and type III PPB who received upfront chemotherapy were enrolled; 132 children (75 with type II and 57 with type III) received IVADo chemotherapy. Adjusted analyses suggest improved overall survival for children treated with IVADo in comparison with historical controls with an estimated hazard ratio of 0.65 (95% CI, 0.39 to 1.08). Compared with localized disease, distant metastasis at diagnosis was associated with worse PPB event-free survival and overall survival with hazard ratio of 4.23 (95% CI, 2.42 to 7.38) and 4.69 (95% CI, 2.50 to 8.80), respectively.

CONCLUSION

The use of IVADo in children with type II and type III PPB resulted in similar-to-improved outcomes compared with historical controls. Inferior outcomes with metastatic disease suggest the need for novel therapies. This large cohort of uniformly treated children with advanced PPB serves as a benchmark for future multicenter therapeutic studies for this rare pediatric tumor.

Treatment and prognosis of pleuropulmonary blastoma: A single-center report of 31 cases

OBJECTIVES

Pleuropulmonary blastoma (PPB) is a very rare and highly aggressive neoplasm occurring in children, mostly under 6 years of age. We assessed the clinical characteristics, treatment modalities, treatment outcomes, and prognostic factors affecting survival in patients with PPB treated at our institution over a 10-year period to improve the prognosis.

METHODS

From November 2008 to November 2019, 31 children (21 boys and 10 girls) with a median age of 30 months (ranging, 22 days to 54 months) were treated at our institution. Here we describe the patient characteristics, treatment modalities, and treatment outcomes. The Kaplan-Meier method was used to estimate the progression-free survival (PFS) and overall survival (OS). Log-rank test was performed for comparison between groups.

RESULTS

Three children were lost to follow-up and two were dead due to postoperative complications. Of the 26 patients included in the follow-up, 16 PPB patients displayed tumor-free survival. The 5-year PFS and OS were 60.4% and 60.1% respectively. By stratified statistical analysis, the 5-year PFS and OS of type I PPB were 100%, while those of type III PPB were 43.7% and 43%, respectively. The 5-year PFS and OS of complete tumor resection were 76.5% and 75.6%, respectively, while those with tumor residue were 31.3%. The 5-year PFS and OS combined with chemotherapy were 62.2% and 61.6%, respectively, while those without chemotherapy were 0%.

CONCLUSIONS

PPB is an aggressive neoplasm. The main factors related to the prognosis of PPB are pathological type, tumor resection degree, and postoperative adjuvant therapy.

Multimodality Imaging of Pleuropulmonary Blastoma: Pearls, Pitfalls, and Differential Diagnosis

Pleuropulmonary blastomas are rare, potentially aggressive embryonal cancers of the lung parenchyma and pleural surfaces that account for 0.25%-0.5% of primary pulmonary malignancies in children. Pleuropulmonary blastomas are classified as cystic (type I), mixed cystic and solid (type II), and solid (type III). Pleuropulmonary blastoma occurs in the same age group (0-6 years) as other more common solid tumors such as neuroblastoma and Wilms tumor. Differential diagnosis includes metastasis from Wilms tumor and macrocystic congenital pulmonary airway malformation (CPAM). A key pathologic and genetic discriminator is the DICER1 germline mutation found in patients with pleuropulmonary blastoma. Imaging, histopathologic, and clinical data are important to use in conjunction in order to determine the diagnosis and risk stratification of pleuropulmonary blastomas. Survival varies from poor to good, depending on type. However, the spectrum of pleuropulmonary blastoma is insufficiently understood due to the variable presentation of this rare disease. We present a current review of the literature regarding pleuropulmonary blastomas in this article.

Children with progressive and relapsed pleuropulmonary blastoma: A European collaborative analysis

BACKGROUND

Children with progressive (PD) or relapsed disease (RD) of pleuropulmonary blastoma (PPB) type II/III are known to have a very poor outcome.

METHODS

A retrospective review of children registered in national and European databases and trials (2000-2018) with diagnosis of PPB type II/III and PD or RD was performed.

RESULTS

A total of 35 patients with PPB were analysed: patients with PD (n = 9) and RD (n = 26). Patients experienced PD at the median age of 3.9 years [range, 0.5-17.8] despite surgery, chemotherapy (CHT, n = 9) and radiotherapy (RT, n = 1) with a median time to progression of 0.58 years [range, 0.02-1.27] from diagnosis. All of them died. Patients suffered from RD at the median age of 4.3 years [1.7-15.1], median delay to relapse 1.03 years [range, 0.03-2.95]. RD occurred locally (n = 12), combined (n = 1) and in metastatic sites (n = 13): central nervous system (n = 11) and unspecified site (n = 2). Patients were treated with salvage CHT (n = 20), surgery (n = 10) ± RT (n = 10). After a median follow-up of 4.2 years [range, 2.1-14.6], a second complete remission (CR) was achieved in nine out of 26 patients. Patients were alive in the second CR (n = 6), in the third CR (n = 1), in partial remission (n = 2) and lost of follow-up (n = 1). Five-year event-free survival (EFS) and overall survival (OS) for patients with RD were both 37% (±19, CI 95%). Local therapy (surgery, RT) had a favourable impact on OS (p = 0.03 and 0.02, respectively).

CONCLUSIONS

Cure of patients with RD of PPB type II/III with multimodal treatment is possible but rare. Progressive PPB is fatal and patients need new treatment options.

Pleuropulmonary blastoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations

Pleuropulmonary blastoma (PPB) is a rare cancer occurring mainly during early childhood and often associated with germline DICER1 mutations. It is classified by the macroscopic appearance into three interrelated clinico-pathologic entities on a developmental continuum. Complete tumor resection is a main prognostic factor and can be performed at diagnosis or after neoadjuvant treatment that includes chemotherapy and in some cases radiotherapy. Optimal modalities of neo- or adjuvant treatments can be challenging taking into account potential long-term toxicities in this young population. This paper presents the recommendations for diagnosis and treatment of children and adolescents with PPB elaborated by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the European Union-funded project PARTNER (Paediatric Rare Tumours Network - European Registry).

Inequalities in diagnosis and registration of pediatric very rare tumors: a European study on pleuropulmonary blastoma

Very rare tumors (VRTs) account for up to 11% of childhood cancers. Dedicated national groups and registries only exist in some European countries. Pleuropulmonary blastoma (PPB) is a very rare intrathoracic pediatric tumor with a potentially severe prognosis. Due to its rarity, it sometimes goes unrecognized. We investigated PPB diagnostic capability and possible correlations between diagnostic performance and VRT-dedicated activities. The number of cases of PPB registered between 2000 and 2014 at pediatric oncology centers in Europe was compared with the number of expected cases. Data sources included VRT registries, population-based cancer registries, and hospital registries. Data were obtained for 25 countries, grouped into 4 geographical regions. The expected cases were 111, and the observed cases were 129. The observed-to-expected ratio was 1.86 for Northern Europe, 1.33 for Southern Europe, 1.22 for Central Europe, and 0.65 for Eastern Europe. More cases than expected were registered in all countries with an official VRT registry.Conclusion: The number of cases observed is consistent with expectations, but disparities exist across Europe. Difficulties in diagnosing PPB emerged in most Eastern countries. The incidence rate of PPB may be underestimated. The creation of VRT-dedicated groups and a European Registry for VRTs could help to reduce inequalities.What is Known:• Very rare pediatric tumors are often not recognized, despite representing almost 11% of childhood cancers .• Pleuropulmonary blastoma is a rare pediatric tumor with a poor prognosis.What is New:• The ability to diagnose and register pleuropulmonary blastoma varies in Europe.Registries dedicated to very rare pediatric tumors improve the diagnostic rates.• The incidence rate of pleuropulmonary blastoma may currently be underestimated.

The Effect of Gross Total Resection on Patients with Pleuropulmonary Blastoma

BACKGROUND

Pleuropulmonary blastoma (PPB) is the most common primary lung cancer in children. While rare, these tumors are highly aggressive. Tumor recurrence and overall survival are dependent on histologic grade and extent of surgical resection. We sought to examine our institutional experience with PPB to determine the effect of gross total resection (GTR) on recurrence and patient outcomes.

MATERIALS AND METHODS

After IRB approval, a retrospective chart review from 1998 to 2018 was performed. Cases were confirmed by histology and Dehner Grade (I to III). Data collection included demographics, treatment, extent of surgical resection, and patient outcomes.

RESULTS

Eight patients with nine procedures were identified. Histologically, three cases were type 1, 2 type 2, and four poor prognosis type 3. Three patients received neoadjuvant chemotherapy to facilitate surgical resection. The operative goal was to achieve GTR (>95%), and to this end, three partial lobectomies, five lobectomies, and one pneumonectomy were performed. All nine cases achieved GTR, of which eight had negative microscopic margins. Two patients with type III disease recurred (one locally, one distant) and died. One type 3 patient had a positive microscopic hilar margin not amenable to further resection. The patient recurred (distant) but is in remission. With respect to patient outcomes, the event-free survival was 2.3 y with an overall survival of 3.3 y.

CONCLUSIONS

From our experience, GTR of PPB is associated with minimal surgical morbidity and good overall survival. Multi-institutional studies are needed to determine if positive surgical margins affect outcomes given the morbidity of mediastinal dissection.

[DICER1 constitutional pathogenic variant syndrome: Where are we in 2019?]

Inactivating germline pathogenic variants of the DICER1 gene are responsible for a spectrum of rare diseases, which expanded a lot in recent years. The constitution of an U.S. registry with these patients and their families as well as the registration of patients in European databases of rare tumors helped to better identify diseases encountered in this syndrome but also to study its pathophysiology (major role in miRNA maturation and recently discovered functions, e.g. in genome integrity maintenance). Most encountered disorders are pediatric malignancies, mainly the pulmonary pneumoblastoma and Sertoli-Leydig tumours. However, benign pathologies such as thyroid goiters, cystic nephromas or pulmonary cystic lesions are also frequently reported. Homogeneous guidelines regimens written by the European groups working on very rare pediatric tumors are proposed but it is important to underscore that they rely on rare scientific data; therefore overall consensus remains precarious. The genetic counseling to families is still difficult due to the large observed spectrum of tumors and the incomplete penetrance. In this article, the authors update current knowledge on the DICER1 syndrome.

Pleuropulmonary blastoma: a report from the TREP (Tumori Rari in Età Pediatrica) Project

INTRODUCTION

Pleuropulmonary blastoma (PPB) is a rare, aggressive mesenchymal tumor of childhood. The Italian Tumori Rari in Età Pediatrica (TREP) Registry was the first in Europe dedicated to prospective data collection on rare pediatric tumors. We analyzed data from an Italian series of patients with PPB, focusing on the role of the TREP Project.

METHODS

We considered patients aged 0-14 with histologically confirmed diagnosis, registered in population-based cancer registries (before 2000) or the TREP Registry (2000 to 2014), and analyzed data on clinical characteristics, treatment, and outcome. Event-free survival (EFS) and overall survival (OS) were estimated. Relevant prognostic factors were identified performing a univariate analysis.

RESULTS

Thirty-seven cases were included (7 type I, 13 type II, 17 type III). The average diagnosis rate rose from 1.10 to 1.73 cases/year after the TREP Project started. All patients underwent surgery, 33 received chemotherapy, and 9 had radiotherapy. The median follow-up was 8.7 years. For type I, II, and III, respectively, the 5-year OS was 85.7% (33.4-97.9), 52.7% (23.4-75.5), and 57.8% (31.1-77.3); the 5-year EFS was 85.7% (33.4-97.9), 52.7% (23.4-75.5), and 52.9% (27.6-73.0). Favorable prognostic factors for EFS were Intergroup Rhabdomyosarcoma Study (IRS) stage I (p = 0.03) and T1 tumor (p = 0.05). A total of 78.3% of patients who had chemotherapy after 2000 received a standardized treatment.

CONCLUSIONS

The TREP Registry showed an excellent capacity for registering cases of PPB. Patients received homogeneous treatment after the TREP Project started. Long-term outcomes were excellent for type I and unsatisfactory for type II and III. Tumor invasiveness and IRS stage were of prognostic value.

Clinical analysis of early death in children with pleuropulmonary blastoma in a single center in China

OBJECTIVE

Pleuropulmonary blastoma (PPB) is a rare malignant tumor in childhood that is highly invasive and has poor prognosis. We retrospectively analyzed patients with PPB who died within 30 days in hopes of providing a basis for improving diagnosis and treatment.

METHODS

We retrospectively reviewed six children with PPB who died within 30 days of admission at our hospital from January 2004 to March 2018, including their clinical features, pathological diagnosis, course of treatment, and major causes of death.

RESULTS

Six patients (two female, four male; median age, 38 months) were included. All patients presented with respiratory symptoms. Chest imaging showed that all tumors had diameters greater than 10 cm, with varying degrees of serous effusion. Four patients underwent ultrasound-guided fine-needle aspiration (FNA), one patient underwent exploratory thoracotomy, and one underwent partial tumor resection. Five cases were type III, and another was type II. Four patients developed adverse events while waiting for pathological results after FNA, and four patients were treated with chemotherapy but their tumors failed to decrease in size one to two weeks later. The median hospitalization to death time was 17 days (range, 5-24 days).

CONCLUSIONS

PPB often presents with respiratory symptoms that rapidly develop into respiratory distress. The rapid tumor enlargement contributes to the disease's progression. Chemoreduction in such tumors is not obviously effective, and the mortality rate is high. The main causes of death were respiratory failure and sepsis. Further clinical studies will be required to evaluate the role of initial biopsy compared with upfront total excision.

Successful treatment of metastatic cerebral recurrence of pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB) is a rare pediatric tumor. The central nervous system (CNS) is the most common site of extrathoracic metastasis. The prognosis of PPB patients with CNS metastases is dismal: most patients die within one year after recurrence. Here, we describe two patients diagnosed with PPB who developed intracranial recurrences shortly after the end of their initial treatment and were successfully treated by gross total resection, radiotherapy, and chemotherapy. Both patients are in complete remission four and three years after recurrence. Although an optimal regimen remains to be determined, these cases demonstrate that PPB with CNS metastases is potentially curable.