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

Abstract

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.

International Society of Paediatric Surgical Oncology (IPSO) Surgical Practice Guidelines

“…Surgery represents the mainstay of treatment, to establish the diagnosis and cure the patient. Although limited by number of patients, published reports have shown that complete tumour resection is a major prognostic factor [ 3 , 9 – 12 ].…”

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

“…Type I PPB is a localized tumor, but Types II or III PPB may be associated with metastasis at diagnosis, during treatment, or after completion of therapy. The most common metastatic sites are within the thorax or CNS although bone, liver, and lymph nodes may also be involved 17,22 …”

“…A surgical procedure is necessary to obtain a tumor sample and establish the diagnosis of PPB. Different series, although with a limited number of patients, have shown that complete tumor resection is a major prognostic factor 16,17,22–24 . Therefore, surgery is fundamental for the diagnosis and treatment in children with PPB (Level IV, Grade A).…”

Incidences and characteristics of primary lung malignancies in childhood in Germany: An analysis of population‐based data from German cancer registries

“…(5-year overall survival 53-71%). 20,54 In our analysis, mean age at diagnosis of 3.1 years was observed for these patients, indicating a higher proportion of type-II-and type-III-PPB. Most children with PPB have a heterozygous DICER1 germline variant, but this mutation has no prognostic impact.…”

“…PPBs are of mesenchymal origin with primitive embryonal‐like blastema and stroma and are classified into three distinct types depending on the mixture of cystic and solid components 1,53 . While type I‐PPB has a higher cystic component and a younger mean age of 8 months at diagnosis that results in a more favorable outcome (5‐year overall survival, 86%–91%), type‐II‐PPB and type‐III‐PPB occur in older children (35 months and 41 months, respectively), have more solid tumor components and are associated with a worse outcome despite the addition of chemotherapy to surgical treatment options (5‐year overall survival 53–71%) 20,54 . In our analysis, mean age at diagnosis of 3.1 years was observed for these patients, indicating a higher proportion of type‐II‐ and type‐III‐PPB.…”