Treatment and prognostic factors in pleuropulmonary blastoma: an EXPeRT report

Pleuropulmonary blastoma (PPB) is an aggressive embryonal malignancy presenting in early childhood, presumably arising from pleuropulmonary mesenchyme. The European Cooperative Study Group for Paediatric Rare Tumours (EXPeRT) analysed its data on this tumour.

This analysis concerns patients aged 0-17years with histologically-confirmed PPB registered up to 2008 in national databases in Italy, France and the United Kingdom and Poland. Lesions were classified as type I, II or III according to Dehner's classification.

Sixty-five patients were considered (13 type I, 24 type II and 28 type III). Most tumours were large (91% >5cm) and invaded the parietal pleura (29), mediastinum (10), major vessels (four) or pericardium (three). Regional nodes were involved in two cases, and three had metastases. The median follow-up was 5years (0.6-22). For type I patients, 5-year progression free survival (PFS) was 83.3% and overall survival 91.7%; six patients received no further treatment after surgery, but two relapsed. All type II/III PPB had chemotherapy (CT) and their 5-year PFS was 42.9% (27.7-57.2). On univariate analysis, favourable prognostic factors were: complete tumour resection at diagnosis (p=0.008); and absence of invasiveness (p=0.02); for type II/III tumours, type of CT was also a significant factor (patients given doxorubicin fared better, with a 5-year PFS of 70% versus 31.3% [p=0.01]).

Type I PPB patients' outcome was satisfactory. Complete resection at diagnosis seems important but rarely feasible for type II/III tumours, who benefited from doxorubicin-containing CT regimens. These results will inform the EXPeRT group's PPB treatment guidelines.