PRIMARY LUNG CARCINOMA IN CHILDREN AND ADOLESCENTS: AN ANALYSIS OF THE EUROPEAN COOPERATIVE STUDY GROUP FOR PEDIATRIC RARE TUMORS (EXPERT)

Background and Aims: Primary lung carcinomas are very rare childhood tumors with an incidence of <2/1,000,000 per year as defined by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT). They represent a challenge to treating physicians as there are few reports on these diseases at this age and no specific recommendations are available. This collaborative analysis of the EXPeRT group was conducted to improve knowledge about the treatment and prognosis of primary lung carcinomas in pediatric patients. Methods:Aretrospective European analysis of all pediatric patients (0- 18 years) with primary lung carcinomas prospectively collected in the EXPeRT databases between 2000 and 2021 was performed. Clinical data including outcomes were analyzed. Results: Thirty-eight patientswere identified with a median age of 12.8 years at diagnosis (range 0 to 17 years). Mucoepidermoid carcinoma (MEC) was the most common entity (n=20), followed by adenocarcinoma (n=12), squamous cell carcinoma (SCC; n=4), adenosquamous carcinoma (n=1) and small-cell lung cancer (n=1). Lymph node metastases occurred rarely in patients with MEC (2 cases), and 19 patients achieved durable remission after surgical resection only. One patient with MEC died after progression of metastasis. Patients with histology other thanMEC often presentedwith advanced disease (stage IV in 14 of 18 cases) and needed multimodality treatment. They had a combined survival rate of 44%. While all patients with SCC died, the 12 patients with adenocarcinoma had a survival rate of 50%. Conclusions: Primary lung carcinoma occur rarely in children. While patients with MEC have a favorable outcome with a survival rate of 95%, patients with other lung carcinoma entities have an unfavorable outcome despite multimodality treatment strategies. This analysis will help propose consensus guidelines for diagnosis and therapy.