Role of Chemotherapy and the Receptor Tyrosine Kinases KIT, PDGFRα, PDGFRβ, and Met in Large-Cell Neuroendocrine Carcinoma of the Lung

Purpose Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a relatively uncommon, high-grade neuroendocrine tumor sharing several features with small-cell lung carcinoma (SCLC) but currently considered as a variant of non-SCLC and accordingly treated with poor results. Little is known about the optimal therapy of LCNEC and the possible therapeutic molecular targets. Patients and Methods We reviewed 83 patients with pure pulmonary LCNEC to investigate their clinicopathologic features, therapeutic strategy, and immunohistochemical expression and the mutational status of the receptor tyrosine kinases (RTKs) KIT, PDGFRα, PDGFRβ, and Met. Results LCNEC histology predicted a dismal outcome (overall median survival, 17 months) even in stage I patients (5-year survival rate, 33%). LCNEC strongly expressed RTKs (KIT in 62.7% of patients, PDGFRα in 60.2%, PDGFRβ in 81.9%, and Met in 47%), but no mutations were detected in the exons encoding for the relevant juxtamembrane domains. Tumor stage and size (≥ 3 cm)...