Clinical features and treatment outcomes of resected large cell neuroendocrine carcinoma of the lung

Purpose: Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a high-grade lung neuroendo-crine tumor with a poor prognosis, similar to small cell lung cancer (SCLC). However, it remains un-clear whether to treat LCNEC as non-small-cell lung cancer (NSCLC) or as SCLC. We reviewed our ex-periences to suggest appropriate treatment strategy for resected pulmonary LCNEC. Materials and Methods: Forty-four patients were treated for pathologically diagnosed pulmonary LCNEC during 2005&#8211;2018. We considered curative surgery first in early-stage or some locally ad-vanced tumors, unless medically inoperable. Adjuvant treatments were decided considering patient’s clinical and pathological features. After excluding two stage I tumors with radiotherapy alone and three stage III tumors with upfront chemotherapy, we analyzed 39 patients with stage I&#8211;III pulmo-nary LCNEC, who underwent curative resection first. Results: Adjuvant chemotherapy (NSCLC-based 91%, SCLC-based 9%) was performed in 62%, and adjuvant radiotherapy was done in three patients for pN2 or positive margin. None received prophy-lactic cranial irradiation (PCI). With a median follow-up of 30 months, the 2- and 5-year overall sur-vival (OS) rates were 68% and 51%, and the 2- and 5-year recurrence-free survival (RFS) rates were 49% and 43%, respectively. Aged ≥67 years and SCLC-mixed pathology were significant poor prog-nostic factors for OS or RFS (p < 0.05). Among 17 recurrences, regional failures were most common (n = 6), and there were five brain metastases. Conclusions: Surgery and adjuvant treatment (without PCI) could achieve favorable outcomes in pul-monary LCNEC, which was more similar to NSCLC, although some factors worsened the prognosis. The importance of intensified adjuvant therapies with multidisciplinary approach remains high.