The differences of biological behavior based on the clinicopathological data between resectable large-cell neuroendocrine carcinoma and small-cell lung carcinoma

Introduction: Large cell neuroendocrine carcinoma of the lung and SCLC are collectively classified as high-grade NECs. However, there have been few reports focusing on the differences of clinicopathological prognostic factors between resectable LCNEC and SCLC. Patients and Methods: We reviewed the clinical data of 140 patients who underwent complete resection of high grade NEC in our institute and analyzed the clinicopathological features in relation to their survival. Results: There were no statistically significant differences in overall and recurrence-free survival between pure and combined subtypes in either LCNEC or SCLC. In LCNEC, larger tumor diameter (P =.01), nodal metastasis (P <.01), lymphatic permeation (P <.01), and vascular invasion (P =.01) were unfavorable prognostic factors. However, in SCLC, tumor diameter and vascular invasion were not prognostic factors, but nodal metastasis (P <.01) and lymphatic permeation (P =.03) were strongly correlated with poor prognosis. Conclusion: There were no apparent differences in biological behavior between pure and combined subtypes in either LCNEC or SCLC. Lymphatic involvement was an important unfavorable prognostic factor in SCLC, whereas tumor diameter, vascular invasion, and lymphatic involvement had a poor prognostic effect in LCNEC.