Comparison of clinicopathologic features and prognosis between surgically resected pulmonary large-cell neuroendocrine carcinoma and small-cell lung cancer.

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung cancer (SCLC) are classified as types of high-grade neuroendocrine carcinoma (HGNEC). The aim of this study was to determine the similarities and differences in clinical features and prognosis between LCNEC and SCLC. We retrospectively compared the clinical features and prognosis of LCNEC and SCLC, along with well as their two subtypes, including pure LCNEC (P-LCNEC) and combined LCNEC (C-LCNEC) and SCLC combined with LCNEC and SCLC combined with non-LCNEC, respectively. Disease-free survival (DFS) and overall survival (OS) were calculated using the Kaplan-Meier method. We included 341 patients with LCNEC and 580 patients with SCLC who underwent surgical treatment. Significant differences in smoking history, primary site, tumor location, pathological (p) N stage, pTNM stage, and visceral pleural invasion (VPI) were observed between LCNEC and SCLC groups (all P values <0.05). The subgroups of LCNEC (P-LCNEC and C-LCNEC) and SCLC (SCLC/LCNEC and SCLC/non-LCNEC) displayed differences in smoking history, primary site, tumor location, pT stage, pN stage, pTNM stage, VPI, adjuvant chemotherapy, and postoperative adjuvant radiotherapy. LCNEC and its subtypes P-LCNEC and C-LCNEC were associated with superior DFS and OS than were SCLC and its subtypes SCLC/LCNEC and SCLC/non-LCNEC (DFS: P=0.008, P=0.001, P=0.049; OS: P=0.005, P=0.005, P=0.006). Compared to patients who did not receive adjuvant chemotherapy, those with stage I SCLC or LCNEC who underwent adjuvant chemotherapy demonstrated a significantly improved DFS (P=0.005 and P=0.048) and OS (P=0.004 and P=0.03). LCNEC and SCLC, as well as their subtypes, have distinct clinical features and survival outcomes. SCLC exhibited more malignant biological behavior and was associated with a worse prognosis compared to LCNEC. Postoperative chemotherapy is recommended for patients with stage I HGNEC.