Prognostic impact of surgical treatment for high-grade neuroendocrine carcinoma of the lung: a multi-institutional retrospective study

Background: High-grade neuroendocrine carcinoma (HGNEC) of the lung, which includes small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC), is an aggressive form of lung cancer. Although lobectomy followed by adjuvant chemotherapy is regarded as the standard therapy for this disease, it would be an uphill struggle for HGNEC patients to receive that multidisciplinary therapy perfectly. This study aimed to examine recurrence and survival outcomes in surgically treated patients with HGNEC of the lung. Methods: The medical records of 104 HGNEC patients who underwent surgical treatment in five institutions were retrospectively analyzed. Standard treatment (ST) was defined as lobectomy, bilobectomy, or pneumonectomy with mediastinal lymph node dissection followed by adjuvant platinum-doublet chemotherapy with more than two cycles. Results: Patients in the ST group (n=31; 30%) were younger and had fewer respiratory complications than those in the non-standard treatment (NST) group (n=73; 70%). A significantly higher proportion of patients in the NST group developed ipsilateral lymph node recurrence (21% vs. 3%; P=0.035) and ipsilateral or contralateral lung recurrence (15% vs. 0%; P=0.031). Five-year overall survival (OS) was 64.2% in the ST group and 38.3% in the NST group (P=0.038). NST was independently associated with worse OS in multivariate analysis (hazard ratio, 2.044; 95% confidence interval, 1.016-4.113; P=0.045). Conclusions: Surgically treated HGNEC patients who received ST had a more favorable outcome than those who received NST. Patients who receive NST may require additional treatment.