High grade neuroendocrine lung tumors: pathological characteristics, surgical management and prognostic implications

Among non-small cell lung cancers (NSCLC), large cell carcinoma (LCC) is credited of significant adverse prognosis. Its neuroendocrine subtype has even a poorer diagnosis, with long-term survival similar to small cell lung cancer (SCLC). Our purpose was to review the surgical characteristics of those tumors. The clinical records of patients who underwent surgery for lung cancer in two French centers from 1980 to 2009 were retrospectively reviewed. We more particularly focused on patients with LCC or with high grade neuroendocrine lung tumors. High grade neuroendocrine tumors were classified as pure large cell neuroendocrine carcinoma (pure LCNEC), NSCLC combined with LCNEC (combined LCNEC), and SCLC combined with LCNEC (combined SCLC). There were 470 LCC and 155 high grade neuroendocrine lung tumors, with no difference concerning gender, mean age, smoking habits. There were significantly more exploratory thoracotomies in LCC, and more frequent postoperative complications in high grade neuroendocrine lung tumors. Pathologic TNM and 5-year survival rates were similar, with 5-year ranging from 34.3% to 37.6% for high grade neuroendocrine lung tumors and LCC, respectively. Induction and adjuvant therapy were not associated with an improved prognosis. The subgroups of LCNEC (pure NE, combined NE) and combined SCLC behaved similarly, except visceral pleura invasion, which proved more frequent in combined NE and less frequent in combined SCLC. Survival analysis showed a trend toward a lower 5-year survival in case of combined SCLC. Therefore, LCC, LCNEC and combined SCLC share the same poor prognosis, but surgical resection is associated with long-term survival in about one third of patients.