Second-Line Treatment and Prognostic Factors in Neuroendocrine Carcinoma.

International audienceNeuroendocrine carcinomas (NEC) are aggressive malignant diseases. Etoposide-based rechallenge (EBR) and the prognostic role of Rb status in second-line chemotherapy (2L) have not been studied. The objectives of this study were to report the results of 2L including EBR as well as prognostic factors in a national retrospective multicenter study. NEC patients treated in 2L and further, with tissue samples available were included. Rb status and morphological classification were reviewed centrally. Among the 121 NEC patients (40% female, median age 61) included, there were 73 small cell NEC (60%), 34 large cell NEC (28%) and 14 NEC (not otherwise specified, 12%). Primary sites were lung (39%), gastro-enteropancreatic (36%), other (13%) and unknown (12%). Median Ki-67 index was 80%. Median progression-free survival (PFS) and overall survival (OS) under 2L were 2.1 and 6.2 months, respectively. No difference was observed between patients who received an "Adenocarcinoma-like" or a "Neuroendocrine-like" 2L or according to the Rb status. Thoracic primary was the only adverse prognostic factor for OS. EBR, administered to 31 patients, resulted in a 62% disease control rate with a median PFS and OS of 3.2 and 11.7 months respectively. In the 94 patients with a relapse-free interval ≥q 3 months after first-line platinum-etoposide, median OS was 12 months in patients who received EBR as compared to 5.9 months in patients who did not (p=0.043). EBR could be the best 2L option for patient with initial response to first line platinum-etoposide lasting at least 3 months. Rb status does not provide prognostic information in this setting