Carboplatin-Etoposide Chemotherapy (CB-ET) for Patients Diagnosed with Advanced Extra-Pulmonary (EP) Poorly Differentiated (PD) Neuroendocrine Carcinoma (NEC): Findings from a European Neuroendocrine Tumor Society Centre of Excellence

Introduction: Carboplatin-Etoposide is a first-line option for patients (pts) with advanced EP-PD-NEC. Data from randomised trials are lacking Aim(s): The aim was to provide real-life activity/efficacy/safety data on CB-ET in this setting Materials and methods: Records of pts with advanced EP-PD-NEC (06/09- 04/17) treated with CB-ET were retrospectively reviewed Results: Seventythree pts were identified; median (med) follow-up 8.9 months (m); med age 70 yrs (range 36-88). Most pts were male (71%), ECOG performance status 0-1 (75%), no/mild comorbidities (73%). Primary tumor in: foregut 29%, hindgut 19%, genitourinary 20.5%, pancreas 7%, biliary tract 4% and unknown 20.5%. Most had stage IV disease (86%; 59% liver metastases). Median Ki-67 80% (95%CI 69-80%). A total of 83 courses of CB-ET were administered; 69 (83%) 1st-line (1L), 13 (16%) 2nd-line (2L) and 1 (1%) 3rd-line (3L); med 4 cycles/line; CB-ET dose-intensity med 96% (1L) and 90% (2L). ET was administered orally (65%), intravenously (34%) or not-specified (1%). In 1L/2L med progression free survival (PFS) was 5.8m (95%CI 4.8-7.1) and 5.2m (95%CI 2.3-11), respectively (p>0.05). Med overall survival for the whole population was 9.33m (95%CI 7.5-12.0). Response (RECIST v1.1; 71 evaluable pts) was achieved in 43%/30% in 1L/2L, respectively. Commonest grade 3-4 adverse events in 1L/2L were myelotoxicity (31%/46%) and venous thromboembolism (10%/15%) (p>0.05). Stage IV disease and liver metastases were significant in the univariate analysis for PFS; liver metastases was the only independent factor related to worse PFS on multivariable analysis (HR 2.2 (95%CI 1.3-3.7); p=0.002) Conclusion: CB-ET is associated with activity/efficacy in real-life comparable to that reported in the current literature and has a manageable safety profile.