Authors
A. CUYPERS (1), T. VANDAMME (1), L. DE BACKER (2), S. STROOBANTS (2), M. SIMOENS (3), I. DERO (4), A. DRIESSEN (2), B. OP DE BEECK (2), W. DEMEY (5), W. LYBAERT (6), M. PEETERS (2), I. ON BEHALF OF THE STEERING COMMITTEE AND ALL NET-SPECIALISTS (1) / [1] Universiteit Antwerpen / Antwerp University Hospital, WILRIJK (Antwerpen), Belgium, NETwerk, [2] UZA, Universitair Ziekenhuis Antwerpen, Edegem, Belgium, NETwerk, [3] ZNA Jan Palfijn, Merksem, Belgium, NETwerk, [4] Sint Augustinus Ziekenhuis GZA, Antwerp, Belgium, NETwerk, [5] KLINA, Brasschaat, Belgium, NETwerk, [6] AZ Nikolaas, Sint-Niklaas, Belgium, NETwerk
Introduction
Overall survival (OS) and progression-free survival (PFS) data of grade 3 NENs remains limited.
Aim
The aim is to report prospective survival data in grade 3 NENs treated within NETwerk.
Methods
Patient characteristics of all grade 3 NENs treated from April 2016 to May 2018 were prospectively recorded. Median OS (mOS) from diagnosis and mOS and median PFS (mPFS) after start cisplatinum/carboplatinum-etoposide chemotherapy was calculated.
Results
Of 79 included NEN grade 3 patients, there were 46 males (58,2%). Mean age at diagnosis was 68 years [range 22-90y]. In 67% (N=53) of the cases, the primary tumor was a GEP-NEN (of which 18 unknown). In our population 44% (N=35) had metastases at diagnoses, 44% (N=35) had a Ki67 index ≥ 55%, 30% (N=24) had a Ki67 index < 55%. Platinum-etoposide chemotherapy was given in 29% (N=23) of the patients. The majority (N=41) had FDG-PET imaging of which 36 were positive and 14 had somatostatin receptor imaging (SRS) of which 11 were positive. Combined FDG-SRS positivity was seen in 5 of 11 patients (45%). Overall mOS was 10.5m (95%CI: 6.6-NR). In GEP-NEN mOS was 8.3m (95% CI: 6.0-18.7), while in NENs from other origin mOS was 12m (95% CI: 6.8-NR, p = 0.2). The mOS for patients with a Ki67 index < 55% was 14.2m (95% CI: 8.9-NA) vs 8.2m (95% CI: 5.6-NA) for patients with Ki67 index ≥ 55% (p=0.3). In multivariate analysis, age at diagnosis had significant impact on OS (HR 0.95, p=0.003), while tumor origin showed trend towards significance (HR 0.49, p= 0.056). The mPFS and mOS after chemotherapy were 6.5m (95%: 4.8 -NR) and 14.2m (95% CI: 8.3-NR). For the chemotherapy-treated group no significant effect of tumor location, metastasis at diagnosis and age at diagnosis was seen on OS and PFS.
Conclusions
In this grade 3 NEN cohort, non-GEP-NENs have a better OS survival than GEP-NENs. Our results confirm the limited PFS and OS after platinum-etoposide chemotherapy in grade 3 NENs, highlighting the need for better treatment. When performed, FDG-PET and SRS-positivity is frequent and could guide treatment.
