Patterns of care and outcome of patients with gastroenteropancreatic neuroendocrine tumors (GNETs): Results from a Spanish multi-center hospital-based tumor registry

Abstract

15110 Background: GNET represent an unusual family of neoplasms with a wide and complex spectrum of clinical behavior. To provide information regarding demographic characteristics, diagnostic procedures, tumor features, therapeutic interventions and outcomes of pts with GNETs, a national tumor registry was launched. We present here the results of this broad-based multi-institutional observational registry that comprises 41 sites representing all regions of Spain. Methods: Data was provided at www.retegep.net by participating centers and assessed for internal consistency by external independent reviewers. Results: The study cohort comprised 474 pts (57% male, median age: 59 years). 52% were carcinoids (C), 18% non-functioning pancreatic tumors (PT), 9% insulinomas and 6% gastrinomas. Most common primary tumor sites included midgut (19%), and head (14%) and body of the pancreas (9%). 10% were of unknown primary. Functioning symptoms led to diagnosis in 29% of cases. 5% were associated to MEN1. Diagnostic workup included serum hormone tests (60%), ultrasound (40%), CT scan (75%) and octreoscan (37%). 32% of pts presented with localized tumors (L), 14% with local-regional spread (LR) and 44% with advanced disease (Adv). Treatment for Adv disease consisted of somatostatin analogues (SA) (48%), surgery (45%), chemotherapy (CT) (42%), interferon (IFN) (23%), chemoembolization (9%) and radiofrequency ablation (5%). 5-year survival (5yS) for the whole group was 61.1% (SD:3.4%), 78.2% (SD:5.4%) for pts with L/LR disease and 47.1% (SD:5.6%) for Adv stages. 5yS rates were similar for C and PT tumors, also when stratifying according to tumor stage (84 and 76% for local-regional disease, and 51 and 49% for Adv disease). 1st line systemic therapy (n=175) consisted of CT (42%), SA (39%), IFN (5%), SA+IFN (10%) and SA+CT (3%), with 5yS rates of 59%, 36%, 42%, 46% and 38%, respectively (p=0.7). As second line systemic treatment (n=65) 45% received CT, 26% SA, 15% immunotherapy and 14% different drug combinations. Conclusions: This national database reveals relevant information regarding current Spanish practices and will provide valuable insights into the epidemiology and management of this heterogeneous uncommon disease No significant financial relationships to disclose.