title: Impact of Vitamin D on the Clinical Outcome of Gastro-Entero-Pancreatic Neuroendocrine Neoplasms: Report on a Series from a Single Institute.
abstract: OBJECTIVE
  Vitamin D deficiency is hypothesized to represent a risk factor in several neoplasms. The aim of this study was to determine whether serum 25-hydroxyvitamin D (25-OHvitD) deficiency represents a risk factor for neuroendocrine neoplasms (NENs) and can be associated with overall survival (OS) and progression-free survival (PFS).
  
  
  METHODS
  From 2010 to 2015, 138 patients with gastro- entero-pancreatic NENs (61 females; median age, 63 years) were included in the study. Serum 25-OHvitD levels, which were measured at baseline, were defined as deficient if ≤20 ng/mL. In such cases, 25-OHvitD supplementation was administered to the patients. The possible associations between 25-OHvitD levels and disease grading, staging, overall OS, and PFS were considered. Furthermore, the possible association between 25-OHvitD supplementation and PFS or OS was evaluated by Cox proportional hazards regression.
  
  
  RESULTS
  Median 25-OHvitD levels were 12.9 ng/mL (range 2-32); in detail, 94 patients (68%) had ≤20 ng/mL, with 46 cases (33%) having ≤10 ng/mL. An inverse correlation was observed between 25-OHvitD levels and OS (p = 0.03, rs = -0.18) and PFS (p = 0.01, rs = -0.22). At Cox proportional hazards regression, mortality was not related to 25-OHvitD levels; however, there was an association between 25-OHvitD supplementation and OS (p < 0.002).
  
  
  CONCLUSIONS
  Vitamin D deficiency is highly prevalent among NEN patients. 25-OHvitD supplementation potentially plays an important role in the correction of 25-OHvitD values, and has an influence on the clinical outcome. However, further studies are needed to confirm this observation.
authors.affiliation: Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Massironi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Zilli
authors.forename: Susanna
authors.initials: S
authors.lastname: Bernasconi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Fanetti
authors.forename: Federica
authors.initials: F
authors.lastname: Cavalcoli
authors.forename: Clorinda
authors.initials: C
authors.lastname: Ciafardini
authors.forename: Irene
authors.initials: I
authors.lastname: Felicetta
authors.forename: Dario
authors.initials: D
authors.lastname: Conte
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000150:complications / Q000453:epidemiology*; D010190:Pancreatic Neoplasms / Q000150:complications / Q000201:enzymology*; D015995:Prevalence; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D014808:Vitamin D Deficiency / Q000453:epidemiology*; D055815:Young Adult
keywords: Gastro-entero-pancreatic neuroendocrine tumors; Neuroendocrine neoplasms; Vitamin D deficiency