title: Incidental diagnosis as prognostic factor in different tumor stages of nonfunctioning pancreatic endocrine tumors.
abstract: BACKGROUND
  Incidentally discovered nonfunctioning pancreatic endocrine tumors (NF-pNETs) increasingly are being detected, and their management is debated. Moreover, the prognostic importance of incidental diagnosis for locally advanced or metastatic NF-pNETs is unknown. The aim of this study is to analyze the outcomes of incidentally discovered/symptomatic NF-pNETs stratified by tumor stage. A preliminary experience with nonoperative treatment of incidental NF-pNETs is reported.
  
  
  METHODS
  Consecutive patients with symptomatic/incidental NF-PETs observed between 1990 and 2009 were analyzed, with different tumor stages considered. Nonoperative management of incidental NF-pNETs was evaluated.
  
  
  RESULTS
  Among 355 patients with NF-pNETs, the diagnosis was incidental in 124 (35%). Incidental NF-pNETs were associated more commonly with lower tumor stages compared with symptomatic tumors (P < .0001), but 30% of incidental NF-pNETs were stage III-IV. Incidental NF-pNETs had greater rates of radical resections and of R0 margins (P < .0001). Five-year progression-free survival (PFS) was 83% and 32% for incidental and symptomatic NF-pNETs, respectively (P < .0001). Five-year PFS was better for incidental NF-pNETs compared with symptomatic tumors for each tumor stage, including stage III (69% vs 27%, P < .0001) and stage IV (60% vs 17%, P = .112). After a median follow-up of 36 months, there was no tumor progression in 12 patients who underwent nonoperative management of incidental NF-pNETs.
  
  
  CONCLUSIONS
  A total of 30% of incidental NF-pNETs present with stage III-IV disease. PFS is much greater for incidental NF-pNETs compared with symptomatic patients, and this difference is evident also for stage III-IV tumors, suggesting that absence of symptoms may indicate a less-aggressive disease. Nonoperative management can be an alternative to surgery in selected incidental NF-pNETs.
authors.affiliation: Department of Surgery, Policlinico GB Rossi, University of Verona, Verona, Italy; Department of Surgery, Ospedale Sacro Cuore-Don Calabria, Negrar (VR), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Crippa
authors.affiliation: Department of Surgery, Policlinico GB Rossi, University of Verona, Verona, Italy; Department of Surgery, Ospedale Sacro Cuore-Don Calabria, Negrar (VR), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Partelli
authors.affiliation: Department of Pathology, Policlinico GB Rossi, University of Verona, Verona, Italy; Department of Pathology, Ospedale Sacro Cuore-Don Calabria, Negrar (VR), Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Zamboni
authors.affiliation: Department of Pathology, Policlinico GB Rossi, University of Verona, Verona, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Scarpa
authors.affiliation: Department of Surgery, Policlinico GB Rossi, University of Verona, Verona, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Tamburrino
authors.affiliation: Department of Surgery, Policlinico GB Rossi, University of Verona, Verona, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bassi
authors.affiliation: Department of Surgery, Policlinico GB Rossi, University of Verona, Verona, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Pederzoli
authors.affiliation: Department of Surgery, Policlinico GB Rossi, University of Verona, Verona, Italy. Electronic address: m.falconi@univpm.it.
authors.forename: Massimo
authors.initials: M
authors.lastname: Falconi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D033162:Incidental Findings; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D010179:Pancreas / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D011379:Prognosis; D016019:Survival Analysis