title: Significance of lymph node metastasis in pancreatic neuroendocrine tumor.
abstract: OBJECTIVE
  Pancreatic neuroendocrine tumor (PNET) is relatively rare and has a generally better prognosis than does pancreatic cancer. However, as its prognosis in patients with lymph node metastasis (LNM) is unclear, lymph node dissection for PNET is controversial. Our study aimed to clarify the significance of LNM in PNET.
  
  
  METHODS
  We retrospectively examined 83 PNET patients who underwent pancreatic resections with lymph node dissection at Kumamoto University Hospital, Saiseikai Kumamoto Hospital, and Kumamoto Regional Medical Center from April 2001 to December 2014. Their clinicopathological parameters were analyzed by the absence or presence of LNM, and with regard to the disease-free survival (DFS) and overall survival (OS). A predictive score of LNM was also made using the age, tumor size, primary tumor location, and tumor function.
  
  
  RESULTS
  Although the 5-year OS was 74.8% for LNM+and 94.6% for LNM-(P = 0.002), LNM was not an independent risk factor for the OS in a multivariate analysis. However, tumors larger than 1.8 cm were found to be an independent prognostic factor, and the cut-off value for the predictive score was 1.69.
  
  
  CONCLUSIONS
  Although LNM was not an independent prognostic factor, lymph node dissection is recommended for patients whose predictive score is larger than 1.69.
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Katsunobu
authors.initials: K
authors.lastname: Taki
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hashimoto
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Nakagawa
authors.affiliation: Department of Surgery, Saiseikai Kumamoto Hospital, 5-3-1 Chikami, Minami-ku, Kumamoto, 861-4193, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ozaki
authors.affiliation: Department of Surgery, Kumamoto Regional Medical Center, 5-16-10 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan.
authors.forename: Shinjiro
authors.initials: S
authors.lastname: Tomiyasu
authors.affiliation: Institute of Resources Development and Analysis, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Ohmuraya
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Kota
authors.initials: K
authors.lastname: Arima
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Kaida
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Higashi
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Sakamoto
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Sakata
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Okabe
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Nitta
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Hayashi
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Chikamoto
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Beppu
authors.affiliation: Department of Surgery, Saiseikai Kumamoto Hospital, 5-3-1 Chikami, Minami-ku, Kumamoto, 861-4193, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takamori
authors.affiliation: Department of Surgery, Kumamoto Regional Medical Center, 5-16-10 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Hirota
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan. hdobaba@kumamoto-u.ac.jp.
authors.forename: Hideo
authors.initials: H
authors.lastname: Baba
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000473:pathology* / Q000601:surgery*; D010180:Pancreatectomy / Q000379:methods; D010190:Pancreatic Neoplasms / Q000473:pathology* / Q000601:surgery*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
keywords: Lymph node metastasis; Neuroendocrine tumor; Pancreas; Pancreatic neuroendocrine tumor; Prognosis