title: Surgical and oncological impact of main pancreatic duct spread in invasive ductal adenocarcinoma: A clinicopathological study of 184 resected cases.
abstract: OBJECTIVE
  This study examined main pancreatic ductal spread in invasive ductal adenocarcinoma (IDC) of the pancreas.
  
  
  METHODS
  Data from IDC patients who underwent radical surgery from 1990 to 2013 in our hospital were examined retrospectively. Incidence of intraductal spread of pancreatic cancer (IS), distance from the tumor edge, direction of IS and clinicopathological factors associated with the presence of IS were retrospectively examined with data from IDC patients who underwent radical surgery.
  
  
  RESULTS
  Among 260 IDC patients who underwent surgery, 184 eligible cases, IS was identified in 42 patients (22.8%) and mean length of IS was 18.7 ± 21.6 mm. Mean distances on the ampullary and distal sides of IS were 11.1 mm and 11.6 mm. IS was significantly more frequent in localized tumors (UICC T1-2 vs. 3-4, p = 0.007), with tumor diameter ≤2 cm (p = 0.034) and in cases with scarce microscopic perineural invasion (p = 0.047). Among patients who underwent pancreaticoduodenectomy and distal pancreatectomy, IS presence (11.6 vs. 21.8%), mean distance to the contralateral side (11.4 vs. 11.6 mm), and IS ≥ 2 cm (3.3 vs. 4.7%) showed no significant differences. Overall survival did not differ significantly between IS-positive and -negative patients in the full analysis set or propensity score-matched patients (42 matched pairs).
  
  
  CONCLUSIONS
  In setting resectional margins at 2 cm, a small proportion of cases (3.8%) showed positive surgical margins. Localized tumor (UICC: T1-2, or <2 cm in diameter) requires more care with surgical margins, warranting intraoperative frozen sections.
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ishii
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan. Electronic address: kimuray@sapmed.ac.jp.
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Kimura
authors.affiliation: Department of Surgical Pathology, Sapporo Medical University Hospital, Sapporo, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Sugita
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Imamura
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ito
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nobuoka
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Meguro
authors.affiliation: Department of Surgical Pathology, Sapporo Medical University Hospital, Sapporo, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hasegawa
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Mizuguchi
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Hirata
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies
keywords: Intraductal carcinoma; Intraductal spread; Pancreatic cancer; Pancreatic ductal carcinoma; R0; Surgical margin