title: Surgical implication of micrometastasis for pancreatic cancer.
abstract: OBJECTIVE
  The clinical significance of micrometastasis to regional lymph nodes for pancreas cancer is controversial in patients who underwent curative resection.
  
  
  METHODS
  Nine of 42 patients who underwent macroscopically curative resection of pancreatic head cancer were found to have pN(-) by routine examination. Complete serial section examination of the resected specimens was done to detect micrometastasis in these 9 patients.
  
  
  RESULTS
  A total of 16,505 sections were examined by immunohistochemistry or hematoxylin and eosin staining. Micrometastases were identified in 7 (78%) of 9 patients and 17 (3.6%) of 474 lymph nodes. All micrometastases were found in the pancreas head area. However, the frequency of micrometastases around the superior mesenteric artery was 44%. There were no micrometastases to the para-aortic nodes. There was a tendency that the patients with micrometastases showed better survival than those with overt nodal involvement (P = 0.053). Micrometastasis did not provide the poor prognostic factor in patients who underwent optimal regional lymphadenectomy.
  
  
  CONCLUSIONS
  Even in overtly pN(-) pancreatic cancer, micrometastases occur high frequently (78%) and widely, including the nodes around the superior mesenteric artery. These results provide important pathological information when we consider the preoperative, perioperative, and postoperative strategies, even when patients seem to have no nodal involvement by preoperative examinations.
authors.affiliation: Division of Cancer Medicine, Department of Gastroenterological Surgery, Graduate School of Medicine, Kanazawa University, Kanazawa, Japan. masatok@staff.kanazawa-u.ac.jp
authors.forename: Masato
authors.initials: M
authors.lastname: Kayahara
authors.forename: Kennichiro
authors.initials: K
authors.lastname: Funaki
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Tajima
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takamura
authors.forename: Itasu
authors.initials: I
authors.lastname: Ninomiya
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Kitagawa
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ohta
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010190:Pancreatic Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D011379:Prognosis; D016019:Survival Analysis; D015996:Survival Rate