title: Ki-67 immunostaining in pancreatic cancer and chronic active pancreatitis: does in vivo FDG uptake correlate with proliferative activity?
abstract: PET with 18F-FDG has been shown to be useful in the detection and staging of pancreatic cancer. However, whether FDG uptake is dependent on proliferative activity is still unclear. The aim of this prospective study was to evaluate a probable correlation between FDG uptake and proliferative activity in benign and malignant pancreatic tumors.
  
  
  METHODS
  Our series consisted of 23 patients with pancreatic cancer and 9 patients with chronic active pancreatitis (CAP). FDG PET was performed within 2 wk before surgery, and standardized uptake values (SUVs) were calculated for benign and malignant pancreatic tumors. Patients were selected when focally increased FDG uptake in previously known pancreatic tumors was present. Proliferation fraction was measured in tissue specimens using the anti-Ki-67 antibody MIB-1. A computer-assisted imaging system was used for quantification of nuclear Ki-67 immunostaining. Immunohistochemical findings were correlated to SUVS:
  
  
  RESULTS
  Pancreatic cancer showed both intense nuclear staining of Ki-67 (39% +/- 16%) and high FDG uptake (SUV = 3.6 +/- 1.6). However, no significant correlation was found between in vivo FDG uptake and Ki-67 immunoreactivity (P = 0.65). By contrast, Ki-67 nuclear staining was significantly lower (3.8% +/- 2.7%, P < 0.05) in CAP, whereas FDG uptake was in the same range as for pancreatic cancer (SUV = 3.5 +/- 1.8).
  
  
  CONCLUSIONS
  FDG uptake did not correlate with proliferative activity in pancreatic cancer. Proliferative activity was tenfold higher in malignant pancreatic tumors than in benign tumors associated with CAP, whereas FDG uptake in vivo did not differ significantly. Thus, a PET tracer indicating cellular proliferation should better differentiate between cancer and inflammatory lesions than do metabolic markers such as FDG.
authors.affiliation: Department of Nuclear Medicine, University of Ulm, Ulm, Germany.
authors.forename: A C
authors.initials: AC
authors.lastname: Buck
authors.forename: H H
authors.initials: HH
authors.lastname: Schirrmeister
authors.forename: C A
authors.initials: CA
authors.lastname: Guhlmann
authors.forename: C G
authors.initials: CG
authors.lastname: Diederichs
authors.forename: C
authors.initials: C
authors.lastname: Shen
authors.forename: I
authors.initials: I
authors.lastname: Buchmann
authors.forename: J
authors.initials: J
authors.lastname: Kotzerke
authors.forename: D
authors.initials: D
authors.lastname: Birk
authors.forename: T
authors.initials: T
authors.lastname: Mattfeldt
authors.forename: S N
authors.initials: SN
authors.lastname: Reske
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000473:pathology; D002455:Cell Division; D002467:Cell Nucleus / Q000737:chemistry; D002908:Chronic Disease; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000473:pathology; D010195:Pancreatitis / Q000000981:diagnostic imaging; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed
chemical_list: D019394:Ki-67 Antigen; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18