[1839] Comparative Analysis of Different Counting Methodologies for Ki-67 in Pancreatic Neuroendocrine Tumors

Pelin Bagci, Nobuyuki Ohike, Nevra Dursun, Kee-Taek Jang, Takuma Tajiri, Olca Basturk, So Yeon Kong, Leslie Ducato, Michelle Reid, Volkan Adsay. Emory University, Atlanta; Showa University, Tokyo, Japan; MSKCC, New York

Background: Ki-67 labeling index is now one of the 2 parameters in the classification of pancreatic NETs in the WHO-2010 classification. However, in adapting this into daily practice, it becomes clear that there are serious challenges in the counting methodologies.
Design: Ki-67 immunohistochemical staining was performed on full sections from 21 NETs, and percentage of the tumor cells stained was counted by 4 different methods by 3 observers: 1) “Eye-balling”, 2) "Eye-counting" through the microscope, 3) Automated counting, 4)Manual counting on camera-captured/printed image of the hot spot.

Results: Considering the balance of accuracy, practicality, and reproducibility, the method that was found to be by far the most preferable (Table) was the manual counting on camera-captured/printed image.

 Impact on turnaround timeAverage time it takes (minutes)PracticalityAccuracyMiscounting of non-target cellsInterobserver agreement (Pearson's correlation)Additional Cost
Eye-ballingNone1HighestVery lowUnlikelyR=23%None
Eye-counting through microscopeNone6LowHighUnlikelyR=32%None
Manual counting on camera captured/printed image of the hot spotMinimal (depending on accessibility of a camera/printer setup)13Very highHighestUnlikelyR=43%Printer + camera $5,400
AutomatedHighest (depends on the technician availability)5Low (accessibility issues)ModerateVery likelyN/AImage analyzer $150,000

Conclusions: Among the 4 methods of counting Ki-67 in pancreatic NETs, the method that was found to be the most accurate, practical and reproducible is the one in which counting is performed on camera-captured/printed image of the hot spot.
Category: Pancreas

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 250, Wednesday Morning


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