A multivariable model using advanced cytologic methods for the evaluation of indeterminate pancreatobiliary...

Area of Science:

• Gastroenterology and Hepatology
• Cytopathology
• Oncology

Background:

• Pancreatobiliary strictures often present diagnostic challenges.
• Ancillary tests like digital image analysis (DIA) and fluorescence in situ hybridization (FISH) aim to enhance routine cytology (RC) sensitivity.
• This study retrospectively compares RC, DIA, and FISH performance.

Purpose of the Study:

• To compare the diagnostic performance of routine cytology (RC), digital image analysis (DIA), and fluorescence in situ hybridization (FISH) for malignancy in pancreatobiliary strictures.
• To evaluate the utility of these methods on clinical brushing specimens.

Main Methods:

• Retrospective analysis of endoscopic retrograde cholangiopancreatography brushings from 498 patients with pancreatobiliary strictures.
• Specimens analyzed by RC, DIA, and FISH (UroVysion assay).
• Diagnostic categories: RC (negative, atypical, suspicious, positive), DIA (aneuploid/tetraploid histograms as positive), FISH (negative, trisomy, tetrasomy, polysomy).

Main Results:

• Polysomy FISH demonstrated significantly higher sensitivity (42.9%) than RC (20.1%) with comparable specificity (99.6%).
• Significant differences in time to carcinoma diagnosis were observed between FISH and RC categories.
• Logistic regression identified polysomy FISH, trisomy FISH, suspicious cytology, primary sclerosing cholangitis, and age as predictors of carcinoma.

Conclusions:

• Polysomy FISH offers high sensitivity for diagnosing malignancy in pancreatobiliary strictures without compromising specificity.
• DIA was not found to be an independent predictor of malignancy.
• Multivariable modeling incorporating RC, FISH, age, and PSC status can estimate individual carcinoma probability.
• FISH is recommended as a routine ancillary test alongside RC for indeterminate pancreatobiliary strictures.