Diagnostic Value of DNA Mutational Analysis of Residual Liquid Gynecologic Cytology in Detecting Malignancy
Shweta Patel, Allan R Smith, Alok Mohanty, Uma Krishnamurti, Candy Binkert, Beth Ujevich, Shahid J Bokhari, Jan F Silverman, Sidney D Finklestein, Yulin Liu. Allegheny General Hospital, Pittsburgh, PA; RedPath Integrated Pathology, Inc., Pittsburgh, PA
Background: Liquid based, monolayer cytology analysis has become the most common approach to manage cervical scrapings and is increasingly applied to other organ specimens. Ancillary molecular mutation testing for cancer-associated changes can be especially useful in these situations. In this study, we investigated the diagnostic utility of DNA mutation analysis from free DNA in the residual gynecological sample fluid that is otherwise not currently utilized.
Design: Cervical scrape specimens were used in this assessment of mutational analysis. Unused residual liquid cytology fluid containing the cellular scraping was centrifuged to create two molecular substrates: 1) cell pellet and 2) cell-free supernatant. DNA was extracted from the cell pellet and 2 ml of the cytocentrifugation supernatant fluid after which mutational analysis was performed by means of PCR/capillary electrophoresis for a broad panel of markers (microsatellite fragment analysis for loss of heterogeneity [LOH] of 16 markers at 19, 3p, 5q, 9p, 10q, 17p, 17q, 21q, 22q). The level and amplifiability of extracted DNA and individual sample mutational profiles were established and compared.
Results: Despite the absence of cells, the cell free component of residual liquid cytology fluid contained abundant (6.7-46.3 ng/ul), amplifiable (Ct less than 30 cycles) DNA suitable for mutation detection and characterization. The benign specimens showed no LOH mutations for the marker panel in either the cellular pellet or the cell free supernatant fluid. The cancer specimen showed extensive loss of heterozygosity mutational change that was highly concordant between the cell pellet sample and the free DNA portion of the specimen. The degree of allelic imbalance was higher in the free DNA sample than the cell pellet indicating greater presence of neoplastic DNA in that compartment compared to the cell pellet.
Conclusions: Our results indicated that DNA molecular mutation analysis on gynecologic fluid can be integrated to a more fully complement liquid based, monolayer cytology practice by utilizing a part of the specimen that is not currently utilized.
Category: Special Category - Pan-genomic/Pan-proteomic approaches to Cancer
Tuesday, March 20, 2012 9:30 AM
Poster Session III # 284, Tuesday Morning