Implementation of BD FocalPoint GS in Clinical Practice: Impact on Human Papillomavirus (HPV) Rates and Biopsy Diagnoses
Tetyana N Mettler, Arbaz Samad, Samy Amirouche, Gol Rahimaghaei, Jana Holler, Stefan E Pambuccian. University of Minnesota Medical Center, Fairview, Minneapolis, MN
Background: The the location-guided imaging system, FocalPoint GS (FPGS) has been recently implemented in clinical use on SurePath Pap tests in a number of institutions, including ours. However, in contrast to the Thinprep Imaging System (TIS), the impact of which has been studied extensively, the clinical performance of FPGS has been, to our knowledge only been the subject of a single study, which found an increase in ASC-US rates after its implementation. The aim of this study was to evaluate the impact of FPGS on the frequency of HPV and follow-up biops rates in ASC-US and negative Pap tests in women over 30 (NILM>30) before and after implementation of FPGS.
Design: We identified all cases diagnosed from 1/1/2007 to 3/30/2011 as ASC-US or NILM>30 that had reflex HPV testing performed by a PCR-based method using MY09/11 consensus primers and typing by RFLP. All cases were diagnosed by 2001 Bethesda System criteria on Surepath Pap tests. FPGS was implemented in our laboratory on 10/1/2010; all cases tested after this date constuituted the POST-FPGS chort, while the cases diagnosed before this date consituted the PRE-FPGS cohort.
The prevalence of any HPV type, high-risk HPV types (HR-HPV) and HPV16/18 and the frequency of abnormal follow-up biopsies diagnosed as CIN1 and above (CIN1+) and CIN2 and above (CIN2+) in the tow cohorts was compared statistically.
Results: During the study period, the ASC-US rate increased from 5.5% (12,464/227972) to 7.4%(4,234/57254. 13999 women with ASC-US and 15403 women with NILM>30 had HPV tests performed in our institution.
|AGE (mean±SD)||Any HPV (n,%)||HR-HPV (n,%)||HPV 16/18 (n,%)||BX rate||CIN1+ (% of BX)||CIN2+ (% of BX)|
|PRE-FPGS ASC-US (n=11551)||36.49±13.26||4690 (40.6%)||2054 (17.8%)||1006 (8.7%)||1764 (15.3%)||790 (44.8%)||278 (15.8%)|
|POST-FPGS ASC-US (n=2448)||38.77±12.91||918 (37.5%)||395 (16.1%)||177 (7.2%)||389 (15.9%)||181 (46.5%)||48 (12.3%)|
|PRE vs. POST p value||<0.0001||0.005||NS (0.053)||0.016||NS||NS||NS (0.1)|
|PRE-FPGS NILM>30 (n=12981)||45.3±10.7||924 (7.1%)||271 (2.1%)||134 (1%)||122 (0.9%)||14 (11.5%)||5 (4.1%)|
|POST-FPGS NILM>30 (n=2422)||45.5±10.5||181 (7.5%)||50 (2.1%)||24 (1%)||17 (0.7%)||5 (29.4%)||0 (0%)|
|PRE vs. POST p value||NS||NS||NS||NS||NS||NS (0.059)||NS|