[355] Significant Cervical Squamous Lesions (CIN2/3) in the Follow-Up of Women with Liquid-Based (Surepath) Pap Tests Interpreted as Atypical Cells of Undetermined Significance: Impact of Changes in Diagnostic Criteria and HPV Vaccination.

Shelly M Cook, Roberto G Gamez, Linjun Xie, Jana Holler, Stefan E Pambuccian, Evin H Gulbahce. University of Minnesota, Minneapolis

Background: The main purpose of identifying atypical squamous cells of undetermined significance (ASCUS) in Pap tests is to identify and treat potential underlying significant cervical carcinoma precursor lesions (CIN2/3).
The aim of this study was to determine the impact of the Bethesda 2001 redefinition of ASCUS and the advent of HPV vaccination on the HPV genotypes and follow-up biopsy diagnoses of CIN2/3 of women diagnosed as ASCUS in our low-risk, relatively older, predominantly suburban screening population.
Design: Cases diagnosed as ASCUS that had a reflex HPV DNA test performed by PCR from 01/01/2001 to 6/30/2001 were identified and histologic diagnoses on biopsies performed within 6 months of the Pap diagnosis were collected. The study period was divided into 3 periods, P1=1/1/2001-12/03/2002, the date of the introduction of B2001 in our institution, P2=12/04/2003-6/30/2006, the date of FDA approval of the HPV vaccine Gardasil(r) and P3=07/01/2006-6/30/2009.
Results: There were a total of 18523 patients identified with an ASC-US diagnosis during the study period. The mean age for the 3 groups was 36.51±12.91, 35.14 1±12.89 and 35.52 ±13.76.

 ASC-USany HPV type (% of all ASC-US)hr-HPV+ (% of all ASC-US)HPV16/18 (% of hr-HPV)Biopsy Rate (% of all ASC-US)CIN1 (% of all Bx)CIN2/3+ (% of all ASC-US)
P12028552 (27.2%)277 (13.6%)207 (74.7%)529 (26.0%)132 (24.9%)68 (3.4%)
P286363215 (37.2%)1496 (17.3%)789 (52.7%)2083 (24.1%)628 (30.1%)248 (2.9%)
P378593284 (41.7%)1666 (21.2%)721 (.43.2%)1235 (15.7%)359 (29.0%)208 (2.6%)
p value* 1,2,3 = <.0011,2,3 = <.0011,2,3 = <.0011=.04, 2,3=<.0011=.018, 2=.2, 3=.51=.2, 2=.09, 3=.4
* 1 =P1 vs P2; 2 = P1 vs. P3; 3 = P2 vs. P3

During the study period there was a drop of the overall ASC-US rate and ASC/SIL ratio due to our laboratory's efforts to reduce these rates. While the overall HPV16/18 rates changed little from period to period, the %HPV16/18 of all hr-HPV types declined significantly.
Conclusions: Our results show that despite a significant increase in overall and hr-HPV rates observed between the periods, the follow-up CIN2/3 rates showed a modest decline instead of the expected increase. This was most likely due to the decrease of HPV16/18 fraction of hr-HPV brought about by the exclusion of ASC-H from ASCUS from P1 to P2 and the effect of vaccination from P2 to P3.
Category: Cytopathology

Monday, February 28, 2011 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 59, Monday Morning

 

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