Impact of HPV Vaccination on HPV Genotypes in Women with Atypical Cells of Undetermined Significance (ASC-US) in a Low-Risk Screening Population.
Roberto G Gamez, Stefan E Pambuccian, Bharat Thyagarajan, Shelly M Cook, Samy Amirouche, Evin H Gulbahce. University of Minnesota, Minneapolis
Background: HPV vaccination with the quadrivalent vaccine Gardasil® was approved by the FDA in June 2006 for use in females aged 9 to 26 and may also be useful in women aged 27-45. To date 44.3% of all U.S. females aged 13-17 have recieved at least one dose (MMWR 2010;59:1018-23). The aim of this study was to determine the potential impact of HPV vaccination on the HPV genotypes detected in women with ASC-US.
Design: All liquid-based (Surepath®) Pap tests diagnosed as ASC-US from 12/3/2002 to 6/30/2009 who had concomitant HPV genotyping were identified. Pap tests were diagnosed according to the 2001 Bethesda System; HPV tests were performed by a "home-brew" PCR-based method using the MY9/11 L1 consensus primers. The 13 HPV types included in the hc2 cocktail (16,18,31,33,35,39,45,51,52,56,58,59,68) were considered as high-rik HPV (HR-HPV). During the study period there were no major changes our screening population, laboratory personnel or molecular methods used. The study interval was divided into two periods: "pre-vaccination" (12/3/2002-6/30/2006) and "post-vaccination" (7/1/2006-6/30/2009). The frequecies of HPV 6, 11, 16 and 18 were compared between the two periods using χ2.
Results: During the study period our laboratory processed 391,845 Pap tests.
|Total Pap tests||% ASC-US||ASC-US Age (mean± SD)||ASC/SIL ratio|
|Pre-vaccination period||215,784||5.31%||35.14 ± 12.89||2.48|
|Post-vaccination period||176,061||4.96%||35.62 ± 13.16||1.88|
|Total||391,845||5.15%||P val .018||2.18|
|Number ASC-US||any HPV type||hr-HPV+||HPV6||HPV11||HPV16||HPV18|
|Pre-Vaccine||8636||3767 (35.3%)||1773(16.65)||202 (6.3%)||24 (0.7%)||634 (19.7%)||155 (4.8%)|
|Post-Vaccine||7958||3284 (42.0%)||1666 (20.9%)||171 (5.5%)||28(0.9%)||522(17.7%)||169 (5.4%)|