O1-S02.06 Detection of cervical cancer precursors and associated HPV types in the USA: HPV-IMPACT preliminary results. (10th July 2011) - Powell, S E
Abstract : Background: Cervical intraepithelial neoplasia (CIN) grade 2 or 3 and adenocarcinoma in situ (AIS) (CIN2+) can be used to monitor HPV vaccine impact. This spectrum of preinvasive cervical lesions are commonly associated with multiple HPV types and detected through screening. This abstract describes baseline CIN2+ data and associated HPV types among defined populations of US females. Methods: As part of a vaccine impact monitoring project (HPV-IMPACT), CIN2+ cases in females 18–39 years were reported from pathology laboratories in five catchment areas (CA, CT, NY, OR, TN). One diagnostic block was selected and unstained serial sections were prepared for PCR. Extracts from samples with residual lesion on both H&Es were used in Roche Linear array to detect and type HPV. CIN2/3 diagnosis rates were determined in catchment areas (CA, CT and NY) with complete case reporting. HPV typing data were analysed from all five defined catchment areas. Results: In 2008, rates per 1000 population in 18–39-year-old females were 2.8 in CA, 5.3 in CT and 4.9 in NY. In all five sites, CIN2 was most common (49%), followed by CIN3 (31%) and AIS (2%). The proportion of lesions not distinguished by grade (CIN2/3) varied across sites (from 12 to 27%). Median diagnosis age was 31 years in CA, 29 in CT, 27 in NY, 29 in OR, 28 in TN. Among 5035 18–39-year-old females, 1413 (28%) specimens were tested; 96% were HPV DNA positive. HPV16 was most prevalent (47%), followed by HPV31 (11%), HPV52 (9%) and HPV51 (8%). HPV18 prevalence was 5.4%. HPV16 prevalence varied by diagnosis: 38% in CIN2, 51% in CIN2/3, and 59% in CIN3. Conclusions: CIN2+ rates varied by catchment area, possibly reflecting differences in screening or case ascertainment. HPV16 or 18 were present in ∼52% of lesions. Type-specific monitoring of CIN2+ can allow evaluation of vaccine impact on cervical disease, and may be useful in determining whether type replacement occurs.