Abstract 550: Increased risk of persistent human papillomavirus infection and abnormal Pap tests in African American compared to European American women in a college-age cohort

Abstract

Abstract Human papillomavirus (HPV) is the causative agent of genital warts, cervical dysplasia and cervical cancer and is also associated with oropharyngeal and ano-rectal cancers. While HPV is necessary for these malignancies to develop, infection with HPV is not predictive of which women will develop cervical dysplasia or cancer. Most high-risk HPV (HR-HPV) infections resolve within 12-24 months. Persistence of HR-HPV infection is a risk factor for the development of pre-cancerous cervical lesions and cervical cancer. A disparity exists in the incidence and mortality rates for cervical cancer, with African American (AA) women being more likely to develop cervical cancer and about twice as likely to die of the disease, as compared to European American (EA) women. The Carolina Women's Care Study (CWCS) was initiated in 2004 to assess HPV infection and persistence in a college-age cohort from the University of South Carolina. In this longitudinal study, 467 study participants (70% EA and 24% AA) underwent biannual pelvic exams during the duration of their college experience. Exfoliated cervical cells were collected at each visit and screened for HPV using PCR and the Inno-LiPA assay was subsequently used to determine HPV types. The AA and EA participants in the CWCS were similar upon comparison of several demographic characteristics, including those often associated with increased risk of cervical lesions, such as age at sexual debut and average number of sexual partners. While the incidence of new HR-HPV infections in AA and EA participants was similar, at any visit AA participants were about 1.5-fold more likely to test HR-HPV positive than EA participants (p <0.0001). In HPV positive individuals, the average number of HPV types (2.28) was similar between AA and EA participants. The most prevalent HR-HPV types detected in the CWCS at enrollment were HPV16 (13.2% of all HPV infections), 51 (9.2%), and 66 (11.3%). Strikingly, when exploring rates of HPV clearance, AA women clear the virus much slower than EA women. At 24 months after incident HR-HPV infection, 56% of AA participants remain infected with HR-HPV, while only 24% of EA participants were still infected (p <0.01). Furthermore, AA participants were about 1.7-fold more likely to have an abnormal (LSIL plus HSIL) Pap test than EA participants (p<0.005). Overall, these results suggest that AA women have more difficulty than EA women clearing a HR-HPV infection, which may provide a biological basis for the increased risk of cervical cancer observed in AA women. This work was supported by grant P20MD001770 from the National Institute on Minority Health and Health Disparities. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 550. doi:1538-7445.AM2012-550