High Risk HPV in Normal Pap Smears: A Long Term Correlation between HPV Viral Load, Age, and Disease Progression
G Levy, A Finkelstein, A Levi, D Kowalski, D Chhieng, M Harigopal. Yale University, New Haven, CT
Background: Human Papilloma virus infection (HPV) is a well established risk factor for cervical cancer. However, the association between HPV viral load and the degree of cytologic atypia remains controversial. Cytologically negative PAP tests that test positive for high risk HPV represent subclinical infection. It is known that older patients with HPV viral load are more likely to harbor subclinical infections. This study aims to establish a link between HPV viral load and age with subsequent detection of significant cervical lesions (cervical intraepithelial neoplasia 2 (CIN2) or higher).
Design: 776 of cases with initially normal PAP smears and positive high risk HPV (Hybrid Capture 2 HPV DIGENE) between January 2004 and December 2007 were collected from the Department of Pathology archives. The initial viral load was recorded as very low, low, moderate, and high. The cases were analyzed for initial viral load, age at initial PAP smear, and follow-up cytologic or surgical gynecologic specimens over a 2-5 year period. Cases with no cytologic or surgical follow-up were rejected. Patients were stratified as less than or greater than or equal to 30 years of age. A Z-test for two proportions analysis was performed to determine associations. A p value of less than 0.05 was considered significant.
Results: Results are summarized in tables 1 and 2. The difference between very low and moderate viral levels (p=0.028) and the difference between low and moderate viral load (p = 0.0038) was statistically significant. The difference between moderate and high viral loads was not statistically significant (p=0.295). The association between age and follow up abnormalities (47% versus 31%) had a two tailed p value < 0.001.
|Initial viral load||Very low||Low||Moderate||High|
|Total # cases||238||538|