Epidemiologic and viral factors associated with cervical neoplasia in HPV-16-positive women

Abstract

While infection with high-risk HPV is the most important risk factor for cervical cancer, HPV alone is insufficient. Our purpose was to identify viral and epidemiologic factors associated with cervical disease in HPV-16 DNA-positive women referred to colposcopy. We used a standardized interview to collect epidemiologic data from consenting women. Total nucleic acids from exfoliated cervical cells were used for all viral assays (HPV detection and typing using L1 consensus PCR with line probe hybridization, variant classification by sequencing, viral load and transcript copy determination by quantitative PCR and transcript pattern by nested RT-PCR). Cervical disease was based on colposcopic biopsy. Logistic regression was used to calculate ORs with 95% CIs. There were 115 HPV-16 positive women among 839 enrollees. By univariate analyses, age >25 years (OR = 3.05, 95% CI 1.20-7.76), smoking (OR = 3.0, 95% CI 1.19-7.56), high viral load (OR = 5.27, 95% CI 2.05-13.60), detection of both E6 and E6*I transcripts (OR = 10.0, 95% CI 2.1-47.58) and high transcript copies (OR = 5.56, 95% CI 2.05-13.60) were significant risk factors for CIN III with reference to No CIN/CIN I. Less than a third of the women (31.5%) had prototype HPV-16 detected, and variants showed no association with disease, viral load or transcription. Viral DNA and transcript copies were highly correlated, and the ratio of transcript copies to DNA copies was not changed with disease status. While viral load, transcript copies and transcript pattern were statistically associated with CIN III, none of these measures effectively discriminated between HPV-16 women with disease requiring treatment and those who could be followed. Cellular proliferation and differentiation pathways affected by HPV should be investigated as biomarkers for cervical cancer screening.