Specific Human Papillomavirus Types and Other Factors on the Risk of Cervical Intraepithelial Neoplasia: A Case-Control Study in Korea

Abstract

Cervical neoplasia is attributed to a persistent human papillomavirus (HPV) infection. We performed a hospital-based, case-control study to evaluate the associations of HPV genotypes and other cofactors with cervical intraepithelial neoplasia (CIN). A total of 158 women were enrolled after we received their informed consent, and the control group (the non-CIN group; n = 80) was selected from women at St Paul's Health Promotion Center. The CIN group (n = 78) was enrolled from the outpatient clinics at Kangnam St Mary's Hospital. Cervical intraepithelial neoplasia was confirmed with colposcopic-guided biopsy or loop electrosurgical excision procedure-conization. A structured questionnaire, Papanicolaou test, and HPV testing were completed. We compared each risk factor using chi2 tests and simple logistic regression analysis between the CIN and non-CIN groups. Finally, odds ratios (ORs) were calculated again by multiple logistic regression analysis. The most frequent HPV types in CIN were HPV-16, HPV-58, HPV-31/-33, and HPV-35/-56. The OR of the A9 group (HPV-16, HPV-31, HPV-33, HPV-35, HPV-52, HPV-58) was 22.7 (95% confidence interval [CI], 8.3-62.5), that of the A6 group (HPV-53, HPV-56, HPV-66) was 2.9 (95% CI, 1.1-7.5), and that of the A7 group (HPV-18, HPV-39, HPV-45, HPV-59, HPV-68) was 1.5. Sexual debut before 20 years old had significantly higher OR than did a sexual debut after 30 years (OR, 32.9; 95% CI, 2.8-364.7). The OR for CIN in single women versus married women was 6.2 (95% CI, 2.5-15.2). Compared with parous women (parity >3), nonparous women had a higher OR (95% CI, 1.4-16.7). On the multiple logistic regression analysis including the sexual debut age, the marital status, parity, cytology, and the HPV groups, the A9 group had a significant OR for CIN (6.1; 95% CI, 1.6-23.6). The risk of CIN was higher for women infected with the HPV-A9 group after multiple logistic regression analysis. The other clinical risk factors were not significant factors of CIN.