Clearance of high-risk human papillomavirus (HPV) DNA and PAP smear abnormalities in a cohort of women subjected to HPV screening in the New Independent States of the former Soviet Union (the NIS cohort study).

ABSTRACT

BACKGROUND: We analysed the temporal relationships of the clearance of human papillomavirus (HPV) DNA and cytological abnormalities in women participating in a screening study in three NIS countries. METHODS: The 274 patients included in this analysis were prospectively followed-up for 21.6 months (range 0.5-42.9). All 274 women had abnormal PAP test (ASC-US or higher) and high-risk HPV-positive test (HCII) at baseline. Two groups were compared 132 women who cleared both tests (Group 1), and 142 women who cleared either HPV or abnormal PAP test (Group 2). The first clearance during the follow-up, and the last visit clearance were modeled using life-table techniques, and the predictive factors were analysed using univariate (Kaplan-Meier) and multivariate (Cox) survival analysis. RESULTS: There was no difference in the mean clearance time for the abnormal PAP test (14.4 months; 0.7-40.5 and 12.6 months; 0.5-35.0) and high-risk HPV DNA (12.67 months; 0.6-33.5 and 10.8 months; 0.7-33.4) in Group 1 and Group 2 (Mann-Whitney P = 0.107 and P = 0.082, respectively). Clearance times for HPV DNA and abnormal PAP test did not deviate from each other in either groups (Wilcoxon P = 0.063 and P = 0.088). The monthly clearance rates for the abnormal PAP test are 1.32 and 1.38%, and those for the HPV DNA 1.62 and 1.61%, in Groups 1 and 2, respectively. Of the factors predicting the last visit clearance, the issues related to smoking are of particular interest. CONCLUSIONS: The clearance of high-risk HPV type and abnormal PAP test shows a close temporal relationship, the former preceding the latter, however, by an interval of 1.0-2.0 months.