A case control study og CIN1 – Investigation of the high-risk HPV detection status and outcome of cytodiagnosis – *
Aims:To determine if the natural history of CIN1 differs with the infection status of HPV and/or HPV-DNA typing in Japanese women. Methods:The 243 patients who were diagnosed as CIN1 between April 1995 and March 2005 were prospectively followed up. Excluded were those who were under follow-up of less than 12 months without progression. The patients were required to visit every three months unless there was“cytological regression”. Pap-smear, HPV-DNA typing, and colposcopy without biopsy were performed during every visit and a biopsy was done when progression was suspected cytologically or colposcopically. Cytological prognosis and HPV disappearance were analyzed by the Kaplan-Meier method and the Log-rank test was performed. Results:The median follow-up was 33.2 months（range 6-128）. Among the 243 patients, 143 were positive for HPV. Among the 143 patients, persistent infection of the same type was detected in 109. Among those 109 patients, 22 progressed to CIN3. The most predominant HPV-DNA type was x52（n＝41, 37.6％ in the Persistent group）followed by x16（n＝30, 27.5％）, x58（n＝30, 27.5％）, and others. The cytological regression rates for patients without HPV infection were 85.2％ and 98.4％ at 24 and 36 months, respectively. Although the regression rates in patients with HPV infections were extremely low（65.1％, and 74.6％, respectively）, those rates in patients without persistent infection did not differ from those without HPV infection. Conclusions:Cytological regression rates in CIN1 without persistent infection of the same type were the same as those without HPV infection. The role of surgical interventions must be clarified in CIN1 patients with persistent infection of the same types for a long term.（Accepted on October 25，2006）
