Abstract
Objective : To be consistent in the definition of atypical squamous cells undetermined significance (ASC-US), we temporally assessed the transition of status in patients diagnosed as having ASC-US after introduction of the Bethesda system (TBS).
Study Design : We compared the frequency, age distribution, Human papillomavirus (HPV) status and histological results of patients with ASC-US between two 3-year periods : the first of 2008 to 2010 and the second from 2011 to 2013.
Results : In first 3-year period, 309 (0.13%) cases of ASC-US were diagnosed from 236121 participants in uterine cervical cancer screening. In second 3-year period, 341 (0.15%) cases of ASC-US were diagnosed from 221143 participants. The proportion of ASC-US with abnormal cytology decreased to 16.8% in the second period from 18.6% in the first. In the first period, 85 patients (30.7%) with≥cervical intraepithelial neoplasm 2 (CIN2) were detected from 309 patients with ASC-US. In the second period, 45 patients (19.7%) with≥CIN2 were detected from 341 patients with ASC-US. There was a significant decrease in high grade lesions in the second period from the first period (p=0.006).
Conclusion : In the temporal spread over two periods to examine the concept of ASC-US, decrease in the frequency of abnormal cytology in ASC-US and in the detection rate of≥CIN2 were seen in the second period. It may demonstrate an adequate status in the diagnosis of ASC-US.
