Document Type : Research Articles
Department of Obstetrics and Gynecology, Jichi Medical University, Yakushiji, Shimotsuke, Tochigi, Japan.
Gynecological Cancer Center, Shinyurigaoka, General Hospital, 255 Furusawa, Asao-ku, Kawasaki, Kanagawa, Japan.
Itsuki Ladies Clinic, 5-18-15 Hitotonoya,Oyama, Tochigi, Japan.
Kimura Ladies Clinic, 1-7-7 Gion, Shimotsuke, Oyama, Tochigi, Japan.
Background: One of the features of cervical cancer screening using the combination of cytology and human
papillomavirus (HPV) testing is the triage for atypical squamous cells of undetermined significance (ASC-US). The
effectiveness of the triage has been recognized widely. However, there are few reports evaluating this triage process in
Japan. Material and Methods: We retrospectively examined the results of cytology and HPV co-testing for cervical
cancer screening in the Oyama area of Tochigi Prefecture between 2012 and 2014. Women who were ASC-US/HPV
positive and had cytologic abnormalities [low-grade squamous intraepithelial lesions (LSIL) or worse] were examined
by colposcopy. The results of the colposcopy testing were evaluated. In addition, we also examined the results of those
who underwent co-testing a year after a ASC-US/HPV-negative result. Results: A total of 21,342 women received
their first screening test during the study period, with 542 (2.5%) found to have ASC-US. Of the ASC-US-positive
women, 289 (53.3%) were also HPV positive. The prevalence of CIN+ (cervical intraepithelial neoplasia or higher)
in the ASC-US/HPV-positive group was 63.2%, with 81.8%, 16.4% and 4.8%. showing CIN 1, CIN 2 and CIN 3+,
respectively. The prevalence of CIN+ in the LSIL group was 66.8%, with the majority having a low risk CIN 1 (76.6%)
compared to CIN 2 (18.6%), and CIN 3+ (4.8%). No significant difference was observed between the LSIL and ASC-US/
HPV-positive groups. The prevalence of women diagnosed with CIN in the ASC-US/HPV-negative group, following
co-testing a year after colposcopy was low (3%). Conclusions: The ASC-US/HPV-positive group was comparable to
the LSIL group in terms of prevalence of CIN+ lesions. Furthermore, low CIN prevalence after one year in the ASCUS/
HPV-negative group provides confirmation that the screening interval could be extended. The application of HPV
triage (which is routine in other countries) to identify these groups would be of benefit in Japan.