CITRUS, cervical cancer screening trial by randomization of HPV testing intervention for upcoming screening: Design, methods and baseline data of 18,471 women

Background To assess the efficacy of screening with concurrent liquid-based cytology and human papillomavirus (HPV) testing for primary cervical cancer screening, we initiated a randomized trial entitled CervIcal cancer screening Trial by Randomization of HPV testing intervention for Upcoming Screening (CITRUS). Methods Between June 2013 and March 2015, women aged 30–64 years of age who participated in a regular cervical cancer screening program (every 2 years) were invited to enrollment of our study. After giving their informed consent, 18,402 women were randomly assigned to liquid-based cytology as the control group (n = 9145) or to HPV DNA testing with liquid-based cytology as the intervention group (n = 9257). We subsequently compared the incidence rate of cervical intraepithelial neoplasia (CIN), the rate of false positive tests and the rate of overdiagnosis, as well as assessing the risks and benefits of receiving screening for women in both groups. The primary outcome of our study was the incidence of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) during the study period of around 6 years. Results In the control group, 97.9% of women were NILM, and 2.06% ASC-US or worse (ASC-US+). In the intervention group, 87.13% of women were NILM/HPV negative, 0.72% ASC-US/HPV negative, 10.34% NILM/HPV positive, 0.69% ASC-US/HPV positive, 0.90% worse than ASC-US/either HPV. Positive HPV testing was not linearly related to age in our study. Conclusions Insights from CITRUS will provide future prospects for cervical cancer screening focused on the use of HPV testing in Japan. Clinical trial registration number: NCT01895517, UMIN000010843, TRIUC1312.