The first-round results of a population-based cohort study of HPV testing in Japanese cervical cancer screening: baseline characteristics, screening results, and referral rate.

Objective: In 2013, a cohort study aimed to clarify the positive and negative effects of introducing the human papillomavirus (HPV) testing for population-based cervical cancer screening has been launched in Japan. This study included four screenings during the subsequent 7-year follow-up period. We aim to describe the results of the first round of this study on cervical cancer screening here.

Methods: This study began in September 2013 with recruitment completed in March 2016. Women aged 30-49 years were divided into 2 groups: those who received uterine cervical cytology alone in the first year (control group), or those who received a combination of cytology and HPV testing (intervention group), based on their age. After first screening, women with positive result of cytology or positive HPV test required referral. We summarized the results of the first round of cervical cancer screening.

Results: Of the 25,074 women who were eligible for the study, 13,845 women (55.2%) were screened with cytology alone; 11,229 women (44.8%) received a combination of cytology and HPV testing. After screening, 407 women (2.9%) in the control group and 1,003 women (8.9%) in the intervention group required referral, respectively. Adding HPV testing increased referral rate significantly (p<0.001).

Conclusion: After first screening, introduction of HPV testing appears to contribute to significantly higher referral rates, suggesting that the number of colposcopies as a detailed examination may increase. These preliminary findings suggest that if HPV testing is introduced into screening, medical institutions need to be prepared for an increasing number of follow-up examinations.