Is cytology/HPV co-testing for cervical cancer screening useful in Japan?

OBJECTIVE In Japan, no region has introduced primary HPV testing for cervical cancer screening. We assessed the diagnostic value and possible harm of HPV testing in Japan. METHODS This cross-sectional study with historical controls used cytology-based screening and co-testing data in Japan. As surrogate indicators of possible harm, colposcopy referral rate and cervical intraepithelial neoplasm (CIN) 1 detection rates were calculated. As surrogate indicators with diagnostic values, the detection rates of CIN2 or greater (CIN2+) and CIN3+ were calculated. RESULTS The data of 297 970 women (182 697 for cytology-based, 115 273 for co-testing) were examined. The detection rates of CIN1, CIN2+, and CIN3+ were significantly higher in the co-testing group than in the cytology-based group (P