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 < 0.001, P < 0.0001, P < 0.01, respectively). Between ages 25-49, CIN2+ detection rates were significantly higher in the co-testing group than in the cytology-based group (P < 0.05 for each 5-year age group). Between ages 30-49, CIN3+ detection rates were significantly higher in the co-testing group than in the cytology-based group (P < 0.05 for each 5-year age group).

Conclusion: Limiting the target age group may minimize the possible harm of screening. Cytology/HPV co-testing may be useful in Japanese populations if balance is maintained between benefit and harm.