Introduction Japan is considering introducing ‘HPV test primary cytology triage’ for cervical cancer screening. Among HPV-positive cases, NILM is considered as negative, and ASC-US or higher as positive for triage result. Since cytology is based on cell morphology, the results of cytological evaluation, whether for triage or screening, should be consistent. However, cytologists not blinded to the results of HPV testing might provide biased results. Therefore, we attempted to confirm if the results of cytological evaluation could be influenced by the results of HPV testing.

Methods From the Usefulness Study on Combined Cytology and HPV Testing, we listed the laboratories conducting cytological evaluation and HPV testing, respectively. We asked cytology laboratories if they could refer to the HPV test results while providing cytology decisions, and if they might change their decisions in cases with positive HPV test results.

Results A total of 52 each of HPV testing laboratories and cytological laboratories were included; 31 of these conducted both HPV testing and cytological evaluations. In all, 6 cytological laboratories had access to the HPV test results, and in 5, the results of cytology could be changed from NILM to ASC-US depending on the HPV test results.

Conclusion/Implications About 10% of cytological laboratories have access to the HPV test results, which often influences the results of their cytology evaluation. In order to ensure accuracy of cytology triage, laboratories should be discouraged from changing their evaluation results based on the HPV test results, and to monitor the distribution of the triage results.