Implementation of primary HPV testing in Japan.

Area of Science:

• Gynecology
• Oncology
• Public Health

Background:

• Cervical cancer screening is transitioning globally from cytology to primary HPV testing due to HPV testing's superior sensitivity.
• A potential drawback of this shift is the risk of missing certain pre-cancerous lesions (CIN2+) in high-risk HPV-negative cases.
• The study addresses the first examination of primary HPV testing feasibility in Japan.

Purpose of the Study:

• To meticulously identify cervical intraepithelial neoplasia grade 2 or worse (CIN2+) cases potentially missed by the transition to primary HPV testing.
• To assess the overall feasibility and effectiveness of implementing primary HPV testing within Japan's cancer screening programs.

Main Methods:

• Analysis of co-testing data from 115,273 women undergoing both cytology and HPV testing for cervical cancer screening.
• Detailed examination of cases negative for high-risk HPV but positive for low-grade squamous intraepithelial lesions (hrHPV-/≥LSIL).
• Prevalence calculation of CIN2+, CIN3, squamous cell carcinoma (SCC), and adenocarcinoma within the hrHPV-/≥LSIL cohort.

Main Results:

• Cases with hrHPV-/≥LSIL represented 0.3% of the total screened population.
• The prevalence of CIN2+ or worse lesions within the hrHPV-/≥LSIL group was low at 0.03%.
• Only one of 14 cervical adenocarcinomas in the ≥LSIL group tested negative for high-risk HPV.
• A higher prevalence of missed cancers was observed in women over 50 compared to those younger than 49.

Conclusions:

• The incidence of CIN2+ potentially missed by shifting to primary HPV testing is notably low in Japanese cancer screening.
• Primary HPV testing demonstrates feasibility in Japan, offering higher sensitivity for CIN2+ detection than primary cytology.
• Introduction of primary HPV testing is particularly advised for women under 50 years old.