Clinical performance of human papillomavirus based cervical cancer screening algorithm: The result of a large Danish implementation study

Introduction: In Denmark, where human papillomavirus (HPV) -based cervical cancer screening is being implemented, the aim of this pilot implementation study was to test a specific screening algorithm, assess follow-up examination attendance, and measure the proportion of precancer lesions found in relation to the number of women referred for colposcopy.

Material and methods: From May 2017 to December 2020, 36 417 women in the uptake area of the Department of Pathology, Vejle Hospital, Region of Southern Denmark, were included in the HPV group. Women positive for HPV16/18 irrespective of cytology and women positive for other high-risk HPV (hrHPV) types having concomitant abnormal cytology were referred directly to colposcopy. Women positive for other hrHPV types and normal cytology were referred to repeat screening after 12 months, and hrHPV negative to routine screening after three years. We obtained information on screening results and subsequent histological diagnosis from the Danish Pathology Databank through September 2022.

Results: 3.6% of the women were referred to colposcopy after primary screening, 5% to repeat screening after 12 months, and 91.4% back to routine screening. High follow-up rates were observed: 96% attended colposcopy after primary screening, with 91% attending colposcopy after repeat screening. CIN3+ was detected at colposcopy following the primary screening in 28.1% of HPV16/18-positive women and 18.2% of those positive for other hrHPV types with concomitant abnormal cytology. Of the women with other hrHPV and simultaneous ASCUS/LSIL, 8% had CIN3+. At the repeat screening, 43% had become hrHPV negative, 55% were persistently positive for other hrHPV, and 2% had turned positive for HPV16/18. At the colposcopy following repeat screening, 10.1% of the women positive for other hrHPV were diagnosed with CIN3+, in comparison with 11.1% of the HPV16/18-positive women.

Conclusions: In this pilot implementation study, an algorithm for HPV-based screening was evaluated in a Danish setting. The results demonstrated high attendance at follow-up examinations and provided insights into the number of colposcopy referrals and the detection of CIN2 and CIN3+ cases. The results suggest that women testing positive for other hrHPV in combination with ASCUS/LSIL at primary screening could potentially be referred to repeat screening instead of an immediate colposcopy.