Diagnostic outcomes after colposcopy at a tertiary clinic for women aged 50-74 referred after detection of oncogenic human papillomavirus at primary screening.

Abstract

To examine outcomes in women aged 50-74 years after detection of oncogenic human papillomavirus (HPV) at cervical screening. A retrospective observational study of 464 women seen in the Royal Women's Hospital Colposcopy Clinic from 1 January 2018 to 31 July 2020, 292 (62.9%) were positive for HPV16/18 and 172 (37.1%) for HPV (not 16/18). Fifty-four women (11.6%) had histologically proven CIN2+ including seven cancers, up to two years after first colposcopy visit (FCV): 48 (88.9%) detected at FCV or at excisional treatment (Excision) arranged after no CIN2+ detected at FCV. There was no significant difference (P = 0.14) in proportion of CIN2+ detected between the two groups, 'HPV16/18' (9.9%) or 'HPV (not 16/18)' (14.5%), nor with reflex cytology types. The positive predictive value (PPV) of high-grade impression at colposcopy was 63.6%. There were 243 (52.4%) who had Type 3 transformation zone (TZ3) with 20 CIN2+ detected, 13 at FCV including all three cancers and five at Excision. There were 214 (73.3%) with positive HPV16/18 who had reflex negative cytology, of which seven had CIN2+ including one cancer but only two (1.4%) CIN2+ when their repeat cytology at colposcopy was negative. Most CIN2+ were detected at first colposcopy or at subsequent excision. We would encourage high biopsy rates at colposcopy and vigilance in selection for excisional treatment in TZ3 cases if there is no significant suspicion of high-grade abnormality. There is a need to refine the algorithm for management of persistent HPV16/18 infections with reflex negative cytology to reduce colposcopy referrals in women aged 50 and above.