Older women testing positive for HPV16/18 on cervical screening and risk of high-grade cervical abnormality.

In Australia's HPV-based cervical screening program, we previously showed that risk of histological high-grade abnormality at 1 year post screening decreased with age in women with oncogenic HPV. In this study, we followed 878 HPV16/18 positive women aged 55 years and over for up to 3 years post screening test, to determine the proportion with histological high-grade abnormality (HGA, incorporating high-grade squamous intraepithelial abnormality (HSIL), adenocarcinoma in situ (AIS), squamous cell carcinoma (SCC) and adenocarcinoma) and to correlate risk of HGA with liquid-based cytology result and with prior screening history. HGA was detected in 7.8% at 1 year and 10.0% at 3 years, with no significant difference (P = .136), despite the number of women with follow-up information significantly increasing from 82.9% to 91.0% (P < .0001). The proportion of HPV16/18 positive women with HGA at 3 years was highest in those with an HSIL cytology result (79.0%) and lowest in those with negative cytology (6.2%). Women with an adequate screening history had fewer HGA than such women with inadequate prior screening (6.6% vs 16.0%, P = .001) or with a history of an abnormality (6.6% vs 14.4%, P = .001). HPV16/18 infection in women over 55 years may have a different natural history from that in younger women, in whom HGA are more common after HPV16/18 detection. In HPV-based cervical screening programs, management algorithms for screen-detected abnormalities based on risk stratification should include factors such as age, screening history and index cytology result, so that women receive appropriate investigation and follow-up.

Detection of high-grade cervical disease among women referred directly to colposcopy after a positive HPV screening test varies with age and cytology findings.

Australia's new HPV-based cervical screening program is based on an algorithm that incorporates reflex cytology to guide decisions about further follow-up with colposcopy and, if indicated, biopsy. We reviewed results for 2300 women referred directly for colposcopy after their first positive HPV screening test, to determine the proportion that had underlying histological high-grade abnormality (HGA). Overall, HGA was detected in 24.3% of women. Among HPV16/18 positive women, 18.0% had HGA, increasing from 6.6% among women with negative cytology to 79.7% among women with high-grade squamous lesion or worse, or any glandular lesion on cytology (HSIL+; P-trend < .001). For this latter group, the proportion with HGA was higher among HPV16/18 positive women than among those positive for other oncogenic types (68.8%; P = .029). Among women with ASC-H cytology, 51.8% had HGA, with no difference between HPV groups (P = .314). In analyses by age-groups, detection of HGA was highest, at 36.4%, among women younger than 35 years, then decreased significantly to 5.9%, among women aged 65 to 74 years (P-trend < .001). The relationship of decreasing HGA detection with increasing age was strong for women with negative cytology, and those with ASC-H cytology (P-trend < .001 for each). For women with HSIL+ cytology, detection of HGA was high and stable, regardless of age (P-trend = .211). This report describes the first follow-up colposcopy findings in Australia's new HPV-based cervical screening program. The results demonstrate the additional value of reflex cytology in managing HPV positive women and suggest that further refinement of the risk-based algorithm to account for age may be warranted.