Thomas Lorey

Impact of repeatedly screening negative on cervical cancer risk

Abstract Background We demonstrated that cervical cancer risk following any screening result is lower if there is a known prior negative screening history vs an unknown screening history. We extended these findings to look at how screening performs following repeatedly negative screening results. Methods Approximately 1.7 million women aged 30-64 years underwent triennial human papillomavirus (HPV) and cytology co-testing from 2003 to 2021. We modeled 5-year risks of cervical intraepithelial neoplasia grade 3 or more severe diagnoses (CIN3+) and invasive cervical cancer for the initial co-test, and then successive rounds following negative co-testing. A logistic-Weibull prevalence-incidence model was used to model risks. Results HPV test positivity was greater than cytology positivity for only the first co-test, and both positivity rates decreased with each screening round. Diagnostic yields of CIN3+ and cancer declined with each round of screening so the first screen yielded 8-fold more CIN3+ and invasive cancer than the fifth screen following 4 consecutive negative co-tests. Five-year risks of CIN3+ for positive and negative HPV and cytology results, individually or combined, decreased considerably after the first screen, with smaller decreases in each subsequent round. For cancer, we noticed a considerable decrease with the first screen only. Five-year CIN3+ risks were greater for positive HPV or cytology results, with a longer antecedent screening interval and younger age at screening (Ptrend < .001). Conclusions Triennial screening that includes HPV testing becomes inefficient after a single and more so after multiple negative screens. These data support the use of longer screening intervals, especially following negative screen(s).

The Improving Risk Informed HPV Screening (IRIS) Study: Design and Baseline Characteristics

Abstract Background: Cervical cancer screening with high-risk human papillomavirus (HrHPV) testing is being introduced. Most HrHPV infections are transient, requiring triage tests to identify individuals at highest risk for progression to cervical cancer. Head-to-head comparisons of available strategies for screening and triage are needed. Endometrial and ovarian cancers could be amenable to similar testing. Methods: Between 2016 and 2020, discarded cervical cancer screening specimens from women ages 25 to 65 undergoing screening at Kaiser Permanente Northern California were collected. Specimens were aliquoted, stabilized, and stored frozen. Human papillomavirus (HPV), cytology, and histopathology results as well as demographic and cofactor information were obtained from electronic medical records (EMR). Follow-up collection of specimens was conducted for 2 years, and EMR-based data collection was planned for 5 years. Results: Collection of enrollment and follow-up specimens is complete, and EMR-based follow-up data collection is ongoing. At baseline, specimens were collected from 54,957 HPV-positive, 10,215 HPV-negative/Pap-positive, and 12,748 HPV-negative/Pap-negative women. Clinical history prior to baseline was available for 72.6% of individuals, of which 53.9% were undergoing routine screening, 8.6% recently had an abnormal screen, 30.3% had previous colposcopy, and 7.2% had previous treatment. As of February 2021, 55.7% had one or more colposcopies, yielding 5,563 cervical intraepithelial neoplasia grade 2 (CIN2), 2,756 cervical intraepithelial neoplasia grade 3 (CIN3), and 146 cancer histopathology diagnoses. Conclusions: This robust population-based cohort study represents all stages of cervical cancer screening, management, and posttreatment follow-up. Impact: The IRIS study is a unique and highly relevant resource allowing for natural history studies and rigorous evaluation of candidate HrHPV screening and triage markers, while permitting studies of biomarkers associated with other gynecologic cancers.

Primary human papillomavirus testing vs cotesting: clinical outcomes in populations with different disease prevalence

Abstract Implementation of primary human papillomavirus (HPV) testing has been slow in the United States perhaps because of concerns of decreased sensitivity compared with concurrent HPV and cytology testing (“cotesting”). We used the National Breast and Cervical Cancer Early Detection Program and the Kaiser Permanente of Northern California cohort to quantify potential trade-offs with primary HPV compared with cotesting in 4 US populations with differing precancer or cancer prevalence. In all settings, cotesting required more lab tests and more colposcopies compared with primary HPV testing. Additional cervical intraepithelial neoplasia grade 3 or cancer immediately detected from cotesting vs primary HPV decreased with decreasing population-average cervical intraepithelial neoplasia grade 3 or cancer prevalence from 71 per 100 000 screened among never or rarely screened individuals in the National Breast and Cervical Cancer Early Detection Program (prevalence = 1212 per 100 000) to 4 per 100 000 screened among individuals with prior HPV-negative results in Kaiser Permanente of Northern California (prevalence = 86 per 100 000). These data suggest that cotesting confer an unfavorable benefit-to-harm ratio over primary HPV testing.

Evaluation of Pre-Analytical Variables for Human Papillomavirus Primary Screening from Self-Collected Vaginal Swabs

Human papillomavirus (HPV) primary screening is an effective approach to assessing cervical cancer risk. Self-collected vaginal swabs can expand testing access, but the data defining analytical performance criteria necessary for adoption of self-collected specimens are limited, especially for those occurring outside the clinic, where the swab remains dry during transport. Here, we evaluated the performance of self-collected vaginal swabs for HPV detection using the Cobas 6800. There was insignificant variability between swabs self-collected by the same individual (n = 15 participants collecting 5 swabs per participant), measured by amplification of HPV and human β-globin control DNA. Comparison of self-collected vaginal swab and provider-collected cervical samples (n = 144 pairs) proved highly concordant for HPV detection (total agreement = 90.3%; positive percentage agreement = 84.2%). There was no relationship between the number of dry storage days and amplification of HPV (n = 68; range, 4 to 41 days). Exposure of self-collected dry swabs to extreme summer and winter temperatures did not affect testing outcomes. A second internal control (RNase P) demonstrated that lack of amplification for β-globin from self-collected specimens was consistent with poor, but not absent, cellularity. These data suggest that self-collected vaginal samples enable accurate clinical HPV testing, and that extended ambient dry storage or exposure to extreme temperatures does not influence HPV detection. Furthermore, lack of β-globin amplification in HPV-negative samples accurately identified participants who required recollection.