Li C Cheung

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.

Hidden mover‐stayer model for disease progression accounting for misclassified and partially observed diagnostic tests: Application to the natural history of human papillomavirus and cervical precancer

Hidden Markov models (HMMs) have been proposed to model the natural history of diseases while accounting for misclassification in state identification. We introduce a discrete time HMM for human papillomavirus (HPV) and cervical precancer/cancer where the hidden and observed state spaces are defined by all possible combinations of HPV, cytology, and colposcopy results. Because the population of women undergoing cervical cancer screening is heterogeneous with respect to sexual behavior, and therefore risk of HPV acquisition and subsequent precancers, we use a mover‐stayer mixture model that assumes a proportion of the population will stay in the healthy state and are not subject to disease progression. As each state is a combination of three distinct tests that characterize the cervix, partially observed data arise when at least one but not every test is observed. The standard forward‐backward algorithm, used for evaluating the E‐step within the E‐M algorithm for maximum‐likelihood estimation of HMMs, cannot incorporate time points with partially observed data. We propose a new forward‐backward algorithm that considers all possible fully observed states that could have occurred across a participant's follow‐up visits. We apply our method to data from a large management trial for women with low‐grade cervical abnormalities. Our simulation study found that our method has relatively little bias and out preforms simpler methods that resulted in larger bias.

Cervical Precancers and Cancers Attributed to HPV Types by Race and Ethnicity: Implications for Vaccination, Screening, and Management

AbstractBackgroundRacial and ethnic variations in attribution of cervical precancer and cancer to human papillomavirus (HPV) types may result in different HPV vaccine protection, screening test coverage, and clinical management.MethodsPooling data from 7 US studies, we calculated the proportional attribution of precancers and cancers to HPV types using HPV DNA typing from diagnosis. All statistical tests were 2-sided.ResultsFor all racial and ethnic groups, most cases of cervical intraepithelial neoplasia grade 3 (CIN3) (84.2%-90.8% of 5526) and squamous cell carcinoma (SCC) (90.4%-93.8% of 1138) were attributed to types targeted by the 9-valent vaccine. A higher proportion of CIN3s were attributed to nonvaccine HPV types among non-Hispanic Black women (15.8%) compared with non-Hispanic Asian or Pacific Islander (9.7%; P = .002), non-Hispanic White (9.2%; P < .001), and Hispanic (11.3%; P = .004) women. The proportion of SCCs attributed to 9-valent types was similar by race and ethnicity (P = .80). A higher proportion of CIN3s were attributed to nonvaccine HPV35 among non-Hispanic Black (9.0%) compared with non-Hispanic Asian or Pacific Islander (2.2%), non-Hispanic White (2.5%), and Hispanic (3.0%; all P < .001) women. Compared with CIN3, the proportion of SCCs attributed to HPV35 among non-Hispanic Black women (3.2%) was lower and closer to other groups (0.3%-2.1%; P = .70).ConclusionThe 9-valent HPV vaccine will prevent nearly all cervical precancers and invasive cancers among major racial and ethnic groups in the United States. Adding HPV35 to vaccines could prevent a small percentage of CIN3s and SCCs, with greater potential impact for CIN3s among Black women. HPV screening tests target high-risk HPV types, including HPV35. Future genotyping triage strategies could consider the importance of HPV35- and other HPV16-related types.

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.

Design of the HPV-automated visual evaluation (PAVE) study: Validating a novel cervical screening strategy

Background: The HPV-automated visual evaluation (PAVE) Study is an extensive, multinational initiative designed to advance cervical cancer prevention in resource-constrained regions. Cervical cancer disproportionally affects regions with limited access to preventive measures. PAVE aims to assess a novel screening-triage-treatment strategy integrating self-sampled HPV testing, deep-learning-based automated visual evaluation (AVE), and targeted therapies. Methods: Phase 1 efficacy involves screening up to 100,000 women aged 25–49 across nine countries, using self-collected vaginal samples for hierarchical HPV evaluation: HPV16, else HPV18/45, else HPV31/33/35/52/58, else HPV39/51/56/59/68 else negative. HPV-positive individuals undergo further evaluation, including pelvic exams, cervical imaging, and biopsies. AVE algorithms analyze images, assigning risk scores for precancer, validated against histologic high-grade precancer. Phase 1, however, does not integrate AVE results into patient management, contrasting them with local standard care. Phase 2 effectiveness focuses on deploying AVE software and HPV genotype data in real-time clinical decision-making, evaluating feasibility, acceptability, cost-effectiveness, and health communication of the PAVE strategy in practice. Results: Currently, sites have commenced fieldwork, and conclusive results are pending. Conclusions: The study aspires to validate a screen-triage-treat protocol utilizing innovative biomarkers to deliver an accurate, feasible, and cost-effective strategy for cervical cancer prevention in resource-limited areas. Should the study validate PAVE, its broader implementation could be recommended, potentially expanding cervical cancer prevention worldwide. Funding: The consortial sites are responsible for their own study costs. Research equipment and supplies, and the NCI-affiliated staff are funded by the National Cancer Institute Intramural Research Program including supplemental funding from the Cancer Cures Moonshot Initiative. No commercial support was obtained. Brian Befano was supported by NCI/ NIH under Grant T32CA09168.

Long-Term Prospective Cohort Study of Cervical Cancer Screening Using Triage of Women Who Are Human Papillomavirus–Positive With Dual Stain and Human Papillomavirus Genotyping

PURPOSE Primary human papillomavirus (HPV) testing has the best tradeoff of benefits and harms for cervical screening but requires triage to determine management among HPV positives. We conducted a prospective observational study to evaluate triage of women who are HPV-positive using dual stain (DS) and HPV genotyping. MATERIALS AND METHODS We included 9,645 consecutive women who are HPV-positive undergoing cervical screening in two periods between 2015 and 2017 in the organized cervical screening program at Kaiser Permanente Northern California. Absolute risk and clinical performance of DS and cytology for detection of cervical intraepithelial neoplasia grade 3 and greater (CIN3+) were estimated overall and by HPV genotype and by age. Cumulative absolute risk of CIN3+ was modeled over 5 years using a prevalence-incidence mixture model, which allows estimating risk accounting for differences in disease ascertainment, surveillance intervals, and compliance. RESULTS The baseline risk of CIN3+ was 9.4% and 0.8% for women testing positive and negative for DS, respectively, and 6.9% and 2.0% for women testing positive and negative for cytology, respectively. Sensitivity, specificity, and predictive values for CIN3+ detection were better for DS compared with cytology over 5 years ( P < .001 for all comparisons). Risk in women with HPV16-positive/negative for intraepithelial lesion or malignancy was substantially higher than the risk in women with HPV16-positive/DS-negative (7.5% v 2.9%, P < .001). DS had better triage performance compared with cytology in all age groups and in women positive for HPV types other than HPV16 or HPV18. CONCLUSION Long-term reassurance of low risk among DS negatives suggests that DS detects molecular changes earlier in the carcinogenic pathway than cytology. DS has better risk stratification than cytology overall, within HPV risk strata, and across all screening age groups and is a better option for triage of vaccinated populations.

Validation of a Lab-free Low-cost Screening Test for Prevention of Cervical Cancer

The purpose of this study is to validate Automated Visual Evaluation (AVE), specifically the CINFinder version developed by DL Analytics, a point-of-care screening and triage diagnostic tool for cervical cancer based on the assessment of digital images through artificial intelligence. Several teams around the world have developed versions of AVE as a triage technology but none as a screening tool.