Absolute risks of cervical precancer among women who fulfill exiting guidelines based on HPV and cytology cotesting.

US guidelines recommend that most women older than 65 years cease cervical screening after two consecutive negative cotests (concurrent HPV and cytology tests) in the previous 10 years, with one in the last 5 years. However, this recommendation was based on expert opinion and modeling rather than empirical data on cancer risk. We therefore estimated the 5-year risks of cervical precancer (cervical intraepithelial neoplasia grade 3 or adenocarcinoma in situ [CIN3]) after one, two and three negative cotests among 346,760 women aged 55-64 years undergoing routine cotesting at Kaiser Permanente Northern California (2003-2015). Women with a history of excisional treatment or CIN2+ were excluded. No woman with one or more negative cotests was diagnosed with cancer during follow-up. Five-year risks of CIN3 after one, two, and three consecutive negative cotests were 0.034% (95% CI: 0.023%-0.046%), 0.041% (95% CI: 0.007%-0.076%) and 0.016% (95% CI: 0.000%-0.052%), respectively (ptrend < 0.001). These risks did not appreciably differ by a positive cotest result prior to the one, two or three negative cotest(s). Since CIN3 risks after one or more negative cotests were significantly below a proposed 0.12% CIN3+ risk threshold for a 5-year screening interval, a longer screening interval in these women is justified. However, the choice of how many negative cotests provide sufficient safety against invasive cancer over a woman's remaining life represents a value judgment based on the harms versus benefits of continued screening. Ideally, this guideline should be informed by longer-term follow-up given that exiting is a long-term decision.

Impact of human papillomavirus vaccination on the clinical meaning of cervical screening results.

Women previously vaccinated against human papillomavirus (HPV) type 16 and 18 are now reaching the age (21 years) at which cervical-cancer screening is recommended in the U.S. The impact of HPV vaccination on risks of cervical precancer following a positive and negative screen among women aged 21-24 years who just started routine cervical screening are not well described. Therefore, three-year absolute and relative (RR) cumulative risks of cervical intraepithelial neoplasia grade 2 or more severe diagnoses (≥CIN2) and grade 3 or more severe diagnoses (≥CIN3) were estimated for women undergoing cervical screening at Kaiser Permanente Northern California. Risks were estimated in women aged 21-24 years (n = 75,008) undergoing cervical screening since late 2006, 6 months after HPV vaccination became available; women were categorized vaccinated at ages <18, 18-20, and 21-24 years and compared to those who were unvaccinated. Three-year risks were estimated for normal, low-grade, and high-grade cytology results. Three-year risks of ≥CIN2 and ≥CIN3 for unvaccinated women following low-grade cytology were 10.89% for and 3.70%, respectively. By comparison, Three-year risks of ≥CIN2 and ≥CIN3 were 5.26% (RR = 0.48, 95%CI = 0.24-0.99) and 0.99% (RR = 0.27, 95%CI = 0.06-1.13), respectively, for women vaccinated under the age of 18 years. Three-year ≥CIN2 and ≥CIN3 risks were lower for those HPV vaccinated at younger age for any screening result (ptrend ≤ 0.01 for all comparisons). These data support initiating cervical screening at an older age or changing the management of a low-grade cytology result in women aged 21-24 years who were vaccinated against HPV younger than age of 18 years.

Effect of Several Negative Rounds of Human Papillomavirus and Cytology Co-testing on Safety Against Cervical Cancer: An Observational Cohort Study.

Background: Current U.S. cervical cancer screening and management guidelines do not consider previous screening history, because data on multiple-round human papillomavirus (HPV) and cytology "co-testing" have been unavailable. Objective: To measure cervical cancer risk in routine practice after successive negative screening co-tests at 3-year intervals. Design: Observational cohort study. Setting: Integrated health care system (Kaiser Permanente Northern California, Oakland, California). Patients: 990 013 women who had 1 or more co-tests from 2003 to 2014. Measurements: 3- and 5-year cumulative detection of (risk for) cervical intraepithelial neoplasia grade 3, adenocarcinoma in situ, and cervical cancer (≥CIN3) in women with different numbers of negative co-tests, overall and within subgroups defined by previous co-test results or baseline age. Results: Five-year ≥CIN3 risks decreased after each successive negative co-test screening round (0.098%, 0.052%, and 0.035%). Five-year ≥CIN3 risks for an HPV-negative co-test, regardless of the cytology result, nearly matched the performance (reassurance) of a negative co-test for each successive round of screening (0.114%, 0.061%, and 0.041%). By comparison, ≥CIN3 risks for the cytology-negative co-test, regardless of the HPV result, also decreased with each successive round, but 3-year risks were as high as 5-year risks after an HPV-negative co-test (0.199%, 0.065%, and 0.043%). No interval cervical cancer cases were diagnosed after the second negative co-test. Independently, ≥CIN3 risks decreased with age. Length of previous screening interval did not influence future ≥CIN3 risks. Limitation: Interval-censored observational data. Conclusion: After 1 or more negative cervical co-tests (or HPV tests), longer screening intervals (every 5 years or more) might be feasible and safe. Primary Funding Source: National Cancer Institute Intramural Research Program.

Adherence patterns to extended cervical screening intervals in women undergoing human papillomavirus (HPV) and cytology cotesting.

Although guidelines have recommended extended interval cervical screening using concurrent human papillomavirus (HPV) and cytology ("cotesting") for over a decade, little is known about its adoption into routine care. Using longitudinal medical record data (2003-2015) from Kaiser Permanente Northern California (KPNC), which adopted triennial cotesting in 2003, we examined adherence to extended interval screening. We analyzed predictors of screening intervals among 491,588 women undergoing routine screening, categorizing interval length into early (<2.5years), adherent (2.5<3.5years), or late (3.5<6.0years). We also examined repeated early screening in a subgroup of 50,691 women. Predictors examined included: cohort year (defined by baseline cotest, 2003-2009), race/ethnicity, and baseline age. Compared to the 2003 cohort, women in the 2009 cohort were significantly less likely to screen early (aOR=0.22, 95% CI=0.21, 0.23) or late (aOR=0.47, 95% CI=0.45, 0.49). African American (AA) and Hispanic women were less adherent overall than Non-Hispanic White women, with increased early [(AA: aOR=1.21, 95%CI=1.17, 1.25) (Hispanic: aOR=1.08, 95%CI=1.06, 1.11)] and late screening [(AA: aOR=1.23, 95%CI=1.19, 1.27) (Hispanic: aOR=1.06, 95%CI=1.03, 1.08)]. Asian women were slightly more likely to screen early (aOR=1.03, 95%CI=1.01, 1.05), and less likely to screen late (aOR=0.92, 95% CI=0.90, 0.94). Women aged 60-64years were most likely to screen early for two consecutive intervals (aOR=2.09, 95%CI=1.91, 2.29). Our study found that widespread and rapid adoption of extended interval cervical cancer screening is possible, at least in this managed care setting. Further research examining multilevel drivers promoting or restricting extended interval screening across diverse healthcare settings is needed.

Challenges in risk estimation using routinely collected clinical data: The example of estimating cervical cancer risks from electronic health-records.

Electronic health-records (EHR) are increasingly used by epidemiologists studying disease following surveillance testing to provide evidence for screening intervals and referral guidelines. Although cost-effective, undiagnosed prevalent disease and interval censoring (in which asymptomatic disease is only observed at the time of testing) raise substantial analytic issues when estimating risk that cannot be addressed using Kaplan-Meier methods. Based on our experience analysing EHR from cervical cancer screening, we previously proposed the logistic-Weibull model to address these issues. Here we demonstrate how the choice of statistical method can impact risk estimates. We use observed data on 41,067 women in the cervical cancer screening program at Kaiser Permanente Northern California, 2003-2013, as well as simulations to evaluate the ability of different methods (Kaplan-Meier, Turnbull, Weibull and logistic-Weibull) to accurately estimate risk within a screening program. Cumulative risk estimates from the statistical methods varied considerably, with the largest differences occurring for prevalent disease risk when baseline disease ascertainment was random but incomplete. Kaplan-Meier underestimated risk at earlier times and overestimated risk at later times in the presence of interval censoring or undiagnosed prevalent disease. Turnbull performed well, though was inefficient and not smooth. The logistic-Weibull model performed well, except when event times didn't follow a Weibull distribution. We have demonstrated that methods for right-censored data, such as Kaplan-Meier, result in biased estimates of disease risks when applied to interval-censored data, such as screening programs using EHR data. The logistic-Weibull model is attractive, but the model fit must be checked against Turnbull non-parametric risk estimates.

Low Risk of Cervical Cancer/Precancer Among Most Women Under Surveillance Postcolposcopy.

OBJECTIVE: To inform impending postcolposcopy guidelines, this analysis examined the subsequent risk of CIN 3+ among women with a grade lower than CIN 2 (< CIN 2) colposcopy results, taking into account the referring results that brought them to colposcopy and cotest results postcolposcopy. METHODS: We analyzed 107,005 women from 25 to 65 years old, recommended for colposcopy at Kaiser Permanente Northern California. We estimated absolute risks of CIN 3+ among women: (1) recommended for colposcopy (precolposcopy), (2) following colposcopy and with histology results < CIN 2 (postcolposcopy), and (3) with cotest results 12 months after a < CIN 2 colposcopy (return cotest). RESULTS: After colposcopy showing < CIN 2 (n = 69,790; 87% of the women at colposcopy), the 1-year risk of CIN 3+ was 1.2%, compared with 6.3% at the time of colposcopy recommendation. Negative cotest results 1 year after colposcopy identified a large group (37.1%) of women whose risk of CIN 3+ (i.e., <0.2% at 3 years after postcolposcopy cotest) was comparable with women with normal cytology in the screening population. These risks are consistent with current guidelines recommending repeat cotesting 12 months after colposcopy < CIN 2 and a 3-year return for women with a negative postcolposcopy cotest. CONCLUSIONS: Most women are at low risk of subsequent CIN 3+ after a colposcopy showing < CIN 2, especially those who are human papillomavirus-negative postcolposcopy, consistent with current management guidelines for repeat testing intervals. Before the finalizing the upcoming guidelines, we will consider additional rounds of postcolposcopy cotesting.

Why does cervical cancer occur in a state-of-the-art screening program?

BACKGROUND: The goal of cervical screening is to detect and treat precancers before some become cancer. We wanted to understand why, despite state-of-the-art methods, cervical cancers occured in relationship to programmatic performance at Kaiser Permanente Northern California (KPNC), where >1,000,000 women aged ≥30years have undergone cervical cancer screening by triennial HPV and cytology cotesting since 2003. METHODS: We reviewed clinical histories preceding cervical cancer diagnoses to assign "causes" of cancer. We calculated surrogate measures of programmatic effectiveness (precancers/(precancers and cancers)) and diagnostic yield (precancers and cancers per 1000 cotests), overall and by age at cotest (30-39, 40-49, and ≥50years). RESULTS: Cancer was rare and found mainly in a localized (treatable) stage. Of 623 cervical cancers with at least one preceding or concurrent cotest, 360 (57.8%) were judged to be prevalent (diagnosed at a localized stage within one year or regional/distant stage within two years of the first cotest). Non-compliance with recommended screening and management preceded 9.0% of all cancers. False-negative cotests/sampling errors (HPV and cytology negative), false-negative histologic diagnoses, and treatment failures preceded 11.2%, 9.0%, and 4.3%, respectively, of all cancers. There was significant heterogeneity in the causes of cancer by histologic category (p<0.001 for all; p=0.002 excluding prevalent cases). Programmatic effectiveness (95.3%) and diagnostic yield were greater for squamous cell versus adenocarcinoma histology (p<0.0001) and both decreased with older ages (ptrend<0.0001). CONCLUSIONS: A state-of-the-art intensive screening program results in very few cervical cancers, most of which are detected early by screening. Screening may become less efficient at older ages.

Protection against cervical cancer versus decreasing harms from screening - What would U.S. patients and clinicians prefer, and do their preferences matter?

The primary goal for many providers in the United States has been to deliver the level of protection against cervical cancer afforded by annual cervical cytology while improving screening test performance. Adoption of recent screening recommendations has been inconsistent and has created considerable consternation and confusion. This editorial addresses the perspective of U.S. patients and providers and how their preferences may run counter to current screening recommendations.

Risks of CIN 2+, CIN 3+, and Cancer by Cytology and Human Papillomavirus Status: The Foundation of Risk-Based Cervical Screening Guidelines.

OBJECTIVES: The next round of the American Society for Colposcopy and Cervical Pathology (ASCCP)-sponsored cervical cancer screening and management guidelines will recommend clinical actions based on risk, rather than test-based algorithms. This article gives preliminary risk estimates for the screening setting, showing combinations of the 2 most important predictors, human papillomavirus (HPV) status and cytology result. MATERIALS AND METHODS: Among 1,262,713 women aged 25 to 77 years co-tested with HC2 (Qiagen) and cytology at Kaiser Permanente Northern California, we estimated 0-5-year cumulative risk of cervical intraepithelial neoplasia (CIN) 2+, CIN 3+, and cancer for combinations of cytology (negative for intraepithelial lesion or malignancy [NILM], atypical squamous cells of undetermined significance [ASC-US], low-grade squamous intraepithelial lesion [LSIL], atypical squamous cells cannot exclude HSIL [ASC-H], high-grade squamous intraepithelial lesion [HSIL], atypical glandular cells [AGC]) and HPV status. RESULTS: Ninety percent of screened women had HPV-negative NILM and an extremely low risk of subsequent cancer. Five-year risks of CIN 3+ were lower after HPV negativity (0.12%) than after NILM (0.25%). Among HPV-negative women, 5-year risks for CIN 3+ were 0.10% for NILM, 0.44% for ASC-US, 1.8% for LSIL, 3.0% for ASC-H, 1.2% for AGC, and 29% for HSIL+ cytology (which was very rare). Among HPV-positive women, 5-year risks were 4.0% for NILM, 6.8% for ASC-US, 6.1% for LSIL, 28% for ASC-H, 30% for AGC, and 50% for HSIL+ cytology. CONCLUSIONS: As a foundation for the next guidelines revision, we confirmed with additional precision the risk estimates previously reported for combinations of HPV and cytology. Future analyses will estimate risks for women being followed in colposcopy clinic and posttreatment and will consider the role of risk modifiers such as age, HPV vaccine status, HPV type, and screening and treatment history.

The population impact of human papillomavirus/cytology cervical cotesting at 3-year intervals: Reduced cervical cancer risk and decreased yield of precancer per screen.

BACKGROUND: The objective of cervical screening is to detect and treat precancer to prevent cervical cancer mortality and morbidity while minimizing overtreatment of benign human papillomavirus (HPV) infections and related minor abnormalities. HPV/cytology cotesting at extended 5-year intervals currently is a recommended screening strategy in the United States, but the interval extension is controversial. In the current study, the authors examined the impact of a decade of an alternative, 3-year cotesting, on rates of precancer and cancer at Kaiser Permanente Northern California. The effect on screening efficiency, defined as numbers of cotests/colposcopy visits needed to detect a precancer, also was considered. METHODS: Two cohorts were defined. The "open cohort" included all women screened at least once during the study period; > 1 million cotests were performed. In a fixed "long-term screening cohort," the authors considered the cumulative impact of repeated screening at 3-year intervals by restricting the cohort to women first cotested in 2003 through 2004 (ie, no women entering screening later were added to this group). RESULTS: Detection of cervical intraepithelial neoplasia 3/adenocarcinoma in situ (CIN3/AIS) increased in the open cohort (2004-2006: 82.0/100,000 women screened; 2007-2009: 140.6/100,000 women screened; and 2010-2012: 126.0/100,000 women screened); cancer diagnoses were unchanged. In the long-term screening cohort, the detection of CIN3/AIS increased and then decreased to the original level (2004-2006: 80.5/100,000 women screened; 2007-2009: 118.6/100,000 women screened; and 2010-2012: 84.9./100,000 women screened). The number of cancer diagnoses was found to decrease. When viewed in terms of screening efficiency, the number of colposcopies performed to detect a single case of CIN3/AIS increased in the cohort with repeat screening. CONCLUSIONS: Repeated cotesting at a 3-year interval eventually lowers population rates of precancer and cancer. However, a greater number of colposcopies are required to detect a single precancer. Cancer 2016;122:3682-6. © 2016 American Cancer Society.

Age-stratified 5-year risks of cervical precancer among women with enrollment and newly detected HPV infection.

It is unclear whether a woman's age influences her risk of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) upon detection of HPV. A large change in risk as women age would influence vaccination and screening policies. Among 972,029 women age 30-64 undergoing screening with Pap and HPV testing (Hybrid Capture 2, Qiagen, Germantown, MD) at Kaiser Permanente Northern California (KPNC), we calculated age-specific 5-year CIN3+ risks among women with HPV infections detected at enrollment, and among women with "newly detected" HPV infections at their second screening visit. Women (57,899, 6.0%) had an enrollment HPV infection. Among the women testing HPV negative at enrollment with a second screening visit, 16,724 (3.3%) had a newly detected HPV infection at their second visit. Both enrollment and newly detected HPV rates declined with age (p < 0.001). Women with enrollment versus newly detected HPV infection had higher 5-year CIN3+ risks: 8.5% versus 3.9%, (p < 0.0001). Risks did not increase with age but declined slightly from 30-34 years to 60-64 years: 9.4% versus 7.4% (p = 0.017) for enrollment HPV and 5.1% versus 3.5% (p = 0.014) for newly detected HPV. Among women age 30-64 in an established screening program, women with newly detected HPV infections were at lower risk than women with enrollment infections, suggesting reduced benefit vaccinating women at older ages. Although the rates of HPV infection declined dramatically with age, the subsequent CIN3+ risks associated with HPV infection declined only slightly. The CIN3+ risks among older women are sufficiently elevated to warrant continued screening through age 65.

Use of primary high-risk human papillomavirus testing for cervical cancer screening: interim clinical guidance.

In 2011, the American Cancer Society, the American Society for Colposcopy and Cervical Pathology, and the American Society for Clinical Pathology updated screening guidelines for the early detection of cervical cancer and its precursors. Recommended screening strategies were cytology and cotesting (cytology in combination with hrHPV testing). These guidelines also addressed the use of hrHPV testing alone as a primary screening approach, which was not recommended for use at that time. There is now a growing body of evidence for screening with primary hrHPV testing, including a prospective US-based registration study. Thirteen experts including representatives from the Society of Gynecologic Oncology, American Society for Colposcopy and Cervical Pathology, American College of Obstetricians and Gynecologists, American Cancer Society, American Society of Cytopathology, College of American Pathologists, and the American Society for Clinical Pathology, convened to provide interim guidance for primary hrHPV screening. This guidance panel was specifically triggered by an application to the FDA for a currently marketed HPV test to be labeled for the additional indication of primary cervical cancer screening. Guidance was based on literature review and review of data from the FDA registration study, supplemented by expert opinion. This document aims to provide information for healthcare providers who are interested in primary hrHPV testing and an overview of the potential advantages and disadvantages of this strategy for screening as well as to highlight areas in need of further investigation.

Use of primary high-risk human papillomavirus testing for cervical cancer screening: interim clinical guidance.

In 2011, the American Cancer Society, the American Society for Colposcopy and Cervical Pathology, and the American Society for Clinical Pathology updated screening guidelines for the early detection of cervical cancer and its precursors. Recommended screening strategies were cytology or cotesting (cytology in combination with high-risk HPV (hrHPV) testing). These guidelines also addressed the use of hrHPV testing alone as a primary screening approach, which was not recommended for use at that time. There is now a growing body of evidence for screening with primary hrHPV testing, including a prospective US-based registration study. Thirteen experts including representatives from the Society of Gynecologic Oncology, American Society for Colposcopy and Cervical Pathology, American College of Obstetricians and Gynecologists, American Cancer Society, American Society of Cytopathology, College of American Pathologists, and the American Society for Clinical Pathology, convened to provide interim guidance for primary hrHPV screening. This guidance panel was specifically triggered by an application to the FDA for a currently marketed HPV test to be labeled for the additional indication of primary cervical cancer screening. Guidance was based on literature review and review of data from the FDA registration study, supplemented by expert opinion. This document aims to provide information for health care providers who are interested in primary hrHPV testing and an overview of the potential advantages and disadvantages of this strategy for screening as well as to highlight areas in need of further investigation.

2012 updated consensus guidelines for the management of abnormal cervical cancer screening tests and cancer precursors.

A group of 47 experts representing 23 professional societies, national and international health organizations, and federal agencies met in Bethesda, MD, September 14-15, 2012, to revise the 2006 American Society for Colposcopy and Cervical Pathology Consensus Guidelines. The group's goal was to provide revised evidence-based consensus guidelines for managing women with abnormal cervical cancer screening tests, cervical intraepithelial neoplasia (CIN) and adenocarcinoma in situ (AIS) following adoption of cervical cancer screening guidelines incorporating longer screening intervals and co-testing. In addition to literature review, data from almost 1.4 million women in the Kaiser Permanente Northern California Medical Care Plan provided evidence on risk after abnormal tests. Where data were available, guidelines prescribed similar management for women with similar risks for CIN 3, AIS, and cancer. Most prior guidelines were reaffirmed. Examples of updates include: Human papillomavirus-negative atypical squamous cells of undetermined significance results are followed with co-testing at 3 years before return to routine screening and are not sufficient for exiting women from screening at age 65 years; women aged 21-24 years need less invasive management, especially for minor abnormalities; postcolposcopy management strategies incorporate co-testing; endocervical sampling reported as CIN 1 should be managed as CIN 1; unsatisfactory cytology should be repeated in most circumstances, even when HPV results from co-testing are known, while most cases of negative cytology with absent or insufficient endocervical cells or transformation zone component can be managed without intensive follow-up.

Benchmarking CIN 3+ risk as the basis for incorporating HPV and Pap cotesting into cervical screening and management guidelines.

OBJECTIVE: In 2012, the US Preventive Services Task Force (USPSTF) and a consensus of 25 organizations endorsed concurrent cytology and human papillomavirus (HPV) testing ("cotesting") for cervical cancer screening. Past screening and management guidelines were implicitly based on risks defined by Pap-alone, without consideration of HPV test results. To promote management that is consistent with accepted practice, new guidelines incorporating cotesting should aim to achieve equal management of women at equal risk of cervical intraepithelial neoplasia grade 3 and cancer (CIN 3+). METHODS: We estimated cumulative 5-year risks of CIN 3+ for 965,360 women aged 30 to 64 years undergoing cotesting at Kaiser Permanente Northern California over 2003 to 2010. We calculated the implicit risk thresholds for Pap-alone and applied them for new management guidance on HPV and Pap cotesting, citing 2 examples: HPV-positive/atypical squamous cells of undetermined significance (ASC-US) and HPV-negative/Pap-negative. We call this guidance process "benchmarking." RESULTS: A low-grade squamous intraepithelial lesion result, for which immediate colposcopy is prescribed, carries a 5-year CIN 3+ risk of 5.2%, suggesting that test results with similar risks should be managed with colposcopy. Similarly, ASC-US (2.6% risk) is managed with a 6- to 12-month follow-up visit and Pap-negative (0.26% risk) is managed with a 3-year follow-up visit. The 5-year CIN 3+ risk for women with HPV-positive/ASC-US was 6.8% (95% confidence interval = 6.2%-7.6%). This is greater than the 5.2% risk implicitly leading to referral to colposcopy, consistent with current management recommendations that HPV-positive/ASC-US should be referred for immediate colposcopy. The 5-year CIN 3+ risk for women with HPV-negative/Pap-negative was 0.08% (95% confidence interval = 0.07%-0.09%), far below the 0.26% implicitly required for a 3-year return and justifying a longer (e.g., 5-year) return. CONCLUSIONS: Using the principle of "equal management of equal risks," benchmarking to implicit risk thresholds based on Pap-alone can be used to achieve safe and consistent incorporation of cotesting.

Five-year risks of CIN 3+ and cervical cancer among women with HPV testing of ASC-US Pap results.

OBJECTIVE: New screening guidelines recommend that human papillomavirus (HPV)-negative/atypical squamous cells of undetermined significance (ASC-US) results be considered as equivalent to HPV-negative/Pap-negative results, leading to rescreening in 5 years. However, despite ample data, the routine clinical performance of HPV testing of women with ASC-US has not been adequately documented. METHODS: We estimated 5-year risks of cervical intraepithelial neoplasia (CIN) 3+ and of cancer among 2 groups of women between 2003 and 2010 at Kaiser Permanente Northern California: 27,050 aged 30 to 64 years who underwent HPV and Pap cotesting and had an ASC-US Pap result and 12,209 aged 25 to 29 years who underwent HPV triage of ASC-US. RESULTS: Five-year risks of CIN 3+ and of cancer among women aged 30 to 64 years testing HPV-negative/ASC-US and among 923,152 women testing Pap-negative alone were similar although statistically distinguishable (CIN 3+, 0.43% vs 0.26%, p = .001; cancer, 0.050% vs 0.025%, p = .1). The increased risk of cancer after HPV-negative/ASC-US versus Pap-negative alone was confined to women aged 60 to 64 years (0.26% vs 0.035%, p = .3). Five-year risks of CIN 3+ and cancer among women with HPV-negative/ASC-US results were substantially higher than those among women testing HPV-negative/Pap-negative (CIN 3+, 0.43% vs 0.08%, p < .0001; cancer, 0.050% vs 0.011%, p = .003). For women aged 30 to 64 years testing HPV-positive/ASC-US, 5-year risks of CIN 3+ and cancer were slightly higher than those among 9,374 women with low-grade squamous intraepithelial lesion (LSIL) (CIN 3+, 6.8% vs 5.2%, p = .0007; cancer, 0.41% vs 0.16%, p = .04). Similar patterns were seen for women aged 25 to 29 years. CONCLUSIONS: Women with HPV-negative/ASC-US had a similar risk as women testing Pap-negative alone but had a higher risk than women testing HPV-negative/Pap-negative. Based upon the principle of "equal management of equal risks," our findings support the equal management of women with HPV-negative/ASC-US and those with Pap-negative alone, except for exiting women from screening because cancer risks at ages 60 to 64 years may be higher for women testing HPV-negative/ASC-US. Our findings also support managing HPV-positive/ASC-US and LSIL similarly.

Five-year risks of CIN 3+ and cervical cancer among women with HPV-positive and HPV-negative high-grade Pap results.

OBJECTIVE: High-grade Pap results (e.g., atypical glandular cells [AGC], atypical squamous cells cannot rule out HSIL [ASC-H], and high-grade squamous intraepithelial lesion [HSIL]) predict high cancer risks, resulting in referral for colposcopy without HPV triage. However, new guidelines recommending cotesting for women 30 years and older imply that clinicians will often receive the HPV test result concurrently for high-grade Pap results. We examined whether HPV testing provides useful risk stratification in this context. METHODS: From a cohort of 965,360 women aged 30 to 64 years undergoing cotesting at Kaiser Permanente Northern California, we estimated 5-year risks for cervical cancer and CIN 3+ after AGC (2,074 women), ASC-H (1,647 women), and HSIL (2,019 women) according to HPV test results. RESULTS: HPV positivity of AGC Pap results was 25% and decreased with age (30 to 34 vs 60 to 64 years, 44% vs 17%, p < .0001), whereas HPV positivity of ASC-H and HSIL was much higher (71% and 94%) and decreased less with age. Even for these high-grade Pap results, 5-year CIN 3+ risks differed substantially between HPV-positive and HPV-negative women (AGC, 33% vs 0.93%, p < .0001; ASC-H, 25% vs 3.5%, p < .0001; HSIL, 49% vs 30%, p = .006). However, except for AGC, cervical cancer risks differed less between HPV-positive and HPV-negative women (AGC, 9.0% vs 0.37%, p < .0001; ASC-H, 2.5% vs 2.1%, p = .8; HSIL, 6.6% vs 6.8%, p = .7). CONCLUSIONS: The risks of CIN 3+ among women with HPV-negative high-grade Pap results were lower than those among women with HPV-positive high-grade Pap results, especially after AGC. However, by the principle of "equal management of equal risks," all HPV-negative high-grade Pap results had cancer risks high enough to warrant colposcopy, confirming that there is no current role for HPV triage of high-grade Pap results.

Five-year risks of CIN 2+ and CIN 3+ among women with HPV-positive and HPV-negative LSIL Pap results.

OBJECTIVE: Low-grade squamous intraepithelial lesion (LSIL) Pap results do not typically lead to human papillomavirus (HPV) testing. HPV triage is not cost-effective because most cases are HPV-positive. However, under new national guidelines recommending cotesting for women aged 30 to 64 years, clinicians will increasingly receive the HPV test result with LSIL Pap results. Some authors have suggested that HPV triage might be effective at older ages, when the percentage of HPV positivity among women with LSIL declines. METHODS: We estimated 5-year risks of CIN 2+ and CIN 3+ among 9,033 women aged 30 to 64 years who had both an HPV test and an LSIL Pap result. RESULTS: HPV positivity among women with LSIL decreased only slightly with age (30 to 34 vs 60 to 64 years, 88% vs 72%, p < .0001). The 5-year risks of CIN 2+ and CIN 3+ of women aged 30 to 64 years testing HPV-positive/LSIL were larger than those among women testing HPV-negative/LSIL (CIN 2+, 19% vs 5.1%, p < .0001; CIN 3+, 6.1% vs 2.0%, p<.0001). The 5-year risk of CIN 3+ in HPV-negative/LSIL women was similar to that for women with atypical squamous cells of undetermined significance (ASC-US) Pap test result without knowledge of HPV test results (2.0% vs 2.6%, p = .4). CONCLUSIONS: HPV-negative/LSIL posed lower risk than other Pap results that guidelines currently recommend for referral to immediate colposcopy. By the principle of "equal management of equal risks," women with HPV-negative/LSIL might reasonably be managed similarly to those with ASC-US Pap results without knowledge of HPV testing, that is, retesting at 6 to 12 months, rather than immediate colposcopy. Although the HPV test result for LSIL Pap results provides actionable information to clinicians who screen with cotesting, the high HPV positivity of LSIL at even the oldest ages suggests the lack of cost-effectiveness of HPV triage of LSIL for clinicians who do not use routine cotesting.

Five-year risks of CIN 3+ and cervical cancer among women who test Pap-negative but are HPV-positive.

OBJECTIVE: Current US guidelines for cotesting recommend that the large numbers of women who test Pap-negative, but human papillomavirus (HPV)-positive, return in 1 year, and those who remain HPV-positive or have low-grade squamous intraepithelial lesion (LSIL) or worse Pap results be referred for colposcopy. However, the performance of these guidelines in routine clinical practice has not been evaluated. METHODS: We estimated cumulative 5-year risks of cervical intraepithelial neoplasia grade 3 or worse (CIN 3+) among 32,374 women aged 30 to 64 years with HPV-positive/Pap-negative cotest results at Kaiser Permanente Northern California during 2003 to 2010. RESULTS: The 5-year CIN 3+ risk after an HPV-positive/Pap-negative cotest result, which was found in 3.6% of women, was 4.5% (95% confidence interval [CI] = 4.2%-4.8%). The 5-year cancer risk was 0.34% (95% CI = 0.26%-0.45%), and half of the cases were adenocarcinoma. Overall, 48% of the women remained HPV-positive on return (median = 418 days after baseline), a percentage that varied little over ages 30 to 64 years. At the return after a baseline HPV-positive/Pap-negative result, almost every repeat cotest result predicted greater subsequent 5-year CIN 3+ risk than the same cotest result had at baseline (HPV-positive/LSIL, 9.2% vs 6.1%, p = .01; HPV-positive/atypical squamous cells of undetermined significance [ASC-US], 7.9% vs 6.8%, p = .2; HPV-positive/Pap-negative, 7.4% vs 4.5%, p < .0001; HPV-negative/LSIL,1.7% vs 2.0%, p = .8; HPV-negative/ASC-US, 2.9% vs 0.43%, p = .0005; HPV-negative/Pap-negative, 0.93% vs 0.08%, p < .0001). CONCLUSIONS: Using the principle of "equal management of equal risks," women testing HPV-positive/Pap-negative had a subsequent CIN 3+ risk consistent with risk thresholds for a 1-year return. However, on returning in approximately 1 year, about one-half of women will be referred for colposcopy because of continued HPV positivity or Pap abnormality. Clinicians should keep in mind that cotest results at the return after a baseline HPV-positive/Pap-negative finding are riskier than the same baseline cotest results in the general population, supporting intensified clinical management at return testing.