Commentary. The Papanicolaou Test and Cervical Cancer in the United States. HPV and Cervical Cancer Screening

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1 Commentary Primary Human Papillomavirus Screening for Cervical Cancer in the United States US Food and Drug Administration Approval, Clinical Trials, and Where We Are Today Ritu Nayar, MD 1 ; Robert A. Goulart, MD 2 ; Patricia G. Tiscornia-Wasserman, MD 3 ; and Diane Davis Davey, MD 4 The Papanicolaou Test and Cervical Cancer in the United States In the 1940s, cervical cancer was a major cause of death among women in the United States. However, after the wide implementation of screening programs, there was a sustained and dramatic reduction, with incidence and death rates declining by greater than 60% between 1955 and Once one of the most common cancers affecting US women, cervical cancer now ranks 14th in frequency. Although the effectiveness of cytologic screening for cervical cancer has never been demonstrated in a randomized trial, the impact of the Papanicolaou (Pap) test has been well documented in numerous observational studies, and its success as one of the most cost-effective screening tests serves a paradigm for successful preventive medicine. Particularly in the United States, where cervical cancer screening was and still is opportunistic, the positive impact of the Pap test on women s health is indeed remarkable. The Pap test is closely tied to key developments related to cervical cancer. It was during its early days that the field of gynecologic cytomorphology was defined; and, since its inception, there has been a gradual increase in understanding of cervical carcinogenesis. Although the Pap test has high specificity, its lower sensitivity requires multiple screenings to detect most precancers and cancers. In an effort to improve sensitivity, the Pap test evolved from conventional smears to liquid-based technologies, along with improved sampling devices, automated processing, and computer-imaging screening devices. The introduction of the Bethesda reporting terminology for Pap tests in correlated well with the increasing understanding of the role of human papillomavirus (HPV) in cervical cancer pathogenesis; and corresponding clinical management guidelines were aligned with Bethesda reporting terminology in Despite these advances, the Pap test has an inherent false-negative rate associated with screening and follow-up compliance, sample collection, and laboratory interpretation. HPV and Cervical Cancer Screening Over 100 HPV types may cause anogenital infections; however, only a limited number of high-risk genotypes have been associated with cervical cancer. 4 Persistent infection with a high-risk HPV (HR-HPV) is the single Corresponding author: Ritu Nayar, MD, Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611; r-nayar@northwestern.edu 1 Division of Cytopathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; 2 Division of Cytopathology, New England Pathology Associates at Mercy Medical Center, Springfield, Massachusetts; 3 Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York; 4 Department of Clinical Sciences, University of Central Florida, Orlando, Florida. Received: August 13, 2014; Accepted: August 14, 2014 Published online September 16, 2014 in Wiley Online Library (wileyonlinelibrary.com) DOI: /cncy.21480, wileyonlinelibrary.com 720 Cancer Cytopathology October 2014

2 Current State of Cervical HPV Screening/Nayer et al most important risk factor for progression to precancer and cancer, and approximately 70% of cancers and 54% of high-grade lesions are attributable to HPV types 16/18. It is important to emphasize that only a minority of women with persistent high-risk infections develop precancer, and only a small fraction of precancers progress to cancer, generally at least 20 years after initial HPV acquisition. The noncarcinogenic or low-risk-hpv subtypes, such as HPV6 and HPV11, are associated with genital warts but have no role in cervical cancer pathogenesis or screening/prevention. Understanding of this basic epidemiology and natural history of cervical carcinogenesis, along with major clinical trials like the US-based Atypical Squamous Cells of Undetermined Significance/Low Grade Squamous Intraepithelial Lesion (ASC-US/LSIL) Triage Study (ALTS), led to the introduction of reflex HR-HPV testing in for ASC-US in the 1990s. 5 In 2001, HPV triage testing was endorsed as the preferred management for the equivocal Pap test. 3 The findings from long-term prospective cohort studies and randomized clinical trials have demonstrated that DNA testing for HPV is substantially more sensitive than cervical cytology for the detection of cervical intraepithelial neoplasia grade 2 (CIN2), CIN grade 3 (CIN3), and cancer The addition of a negative HPV test helps ascertain a very low risk of CIN3 for a prolonged period, even up to 10 years from the time of the test. 11,12 The lower specificity of HPV testing and the potential for increased colposcopy/harm was mitigated initially by establishing a 3-year cotesting interval; this interval was subsequently increased to 5 years in 2012 based on accumulating data on the high negative predictive value (NPV) of a double-negative cotest. 13 The first generation of prophylactic HPV vaccines, composed of viral-like particles produced by cloning the major viral capsid genes (L1) that target HPV16/18, were approved in the United States in 2006 (Gardasil; Merck & Company, Inc., New York, NY) and 2009 (Cervarix; GlaxoSmithKline plc, Brentford, United Kingdom). Promising research is underway to develop the next generation of HPV vaccines, which will include up to 9 HPV types and prevent 90% of cervical cancer, have a therapeutic component, and be more affordable formulations with easier delivery methods. Current and future vaccines hold great promise for cervical cancer prevention in the next generation of women who are immunized in adolescence. Questions remain regarding vaccine target population, crossprotection, cost, and long-term efficacy. It will be decades before the impact of preventive vaccines on cervical cancer will be observed. 14 Currently, combining vaccination and screening will offer the best protection from cervical cancer. Primary Screening With HPV: US Food and Drug Administration Approval The high sensitivity of clinically validated HPV tests and issues with establishing quality cytology services in some locales led to the evaluation of primary HPV testing as a stand-alone screening modality for cervical cancer. On the basis of several large randomized controlled trials, there is now a high level of evidence that, in organized screening programs, HPV testing will detect CIN3 and cancer with significantly higher sensitivity than cytology, will be more efficient in preventing invasive disease than cytology, and will have a better NPV, allowing longer screening intervals than cytology alone. 10 On March 12, 2014, the US Food and Drug Administration (FDA) Microbiology Devices Panel of the Medical Devices Advisory Committee convened a hearing on a proposal by Roche Molecular Systems, Inc. (RMS) (Pleasanton, Calif) to seek approval for the cobas HPV test as an alternate primary screening method for women aged 25 years. 15 The RMS cobas HPV test is a qualitative in vitro test for the detection of HPV that was initially approved for use in conjunction with cervical cytology. The test uses amplification of target DNA by polymerase chain reaction (PCR) and nucleic acid hybridization for the detection of 14 HR-HPV types in a single study. The test identifies types HPV16 and HPV18 while synchronously detecting 12 other HR types (31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68). The role of the FDA was to define the safety and efficacy of the candidate test (the RMS cobas HPV test as primary screening) relative to the comparator test (cytology alone as primary screening). In their presentation, RMS reviewed the technical aspects of the cobas HPV test, the Addressing the Need for Advanced HPV Diagnostics (ATHENA) clinical study design, 15 demographics, and the distribution of cytology results and cobas HPV test results. RMS also defined the proposed new indication for use and offered a summary of the performance data to support their proposal. They concluded that HPV primary screening offers greater protection against CIN3 and invasive cervical cancer compared with cytology alone and also provides protection against CIN3 and invasive cervical cancer similar Cancer Cytopathology October

3 Commentary to the protection provided by cytology and HPV cotesting. The 13-member advisory panel unanimously approved the test as safe and effective and deemed that the benefits outweighed the risks for this indication. The FDA officially approved the additional Primary Screening Testing indication on April 24, ATHENA Trial Design Noteworthy points from the ATHENA trial include the following: The trial was prospective and representative of the US population ethnic and risk demographics, with participation from 4 clinical laboratories in 61 clinical centers representing 23 states. ATHENA was an observational study that was adjusted for verification bias, in which all abnormal test combinations and a subset of women with negative tests had identical disease assessment. This contrasts with randomized clinical trials. 15,16 In total, 47,208 women aged 21 years who underwent routine cervical screening with cytology and the RMS cobas HPV test 17 were included. Note that, initially, the Amplicor and Linear Array tests (both from RMS) were used for HPV testing in the trial, and cobas testing was done subsequently. 15,16 Women aged <25 years and those who had missing results were excluded from the primary screening study, leaving 40,944 women with a median age of 41 years. The proportion of women in various age groups were as follows: ages 25 to 29 years, 16%; ages 30 to 39 years, 30%; ages 40 to 49 years, 29%; and aged 50 years, 25%. Women who were status post hysterectomy were not included in the ATHENA trial. HPV-vaccinated women comprised <2%. In total, 7642 eligible women who had undergone colposcopy and biopsy with results that indicated CIN1 or less as well as a subset of women who had negative cytology and HPV testing were selected randomly for a 3-year follow-up study. 15,16 The proposed cobas candidate algorithm was HPV primary screening, and women who tested positive for HPV genotypes 16/18 were referred to colposcopy. Women who tested positive for the other 12 HPV types received reflex cytology, and those with a result of ASC- US or higher underwent colposcopy. 15,16 The cobas HPV test performance was compared with cytology alone in which all women with abnormal results proceeded to colposcopy with no use of ASC-US-HPV triage. Performance characteristics assessed included sensitivity, specificity, positive predictive value (PPV), NPV, and colposcopy rate. The sponsors analyzed an additional comparator that included cotesting of women aged 30 years and ASC-US triage for women aged <30 years. 15,16 Results The rate of cytologic abnormality on the ThinPrep Pap test was 6.4% with an ASC-US:squamous intraepithelial lesion (SIL) ratio of 1.7:1.0. The overall positive rate for the cobas HPV test was 10.5%. 15,16 After adjustments for verification bias, the results indicated the following: 1. The sensitivity of the candidate (primary HPV screening algorithm) was 45.4% for the detection of CIN2, CIN3 or cancer (CIN2) compared with a cytology (comparator) sensitivity of 35.3%. The candidate sensitivity for the CIN3 or cancer (CIN3)thresholdwas58.3%,and cytology sensitivity was 42.6%, leading to a sensitivity gain of 1.37 (37%). The cobas candidate HPV algorithm was statistically better than the cytology comparator in terms of PPV, NPV, sensitivity, specificity, and positive and negative likelihood ratios; and, in addition to this performance, cobas required fewer colposcopy procedures for the detection of CIN3. 15,16 2. The additional comparator that included cotesting for women ages 30 years and ASC-US triage for younger women had sensitivities of 41.5% and 53.2% for CIN2 and CIN3, respectively. The candidate algorithm performed statistically better than the cotesting comparator for the parameters of sensitivity, predictive values, and likelihood ratios, it but did not differ statistically in the number of colposcopy procedures. 15,16 The cotesting additional comparator had statistically higher sensitivity for CIN3 lesions than the cobas candidate algorithm when women aged 30 years were analyzed (56.7% vs 53.6%). The cobas algorithm produced a much higher gain in sensitivity (disease detection) among women ages 25 to 29 years, who comprised 30% of those with CIN3 lesions. Over half of these young women had negative cytology; thus, starting HPV testing at this age would likely lead to more colposcopy procedures. RMS stated that, in the ATHENA trial, the addition of a negative Pap result to a negative HR-HPV result at baseline added little benefit andincreasedthecolposcopyratefrom4.6%to5.4%. 15,16 Observations with respect to the ATHENA data The long-term performance of HPV primary screening compared with other screening methods, including contesting, is not yet known, because the ATHENA trial has 722 Cancer Cytopathology October 2014

4 Current State of Cervical HPV Screening/Nayer et al only 3 years of follow-up. Additional studies are needed to determine which lifelong strategies will provide the best balance of access and cost in addition to an appropriate balance of harm and benefit. The cytology abnormal rate of 6.4% in the ATHENA trial is lower than average: it represents the 25th percentile reporting rate for laboratories surveyed by the College of American Pathologists (CAP), as published in recent laboratory accreditation checklists. 18 This low abnormal rate may have had an impact on verification bias adjusted sensitivity calculations. In addition, all women with abnormal cytology results were referred to colposcopy without the use of ASC-US/HPV triage per routine practice. This decreased the specificity of an abnormal cytology result in the ATHENA trial. Cytology and HPV testing achieved only 42.6% sensitivity and 58.3% sensitivity, respectively, for CIN3 lesions. Because these sensitivity rates are lower than much of the published literature, FDA panelists questioned RMS about the determination of disease status. Publication of data from the end of the ATHENA trial was pending as of the time of this publication. Other noteworthy points from the FDA hearing include the following: 1. The FDA presentation discussed potential bias introduced by knowledge of concurrent HR-HPV status on cytology performance, concluding that this leads to an approximately 1.3 times increased rate of diagnoses of abnormal cytology results. This bias ultimately would lead to an increase in colposcopy procedures and decreases in both specificity and PPV Clinicians expressed concern about the potential overtreatment of younger women. They noted that, in actual practice, any positive HR-HPV may trigger colposcopy without the suggested cytology triage for non-hpv16/ 18 genotypes. Because the suggested algorithm is a significant deviation from current practice, it could substantially increase colposcopy rates. Data assessing specificity and relative harms were of low quality and were limited to women aged 30 years, primarily from studies outside the United States. A major point raised was that the RMS candidate algorithm may be appropriate for settings in which there is organized screening and referral to specialized centers for evaluation and management; however, those conditions do not apply currently to most clinical settings in the United States. 3. When discussing the impact of HPV vaccination on screening, it was pointed out that sensitivity would decrease for both cytology and HPV, and RMS as well as the panel concluded that there will likely be a greater impact on the PPV of cytology, which is more subjective. 4. Questions regarding the potential loss of possible detection of noncervical cancers and organisms by cytology were mitigated by reiterating that cervical cytology is not considered appropriate for screening for other cancers by professional societies and that there are more sensitive and specific tests for infectious organisms. Other outstanding questions were summarized well by Dr. Francisco Garcia, who was a guest presenter to the FDA panel, 15 and included the following: 1. Is primary HPV screening clearly superior to HPV/ cytology cotesting? 2. Which triage strategy is most efficacious and cost effective? Cost-benefit analysis between different management algorithms was not a deliberation for FDA approval, but system costs in the current health care environment could prove to be important in the consideration of a new screening paradigm. 3. What are the optimal screening intervals? 4. What is the appropriate management of the HPV16/ 18-negative/HR-HPV-positive patient in this scenario? Considerations for Laboratorians The Cytopathology Education and Technology Consortium, which includes members of the American Society of Cytopathology (ASC), the American Society of Clinical Pathology (ASCP), CAP, the American Society for Cytotechnology, the International Academy of Cytology, and the Papanicolaou Society of Cytopathology, submitted a written statement to the FDA advisory panel before this hearing. 20 The Cytopathology Education and Technology Consortium report, which was read during the public comment period, raised concerns that included the use of laboratory-developed HPV tests, quality-control specimen adequacy, and HPV-negative cancers. These considerations are especially important when HPV testing is performed in practice outside of clinical trials. 15 HPV testing modalities and quality control In the United States, there are currently 4 FDA-approved HPV assays, specifically, the Digene Hybrid Capture 2 Cancer Cytopathology October

5 Commentary High-Risk HPV DNA test (Qiagen Group, Hilden, Germany); the Cervista HR-HPV and Cervista HPV16/18 tests (Hologic, Inc., Marlborough, Mass); the Aptima HPV assay and Aptima HPV16-18/45 genotype assay (Hologic, Inc.); and the Roche cobas HPV test (RMS). The RMS cobas HPV test is currently the only test approved by the FDA as a stand-alone test for primary screening. It is approved by the FDA explicitly for use with ThinPrep Pap test PreservCyt specimens (Hologic, Inc.) collected using an endocervical brush and spatula from cervical samples. The guidelines governing the use of HPV testing in cervical screening and management depend totally on the clinically validated performance of the HPV tests. However, some laboratories are using laboratory-developed HPV tests or off-label techniques, including alternative collection media for other liquidbased cytology tests and alternate collection devices. Because primary HPV screening represents a major paradigm shift in women s preventive health screening, the FDA and major pathology and clinical groups do not recommend the use of any HPV test for primary screening that is not approved for that specific indication Laboratories should be enrolled in adequate proficiency testing and should perform regular quality control and statistical analysis of all HPV tests that are used for screening (cotesting, primary screening) and triage. Laboratorians should communicate with their clinical colleagues to clarify the various HPV testing modalities that the laboratory is able to offer for cervical cancer screening and provide adequate and clear test-ordering options to encourage appropriate test utilization. 23 Specimen adequacy Internal control The cobas HPV test has an internal control for the b-globin gene. 24 Although this ensures that sufficient human DNA is present, the b-globin gene is not specific for cervical or vaginal epithelial cells. The effect of the presence of abundant inflammatory or contaminating cells was not specifically analyzed in the HPV primary screening trial. Without the inclusion of a morphologic control, there is a concern that specimens that test negative for HPV may inappropriately be labeled as negative. In clinical practice, it is possible that specimens containing epithelial cells outside the cervical-vaginal area or abundant inflammation with insufficient epithelial cells could be tested and not recognized, leading to potential false-negative HPV results. Women with unsatisfactory cytology results were excluded from the ATHENA trial, but the FDA conducted an additional analysis of unsatisfactory cytology results. 16 Of the total samples, 1.8% had an unsatisfactory cytology result, and most of these had a valid HPV result. The percentage of HPV-negative, HPV-positive, and HPV16/18- positive results in the unsatisfactory cytology group was similar to that from the overall trial results, and the FDA concluded that the study results would have been identical had the unsatisfactory cytology results been included. The unsatisfactory cytology rate was similar to the percentages reported nationally in surveys conducted by the CAP, in which a median of 1.1% of ThinPrep specimens were reported as unsatisfactory for evaluation. 25 Other studies have documented that HPV test results may be positive despite unsatisfactory cytology results and can provide clinically useful follow-up information However, those studies were conducted in conjunction with cytology testing, and the study by Rossi et al classified specimens that lacked a transformation zone component as unsatisfactory. Prior studies had indicated that women with unsatisfactory cytology results may be at increased risk of significant disease on followup. 29 However, with the advent of liquid-based cytology testing, most of the unsatisfactory results are related to scant cellularity, and various results in terms of risk status have been reported. 30,31 Additional causes of unsatisfactory results include bloody/menstrual specimens and the presence of certain types of lubricants, which interfere with ThinPrep processing. The 2012 American Society for Colposcopy and Cervical Pathology (ASCCP) Consensus Conference included clinical management guidelines regarding unsatisfactory cervical cytology. 32 The role of HPV triage and cotesting was explicitly addressed. It was recognized that some HPV tests do not use a negative cellular control, and others may not indicate epithelial origin. Thus, a negative HPV test cannot be relied on when the cervical cytology is unsatisfactory, and a woman with an unsatisfactory cytology sample that tests positive for HPV will require additional follow-up. Laboratories need to be aware that the internal control in the cobas HPV test is limited to human DNA and that a low-cellularity or contaminated sample can still provide a valid HPV test result. If the HPV test is positive for types other than HPV16/18, then the cobas HPV test algorithm recommends reflex cytology. This reflex 724 Cancer Cytopathology October 2014

6 Current State of Cervical HPV Screening/Nayer et al cytology result could still be unsatisfactory, requiring further follow-up testing. Laboratories may want to remind clinicians about the importance of correct sampling methods that will allow the algorithm to work as expected if they choose to offer HPV primary testing. Interfering substances The cobas labeling package insert includes limited information about potential interfering substances, including both endogenous (blood, peripheral blood mononuclear cells, mucus) and exogenous (vaginal lubricants and medications) substances. 23 Although no potential interfering substances were identified, it is possible that additional interfering substances will be identified with clinical use outside of trial settings. False-negative HPV results versus HPV-negative cervical cancer False-negative results can occur with HPV testing, and the analytic causes include: absence of specimen in the vial, the detection assay does not test for a specific HPV type, low copy number of HPV, the presence of inhibitors in the specimen tested, limitation of analytic sensitivity, and an inadequate specimen. 33 Even with good quality control, HPV testing cannot predict all types of cervical disease, including cancer. Large-scale studies have provided solid evidence of a subgroup of carcinomas, both squamous and glandular, and other tumor types that may be undetectable by HPV testing. A recently published US cancer registry study 34 revealed that HPV was not detected in 9.4% of cervical cancers, and an additional 3.2% of cervical cancers had rare HPV subtypes. A metaanalysis of cervical adenocarcinomas summarized by Zhao et al 35 demonstrated that approximately 90% of cervical adenocarcinomas are positive for HR-HPV, with a slightly lower detection rate than cervical squamous cell carcinoma. Negative HPV status also raises questions about the currently recommended 5-year interval for cotesting. Katki et al 12 reported that 37% of squamous carcinomas and 22% of cervical adenocarcinomas had a negative HPV test 5 years before the confirmed histologic diagnosis of cervical cancer. A multicenter study of 16 US institutions 36 indicated that 8.9% of patients with cervical cancer had a negative HPV test within the prior year. Extending the study beyond the prior year and including HPV detection rates from 1 to 3 years and from 3 to 5 years revealed negative HPV rates of 22.7% and 25%, respectively. Studies based on PCR tests performed on formalin-fixed, paraffinembedded tissues also confirmed the existence of true HPV-negative cervical cancers, probably derived independently from the HR-HPV pathway. 35 Evidence of HPV-negative tests is also well recognized and documented beyond our borders. In the United Kingdom trial A Randomized Trial of HPV Testing in Primary Cervical Screening (ARTISTIC), 37 HPV testing was negative in 25% of women who subsequently were diagnosed with invasive cervical carcinoma during 2 screening rounds. In the 20-year-old standardized and effective Australian National Cervical Screening Program, 38 Farnsworth reported an 8% negative HPV rate for cervical squamous carcinoma and an 80% negative HPV rate for cervical adenocarcinoma. A meta-analysis of worldwide studies, 39 which included >40,000 invasive cervical carcinomas, indicated that 89% were HPVpositive, and the 11% negative HPV cancers included adenocarcinomas and squamous carcinomas in older age groups. Considerations With Respect to Cervical Cancer Screening and Management Guidelines With the FDA approval of the first HPV test for primary cervical cancer screening for women aged 25 years, clinicians in the United States now have 3 different first-line screening options that they may offer to patients: the Pap test, cotesting with Pap and HPV tests, and HPV testing as a stand-alone test. Screening: Cotesting versus primary HPV testing In the United States, the 2012 screening guidelines recommended concurrent HPV and Pap testing ( cotesting ) every 5 years as the preferred option for screening women ages 30 to 65 years. 13 These guidelines strongly emphasize the need for balancing the sensitivity and specificity of screening tests to balance the harms with the benefits of screening. The guidelines group determined that there were insufficient data to recommend HPV primary screening as an alternative to cotesting at 5- year intervals or cytology alone at 3-year intervals. The data to support the 2012 recommendations came largely from Kaiser Permanente of Northern California (KPNC), an established screening program for which risk estimates were available from large numbers of women who Cancer Cytopathology October

7 Commentary have been screened with cotesting every 3 years since ,32 Subsequent to 2011, several studies have been published and/or presented at professional society meetings that suggest the screening interval between cotesting, currently recommended at 5 years, requires re-examination in light of the large number of negative results for both cytology and HPV tests within the 3-year to 5-year cycle before the diagnosis of invasive cervical cancer. 33,36,40 Like most cancers, clinical outcomes are better when cervical tumors are detected at a lower stage, and there is concern about delayed diagnoses resulting in higher stage tumors because of longer screening intervals after negative HPV results. Recent data published from the KPNC database 41 compared primary HPV testing (without concurrent Pap tests) every 3 years, primary Pap testing every 3 years, and concurrent Pap and HPV cotesting every 5 years. By using logistic regression and Weibull survival models, the authors estimated and compared risks of cancer and CIN3 for these 3 strategies among 1,011,092 women ages 30 to 64 years who tested HPV-negative and/or Papnegative in routine screening since The 3-year risk after a negative HPV result was lower than the 3-year risk after a negative Pap result (CIN % vs 0.19%; P<.0001; cancer50.011% vs 0.020%; P<.0001) and also was lower than the 5-year risk after an HPV-negative/ Pap-negative cotest (CIN % vs 0.11%; P<.0001; cancer50.011% vs 0.014%; P5.21). The authors concluded that the findings suggest that primary HPV testing merits consideration as another alternative for cervical screening, because primary HPV testing every 3 years may provide as much, if not more, reassurance against precancer and cancer compared with other currently recommended screening modalities. However, examination of Figure 1 in the article by Gage et al 41 indicates that a cotest performed at a 3-year interval provides slightly greater protection than HPV primary screening every 3 years. Thus, it remains to be determined whether cumulative HPV primary screening over many cycles provides the same protection as cotesting performed at 3-year or 5-year intervals. For example, the ASCCP guidelines recommend that older women with HPV-negative ASC- US results should not exit screening because of a slightly higher risk of CIN3 and cancer compared with women who cotest negative; the increased risk of high-grade disease in older women with HPV-negative ASC-US is well illustrated in a recent KPNC publication. 32,42 Should women who elect to undergo HPV primary screening also receive cytology screening at certain intervals, including exit of screening? Management guidelines for abnormal screening results Cervical cancer screening guidelines allow professional societies to distinguish preferred screening algorithms from acceptable screening algorithms. They are also able to provide detailed recommendations regarding the follow-up of specific cytology results and/or specific combinations of cytology and HPV test results over time, even for women who do not undergo immediate colposcopy. A woman who is not sent immediately to colposcopy may be followed in different ways, depending on her test results, history, and clinical findings. The algorithm proposed by RMS for screening women aged 25 years is as follows: 1. Women who test negative for high-risk HPV types by the cobas HPV test should be followed in accordance with the physician assessment of screening and medical history, other risk factors, and professional guidelines; 2. Women who test positive for HPV genotypes 16 and/ or 18 by the cobas HPV test should be referred to colposcopy; and 3. Women who test positive for HR-HPV and negative for HPV16/18 by the cobas HPV test (which includes the other 12 HR-HPV types) should be evaluated by cervical cytology to determine the need for referral to colposcopy. However, the FDA approval of primary HPV screening with the cobas test does not change current medical practice guidelines for cervical cancer screening in the United States. A task force appointed by the Society of Gynecologic Oncology and the ASCCP, which includes pathology representatives from the ASC, ASCP, and CAP, has prepared an interim clinical guidance document to provide information for health care providers who are interested in primary HPV testing. This document provides an overview of the potential advantages and disadvantages of this strategy for screening and highlights areas in need of further investigation. 22 We know from experience with prior guidelines that it takes substantial time and effort to develop evidence-based algorithms and to provide education for providers and patients. Despite concerted efforts to 726 Cancer Cytopathology October 2014

8 Current State of Cervical HPV Screening/Nayer et al Table 1. Primary Human Papillomavirus Screening Summary Points 1. Roche cobas (Roche Molecular Systems, Inc., Pleasanton, Calif) is the only test approved by the FDA for primary screening in United States 2. Roche cobas is approved for ThinPrep Pap test PreservCyt (Hologic, Marlborough, Mass) cervical specimens collected using an endocervical brush and spatula 3. Off-label HPV tests are not recommended for primary screening use 4. Roche cobas detects 14 high-risk HPV types and separately identifies genotypes 16/18 (HPV16/18) 5. Internal control for b-globin gene is not specific for cervical epithelial cells 6. There are limited data regarding interfering substances 7. Laboratories offering primary screening should be enrolled in proficiency testing and should perform quality-control measures 8. HPV-negative cervical cancers, both squamous and adenocarcinoma, are well documented 9. The suggested management algorithm is: a. Women negative for high-risk HPV primary screening should be rescreened no sooner than 3 years. b. Women positive for HPV16/18 by primary screening are referred for colposcopy c. Women positive for other HPV types by primary screening receive reflex cytology d. Interim clinical guidance document from ASCCP/SGO pending publication 10. Issues related to the ATHENA trial: a. Almost 33% of women identified with high-grade lesions were ages y, and colposcopy procedures would likely increase b. Data from 3 y of follow-up limit ability to predict the best longterm screening strategy c. There are limited data on the appropriate management of women who are persistently positive for HPV16/18 and negative on colposcopy 11. The United States has an opportunistic screening strategy, and patient access to screening and compliance varies considerably Abbreviations: ASCCP/SGO, American Society for Colposcopy and Cervical Pathology/Society of Gynecologic Oncology; ATHENA, Addressing the Need for Advanced HPV Diagnostics; FDA, US Food and Drug Administration; HPV, human papillomavirus; Pap, Papanicolaou. disseminate the 2012 ASCCP Consensus Guidelines for the management of abnormal cervical cancer screening tests and cancer precursors, there is still significant variation with compliance. Currently, cytology-only testing and cytology and HPV cotesting are being used variously in different age groups for cervical cancer screening. It is estimated that cotesting is being used in <50% of patients in the United States. 43 Thus, as with any new testing strategy, the adoption of primary HPV testing will most certainly require time, ongoing monitoring of clinician acceptance, patient compliance, as well as costbenefit and outcomes analyses. The Challenges That Remain Despite advances like liquid-based cytology, computerassisted screening, and the addition of HPV testing, the incidence and mortality from cervical cancer in the United States has remained relatively unchanged from 2002 to The American Cancer Society estimates that, in 2014, approximately 12,360 invasive cervical cancers will be diagnosed, and 4020 women will die of the disease. 44 Recent estimates from the US Surveillance, Epidemiology, and End Results (SEER) registry indicate that, after correction for hysterectomy prevalence, there may a second peak of cervical cancer in the sixth decade of life. 45 Cervical cancer screening in the United States remains opportunistic, with far from uniform test accessibility and patient compliance. It is not an organized national program with patient reminders like those in the United Kingdom and other European countries, that are considering the adoption of primary HPV screening. In addition, HPV vaccination uptake in the United States is far lower than that in countries like the United Kingdom, Australia, and Canada. 46 We also have an increasing number of immigrants, with the result that the relative frequency of HPV types is changing in our diverse ethnic population. Table 1 includes an overview of the status and recommendations for primary HPV screening, highlighting areas that require future research because of the currently limited data. Conclusions We must not waiver in our overriding goal to provide the highest level of preventive quality care to women as we consider the current and future scientific data and literature. However, we must remember and reiterate that no screening test is perfect. We cannot eliminate all risk with screening, no matter the test or target. The very basis of screening requires doing it periodically and repeatedly, whether it is a Pap test, cotesting, primary HPV screening, or mammography. The choice of cervical screening method may vary for a variety of reasons. Patient and provider preference along with geographic, demographic, and socioeconomic considerations all affect the choice of screening modality in a specific country, region, or practice setting. The American Society of Cytopathology supports these principles. 47 To avoid an increase in cervical cancer, we must prioritize access and cost while providing testing options that are scientifically valid and of high quality. FUNDING SUPPORT No specific funding was disclosed. CONFLICT OF INTEREST DISCLOSURES Dr. Nayar is currently President of the American Society of Cytopathology. Cancer Cytopathology October

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