Cost-effectiveness of alternative triage strategies for atypical squamous cells of undetermined significance

The development of cervical cancer and its precursors: what is the role of human papillomavirus infection?

Human papillomavirus (HPV) is a significant health care burden in the United States. The majority of sexually active men and women will be infected with HPV at some point in their lives and are subject to developing human papillomavirus-associated disease. Current estimates suggest that 20 million Americans are currently infected, and more than 5 million new infections occur each year. The prevalence of human papillomavirus is highest in populations in their late teens and early twenties, with nearly half of all new human papillomavirus infections occurring within 3 years of first intercourse. HPV is the necessary cause of genital warts, cervical intraepithelial neoplasia, and invasive cervical cancer. As such, human papillomavirus is responsible for significant medical morbidity and health care costs. Screening with cervical cytology has significantly reduced mortality rates; however, approximately 3900 women will die in 2005 from cervical cancer in the United States. Human papillomavirus DNA testing has shown promise in identifying high-grade abnormalities as an adjunct to traditional cytology, and should be used according to guidelines established by the American Cancer Society and the American College of Obstetricians and Gynecologists. The epidemiology of HPV infection and a brief introduction to the natural history of HPV infection will be presented here.

Cost-Effectiveness Analysis Based on the Atypical Squamous Cells of Undetermined Significance/Low-Grade Squamous Intraepithelial Lesion Triage Study (ALTS)

BACKGROUND

The ALTS (atypical squamous cells of undetermined significance [ASCUS] and low-grade squamous intraepithelial lesion [LSIL] Triage Study) suggests that, for women diagnosed with ASCUS, human papillomavirus (HPV) DNA testing followed by referral to colposcopy of only those women with oncogenic HPV (i.e., HPV DNA testing) is as effective at detecting cervical intraepithelial neoplasia (CIN) 3 or cancer (CIN3+) as referring all women with ASCUS for immediate colposcopy. We conducted a cost-effectiveness analysis of the ALTS trial to determine whether HPV DNA testing is a cost-effective alternative to immediate colposcopy or conservative management with up to three cytology examinations.

METHODS

Data from the ALTS trial were used in conjunction with medical care costs in a short-term decision model. The model compared the incremental costs per case of CIN3+ detected as measured by the incremental cost-effectiveness ratio (ICER) for the following management strategies for women with ASCUS: immediate colposcopy, HPV DNA testing, and conservative management with up to three cytology examinations.

RESULTS

The least costly and least sensitive strategy was conservative management with one repeat cytology examination using a threshold of high-grade squamous intraepithelial lesion (HSIL) for referral to colposcopy. Compared with this strategy, triage to colposcopy based on a positive HPV DNA test result had an ICER of 3517 dollars per case of CIN3+ detected. Immediate colposcopy and conservative management with up to three repeat cytology visits detected fewer cases of CIN3+ and were more costly than HPV DNA testing. Immediate colposcopy became cost-effective at 20,370 dollars compared with HPV DNA testing only if colposcopy and biopsy were assumed to be 100% sensitive.

CONCLUSIONS

HPV DNA testing is an economically viable strategy for triage of ASCUS cytology. The less than perfect sensitivity of colposcopy and biopsy needs to be accounted for in future clinical guidelines and policy analyses.

Lifetime effects, costs, and cost effectiveness of testing for human papillomavirus to manage low grade cytological abnormalities: results of the NHS pilot studies

OBJECTIVES

To predict the incremental lifetime effects, costs, and cost effectiveness of using human papillomavirus testing to triage women with borderline or mildly dyskaryotic cervical smear results for immediate colposcopy.

DESIGN

Modelling study.

SETTING

Three centres participating in NHS pilot studies, United Kingdom. Population Women aged 25-64 with borderline or mildly dyskaryotic cervical smear results.

INTERVENTIONS

Screening using conventional cytology, liquid based cytology, and four strategies with different age cut-off points and follow up times that used combined liquid based cytology and human papillomavirus testing (adjunctive human papillomavirus testing).

RESULTS

The model predicts that compared with using conventional cytology without testing for human papillomavirus, testing for the virus in conjunction with liquid based cytology for women with borderline or mildly dyskaryotic cervical smear results (aged 35 or more) would cost 3735 pounds sterling (5528 euros; 6474 dollars) per life year saved. Extending adjunctive human papillomavirus testing in combination with liquid based cytology to include women aged between 25 and 34 costs an additional 4233 pounds sterling per life year saved. Human papillomavirus testing is likely to reduce lifetime repeat smears by 52%-86% but increase lifetime colposcopies by 64%-138%.

CONCLUSIONS

Testing for human papillomavirus to manage all women with borderline or mildly dyskaryotic cervical smear results is likely to be cost effective. The predicted increase in lifetime colposcopies, however, deserves careful consideration.

Acceptability of self-collection of specimens for HPV DNA testing in an urban population

PURPOSE

To assess the acceptability of self-collection of specimens for human papillomavirus (HPV) DNA testing and to explore whether use of self-collected specimens would increase intention to participate in regular screening among low-income, inner-city, minority women.

METHODS

A written survey was administered to 172 women after they underwent gynecological examination and self-collection of a sample for HPV DNA testing.

RESULTS

Participants agreed that ease of use (69%), less painful procedure (62%), "could do it myself" (56%), and privacy (52%) were desirable characteristics of the self-sampling procedure they performed. Most of the participants (57%) reported that there was nothing they did not like about self-sampling; however, the majority (68%) preferred the clinician-collected test. Those recruited through a sexually transmitted disease (STD) clinic were significantly more likely than those recruited at a cancer screening clinic (57% vs. 24%), those with some or more college education were significantly more likely than those with less education (43% vs. 26%), and those who were not Hispanic were significantly more likely than those who were Hispanic (49% vs. 28%) to prefer the self-collected test. Although most women (47%) reported that they would be most likely to attend regular screening if tested by a clinician during a pelvic examination, 21% asserted that self-collection at home would increase their likelihood of participation in screening.

CONCLUSIONS

Although most of the predominantly Hispanic, low-income, uninsured, and recently screened women in the study preferred clinician-collected HPV tests to self-collected sampling, self-sampling is acceptable to the majority and may increase the likelihood of participation in cervical cancer screening programs.

Improving Papanicolaou test quality and reducing medical errors by using Toyota production system methods

OBJECTIVE

The objective of the study was to determine whether the Toyota production system process improves Papanicolaou test quality and patient safety.

STUDY DESIGN

An 8-month nonconcurrent cohort study that included 464 case and 639 control women who had a Papanicolaou test was performed. Office workflow was redesigned using Toyota production system methods by introducing a 1-by-1 continuous flow process. We measured the frequency of Papanicolaou tests without a transformation zone component, follow-up and Bethesda System diagnostic frequency of atypical squamous cells of undetermined significance, and diagnostic error frequency.

RESULTS

After the intervention, the percentage of Papanicolaou tests lacking a transformation zone component decreased from 9.9% to 4.7% (P = .001). The percentage of Papanicolaou tests with a diagnosis of atypical squamous cells of undetermined significance decreased from 7.8% to 3.9% (P = .007). The frequency of error per correlating cytologic-histologic specimen pair decreased from 9.52% to 7.84%.

CONCLUSIONS

The introduction of the Toyota production system process resulted in improved Papanicolaou test quality.

Is Cytologic Screening an Effective Surveillance Method for Detection of Vaginal Recurrence of Uterine Cancer?

OBJECTIVE

Cytologic screening is commonly used in follow-up of women with uterine cancer to detect vaginal recurrence. The study objective was to assess the efficacy and costs associated with Pap tests in routine surveillance of women with uterine cancer.

METHODS

Medical records and pathology databases identified patients with uterine cancer at one institution from 1990 to 2002. Patients with their cytologic follow-up at our institution were selected for a subset analysis of Pap tests to estimate the number of Paps and associated charges and costs during follow-up.

RESULTS

Seven hundred seventeen women were diagnosed with uterine cancer; the mean age was 60.9 years and the median follow-up was 46 months. A total of 36 women had a recurrence in the vagina; 31 (86%) were apparent clinically, and only 5 (14%) were asymptomatic and identified by Pap test. Women with grade 1 tumors had decreased risk of vaginal recurrence, with an odds ratio of 0.186 (95% confidence interval 0.49-0.712) on multivariate analysis (stage and histology were not significant factors for vaginal recurrence). A subset of 435 patients received cytologic follow-up at our institution, with a median 3 Pap tests/patient (mean 4.25, range 1-24). Estimates based on our data demonstrate that 430 Pap tests are required to detect one asymptomatic vaginal recurrence, and the addition of the Pap test increases the cost of surveillance by $15,142 per asymptomatic recurrence detected (but a charge to insurance of $23,487). Pap tests identified an asymptomatic vaginal recurrence in only 0.7% of this uterine cancer population.

CONCLUSION

Pap tests after diagnosis and treatment of uterine cancer infrequently detect asymptomatic vaginal recurrences and may not be cost-effective.

LEVEL OF EVIDENCE

III.

Cervical Neoplasia Complicating Pregnancy

This article reviews the key concepts regarding the counseling and management of cervical dysplasia and invasive cervical cancer diagnosed during pregnancy. Emphasis is placed on balancing the maternal and fetal well-being in collaboration with appropriate multidisciplinary teams. Information regarding appropriate diagnosis strategies and the impact of delay in treatment, subsequent prognosis, and treatment algorithms are discussed. Novel fertility-sparing techniques for cervical cancer and their impact on complications of future pregnancies are also discussed.

Acceptability of human papillomavirus self testing in female adolescents

OBJECTIVES

To develop scales assessing acceptability of human papillomavirus (HPV) testing in adolescents, to compare acceptability of self to clinician testing, and to identify adolescent characteristics associated with acceptability.

METHODS

Female adolescents 14-21 years of age attending a hospital based teen health centre self collected vaginal samples and a clinician, using a speculum, collected cervicovaginal samples for HPV DNA. Acceptability of and preferences for self and clinician testing were assessed at baseline and 2 week visits.

RESULTS

The mean age of the 121 participants was 17.8 years and 82% were black. The acceptability scales demonstrated good internal consistency, reliability, test-retest reliability, and factorial validity. Scores were significantly lower for self testing than clinician testing on the acceptability scale and three subscales measuring trust of the test result, confidence in one's ability to collect a specimen, and perceived effects of testing (p < 0.01). Of those who reported a preference, 73% preferred clinician to self testing. Acceptability scores for both self and clinician testing increased significantly pre-examination to post-examination (p < 0.01). Multivariable analyses demonstrated that race was independently associated with pre-examination and post-examination acceptability of self testing, and that sexual behaviours and gynaecological experiences were associated with specific acceptability subscales.

CONCLUSIONS

This sample of adolescents found clinician testing for HPV to be more acceptable than self testing and preferred clinician to self testing. If self testing for HPV is offered in the future, clinicians should not assume that adolescent patients will prefer self testing. Instead, they should educate adolescents about available testing options and discuss any concerns regarding self collection technique or accuracy of test results.

The prevalence of HR-HPV DNA in ASC-US Pap smears: A military population study

OBJECTIVE

To determine the prevalence of HR-HPV DNA in ASC-US Pap smears following implementation of the Bethesda 2001 classification system.

METHODS

A computer database of Pap smears obtained within Department of the Army medical facilities was queried for the study period August 2002 to June 2004. All ASC-US Pap smears that underwent reflex testing for HR-HPV DNA were included. Additional clinical and demographic data were obtained from facilities within the US northeast region to evaluate the differences in ASC-US and SIL rates between the current and former Bethesda classification systems.

RESULTS

550,000 Pap smears were collected during the study period. The HR-HPV prevalence was 40.8% (95% confidence interval [CI] = 40.3 to 41.3) among 40,870 patients with ASC-US Pap smears. Within the northeast region, the HR-HPV prevalence in ASC-US Pap smears decreased from 61.2% (95% CI = 57.4 to 64.8%) in patients 18-22 years old to 24.9% (95% CI = 23.1 to 26.8%) in patients age 29 and older. When comparing the two classification systems, significant increases in both ASC-H and SIL and decreases in ASC-US were appreciated after the institution of Bethesda system 2001.

CONCLUSION

In our large, diverse cohort, the implementation of the Bethesda II system has resulted in a decrease in ASC-US Pap smear results. Additionally, the prevalence of HR-HPV in the ASC-US population was 40.8%, significantly lower than the rate noted in the ALTS trial under the Bethesda I classification system.

HPV DNA testing in the triage of atypical squamous cells of undetermined significance (ASCUS): cost comparison of two methods

Human papillomavirus (HPV) DNA testing for triage of cervical cytologies showing atypical squamous cells of undetermined significance (ASCUS) has become the standard of practice. Currently, Hybrid Capture II (HCII) is the preferred method for ASCUS triage. In situ hybridization for HPV represents an alternative to HCII and appears to have a superior specificity but is more expensive. We compare the reimbursement rates of ASCUS triage (HPV high risk) using the methods of HCII and INFORM (in situ hybridization for HPV) in a series of 431 ASCUS patients. The patients were followed for 1 yr, during which each patient had either colposcopic biopsy or follow-up cervical cytology after ASCUS HPV DNA triage. Eighty-nine patients were excluded from the analysis because of incomplete follow-up. The HPV triage percentages, colposcopic biopsy positivity rates and cervical cytology positivity percentages were calculated for each method. The reimbursement rates of the tests/procedures used in the analysis were those in effect at the University of Utah in 2003. The total triage and follow-up reimbursement costs were calculated for HCII and INFORM and compared.HCII referred 19.9% of patients to colposcopy, with a biopsy positivity rate of 25.6% for dysplasia. INFORM referred 11.8% of patients to colposcopy, of whom 34% had a biopsy diagnosis of dysplasia. HCII negative cases revealed 19% to have ASCUS or higher on the follow-up cervical cytology, while 19.9% of INFORM negative cases had a reading of ASCUS or higher at follow-up cytologic examination. The 1-yr HPV DNA triage and follow-up reimbursements for HCII were 316,942.00 US dollars per 1,000 women, and for the INFORM methodology, the reimbursements were 369,484.00 US dollars per 1,000 women. The INFORM method was associated with higher specificity and sent fewer (41%) patients to colposcopy than did HCII. Although this smaller referral rate reduced reimbursement costs associated with colposcopy, the increased reimbursement paid for follow-up cytologies and office visits of HPV DNA negative patient and the greater cost of the INFORM test results in higher overall reimbursement for INFORM. Based on these costs and diagnostic accuracies, it appears that the INFORM HPV technology represents a viable option to HCII ASCUS triage. INFORM HPV appears to be 16% more expensive than HCII but has the advantage of sending 41% fewer women to colposcopy.

Delivering cervical cancer prevention services in low-resource settings

The goals of any cervical cancer prevention program should be threefold: to achieve high coverage of the population at risk, to screen women with an accurate test as part of high-quality services, and to ensure that women with positive test results are properly managed. This article focuses on the experiences of the Alliance for Cervical Cancer Prevention (ACCP) in delivery of screening and treatment services as part of cervical cancer prevention projects in Africa, Latin America, and Asia. Research and experience show that cervical cancer can be prevented when strategies and services are well planned and well managed and when attention is paid to program monitoring and evaluation. Coordination of program components, reduction of the number of visits, improvement of service quality, and flexibility in how services are delivered are all essential features of an effective service.

Diagnosis and management of oncogenic cervical human papillomavirus infection

Cervical HPV infection should be managed less as a typical STI and more as a strong risk factor predisposing to cervical cancer development. HPV infection is undeniably transmitted predominately through sexual contact.However, the fact that more than 80% of women followed over time will acquire at least one HR-HPV infection reflects the ubiquitous nature of the infection and the ease of transmission. Although the behavioral profiles typically associated with an increased risk for STI (including lifetime partner number, age at first intercourse, and so forth) will certainly lead to an increased risk for HPV detection, there is a high absolute prevalence of HPV even among women who have few lifetime sex partners. It could be argued that to counsel patients for an HPV infection as an STI would be counterproductive, as short of absolute abstinence, the prevention of infection is difficult and treatment options, short of excisional procedures for neoplasia, are limited. The real promise held in this area is the availability of an apparently highly effective prophylactic HPV vaccine, targeting at least HPV 16, 18, 6, and 11[33,34]. This vaccine cocktail, if it achieved 100% coverage, could theoretically prevent 50% to 70% of invasive cervical cancers and most genital warts. Vaccination will be required among women before initiation of sexual contact, presumably among girls 10 to 13 years of age. Many programmatic issues remain regarding the implementation of HPV vaccine programs, including the marketing of the vaccine as STI or cancer prevention,as reviewed in detail by Gravitt and Shah [72]. Even in the era of potentially effective vaccines, screening for cervical cancer is likely to remain a priority in cervical cancer prevention programs for at least several decades. Vaccine trials have proven high short-term efficacy; however, these effects were clearly type-specific and antibody titers gradually decrease postvaccination. It is unclear whether the protection will remain over an individual's lifetime without vaccine booster, and oncogenic HPV infections not targeted by vaccination will continue to contribute to risk for development of cervical intraepithelial neoplasia and cancer. Therefore, although the public health success of HPV vaccination is undoubtedly promising, the role of cervical cancer screening as a secondary prevention effort should not be trivialized. In fact, the nature of screening programs should continue to be reevaluated in the context of effective but limited spectrum vaccines.

Screening for cervical cancer and initial treatment of patients with abnormal results from papanicolaou testing

New techniques for cervical cancer screening and a better understanding of the natural history of human papillomavirus (HPV) and cervical neoplasia have inspired a quest for more rational screening strategies for cervical cancer. Often, screening intervals for women older than 30 years can be expanded safely to every 3 years, and experts now agree that screening may cease after hysterectomy and in elderly women (provided certain criteria have been met). Liquid-based cytology produces more satisfactory specimens than conventional testing and offers the valuable option of treating atypical squamous cells of undetermined significance by "reflex" testing for high-risk types of HPV on the original specimen. Testing for HPV as an adjunct to cervical cytology for primary screening is now considered reasonable for many women older than 30 years.

Cost-effectiveness of human papillomavirus DNA testing in the United Kingdom, The Netherlands, France, and Italy

BACKGROUND

European countries with established cytology-based screening programs for cervical cancer will soon face decisions about whether to incorporate human papillomavirus (HPV) DNA testing and what strategies will be most cost-effective. We assessed the cost-effectiveness of incorporating HPV DNA testing into existing cervical cancer screening programs in the United Kingdom, The Netherlands, France, and Italy.

METHODS

We created a computer-based model of the natural history of cervical carcinogenesis for each using country-specific data on cervical cancer risk and compared each country's current screening policy with two new strategies: 1) cytology throughout a woman's lifetime, using HPV DNA testing as a triage strategy for equivocal cytology results ("HPV triage"), as well as 2) cytology until age 30 years and HPV DNA testing in combination with cytology in women more than 30 years of age ("combination testing"). Outcomes included reduction in lifetime cervical cancer risk, increase in life expectancy, lifetime costs, and incremental cost-effectiveness ratios, expressed as cost per year of life saved. We explored alternative protocols and conducted sensitivity analysis on key parameters of the model over a relevant range of values to identify the most cost-effective options for each country.

RESULTS

Both HPV DNA testing strategies, HPV triage and combination testing, were more effective than each country's status quo screening policy. Incremental cost-effectiveness ratios for HPV triage were less than $13,000 per year of life saved, whereas those for combination testing ranged from $9800 to $75,900 per year of life saved, depending on screening interval. We identified options that would be very cost-effective (i.e., cost-effectiveness ratio less than the gross domestic product per capita) in each of the four countries.

CONCLUSIONS

HPV DNA testing has the potential to improve health benefits at a reasonable cost compared with current screening policies in four European countries.

Should liquid-based cytology be repeated at the time of colposcopy?

OBJECTIVE

To evaluate the usefulness of repeated liquid cytology at the time of colposcopy.

MATERIALS AND METHODS

We screened 5,100 women with liquid-based cytology and human papillomavirus (HPV) DNA testing. Women with any abnormal cytology result including atypical squamous cells of undetermined significance (ASCUS) or a positive high-risk HPV DNA test result were referred for colposcopy. One thousand three hundred thirty-three women returned for colposcopy with repeated cytology and cervical biopsy.

RESULTS

Twenty-one women had less than high-grade squamous intraepithelial lesion (HSIL) screening cytology and cervical biopsy results; however, their repeated cytology at the colposcopy visit revealed HSIL, and excisional treatment was recommended. Repeated cytology at colposcopy significantly changed the clinical management for 1.6% (21) of 1,333 women.

CONCLUSIONS

As an adjunct test to colposcopy, liquid cytology was similar to conventional cytology. Given current practice patterns, repeated liquid cytology at the time of colposcopy is rarely clinically useful.

Report of the 2003 pan-Canadian forum on cervical cancer prevention and control

OBJECTIVE

To develop evidence-based consensus recommendations on the delivery of cervical cancer screening, human papillomavirus (HPV) education, HPV testing, and the optimal tool for cervical cytology within the Canadian health system.

PARTICIPANTS

Leading up to a forum held in Ottawa on November 21 and 22, 2003, 254 registrants reviewed position papers through a Web-based discussion group. Experts in program management, clinical practice, epidemiology, public health, economics, and women's health, representing 48 organizations, then participated in the 2-day forum to develop consensus recommendations.

EVIDENCE

Writing groups prepared position papers on optimal methods for cervical cytology; education concerning HPV; HPV testing in primary screening; HPV testing as a triage tool in cytopathology; and delivery mechanisms for cervical screening. Systematic reviews were the primary source of evidence supplemented by literature searches.

CONSENSUS PROCESS

Feedback from Web-based discussions was incorporated into consecutive drafts of position papers. At the forum, recommendations and supporting evidence were presented, further debated in small-group sessions, and discussed in a plenary session. Despite divergent professional mandates and opinions, consensus was achieved on 15 recommendations across all areas. Final recommendations were posted to the Web for further input and circulated for written consensus by participants.

CONCLUSIONS

The recommendations cover the use of new evidence and technologies in cervical cancer prevention in Canada and provide a framework for provision of HPV education, planning the implementation of new cervical screening technologies in Canada, the development of evaluation plans, and new research areas.

Management of cervical premalignant lesions

Management of cervical preneoplasia starts with an abnormal smear result. The use of the Bethesda system is recommended. The management of patients with low-grade abnormal smear results varies around the world. Patients with atypical squamous cells on cytology are recommended to be subclassified into atypical squamous cells of undetermined significance (ASCUS) and atypical squamous cells where high-grade squamous intra-epithelial lesions (HSIL) cannot be excluded (ASCH) groups. While patients with ASCUS can be followed with cytology or colposcopy, the risk of having cervical intra-epithelial neoplasia (CIN) is higher in patients with ASCH. Such patients, as well as those with low-grade squamous intra-epithelial lesions on cytology, should be referred for colposcopy to ensure that diagnosis and treatment in CIN is detected. Patients with HSIL should be referred promptly for colposcopic assessment. This should, usually at the same clinic visit, be followed by large loop excision of the transformation zone (LLETZ). Although this is effective treatment, around 15% of patients will have persistent/recurrent disease on cytological follow-up. Patients with positive human papillomavirus DNA tests at follow-up seem to have a considerably higher risk of recurrent preneoplasia than those who have negative tests. Patients over 50 years of age have much higher recurrence risks than younger patients. These factors impact on second-line treatment and follow-up schedules. An important benefit of conservative treatment for CIN with LLETZ is retention of fertility. LLETZ is associated with an increased risk of preterm prelabour rupture of membranes and preterm birth, but not with other adverse pregnancy outcome measures. Conservative excisional management of adenocarcinoma in situ by LLETZ or cold knife cone biopsy is not reported to be as effective as that of CIN, with high risk of residual and recurrent disease at follow-up. Conversely, LLETZ may be acceptable treatment for micro-invasive squamous carcinoma if the excision margins are free of disease and there is no evidence of lymphovascular involvement. The ability to detect and treat premalignant lesions on the cervix reversed the natural history of cervical cancer. Methods of conservative treatment that evolved over decades have been proven safe and effective, allowing retention of fertility. Good clinical guidelines have been developed for most clinical scenarios while some uncertainties persist for other scenarios.

Human papillomavirus testing and screening

Cervical cancer is a largely preventable disease through the detection, treatment and follow-up of its precursors. Traditionally, this has been accomplished through screening women with cervical cytology, and referring women with abnormal cytology for colposcopy, histological sampling and treatment. In organized programmes that achieve wide coverage of the target population at frequent intervals, this approach has resulted in a considerable reduction in cervical cancer. Recently, however, the development of reliable and reproducible tests for the detection of human papillomavirus (HPV) infection of the cervix (which is now accepted to be causally associated with the development of almost all cervical cancers) has led to the evaluation of HPV de-oxyribonucleic acid (DNA) testing as either an alternative or adjunctive test to cytology for the detection of cervical cancer and its precursors. There is now a large body of data supporting the clinical utility of HPV DNA testing for the prevention of cervical cancer, particularly in the settings of primary screening of women older than 30 years, in the triage of women with equivocal cytology and for the follow-up of women post-treatment.

A simple method to determine the need for glacial acetic acid treatment of bloody ThinPrep Pap tests before slide processing

ThinPrep (TP) Papanicolaou (Pap) samples containing excessive blood often result in unsatisfactory preparations, possibly leading to undetected gynecologic disease, and added inconvenience to patients and clinicians. Reprocessing of these samples with a glacial acetic acid wash is effective at eliminating blood, providing satisfactory preparation and detection of lesions. However, it increases laboratory costs and decreases work flow efficiency. We report the use of a color standard for gauging the necessity of performing a glacial acetic acid wash before TP processing. This "preprocessing" was found to reduce the costs associated with reprocessing by 48%, while maintaining high preparation quality by improved sample adequacy.

The cost-effectiveness of human papillomavirus screening for cervical cancer. A review of recent modelling studies

We compared findings from recent studies modelling the cost-effectiveness of screening for cervical cancer using human papillomavirus (HPV) testing and alternative strategies. Data were standardized to facilitate comparison of costs per life year or costs per QALY gained in six studies. Absolute changes in costs, life years and QALYs for each strategy were normalized to a comparison with no screening. Costs were standardized to US$ in 2000 values. Most models assume screening starts at age 18 or 20 years. Assumed prevalence of HPV ranges from 10% for those aged 18 years to 20% for those aged 20-25 years and drops substantially after age 30. All except one model assume sensitivity to LSIL of 83% or higher. Two models distinguish the increasing specificity of HPV testing in older age groups (up to 95% for LSIL in women aged 55 years or older). All the models include consultation costs as well as screening and treatment costs, but costs for follow-up diagnosis and treatment vary considerably. Two models also include patient time costs. Despite these differences all strategies involving HPV testing have cost per quality-adjusted life-year (QALY) ratios in the range of USD 12,400-16,600. Costs per life year vary more widely, the highest being USD 19,246 (annual screening with liquid cytology and HPV). However, excluding strategies using liquid cytology, the highest costs per life year for a strategy including HPV testing are under USD 14,000 (simultaneous conventional cytology and HPV every two years). The cost per life year for HPV testing alone triennially is lower than for Pap smear testing alone biennially. Costs per QALY are generally lower than costs per life year (given the reported modelling assumptions and settings). Even with inclusion of patient costs, no strategies involving HPV testing cost more than USD 16,600 per QALY. Adoption of the ACOG guidelines to include HPV testing with cytology as a screening option for women aged 30 years or older therefore appears to be cost-effective.

HPV triage of women with atypical squamous cells of undetermined significance: a 3-year experience in an Italian organized programme

OBJECTIVE

The purpose of our study was to determine if Hybrid Capture II assay (HCII) on Liquid Based Cytology (LCB) improves the accuracy (higher sensitivity, similar specificity) than the repeat conventional Pap smear in smears with Atypical Squamous Cell (ASC) of Undetermined Significance diagnosis.

METHODS

HPV testing was used to manage women, especially the older ones, with cervical abnormalities detected through our triennial organized screening in order to avoid unnecessary colposcopy and excessive follow-up if the woman is HPV negative. The HPV DNA Triage was offered without any charge to 909 women with ASC. The Bethesda System was used for the classification of these equivocal cytological findings and more precisely the 1991 version (ASCUS) until the summer 2001 (315 cases) and the new one 2001 classification (ASC-US and ASC-H) after this date (594 cases). The presence or absence of a cervical intraepithelial neoplasia of grade I or worse [CIN1+], and of grade II or worse [CIN2+], was confirmed by biopsy.

RESULTS

The HPV DNA Triage showed a good accuracy (specificity over 94%, sensitivity of 37% and PPV for CIN2+ lesions around 30%). The higher values of ASC-H lesions (.462) for the sensitivity for CIN 2+ probably signify that this lesion is already a SIL.

CONCLUSIONS

Our data were comparable with those recently published on the meta-analysis by Arbyn et al., confirming the promising approach of our guidelines for the treatment of these patients even in terms of Health Technology Assessment (HTA).

Prevalence and typing of HPV DNA by hybrid capture II in women with ASCUS, ASC-H, LSIL, and AGC on ThinPrep Pap tests

Testing for human papillomavirus (HPV) DNA is now a viable option for the management of women with atypical squamous cells of undetermined significance (ASCUS). The utility of reflexive HPV DNA testing for women with a cytologic diagnosis of atypical glandular cells-not otherwise specified (AGC-NOS), ASCUS subtypes, and low-grade squamous intraepithelial lesion (LSIL) has not been well established. In the present investigation, reflex Hybrid Capture II HPV DNA testing results were evaluated for HPV prevalence and type in 371 women with abnormal cytologic diagnoses of ASCUS-not otherwise specified (ASCUS-NOS), ASCUS-suspicious for low-grade squamous intraepithelial lesion (ASCUS-L), atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion (ASC-H), AGC-NOS, and LSIL on ThinPrep Pap tests. Positive high-risk HPV DNA was identified in 53.6% of the study samples, including ASCUS-NOS 40.2% ASCUS-L 71.4%, ASC-H 37.5%, LSIL 88.6%, and AGC-NOS 0%. We conclude that reflex HPV DNA testing appears to not be useful for colposcopy triage for cytologic diagnoses of LSIL or AGC-NOS.

Beyond the Pap: assessing patients' priorities for the annual examination

PURPOSE

Recent cervical cancer screening technologies depend on biennial and triennial screening of cytologically normal women to be cost-effective. The guidelines for these technologies cannot be appropriately implemented if women demand continued cervical screening at their annual examinations. The purpose of this study was to identify the reasons for an annual examination that are important to women.

METHODS

Age-specific focus groups elicited 22 consistently important reasons that were then incorporated into a survey given to northern New England women seeking healthcare. The reasons were classified as test-seeking reasons and as provider-patient relationship reasons. A distribution matrix of the test-seeking and provider-patient relationship reasons was constructed for paired McNemar chi-square analysis. Multivariate regression analyses compared the selected reasons to the women's demographic characteristics.

RESULTS

There were 121 women from three distinct primary care offices who completed the surveys. Women were highly likely to chose patient-provider reasons as more important components of the annual examination than test-seeking reasons (chi-square for symmetry = 54.44, p < 0.001). The lesser importance of an annual Pap test did not vary by age, education level, and number of healthcare visits made in the last year.

CONCLUSIONS

Our results indicate that northern New England women value the provider-patient relationship as paramount for the annual examination, thus supporting the notion that the biennial and triennial Pap intervals for cytologically normal women provided by the new cervical cancer screening technologies would be acceptable in this population.

A cost-effectiveness analysis of four management strategies in the determination and follow-up of atypical squamous cells of undetermined significance

Atypical squamous cells of undetermined significance (ASC-US) are the most common abnormal cytological result on Papanicolaou (Pap) smear. We analyzed four management strategies in a hypothetical cohort of women divided by age group: (1) immediate colposcopy, (2) repeat cytology after an ASC-US Pap smear result, (3) conventional Pap with reflex human papillomavirus (HPV) testing, and (4) liquid-based cytology with reflex HPV testing. Parameter variables were collected from previously published data. Strategies that included reflex HPV testing had the lowest overall costs for all age groups combined. Repeat Pap smears had the highest number of true positive results throughout all stages but also had the uppermost number of missed cancers and highest costs. Immediate colposcopy had the second highest overall costs and detected fewer true positive results than liquid-based cytology. Younger women (aged 18-24 yr) consistently had higher total costs for all strategies investigated. Using the incremental cost-effectiveness (CE) ratio, the immediate colposcopy strategy was more costly and less effective than liquid-based cytology and, therefore, was dominated. The incremental CE ratio was lowest for liquid-based cytology compared with conventional cytology and liquid-based cytology with reflex HPV testing was the most cost-effective strategy.

Natural history and screening model for high-risk human papillomavirus infection, neoplasia and cervical cancer in the Netherlands

A simulation model is presented that assumes that persistent infection with high-risk human papillomavirus (hrHPV) is a necessary cause of cervical cancer. For the estimation of the model parameters, data of recent Dutch follow-up studies were reanalyzed. The predicted incidences of cervical cancer, cervical intraepithelial neoplasia (CIN1, CIN2 and CIN3) and abnormal cytology were validated with nationwide figures and population-based screening results. The model predicted a lifetime risk for cervical cancer of 2.9% with a peak at age 48 years. The predicted lifetime risk dropped to 0.4% when attending cervical screening. For women who were not hrHPV infected at 30 years, the lifetime risk was 1.6%. Sensitivity analyses were performed to check natural history assumptions that were only weakly identified from available data sets. The incidence of CIN3 observed with screening appeared a useful clinical end point as the predicted incidence was robust against changes in the sensitivity of cervical cytology and the duration to CIN3. The model can be used to study the health-economic benefits that can be achieved in nationwide screening when including an hrHPV test.

Cervical cancer screening

Although primary prevention of human papillomavirus (HPV) infections that are causally associated with invasive cervical cancer may be within our grasp, it is unlikely that these approaches will replace existing cervical cancer screening strategies for many years. Experts agree and data support periodic cytology screening for young-adult women using one of several technologies. Recent analyses of cost-effectiveness suggest that the addition of molecular HPV DNA testing for women aged over 30 years may allow the screening interval to be lengthened to 3 years for most women. Women at high risk for HPV infection and its associated cellular atypias warrant closer monitoring and follow-up. These patients would include organ transplant recipients, women exposed to diethylstilbestrol (DES), and HIV-infected women.

An evaluation of liquid-based cytology and human papillomavirus testing within the UK cervical cancer screening programme

The aim of this study is to evaluate different options for introducing liquid-based cytology (LBC) and human papillomavirus (HPV) testing into the UK cervical cancer screening programme. These include options that incorporate HPV testing either as a triage for mild and borderline smear abnormalities or as a primary screening test. Outcomes include the predicted impact on resource use, total cost, life years and cost–effectiveness. Extensive sensitivity analysis has been carried out to explore the importance of the uncertainty associated with disease natural history and the impact of screening. Under baseline assumptions, the cost–effectiveness of different options for introducing LBC appears favourable, and these results are consistent under a range of assumptions for its impact on the diagnostic effectiveness of cytology. However, if we assume a higher marginal cost of LBC in comparison to conventional methods, primary smear testing options are predicted to be more cost-effective without LBC. Combined LBC primary smear and HPV testing with a 5-year interval is similar in both cost and effectiveness to the other 3-yearly options of primary smear testing or primary HPV testing alone. However, both primary HPV testing and combined options would give rise to a far greater risk of inappropriate colposcopy throughout a woman's lifetime.

Cost-effectiveness analyses in gynecologic oncology: methodological quality and trends

OBJECTIVES

To evaluate methodological quality and trends of cost-effectiveness analyses (CEA) published in gynecologic oncology.

METHODS

A medical literature search of articles from 1966 through 2002 was performed to identify original, English-language articles that included economic analyses in gynecologic oncology. We included articles that were cost-effectiveness or cost-benefit analyses or performed these analyses as part of their study. Ten methodological principles that should be incorporated in CEAs were assessed for each study. Each article was given a score of 0, 1, or 2 for each of the 10 methodological principles (max score = 20). Data were analyzed using the Student t test, ANOVA, and linear regression.

RESULTS

We screened 693 articles to identify 68 that met our inclusion criteria. The articles focused on cervical cancer (n = 53; 78%), ovarian cancer (n = 11; 16%), uterine cancer (n = 2; 3%), and general perioperative care (n = 2; 3%). The mean (+/-SD) methodological principle score was 16.1 (+/-4.1) and we observed a significant improvement in the total score over time (P = 0.01). Primary CEA's (CEA identified as the objective of the study) were of higher quality than secondary CEA's (primary objective of the study was not CEA but CEA was included in the study; total scores 18.2 vs. 11.6, respectively; P<0.0001). Studies with at least one investigator in public health or healthcare economies also had higher quality (mean total score 17.7 vs. 15.2; P=0.006). The most common limitations of published CEAs were in methodology or presentation of incremental analyses, sensitivity analyses, and discounting.

CONCLUSIONS

Cost-effectiveness analyses in gynecologic oncology showed significant improvement in quality over the last two decades. Despite this progress, methodological improvement is still needed in the areas of incremental comparisons and sensitivity analysis. Understanding the methodology of cost-effectiveness analysis is critical for researchers, editors, and readers to accurately interpret results of the growing body of CEA articles.

Cost-effectiveness of human papillomavirus DNA testing for cervical cancer screening in women aged 30 years or more

OBJECTIVE

To evaluate the cost-effectiveness of human papillomavirus (HPV) DNA testing as a primary screening test in combination with cervical cytology in women aged 30 years or more.

METHODS

A state-transition mathematical model was used to simulate the natural history of HPV and cervical cancer in a cohort of U.S. women. Strategies included no screening and screening at different frequencies with conventional cytology, liquid-based cytology with HPV testing used for triage of equivocal results, and HPV DNA testing and cytology in combination after women had reached the age of 30. Outcomes measured included cancer incidence, life expectancy, lifetime costs, and incremental cost-effectiveness ratios.

RESULTS

The estimated reduction in lifetime risk of cervical cancer varies from 81% to 93% depending on the screening frequency, type of cytology, and test strategy. Every 3-year screening with liquid-based cytology administered to women at all ages and every 3-year screening using HPV DNA testing and cytology in combination administered to women aged 30 years or more provide equivalent or greater benefits than those provided by annual conventional cytology and have incremental cost-effectiveness ratios of US dollars 95300 and US dollars 228700 per year of life gained, respectively. In comparison, annual screening with HPV DNA testing and cytology in combination provides only a few hours of additional life expectancy and has a cost-effectiveness ratio of more than Us dollars 2000000 per year of life gained.

CONCLUSIONS

For women aged 30 years and more, every 2- or 3-year screening strategy that uses either HPV DNA testing in combination with cytology for primary screening or cytology with reflex HPV DNA testing for equivocal results will provide a greater reduction in cancer and be less costly than annual conventional cytology.

Comparison of Adolescent and Young Adult Self-Collected and Clinician-Collected Samples for Human Papillomavirus

OBJECTIVE

To examine the concordance between self-collected and clinician-collected samples for human papillomavirus (HPV) DNA.

METHODS

Sexually active adolescent and young adult women aged 14-21 years (N = 101) were enrolled in a prospective cohort study of HPV testing. Participants self-collected vaginal samples for HPV DNA, and clinicians collected cervicovaginal samples for HPV DNA and a cervical cytology specimen. We determined concordance between the results of self- and clinician-collected specimens using a kappa statistic and McNemar's test.

RESULTS

Of the 51% of participants who were HPV positive, 53% had 1 type, 25% had 2 types, and 22% had 3 types or more; 25 different HPV types were identified. Self-collected samples detected more participants with HPV than clinician-collected samples (45% versus 42%, P =.65). When results were categorized into presence or absence of high-risk HPV types, agreement between self- and clinician-collected specimens was high (kappa 0.72) and the difference between test results was not significant (McNemar's P =.41). However, when all HPV types detected were considered, agreement was perfect in only 51% of those with 1 or more types of high-risk HPV type. There was no association between agreement and age or HPV type.

CONCLUSION

Self testing for HPV DNA may be sufficiently sensitive for the detection of high-risk HPV DNA among adolescent and young adult women in clinical settings.

Projected Clinical Benefits and Cost-effectiveness of a Human Papillomavirus 16/18 Vaccine

BACKGROUND

Human papillomavirus (HPV) vaccine may be commercially available in a few years. We explored the clinical benefits and cost-effectiveness of introducing an HPV16/18 vaccine in a population with an organized cervical cancer screening program.

METHODS

A computer-based model of the natural history of HPV and cervical cancer was used to project cancer incidence and mortality, life expectancy (adjusted and unadjusted for quality of life), lifetime costs, and incremental cost-effectiveness ratios (i.e., the additional cost of a strategy divided by its additional clinical benefit compared with the next most expensive strategy) associated with different cancer prevention policies, including vaccination (initiated at age 12 years), cytologic screening (initiated at 18, 21, 25, 30, or 35 years), and combined vaccination and screening strategies. We assumed that vaccination was 90% effective in reducing the risk of persistent HPV16/18 infections and evaluated alternative assumptions about vaccine efficacy, waning immunity, and risk of replacement with non-16/18 HPV types.

RESULTS

Our model showed that the most effective strategy with an incremental cost-effectiveness ratio of less than 60 dollars-000 per quality-adjusted life year is one combining vaccination at age 12 years with triennial conventional cytologic screening beginning at age 25 years, compared with the next best strategy of vaccination and cytologic screening every 5 years beginning at age 21 years. This triennial strategy would reduce the absolute lifetime risk of cervical cancer by 94% compared with no intervention. These results were sensitive to alternative assumptions about the underlying patterns of cervical cancer screening, duration of vaccine efficacy, and natural history of HPV infection in older women.

CONCLUSIONS

Our model predicts that a vaccine that prevents persistent HPV16/18 infection will reduce the incidence of HPV16/18-associated cervical cancer, even in a setting of cytologic screening. A program of vaccination that permits a later age of screening initiation and a less frequent screening interval is likely to be a cost-effective use of health care resources.

Morphological analysis of squamous cells in routine Pap smears as a predictor of bone mineral density in asymptomatic women

OBJECTIVE

The present study attempted to find out possible coherence between morphologic characteristics in Pap smears and bone mineral density (BMD) as measured by DEXA.

STUDY DESIGN

DEXA measurement (with the result expressed as T-score) was performed in 79 women in whom Pap smears for routine cervical cancer screening were obtained. The smears were grouped into atrophic and mature cell patterns. Using astereological analysis, the mean areas of squamous cells, their nuclei and cytoplasm were estimated.

RESULTS

The mean areas of cells and cytoplasm were significantly lower at lower T-scores (P < 0.01), while the mean areas of nuclei were not (P > 0.5). T-scores were significantly lower in the atrophic cell pattern group (P < 0.001). The study group indicated concurrently high sensitivity of 80.9% and specificity of 78.1%, with positive predictive value of 84.4%.

CONCLUSION

These results suggest that a significant number of women with low BMD could be identified parallel with the routine Pap test for cervical cancer screening without additional costs.

Virologic Versus Cytologic Triage of Women With Equivocal Pap Smears: A Meta-analysis of the Accuracy To Detect High-Grade Intraepithelial Neoplasia

BACKGROUND

The appropriate management of women with minor cytologic lesions in their cervix is unclear. We performed a meta-analysis to assess the accuracy of human papillomavirus (HPV) DNA testing as an alternative to repeat cytology in women who had equivocal results on a previous Pap smear.

METHODS

Data were extracted from articles published between 1992 and 2002 that contained results of virologic and cytologic testing followed by colposcopically directed biopsy in women with an index smear showing atypical cells of undetermined significance (ASCUS). Fifteen studies were identified in which HPV triage and the histologic outcome (presence or absence of a cervical intraepithelial neoplasia of grade II or worse [CIN2+]) was documented. Nine, seven, and two studies also documented the accuracy of repeat cytology when the cutoff for abnormal cytology was set at a threshold of ASCUS or worse, low-grade squamous intraepithelial lesion (LSIL) or worse, or high-grade squamous intraepithelial lesion (HSIL) or worse, respectively. Random-effects models were used for pooling of accuracy parameters in case of interstudy heterogeneity. Differences in accuracy were assessed by pooling the ratio of the sensitivity (or specificity) of HPV testing to that of repeat cytology.

RESULTS

The sensitivity and specificity were 84.4% (95% confidence interval [CI] = 77.6% to 91.1%) and 72.9% (95% CI = 62.5% to 83.3%), respectively, for HPV testing overall and 94.8% (95% CI = 92.7% to 96.9%) and 67.3% (95% CI = 58.2% to 76.4%), respectively, for HPV testing in the eight studies that used the Hybrid Capture II assay. Sensitivity and specificity of repeat cytology at a threshold for abnormal cytology of ASCUS or worse was 81.8% (95% CI = 73.5% to 84.3%) and 57.6% (95% CI = 49.5% to 65.7%), respectively. Repeat cytology that used higher cytologic thresholds yielded substantially lower sensitivity but higher specificity than triage with the Hybrid Capture II assay. The ratio of the sensitivity of the Hybrid Capture II assay to that of repeat cytology at a threshold of ASCUS or worse pooled from the four studies that used both triage tests was 1.16 (95% CI = 1.04 to 1.29). The specificity ratio was not statistically different from unity.

CONCLUSION

The published literature indicates that the Hybrid Capture II assay has improved accuracy (higher sensitivity, similar specificity) than the repeat Pap smear using the threshold of ASCUS for an outcome of CIN2+ among women with equivocal cytologic results. The sensitivity of triage at higher cytologic cutoffs is poor.

Extended duration of the detectable stage by adding HPV test in cervical cancer screening

The human papillomavirus test (HPV) test could improve the (cost−) effectiveness of cervical screening by selecting women with a very low risk for cervical cancer during a long period. An analysis of a longitudinal study suggests that women with a negative Pap smear and a negative HPV test have a strongly reduced risk of developing cervical abnormalities in the years following the test, and that HPV testing lengthens the detectable stage by 2–5 years, compared to Pap smear detection alone.

News media coverage of human papillomavirus

BACKGROUND

Now that human papillomavirus (HPV) DNA testing is being incorporated into cervical cancer screening programs, salient and accurate media information about HPV will be crucial to inform women's screening choices and to manage psychosocial responses to HPV DNA test results.

METHODS

The authors conducted a content analysis of 111 news stories about HPV from the 10 most circulated newspapers and from 3 major television networks for the period from January 1995 through July 2002. Stories were assessed for predominant theme (STD, cancer, or new tests); information about symptoms, transmission, prevention, and cancer-causing properties of HPV; screening test descriptions; and recommended screening guidelines.

RESULTS

Thirty-six percent of stories primarily were about new tests for HPV or cervical cancer, 30% of stories focused on cervical cancer or its link to HPV, and 27% of stories emphasized sexually transmitted diseases (STDs) or genital warts. Seventy-nine percent of stories mentioned that HPV is an STD, and 50% of stories reported that HPV is very common. Twenty-six percent of stories reported that most women with HPV will not develop cervical carcinoma. Of 81 stories that mentioned a screening test for HPV or cervical carcinoma, 38% reported the sensitivity of the test; 30% mentioned wrong, uncertain, or unnecessary test results; and 25% mentioned consequences of such results.

CONCLUSIONS

Media coverage of HPV could better fulfill women's educational needs by including information about low-risk and high-risk types of HPV and their differing links to cervical cancer; describing HPV prevention, transmission, and symptoms; explaining the benefits and consequences of HPV testing; and outlining the latest screening guidelines in every story.

Women's desired information about human papillomavirus

BACKGROUND

As human papillomavirus (HPV) DNA testing is incorporated into cervical carcinoma screening programs, educational messages must be developed to inform women's screening choices and manage psychosocial responses to HPV DNA test results. However, little is known about women's questions and concerns about HPV or their attitudes toward HPV testing.

METHODS

Eight focus groups with 48 ethnically diverse, low-income women were conducted at community centers, family planning and primary care clinics, and substance abuse rehabilitation facilities in Massachusetts.

RESULTS

The participants' comments and questions about HPV revealed five major themes. First, most women overestimated the likelihood that women with HPV would develop cancer. Second, women struggled to balance the anxiety of knowing that HPV infection causes cervical carcinoma with the information that HPV infection often regresses without treatment. Third, many women were confused that Papanicolaou smear results could be normal when HPV infection is present. Fourth, women preferred to receive a personalized risk profile to assess their own likelihood of contracting HPV infection and cervical carcinoma. Fifth, younger women focused on the sexual transmission of HPV infection, rather than on its potential to cause cancer.

CONCLUSIONS

Effective HPV education must include information about transmission, prevention, treatment, and cervical carcinoma risk; tailor messages to describe HPV susceptibility according to age and risk profile; present clarification regarding HPV strains and their consequences; offer explanations of different types of tests and their results; and provide a balance between accurate discussion of cancer risk and reassurance that following recommended screening practices will reduce risk to negligible levels.

Cost-effectiveness versus cost-utility analysis of interventions for cancer: does adjusting for health-related quality of life really matter?

OBJECTIVE

The US Public Health Service Panel on Cost-Effectiveness has recommended the use of quality-adjusted life-years (QALYs) as the best way to estimate outcomes in a cost-effectiveness analysis. We evaluate the importance of this recommendation by assessing whether adjusting for health-related quality of life affects the ultimate resource allocation decision implied by the cost-effectiveness ratio for interventions aimed at cancer prevention and control.

METHODS

We identified 110 interventions in 39 articles for which both cost/life-year and cost/QALY were reported. Interventions were forms of prevention, early detection, or treatment of cancer. We calculated a Spearman correlation to assess the ordinal relationship between cost/life-year and cost/QALY. In addition, we employed various decision thresholds to assess whether the use of cost/life-year would yield different resource allocation decisions than the use of cost/QALY.

RESULTS

The correlation between cost/life-year and cost/QALY is 0.96 (P <.0001). Assuming a US dollars 50000 decision threshold, adjustment for quality of life would affect the implied choice in 5% of cases. With a US dollars 400000 threshold, adjustment for quality of life would affect choice for 2% of interventions.

CONCLUSIONS

For interventions aimed at cancer, the outcome measures of cost/life-year and cost/QALY are highly correlated with one another. Although adjusting for quality of life can make an important difference in the evaluation of alternative approaches to cancer prevention and control, it often does not.

Chapter 14: Role of triage testing in cervical cancer screening

The classic model of cervical cancer prevention-primary screening with cytology, followed by diagnostic colposcopically directed biopsy, and finally treatment of cancer precursors-is undergoing dynamic change. The introduction of human papillomavirus (HPV) DNA testing and other new modalities provides more options but increases complexity in the sequence of screening, triage, diagnosis, and patient management. This chapter will focus on the role of triage and risk stratification in management. The utility of HPV testing has been established for triage of cytologic findings of atypical squamous cells of undetermined significance but not for low-grade squamous intraepithelial lesions or worse. Countries without established cytology services may consider alternative screening, triage, and treatment programs that may be more readily implemented than a resource-rich "cytology followed by colposcopy" paradigm requiring an infrastructure of highly trained personnel. The diagnostic step of colposcopy and directed biopsy is not completely sensitive in the detection of cervical intraepithelial neoplasia (CIN) 2 or 3 as is sometimes assumed. The partial insensitivity of this diagnostic step results in a population of women with negative colposcopically directed-biopsy findings but at increased risk for missed prevalent disease: these women may require additional triage rather than resumption of routine screening. As more efficient screening, triage, and diagnosis increase the sensitivity of detection of even very small CIN2 or CIN3, overtreatment of lesions that might otherwise regress becomes a concern and highlights the need to identify accurate markers of risk of progression to cancer. Markers of molecular events further along the pathway from HPV infection to development of cancer may ultimately provide more specificity in triage and diagnosis.

Chapter 15: Public health policy and cost-effectiveness analysis

Recent scientific advances are providing an opportunity to revisit strategies for cervical cancer prevention. How to invest health resources wisely, such that public health benefits are maximized-and opportunity costs are minimized-is a critical question in the setting of enhanced cytologic screening methods, human papillomavirus DNA testing, and vaccine development. Developing sound clinical guidelines and public health policy will require careful consideration of the incremental benefits, harms, and costs associated with new interventions compared with existing interventions, at both an individual and a population level. In addition to an intervention's effectiveness, public health decision making requires the consideration of its feasibility, sustainability, and affordability. No clinical trial or single cohort study will be able to simultaneously consider all of these components. Cost-effectiveness analysis and disease-simulation modeling, capitalizing on data from multiple sources, can serve as a valuable tool to extend the time horizon of clinical trials, to evaluate more strategies than possible in a single clinical trial, and to assess the relative costs and benefits of alternative policies to reduce mortality from cervical cancer.

Decision science and cervical cancer

Mathematical modeling is an effective tool for guiding cervical cancer screening, diagnosis, and treatment decisions for patients and policymakers. This article describes the use of mathematical modeling as outlined in five presentations from the Decision Science and Cervical Cancer session of the Second International Conference on Cervical Cancer held at The University of Texas M. D. Anderson Cancer Center, April 11-14, 2002. The authors provide an overview of mathematical modeling, especially decision analysis and cost-effectiveness analysis, and examples of how it can be used for clinical decision making regarding the prevention, diagnosis, and treatment of cervical cancer. Included are applications as well as theory regarding decision science and cervical cancer. Mathematical modeling can answer such questions as the optimal frequency for screening, the optimal age to stop screening, and the optimal way to diagnose cervical cancer. Results from one mathematical model demonstrated that a vaccine against high-risk strains of human papillomavirus was a cost-effective use of resources, and discussion of another model demonstrated the importance of collecting direct non-health care costs and time costs for cost-effectiveness analysis. Research presented indicated that care must be taken when applying the results of population-wide, cost-effectiveness analyses to reduce health disparities. Mathematical modeling can encompass a variety of theoretical and applied issues regarding decision science and cervical cancer. The ultimate objective of using decision-analytic and cost-effectiveness models is to identify ways to improve women's health at an economically reasonable cost.

Role of HPV DNA testing in predicting cervical intraepithelial lesions: comparison of HC HPV and ISH HPV

Human papillomavirus (HPV) is widely accepted as the primary agent involved in the development of squamous intraepithelial neoplasia and cervical carcinoma. Several commercial tests are available for detecting HPV DNA. This study compares the efficacy of INFORM HPV (in situ hybridization [ISH] HPV) and HCII (HC HPV) in predicting cervical lesions. A total of 762 sequential Papanicolaou (Pap) smears determined by cytologic examination to be either atypical squamous cells of undetermined significance (ASC-US) or low-grade squamous intraepithelial lesions (LSIL) were tested by both Hybrid Capture (HC) HPV and ISH HPV; 250 follow-up biopsies were reviewed as the reference standard for presence or absence of a lesion. ISH HPV and HC HPV differed significantly in accurately predicting biopsy findings from ASC-US and LSIL cases. The overall sensitivity and specificity of ISH HPV were 97% (28/29) and 86% (191/221); and HC HPV was 79% (23/29) and 56% (123/221). The positive predictive value (PPV) of ISH HPV was 48% (28/58) vs HC HPV value of 19% (23/121). Negative predictive value (NPV) was also better with ISH HPV at 99% (191/192) and HC HPV at 95% (123/129). Of equal importance, ISH HPV demonstrated a lower false-positive rate compared to HC HPV, 12% (30/250) vs 39% (98/250), as well as having a slightly lower false-negative rate 0.4% (1/250) vs 2.4% (6/250). ISH HPV is more predictive of biopsy histopathology in patients with detectable cervical lesions than is HC HPV. Effective triage of patients by HPV analysis using ISH HPV as compared to HC HPV has the potential of significant public health impact by reducing unnecessary colposcopies, as well as adverse medical, social, and psychological patient consequences.

The many faces of atrophy in gynecologic cytology

As more attention is paid to cervical cancer screening in the postmenopausal population, increased numbers of atrophic specimens will be evaluated in the cytology laboratory. In addition, specimens that have cell patterns that mimic the nonestrogen or partially estrogen-stimulated state occur in a variety of situations, including pregnancy, the postpartum period, and in individuals who are treated with progesterone. A firm understanding of the cellular changes that are within the range of normal in such circumstances is critical to ensure the specificity of interpretation. This article has detailed the conditions under which nonestrogen stimulated patterns occur and addressed the cytologic changes that are noted. Hints to avoid pitfalls have been offered. There is no substitute for a thorough evaluation of each case, and with continued experience and understanding of these principles, the correct interpretations, and, ultimately, correct management of patients, can be optimized.

Molecular markers in cervical cytology

It is expected that in the near future, the high sensitivity of array-based technologies and identification of panels of molecular fingerprints that are specific for each disease process will allow the pathologist to analyze cytologic samples and tissue biopsies by these technologies in conjunction with morphologic evaluation. This approach could lead to a new era in diagnosis and patient management, where each patient may receive individualized treatment according to the molecular characteristics of the disease that are obtained from a minute amount of tissue. Therefore, it is important for pathologists and other clinical specialists to have an understanding of these molecular technologies. It is hoped that this article will allow practitioners to incorporate these concepts into their training, and, eventually, into their daily practice.

Atypical squamous cells: update on current concepts

Besides all the confusion and associated problems that the use of ASC has created, it has initiated substantial investigational interest that has resulted in a better understanding of squamous intraepithelial lesions and the biology of cervical neoplasia. Although the category of ASC has created, and will continue to create, controversy in the diagnostic and management fields, it allows the pathologist to convey uncertainty that may be the result of poor sampling or difficulty in interpretation of a case. It is a valuable tool that the cytopathologist can use to make it known that the Papanicolaou test has its limitations and may need and benefit, in some instances, from support from ancillary studies. Similar limitations are recognized in other areas of pathology and the use of immunohistochemistry or molecular studies is widely accepted as an aid to a more specific and definitive interpretation. The time for the Papanicolaou test to be considered similarly has arrived. HPV DNA testing may not be the perfect test for cervical cancer screening because of high prevalence of HPV infection in the general population; however, it is currently the best-studied ancillary test and has been proven to be cost-effective for the triage of Papanicolaou tests with equivocal squamous cells. It is important for the cytopathologist to have well-developed diagnostic skills in interpreting gynecologic preparations, and to classify cases as ASC only when deemed appropriate. Downgrading cytologic findings that are diagnostic of a squamous intraepithelial lesion to ASC with the hope of supporting it by an HPV test will only result in a devaluation of the Papanicolaou test. Such recourse may, however, be acceptable in specific situations, such as in patients who have complex histories, atypical clinical presentations, or during pregnancy. Quality assurance measures to closely monitor the ASC:SIL ratio and the rate of HPV positivity in ASC cases will be essential to ensure the appropriate use of this interpretive category. The coordination of the 2001 Bethesda and ASCCP consensus meetings resulted in the new subcategories of ASC-US and ASC-H, along with well-defined management strategies for these interpretations. This new and clinically relevant terminology should lead to a reduction in difficulties at the clinical level and a more uniform management of patients, unlike the situation following Bethesda 1991 where the gynecologist was faced with a new "diagnosis" without specific management recommendations. The standardization of reporting and clinical management will also allow more reliable evaluation of patient outcomes and cost analysis. The 2002 American Cancer Society guidelines did not make specific recommendations regarding HPV DNA testing for the triage of patients who have a cytology result of ASC-US [64]. The FDA approved the expanded use of HPV testing in conjunction with the Papanicolaou test for cervical cancer screening in March of 2003. The future is likely to bring additional testing modalities that may be more specific for detecting squamous lesions that are more likely to persist or progress to carcinoma, than the currently available HPV tests. In addition, looking to the more distant future, recently published data from HPV vaccine trials suggests that immunizing women who are negative for HPV-16 may eventually reduce the incidence of cervical cancer [65]. At the present, however, the most effective method to decrease the mortality of this disease process is to make sure that all women have access to, and receive, effective cervical cytologic screening.