Effects and Costs of Cervical Cancer Screening

The objective of this thesis is to evaluate cervical eaueer screening by assessing its various effects and costs. Questions to be addressed concern the rednetion in incidence and mortality, the unfavourablc effects and the cost-effectiveness of different screening polides (age range and interval combinations). To this end, we used acervical eaueer version of MISCAN, a simulation model that was designed and programmed to evaluate cancer screening. This cervical eaueer screening model. had already been tested against screening data sets from British Columbia (Canada) and from Dutch pilot screeningprojectsin 1976- 1985. The potential impact of new developments in cervical eaueer screening, such as auto~1ated cytological evaluation and HPV-testing, has been investigated. The ultimate questions are: should ccrvical caoeer screening be conti. nued, and what changes should be recommended in order to iinprove its efficiency? The relationship between benefits and unfavourable effects was stuclied for three efficient cervical cancer screening strategies incorporating 5, 10 and 25 smears per woman (Chapter 2). It was concluded that wlien the screening frequency was increased, the ratio of favourable to unfavourable effects became worse

The management of cervical intra-epithelial neoplasia (CIN): Extensiveness and costs in The Netherlands

In order to provide greater insight into both the extensiveness and the medical costs of the diagnosis and treatment of screen-detected cervical intra-epithelial neoplasia (CIN) in general medical practice in The Netherlands, data from national registries and gynaecology departments were retrieved, and experts were interviewed. Of the 5060 women diagnosed with CIN in 1988, more than 50% were treated in hospital with conisation or hysterectomy, which on average took 5.5 days stay per admission. The assessed average duration of the total pre- and post-treatment period is 4.6 years. The average total medical costs in women with detected CIN III are Dfl 3700 per woman. The diagnosis of CIN I and II involves more medical procedures and time than CIN III, but fewer women have conisation or hysterectomy, resulting in lower total medical costs (Dfl 2572). The overall extent and costs of the management of CIN should be accounted for when balancing the benefits, unfavourable effects and costs of cervical cancer screening

Positive diagnostic values and histological detection ratios from the Rotterdam cervical cancer screening programme

BACKGROUND: In organized screening programmes for cervical cancer, pre-cancerous lesions are detected by cervical smears. However, during follow-up after a positive smear these pre-cancerous lesions are not always found. The purpose of the study is to analyse positive diagnostic values of smears of at least mild dysplasia, made under the organized screening programmes in the Rotterdam area (1979-1991), and detection ratios of histologically confirmed CIN > or =3, among women participating in these screening programmes. METHODS: Positive diagnostic values and histological detection ratios, by age and history of previous smears, recorded during the national screening programme (1989-1991), were compared with those of the experimental cervical cancer screening project (1976-1984). RESULTS: The positive diagnostic value of a smear with at least severe dysplasia (histologically confirmed CIN > or =3) remains approximately 78%. For smears with mild and moderate dysplasia only lower limits of the diagnostic value could be determined. This was 9% for a smear with mild dysplasia obtained during the national screening programme and 25% and 35% for smears with moderate dysplasia taken during the experimental and national screening programmes respectively. Histological detection ratios for CIN > or =3 in the three rounds of the experimental screening project were 4.7, 2.9 and 1.9. In the first round of the national screening programme the ratio was 4.7, and about three times higher in younger compared to older women. CONCLUSION: Immediate referral for colposcopy after a smear showing moderate dysplasia seems questionable. Whether the increased detection ratio among young women indicates a rise in the risk of cervical cancer is unclear

The potential harms of primary human papillomavirus screening in over-screened women: a microsimulation study

Background: It is well acknowledged that HPV testing should not be performed at young age and at short intervals. Cytological screening practices have shown that over-screening, i.e., from a younger age and at shorter intervals than recommended, is hard to avoid. We quantified the consequences of a switch to primary HPV screening for over-screened women, taking into account its higher sensitivity but lower specificity than cytology. Methods: The health effects of using the HPV test instead of cytology as the primary screening method were determined with the MISCAN-Cervix model. We varied the age women start screening and the interval between screens. In the sensitivity analyses, we varied the background risk of cervical cancer, the HPV prevalence, the discount rate, the triage strategy after cytology, and the test characteristics of both cytology and the HPV test. Results: For women screened 5 yearly from age 30, 32 extra deaths per 100,000 simulated women were prevented when switching from primary cytology to primary HPV testing. For annual screening from age 20, such a switch resulted in 6 extra deaths prevented. It was associated with 9,044 more positive primary screens in the former scenario versus 76,480 in the latter. Under all conditions, for women screened annually, switching to HPV screening resulted in a net loss of quality-adjusted life years. Conclusion: For over-screened women, the harms associated with a lower test specificity outweigh the life years gained when switching from primary cytology to primary HPV testing. The extent of over-screening should be considered when deciding on inclusion of primary HPV screening in cervical cancer screening guidelines

Cost-effectiveness of cervical cancer screening: comparison of screening policies

BACKGROUND: Recommended screening policies for cervical cancer differ widely among countries with respect to targeted age range, screening interval, and total number of scheduled screening examinations (i.e., Pap smears). We compared the efficiency of cervical cancer-screening programs by performing a cost-effectiveness analysis of cervical cancer-screening policies from high-income countries. METHODS: We used the microsimulation screening analysis (MISCAN) program to model and determine the costs and effects of almost 500 screening policies, some fictitious and some actual (i.e., recommended by national guidelines). The costs (in U.S. dollars) and effects (in years of life gained) were compared for each policy to identify the most efficient policies. RESULTS: There were 15 efficient screening policies (i.e., no alternative policy exists that results in more life-years gained for lower costs). For these policies, which considered two to 40 total scheduled examinations, the age range expanded gradually from 40-52 years to 20-80 years as the screening interval decreased from 12 to 1.5 years. For the efficient policies, the predicted gain in life expectancy ranged from 11.6 to 32.4 days, compared with a gain of 46 days if cervical cancer mortality were eliminated entirely. The average cost-effectiveness ratios increased from $6700 (for the longest screening interval) to$23 900 per life-year gained. For some countries, the recommended screening policies were close to efficient, but the cost-effectiveness could be improved by reducing the number of scheduled examinations, starting them at later ages, or lengthening the screening interval. CONCLUSIONS: The basis for the diversity in the screening policies among high-income countries does not appear to relate to the screening policies' cost-effectiveness ratios, which are highly sensitive to the number of Pap smears offered during a lifetime

Primary screening for human papillomavirus compared with cytology screening for cervical cancer in European settings: cost effectiveness analysis based on a Dutch microsimulation model

Objectives To investigate, using a Dutch model, whether and under what variables framed for other European countries screening for human papillomavirus (HPV) is preferred over cytology screening for cervical cancer, and to calculate the preferred number of examinations over a woman’s lifetime

Endoscopic colorectal cancer screening: a cost-saving analysis

BACKGROUND: Comprehensive analyses have shown that screening for cancer usually induces net costs. In this study, the possible costs and savings of endoscopic colorectal cancer screening are explored to investigate whether the induced savings may compensate for the costs of screening. METHODS: A simulation model for evaluation of colorectal cancer screening, MISCAN-COLON, is used to predict costs and savings for the U.S. population, assuming that screening is performed during a period of 30 years. Plausible baseline parameter values of epidemiology, natural history, screening test characteristics, and unit costs are based on available data and expert opinion. Important parameters are varied to extreme but plausible values. RESULTS: Given the expert opinion-based assumptions, a program based on every 5-year sigmoidoscopy screenings could result in a net savings of direct health care costs due to prevention of cancer treatment costs that compensate for the costs of screening, diagnostic follow-up, and surveillance. This result persists when costs and health effects are discounted at 3%. The "break-even" point, the time required before savings exceed costs, is 35 years for a screening program that terminates after 30 years and 44 years for a screening program that continues on indefinitely. However, net savings increase or turn into net costs when alternative assumptions about natural history of colorectal cancer, costs of screening, surveillance, and diagnostics are considered. CONCLUSIONS: Given the present, limited knowledge of the disease process of colorectal cancer, test characteristics, and costs, it may well be that the induced savings by endoscopic colorectal cancer screening completely compensate for the costs

Risk of cervical cancer after completed post-treatment follow-up of cervical intraepithelial neoplasia: Population based cohort study

Abstract Objective To compare the risk of cervical cancer in women with histologically confirmed cervical intraepithelial neoplasia who returned to routine screening after having completed post-treatment follow-up with consecutive normal smear test results with women with a normal primary smear test result. Design Population based cohort study using data from a nationwide pathology register. Setting The Netherlands, 1994 to 2006. Population 38 956 women with histologically confirmed intraepithelial neoplasia grades 1 to 3 with completed follow-up after treatment. Intervention Routine post-treatment follow-up of cervical intraepithelial neoplasia, recommending smear tests at six, 12, and 24 months. Main outcome measure Incidence of cervical cancer in the period from completed follow-up with negative test results after cervical intraepithelial neoplasia to the next primary test. 10-year hazard ratios were compared with periods after normal results for the primary smear test, adjusted for year in follow-up. Results 20 cervical cancers were diagnosed during 56 956 woman years after completed follow-up of cervical intraepithelial neoplasia, whereas 1613 cervical cancers were diagnosed during 25 020 697 woman years after a normal primary smear test result. The incidence of 35.1 (95% confidence interval 21.4 to 54.2) per 100 000 woman years and 6.4 (6.1 to 6.8) per 100 000 woman years, respectively, led to an adjusted hazard ratio of 4.2 (95% confidence interval 2.7 to 6.5) for periods after completed follow-up compared with periods after normal primary smear test results. This hazard ratio was increased for all ages. No significant difference in risk of cervical cancer was observed by grade of cervical intraepithelial neoplasia. Conclusions An excess risk

Diagnostic and treatment procedures induced by cervical cancer screening

Abstract The amount of diagnostic and treatment procedures induced by cervical cancer screening has been assessed prospectively and related to mortality reduction. Assumptions are based on data from Dutch screening programmes and on a scenario for future developments. With 5 invitations for screening, between ages 37–70 every eight years, 13 deaths are avoided per million women per screening year. Each death avoided is balanced by 2800 preventive smears, 9 women referred to a gynaecology department and 4 minor treatment procedures (conserving treatment or exconisation). 25 invitations in a life-time avoids 27 deaths per million women per screening year but with 7300 preventive smears, 22 referrals and 8 small treatment procedures. Thus intensifying screening will not only result in diminishing returns of extra screening efforts, but also in increasing risk for women to undergo unnecessary (no invasive disease or death avoided) diagnostic and treatment procedures. The balance between beneficial and adverse effects deteriorates strongly when hysterectomies play an important part in the management of cervical intraepithelial neoplasia