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M van Ballegooijen

Publications and source records attributed to M van Ballegooijen.

At least 19 recordsLinked to original sources
PubMed2005

Colorectal cancer risk after colonoscopic polypectomy: a population-based study and literature search.

Adenoma patients are considered to be at an elevated risk for colorectal cancer, even after their adenomas have been removed. The aim of this study was to estimate the colorectal cancer risk after colonoscopic polypectomy compared with age- and gender-matched general population controls. Colorectal cancer incidence was studied in 553 consecutive patients without cancer whose adenomas were colonoscopically removed in the endoscopy department of a general hospital. The colorectal cancer relative risk in these patients was 0.9 (0.3-2.0). A literature search was performed to identify all published studies on relative colorectal cancer risk after polypectomy. The relative risk estimates in seven other studies ranged from 0.2 (0.1-0.6) to 1.3 (0.6-2.3). The difference can, be explained partially by the inclusion or exclusion of patients with large sessile polyps and other factors. Our review shows that colorectal cancer risk after colonoscopic polypectomy does not exceed the risk in the general population.

Adenoma↗
PubMed2005

Report on the Dutch consensus development meeting for implementation and further development of population screening for colorectal cancer based on FOBT.

A consensus development meeting was held to evaluate whether or not in the Netherlands all requirements were fulfilled for implementation of population screening with FOBT for colorectal cancer, or whether consensus was present that fulfilment by additional research or organisational actions could be obtained within 2-3 years. There was consensus that all classical Wilson and Jungner (1968) criteria, and six additional ones added more recently, had already been fulfilled or could be fulfilled within 2-3 years. Consequently, it was concluded that a national population screening for colorectal cancer should be implemented and carried out in the Netherlands in line with current national and European cancer screening programmes. A list of organisational actions to be taken was established. Research that is needed before the actual national launch of the screening within 2-3 years has been defined. Priorities have to be set for research and organisational actions for the coming 2-3 years for the implementation of population screening. In addition, research suggestions have been defined for the next 10-15 years for evaluation and/or improvement of implemented FOBT screening, and for future screening methodology. It was considered essential that infrastructure for future research would be embedded in the screening programme. A project group to arrange this should be formed.

Adenoma↗
PubMed2004

Colorectal cancer risk in adenoma patients: a nation-wide study.

Colorectal cancer incidence after adenoma removal has been studied in selected populations of adenoma patients. Our study estimates the trend in colorectal cancer incidence after adenoma removal in actual clinical practice. From PALGA, a nationwide network and registry of histo- and cytopathology in the Netherlands, we extracted data of all patients diagnosed with colorectal adenomas between 1 January 1988 and 1 October 1998. The data were used to calculate population-based colorectal cancer incidence rates after adenoma removal. A total of 78,473 adenoma patients were followed for a mean of 4.5 years after the first adenoma removal. The colorectal cancer incidence ratio compared with the general population matched by age and gender was 38.4 (37.3-39.5) in the first year after adenoma removal and 1.5 (95% confidence interval (CI): 1.4-1.6) after Year 1. The incidence ratio decreased from 2.8 (2.5-3.1) in Year 2 to 0.9 (0.6-1.2) in Years 9-11. This time trend is the opposite of the upward time trend that was expected after adenoma removal. Adenoma patients in the Netherlands are at increased risk for colorectal cancer compared to the general population. The high cancer incidence in Years 1-5 after polypectomy can be explained by a colonoscopic sensitivity for cancer of approximately 90%.

Adenoma↗
PubMed2003

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.

Adult↗
PubMed2003

Low risk of cervical cancer during a long period after negative screening in the Netherlands.

A condition for effective cervical cancer screening is a low incidence of cervical cancer after negative screening compared to that in the absence of screening. This relative risk was studied for the period 1994-1997 in the Netherlands and compared with previous studies. All cases of invasive cervical cancer diagnosed from 1994 to 1997 in the Netherlands were related to woman-years at risk, stratified by age, number of preceding negative screenings and time since the preceding negative screening. These incidence rates were compared with that before screening started in the Netherlands. The relative risk increases from 0.13 in the first year after screening to 0.24 after more than 6 years after screening for women with one previous negative screening. These figures reduce to 0.06 and 0.18, respectively, for women with two or more previous screenings. However, these estimates are less favourable when account is taken of the likely decrease in risk for cervical cancer in the period studied. Our data show a low relative risk of cervical cancer for several years following the last negative Pap smear. However, the denominator of the relative risk, that is, the incidence without screening, may have been overestimated. This applies also to the IARC multicountry study, and may have caused too optimistic expectations about the effectiveness of cervical cancer screening.

Adult↗
PubMed2002

[Less pap-2 results ('minor abnormalities') in the population screening for cervical cancer since the introduction of new guidelines in 1996].

OBJECTIVE: To determine whether the 1996 implementation of new guidelines for the classification and management of cervical smears in the Dutch population screening programme for cervical cancer (i.e. inflammatory symptoms are no longer classified as moderate dysplasia and women with two smears with moderate dysplasia are referred directly to the gynaecologist) was followed by a reduction in both the number of women with repeat smears and the length of follow-up. METHODS: The results of all smears of women aged 35-54 years from 1990 onwards, were retrieved from the Dutch Network and National Database for Pathology (PALGA). The percentage of smears with moderate dysplasia was analysed with respect to time. The percentage of women with a histological examination during the follow-up phase of the population screening programme (1990 and 1991) was compared with that for the new screening programme (1996). RESULTS: Following the implementation of the new guidelines, the percentage of smears with moderate dysplasia was reduced from 10% to 2%. The percentage of women with a histological examination during the follow up of two smears with moderate dysplasia remained the same. The new recommendations for additional smears were not followed: for 28% no repeat smear was available after 2.25 years versus 10% in 1992. There were indications that the referral of women with two cases of moderate dysplasia to a gynaecologist was not strictly adhered to either. Since the introduction of the new guidelines, the estimated percentage of women that should be referred to the gynaecologist following smears with moderate dysplasia has not changed. CONCLUSION: The new recommendations have lead to fewer smears being classified as moderate dysplasia. The long-term effects, such as a reduction in the length of the follow-up period, can only be analysed in a few years time.

Adult↗
PubMed2002

Women who participate in spontaneous screening are not at higher risk for cervical cancer than women who attend programme screening.

Up to 1995, programme screening for cervical cancer in The Netherlands was targeted at women between 35 and 54 years of age at 3-yearly intervals. Spontaneous screening in addition to programme screening was common practice. Our aim was to compare the underlying risk for cervical neoplasia for women involved in both types of screening. From the national pathological database, we retrieved all primary smears (n=693318) taken in 1994 in The Netherlands. Among the smears registered for screening purposes (39%), 79% was taken within the mass screening programme and 21% was taken for spontaneous screening. The underlying risk was studied from the detection rates of histologically confirmed severe dysplasia or worse, using a multivariate loglinear model, including age and screening history. The detection rate of at least severe dysplasia, adjusted for age and screening history, was equal for women who had a spontaneous smear and for those who had a programme smear (odds ratio (OR): 0.97; 95% Confidence Interval (CI): 0.84-1.14). In our data, women participating in spontaneous screening were not at a higher risk for cervical cancer than women who used programme screening. Therefore, all asymptomatic women in the Netherlands should follow the general guidelines for age-range and screening-interval.

Adult↗
PubMed2001

Impact of systematic false-negative test results on the performance of faecal occult blood screening.

The impact of systematic false-negative test results on mortality reduction and on programme sensitivity of annual faecal occult blood testing in ages 50-84 years is explored using a microsimulation model. We made calculations for test sensitivities of 80, 50 and 30%. In order to reproduce a cancer detection rate of 2.2 per 1000 at the first screening, the corresponding mean preclinical sojourn times had to be 1.42, 2.30 and 3.84 years, respectively. The fraction systematic results among the false-negative results is varied between 0 and 100%. With 80% test sensitivity, the reduction in mortality due to screening decreases from 25% without systematic results to 23% when all false-negative results are systematic and the programme sensitivity decreases from 63 to 58%. With 30% test sensitivity, mortality reduction decreases from 21 to 11% and programme sensitivity decreases from 52 to 27%. The impact of systematic false-negative test results is important if annual FOBT screening is considered.

Aged↗
PubMed2001

Endocervical status is not predictive of the incidence of cervical cancer in the years after negative smears.

The clinical relevance of the lack of endocervical cells was never well established in a longitudinal study with histologically proven cervical cancer as an end point. From the Dutch Network and National Database for Pathology, results for all negative smears obtained in 1990 and 1991 in the Netherlands were retrieved, as were data for all cytologic and histologic examinations performed after the negative smears before April 1998. There were no significant differences between the proportion of preinvasive lesions (cervical intraepithelial neoplasia 1, 2, and 3) detected after negative smears without endocervical cells compared with negative smears with endocervical cells. The proportion of women in whom invasive cancer developed was the same in both groups. These data suggest there is no reason to advise women with negative smears without endocervical cells to undergo an additional smear.

Adult↗
PubMed2000

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.

Adenoma↗
PubMed2000

Cervical cancer screening in the Netherlands.

The Netherlands is among the European countries with low incidence and almost lowest mortality from cancer of the uterine cervix. Screening started around 1970, being a combination of local and regional invitational programmes and opportunistic screening. In 1996 screening activities have been structured to a new national and nationwide programme. The restructuring concerned the management and financing of the programme, organisation, target age-ranges and interval, follow-up of abnormal test results, and evaluation. At the moment short-term results of implementation of the new screening programme are becoming available. It will take many more years before long-term effects of the new programme will emerge.

Adult↗
PubMed2000

Overview of important cervical cancer screening process values in European Union (EU) countries, and tentative predictions of the corresponding effectiveness and cost-effectiveness.

The objective was the evaluation of the (cost-)effectiveness of cervical cancer screening in the European Union (EU) countries. Data were collected on recommended screening age ranges and intervals, coverage, proportion of non-negative smears and smear use. Estimates reported by representatives of each participating Member State were compared, and used as input for model based on (using the MISCAN simulation model for cancer screening) effectiveness and cost-effectiveness calculations. Differences in coverage from below 50 to 82% resulted in more or less proportional differences in expected percentage life-years lost reduction, almost regardless of differences in 7-50+ smears recommended in a lifetime. Differences in screening intensity (resulting from the recommended number of smears per lifetime and the number of excess smears on top of these recommendations) resulted in more than 2-fold difference in the expected number of smears per percentage life-years lost reduction. (Cost-)effectiveness predictions would have greatly improved if estimates of long-term coverage had also been available. To conclude, estimates for a restricted set of well defined parameters - a few for short and long-term coverage and one for the total number of smears - are quite useful for country-specific (cost-)effectiveness evaluations. The main, and to some extent, unsolvable problem for further improvement of the analysis is the lack of reliable country-specific estimates for the background risk of cervical cancer in women eligible for screening in the near future.

Age Distribution↗
PubMed2000

A systematic review of the role of human papilloma virus (HPV) testing within a cervical screening programme: summary and conclusions.

A systematic review of the available evidence on the role of HPV testing in cervical screening has been published by the Health Technology Assessment Committee of the UK Department of Health. The review summarized relevant data on testing methods, natural history, and prevalence of the virus in different disease groups. Cost-effectiveness modelling was undertaken. Ten major conclusions were reached and are reported here. The key conclusions were that HPV testing was more sensitive than cytology, but that there were concerns about specificity, especially in young women. The increased sensitivity led to a recommendation that HPV testing be introduced on a pilot basis for women with borderline and mild smears. HPV testing has great potential as a primary screening test, but large trials are needed to properly evaluate this application and to determine if its introduction can reduce invasive cancer rates. There is an urgent need to undertake a large trial of HPV testing in conjunction with other new technologies (liquid-based cytology and computer-assisted cytology reading) to determine the best way to integrate them into ongoing screening programmes. A range of issues including the age to start and stop screening, the appropriate screening interval, the role of self-sampling for HPV testing and the choice of primary test (HPV and/or cytology) require further evaluation.

Adult↗
PubMed1999

The MISCAN-COLON simulation model for the evaluation of colorectal cancer screening.

A general model for evaluation of colorectal cancer screening has been implemented in the microsimulation program MISCAN-COLON. A large number of fictitious individual life histories are simulated in each of which several colorectal lesions can emerge. Next, screening for colorectal cancer is simulated, which will change some of the life histories. The demographic characteristics, the epidemiology and natural history of the disease, and the characteristics of screening are defined in the input. All kinds of assumptions on the natural history of colorectal cancer and screening and surveillance strategies can easily be incorporated in the model. MISCAN-COLON gives detailed output of incidence, prevalence and mortality, and the results and effects of screening. It can be used to test hypotheses about the natural history of colorectal cancer, such as the duration of progressive adenomas, and screening characteristics, such as sensitivity of tests, against empirical data. In decision making about screening, the model can be used for evaluation of screening policies, and for choosing between competing policies by comparing their simulated incremental costs and effectiveness outcomes.

Colorectal Neoplasms↗
PubMed1998

A cost-effectiveness analysis of colorectal screening of hereditary nonpolyposis colorectal carcinoma gene carriers.

BACKGROUND: It has been estimated that the prevalence of carriers of a mutated mismatch repair (MMR) gene among the general population in Western countries is between 5 and 50 per 10,000. These carriers have a risk of >85% of developing colorectal carcinoma (CRC) and therefore need careful follow-up. The objective of this study was to analyze the cost-effectiveness of CRC surveillance of carriers of a mutated MMR gene. METHODS: The authors constructed a model to estimate the potential health effects (life expectancy) and healthcare costs of two strategies: 1) surveillance, with colonoscopy every 2-3 years, and 2) no CRC surveillance. Estimates of the lifetime risk of developing CRC and the stage distribution of CRC for symptomatic patients were derived from the Dutch hereditary nonpolyposis colorectal carcinoma (HNPCC) registry. The CRC stage specific relative survival rates and the effectiveness of surveillance in preventing or detecting cancer early were based on Finnish studies. The costs of surveillance and treatment were derived from recent American studies. RESULTS: The results showed that 1) surveillance of gene carriers led to an increase in life expectancy of 7 years, and 2) the costs of surveillance under a wide range of assumptions are less than the costs of no CRC surveillance. CONCLUSIONS: CRC surveillance of HNPCC gene carriers appears to be effective and considerably less costly than no CRC surveillance and therefore deserves to be supported by governmental agencies and health insurance organizations.

Adult↗