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Biomedical subjects

J H Hendriks

Publications and source records attributed to J H Hendriks.

At least 55 records · Page 3Linked to original sources
PubMed1994

Efficacy of mammographic screening of the elderly: a case-referent study in the Nijmegen program in The Netherlands.

BACKGROUND: Only a few small studies have been conducted to examine the usefulness of mammographic screening in elderly women. These studies suggest that the screening-related reduction in breast cancer mortality rates is less than the estimated 20%-40% reduction observed for women aged 50-70 years at the time of their first screening. PURPOSE: We have studied the efficacy of continued mammographic screening for breast cancer of elderly women within our screening program. METHODS: In 1975, a breast cancer screening program was started in the city of Nijmegen. The Netherlands. During each biennial screening round, approximately 30,000 women aged 40 years and older were personally invited to participate. Single-view mammography was administered. The present study was conducted using a case-referent design. In order to be eligible for inclusion in this study, women had to have been invited to participate in the mammography screening program at least twice, with the most recent invitation having occurred when each woman was 65 years or older. The cases studied comprised 33 women in this group who had died of breast cancer at some point during 1977 through 1988. Referents were matched for age at last invitation to screening prior to the diagnosis of breast cancer and for the number of previous invitations to screenings. Five referents were randomly selected for each case. Breast cancer mortality rate ratios (RR) were calculated for several categories of attendance to the screening. RESULTS: The RR of those who attended the last screening versus those who failed to do so was 0.58 (95% confidence interval [CI] = 0.24-1.41); for women aged 65-74, the RR was 0.34 (95% CI = 0.12-0.97) and for women aged 75 or over, 2.87 (95% CI = 0.62-13.2). The RR of those who attended the screening before and after the age of 65, relative to those who attended before 65 only, was 0.26 (95% CI = 0.05-1.32). CONCLUSION: Although self-selection bias was present in our data, it was not likely to be responsible for the beneficial effect in women aged 65-74 at the time of invitation to screenings. It probably was responsible for the reversed RR (RR > 1) in the group of women 75 years and older. IMPLICATION: Continuation of mammographic screening until at least the age of 75 years may lead to a reduction of breast cancer mortality among elderly women.

Age Factors↗
PubMed1994

Age-specific effectiveness of the Nijmegen population-based breast cancer-screening program: assessment of early indicators of screening effectiveness.

BACKGROUND: The benefits of mammographic screening for breast cancer are not clear for women less than 50 years old. PURPOSE: Our aim was to evaluate the effectiveness of breast cancer screening in different age groups. METHODS: A mammographic breast cancer-screening program with a 2-year screening interval has been under way in Nijmegen, The Netherlands, since 1975. After eight rounds, more than 40,000 women have been invited to participate. All breast cancer cases diagnosed in the invited population, whether detected by screening or clinically, have been considered in this study. The age groups are younger than 50 years, 50-69 years, and 70 years or older at last invitation before diagnosis. Our assessment of the effectiveness of screening is based on the proportion of screen-detected cancers among all cancers and on the disease stage at diagnosis. RESULTS: For women younger than 50, compliance was 75%, and 37% (85/230) of the cancers were detected by screening. The age group 50-69 years had a compliance of 65% with 48% (288/595) of cancers detected by screening, and the group 70 years or older had a 25% compliance with 35% (108/305) of cancers detected by screening. The sizes of the cancers detected by screening were smaller than those detected clinically for all age groups. The age group under 50 showed no substantial difference in the proportion of positive axillary lymph node status between screening-detected and clinically diagnosed cancers, while among older women, the proportion of lymph node involvement was substantially higher for clinically detected cases. A significantly lower frequency of advanced stages was observed in screen-detected compared with clinically diagnosed cancers for women 50 years of age or older (P < .001) but not in women under 50 (P = .35). CONCLUSIONS: No positive effect of the biennial screening program is apparent for women under age 50. For women aged 50 and above, the screen-detected cancers have a more favorable stage distribution than clinically diagnosed cancers, a prerequisite for a reduction in breast cancer mortality.

Adult↗
PubMed1994

MR characterization of suspicious breast lesions with a gadolinium-enhanced TurboFLASH subtraction technique.

PURPOSE: To assess the utility of gadolinium-enhanced dynamic magnetic resonance (MR) imaging with turbo fast low-angle shot (TurboFLASH) technique in the differentiation of benign from malignant lesions of the breast. MATERIALS AND METHODS: Contrast material-enhanced MR images were obtained at intervals of 2.3 seconds for 2 minutes. After the first four images were obtained, contrast medium was intravenously injected within 10 seconds. Lesions that enhanced within 11.5 seconds after the aorta opacified were regarded as malignant. Lesions that enhanced more than 11.5 seconds after the aorta were regarded as benign. A centrifugal pattern of enhancement was regarded as a sign that a lesion was benign. RESULTS: Eighty-seven lesions were evaluated. Histologic examination showed 65 lesions were malignant and 22 were benign. Gadolinium-enhanced TurboFLASH imaging had a sensitivity of 95%, a specificity of 86%, and an overall accuracy of 93% in differentiating benign from malignant lesions. CONCLUSION: Gadolinium-enhanced TurboFLASH imaging is a valuable method in the examination of breast lesions suspected of being malignant.

Breast↗
PubMed1994

Microcalcifications associated with ductal carcinoma in situ: mammographic-pathologic correlation.

Because of the large scale use of mammography, the incidence of ductal carcinoma in situ (DCIS) has been increased fivefold to sixfold. The majority of these tumors are detected by mammographically significant microcalcifications. Their mammographic and histologic appearance is rather characteristic for the different types of DCIS. Microcalcifications associated with poorly differentiated DCIS appear on the mammogram as either linear, often branching, or as granular microcalcifications which are usually coarse. They correspond to the amorphous type calcifications on histology. Microcalcifications associated with well-differentiated DCIS appear on the mammogram usually as multiple clusters of fine granular microcalcifications, which correspond to the clusters of laminated, crystalline calcifications on histology. The distribution of DCIS is typically unicentric and segmental. In a series of 119 mastectomies, only a single case had a multicentric distribution. Based on the extent of microcalcifications, mammography usually underestimates the size of DCIS; although this discrepancy is less than 2 cm in 80% to 85% of the cases if state-of-the-art mammography, including magnification views, is used. Close co-operation between radiologist, pathologist, and surgeon is essential for the optimum management of patients with DCIS.

Breast Neoplasms↗
PubMed1993

The current detectability of breast cancer in a mammographic screening program. A review of the previous mammograms of interval and screen-detected cancers.

BACKGROUND: The occurrence of an interval cancer in a mammographic screening program is indicative of a suboptimum effect on mortality, because the very aim of the screening is to detect as many cancers as possible and at their earliest possible stage. In several studies, the previous screening mammograms of patients with an interval cancer were reviewed and the reasons for the "missed diagnosis" were classified into four categories: "screening error" (20-29%), "minimal sign present" (30-40%), "radiographically occult" (33-58%), or "radiographically occult at diagnosis" (occult both at previous screening and diagnosis; 7-16%). A similar procedure was followed in the Nijmegen screening project with patients recently diagnosed as having interval cancer or screen-detected cancer. METHODS: The previous screening mammograms of 40 interval and 44 screen-detected cases from the breast cancer screening program in Nijmegen were reviewed and categorized as specified above. These breast cancers were diagnosed clinically before the patient was invited to the eighth screening round (interval cancer) or were detected at the eighth screening round (screen-detected cancer). All these patients had been screened in the seventh round (1987-88). RESULTS: Thirteen percent of all cases were classified as "screening error," 38% as "minimal sign present," 43% as "radiographically occult," and 6% as "radiographically occult at diagnosis." In nearly half of the screen-detected cancers, minimal signs appeared to be present on the previous screening mammogram 2 years before the diagnosis. CONCLUSIONS: Annual instead of biennial screening may advance detection in most of the "screening error" cases as well as in some in the categories "minimal sign present" and "radiographically occult" at the previous screening. Meticulous analysis of the radiologic characteristics of the "minimal sign present" cases may very well lead to results showing that earlier detection is possible without a significant decrease in the specificity of the screening test.

Breast Neoplasms↗
PubMed1993

Age-dependent growth rate of primary breast cancer.

BACKGROUND: Currently, there have been no reports of clear-cut beneficial effects of regular screening with mammography at a mean screening interval of 2 years in women younger than 50 years of age. It may be that, because of a higher growth rate of breast cancer, more frequent screening is necessary if any effect is to be observed in this age group. However, good quantitative estimates for the growth rate in different age groups are lacking. METHODS: The study group consisted of cancers diagnosed in women who participated in a screening program with serial mammography available. The growth rate, expressed as the tumor volume doubling time, was calculated on the assumption of exponential growth. The analysis was based, not only on the increase in tumor volume for cancers with at least two mammograms showing a measurable tumor nucleus shadow (n = 85), but also on censored values, calculated for cancers showing no growth (n = 6) and for cancers showing only a measurable tumor nucleus shadow on the mammogram at diagnosis (n = 109). In calculating these latter growth rates, the density of the breast parenchyma was taken into account. RESULTS: The median volume doubling time of the primary breast cancers diagnosed in women aged 50-70 years was 157 days (95% confidence limits, 121-204 days). This was significantly longer than in women younger than 50 years of age at diagnosis (80 days; 95% confidence limits, 44-147 days). Primary breast cancer in women older than 70 years of age at diagnosis grew even more slowly (median, 188 days; 95% confidence limits, 120-295). CONCLUSIONS: To observe a beneficial effect of screening, if any, for women younger than age 50 years, more frequent screening than in the older age group is necessary.

Age Factors↗
PubMed1993

Rationality, emotional expression and control: psychometric characteristics of a questionnaire for research in psycho-oncology.

In some studies rationality, anti-emotionality and the control of (negative) emotions were found to be psychological risk factors for cancer. In the present study instruments were developed in order to cross-validate the role of the 'rationality/anti-emotionality (RAE)'-concept and the 'emotional expression and control (EEC)'-concept. The psychometric characteristics of a RAE-scale and EEC-scales were investigated in 4302 healthy women attending a breast cancer screening programme in The Netherlands. Principal components analysis revealed three factors for the RAE-scale: (1) Rationality; (2) Emotionality; and (3) Understanding. The EEC-scales consist of three factors that indicate: (1) expression of emotions to oneself; (2) expression of emotions towards others; and (3) control of emotions. These RAE and EEC scales can be of importance in psycho-oncological research, especially when: (1) the more refined subscales are used; and (2) age of the subjects is taken into account.

Adult↗
PubMed1993

Spatial resolution in digital mammography.

RATIONAL AND OBJECTIVES: Digital acquisition systems currently available limit spatial resolution in digital mammography to roughly 0.1 mm/pixel. The objective of this study is to determine if high-quality mammography is possible at this resolution. METHODS: The influence of spatial resolution on diagnostic quality was investigated by comparing observer performance on film to that on digitized film. A 0.1-mm sampling distance was used for digitization. Detection of mammographic details was studied by measuring threshold contrast as a function of detail size for small circular objects in the range of 0.12 to 2.5 mm. Characterization of microcalcifications was investigated in a receiver operating characteristic (ROC) study, in which 10 radiologists read 72 mammographic details with microcalcifications, both digitally and on film. RESULTS: Digitization improved the detectability of the larger, low contrast objects, whereas for small objects the detectability did not change. The authors found that even under the most optimal circumstances, isolated spherical calcifications with diameters smaller than 0.13 mm are not detectable with film-screen mammography, despite its resolution limit of 15 line patterns per mm (lp/mm). The ability to characterize microcalcification clusters did not change significantly with digitization. However, the results suggest that differentiation of benign from malignant cases decreases slightly, and that characterization of different types of malignancies somewhat improves by digitization. Mean differences between the two modalities were considerably smaller than the interobserver variability. CONCLUSION: A relatively low spatial resolution of 0.1 mm/pixel does not prohibit high-quality diagnostic performance in digital mammography.

Breast Diseases↗
PubMed1993

Identification of F11 fimbriae on chicken Escherichia coli strains.

Fimbriae were purified from Escherichia coli strains isolated from chickens with septicemia or colibacillosis. When grown on solid media, these strains expressed fimbriae with an apparent subunit molecular mass of 18 kDa. Morphological, biochemical, serological, functional, and molecular characterization revealed that these 18-kDa fimbriae are identical to F11 fimbriae, which were previously found to be involved in the pathogenesis of human urinary tract infection. Screening of a large strain collection showed that 78% of chicken E. coli strains expressed F11 fimbriae, whereas this percentage increased to 96% when the only strains taken into account were those with the serotypes most commonly encountered in avian colibacillosis (O1:K1, O2:K1, O35, and O78:K80). The prevalence of F11 fimbrial expression appeared to be independent of the country of isolation of the strains, except for the United States, where the prevalence seemed higher. Expression of F11 fimbriae by chicken E. coli strains could not be correlated with adherence to chicken tracheal or pharyngeal cells.

Animals↗
PubMed1992

One-view versus two-view mammography in baseline screening for breast cancer: a review.

Two-view mammography is generally preferred as an initial screening examination because the number of missed carcinomas and false positive results in one-view mammography is considered too large. The present review was performed to assess the difference in screening quality between one- and two-view mammography. Nineteen previous studies were reviewed and differences in sensitivity as well as specificity between two-view and one-view mammography were calculated. The results ranged from -5.7% to 19.4% (median 3.9%), and 2.7% to 36.1% (median 14.8%), respectively, and indicate a higher screening quality of two-view mammography. However, in the studies considered there is a large variation in study population, screening tests used and assessment of disease outcome, which makes the numerical results less conclusive. None of the studies provided adequate information for deciding whether two-view mammography in baseline screening for breast cancer is preferable to one-view mammography. If a screening programme using one-view mammography has already achieved high sensitivity and specificity, the value of an additional craniocaudal view is only marginal.

Breast Neoplasms↗
PubMed1991

Breast cancer screening and cost-effectiveness; policy alternatives, quality of life considerations and the possible impact of uncertain factors.

Mammographic screening for women aged 50-70 is effective in reducing breast cancer mortality, but the impact on quality of life and the attainable mortality reduction remain to be discussed. The consequences of expanding screening programmes to include women in other age groups are uncertain. We have predicted the effects and costs for 5 popular screening variants, differing in age group and screening interval, on the basis of our analysis of the Dutch screening trials and of the reported mortality reductions in other trials. We have also investigated the influence of a large number of uncertain factors. Screening for women aged 50 and over with a 2- or 3-year interval is very cost-effective and will result in reductions of respectively 16% or 10% in breast cancer mortality in a real population. Variation of most variables keeps the cost-effectiveness (CE) ratio limited to the range of US $3,000 to 5,000 per life-year gained. A 2- to 3-fold change in CE ratio would only occur if the extreme estimates of mortality reduction in the Swedish screening trials were applied. The impact on quality of life (QoL) is limited: for the 2-yearly screening policy for women aged 50-70, the cost per Quality-Adjusted Life-Year (QALY) gained is 4,050, whereas the cost per life-year gained is US $3,825. The CE ratio for 2-yearly screening of women aged 40-70 is 5,400, but the additional cost per additional life-year gained is US $35,000. It would be preferable by far to extend the screening programme to women over the age of 70 or to shorten the screening interval for women aged 50-70. Screening performances, the demand for mammograms outside screening and the possibility of a survival improvement irrespective of screening have a strong impact on QoL and CE.

Adult↗
PubMed1991

The contribution of routine follow-up mammography to an early detection of asynchronous contralateral breast cancer.

The role of routine mammography was assessed in the early detection of asynchronous contralateral breast cancer (ACBC). The breast cancer patient populations of two cities, Nijmegen and Eindhoven, The Netherlands, which were subjected to a well-defined follow-up program, were compared. The program consisted of regular physical examination and annual mammography in Nijmegen and physical examination only in Eindhoven. From 1975 until 1987, 24 ACBC patients were detected within a group of 880 breast cancer patients in Nijmegen (3%) and, from 1971 until 1984, 14 ACBC patients within a group of 411 patients in Eindhoven (3%). In Nijmegen, eight of the 23 evaluable patients (35%) had a contralateral tumor with a histologic size smaller than 10 mm or an in situ carcinoma, compared with one of the 14 of the Eindhoven patients (7%), whereas 18 of the 24 (75%) versus eight of the 14 patients (57%) were node-negative. Thus annual mammography is very likely a contribution in the early detection of contralateral breast cancer as compared with follow-up by regular physical examination only.

Breast Neoplasms↗
PubMed1991

A proposal for short-term quality control in breast cancer screening.

Current proposals for a monitoring and evaluation system in breast cancer screening programmes focus on mortality reduction. Here emphasis is laid on the prevention of too high a number of false-positive screening results, i.e. no subsequent demonstration of malignancy. By comparing the specificity of the screening test, the positive predictive value and the detection rate with reference values, the screening performance can be measured in a very early phase of the programme, even before the registration results on interval cancers become available. The proposed average reference values for the first screening round are 99.2%, 40% and 5.4/1000, respectively. Measures specifically for the age groups 45-49, 50-59 and 60-69 will be given, thus allowing improvements to be made if necessary.

Aged↗
PubMed1990

[Digital mammography is very useful in mass screening of breast cancer].

Mammograms made between 1981 and 1989 in the Nijmegen screening programme for breast cancer were retrospectively reviewed. Those made before detection of breast cancer showed signs of tumour growth in the place of the subsequently detected malignancy in 22% of the cases. A work station was set up for image digitization and image processing. Display with optimal contrast and image processing of mammograms is possible. Diagnoses based on digitized mammograms displayed on a monitor were as good as those based on the conventional images on film. Automatic detection of image features has been investigated. A procedure for automatic detection of microcalcifications was developed. This research is important for optimalization of diagnosis in screening and because of the expected introduction of direct digital imaging techniques.

Breast Neoplasms↗
PubMed1990

[Efficacy of mass screening for breast cancer; reduced mortality nationally and internationally].

Breast cancer screening trials in several countries have proved to reduce breast cancer mortality. However, the trials show considerable differences in the extent of this reduction. The Swedish projects in Kopparberg/Ostergötland and Malmö are the most similar to the Dutch situation. The confidence intervals of the effect estimates of both projects are large. A critical review of all differences cannot yet lead to a conclusion on the difference in the estimated effects of both trials. Assuming equal mammographic quality in both projects, a reduction of 33% in breast cancer mortality for women in the age-group of 50 to 70 years seems a good estimate for similar projects. This assumption applied to a Dutch nationwide project, it will eventually lead to a reduction in breast cancer mortality of 16% for the entire population. In the year 2015 about 700 women will not die of breast cancer who would have without screening.

Adult↗
PubMed1990

Extent, distribution, and mammographic/histological correlations of breast ductal carcinoma in situ.

To assess the potential of breast-conserving treatment for ductal carcinoma in situ (DCIS), 82 mastectomy specimens were studied by Egan's serial subgross method. 42 (51%) of the tumours were larger than 50 mm and only 12 (15%) were smaller than 20 mm; the size distribution was not affected by the mode of detection (mammography 52 cases, clinical examination 30). All but 1 case showed only 1 region of tumour. 66% of tumours involved one breast quadrant, 23% extended over more than one quadrant, and 11% were centrally located. Mammographic estimates, based on the extent of microcalcifications, frequently underestimated the histological size of tumours, the extent of the discrepancy being related to the histological type--8/50 predominantly micropapillary/cribriform. In view of the frequently large size, adequate excision of many DCIS will require a wide excision involving up to a whole quadrant.

Breast Neoplasms↗
PubMed1990

[Observed effects of the mass screening program for breast cancer in Nijmegen in 1975-1986].

Since January 1975, the start of the screening programme for breast cancer in the city of Nijmegen, The Netherlands, over 14 years have elapsed. Data up to the end of 1986 have been processed and are presented in this article. The younger the birth cohort, the higher the attendance rate. In the course of the screening programme, attendance rates decline. Referral rates are highest in the first screening round and for the eldest birth cohort. Detection rates increased during the most recent screening rounds, after an initial decrease during the earliest rounds. They are higher for the eldest birth cohort also. The relative number of interval carcinomas is highest among younger women (as related to the screening-detected carcinomas).

Adult↗