Screening mammography in community practice: positive predictive value of abnormal findings and yield of follow-up diagnostic procedures

Adverse effects of screening mammography

The main risks and other adverse consequences from screening mammography include discomfort from breast compression, patient recall for additional imaging, and false positive biopsies. Although these risks affect a larger number of women than those who benefit from screening, the risks are less consequential than the life-sparing benefits from early detection. Radiation risk, even for multiple screenings, is negligible at current mammography doses. Anxiety before screening or resulting from supplementary imaging work-up, short-term follow-up, cyst aspiration, and biopsy has not dampened the enthusiasm of most women for the value of early detection.

Radiologist uncertainty and the interpretation of screening

OBJECTIVE

To determine radiologists' reactions to uncertainty when interpreting mammography and the extent to which radiologist uncertainty explains variability in interpretive performance.

METHODS

The authors used a mailed survey to assess demographic and clinical characteristics of radiologists and reactions to uncertainty associated with practice. Responses were linked to radiologists' actual interpretive performance data obtained from 3 regionally located mammography registries.

RESULTS

More than 180 radiologists were eligible to participate, and 139 consented for a response rate of 76.8%. Radiologist gender, more years interpreting, and higher volume were associated with lower uncertainty scores. Positive predictive value, recall rates, and specificity were more affected by reactions to uncertainty than sensitivity or negative predictive value; however, none of these relationships was statistically significant.

CONCLUSION

Certain practice factors, such as gender and years of interpretive experience, affect uncertainty scores. Radiologists' reactions to uncertainty do not appear to affect interpretive performance.

Probability modeling applied to CAD systems for mammography

A practical model based on basic probability theory is developed to evaluate the operational and financial performance of mammography systems. The model is intended to be used by decision makers to evaluate overall sensitivity, overall specificity, positive and negative predictive values, and expected cost. As an illustration, computer aided detection (CAD) systems that support a radiologist's diagnosis are compared with standard mammography to determine conditions that would support their use. The model's input parameters include the operational performance of mammography (with and without CAD), the age of the patient, the cost of administering the mammogram and the expected costs associated with false positive and false negative outcomes. Sensitivity analyses are presented that show the CAD system projecting financial benefit over ranges of uncertainty associated with each model parameter.

Screening for pancreatic neoplasia in high-risk individuals: an EUS-based approach

BACKGROUND & AIMS

Relatives of patients with pancreatic cancer and persons with certain inherited syndromes are at increased risk for developing pancreatic cancer. We prospectively evaluated the feasibility of screening for pancreatic neoplasia in high-risk individuals.

METHODS

Individuals from familial pancreatic cancer kindreds and a patient with Peutz-Jeghers syndrome underwent screening endoscopic ultrasound (EUS). If the EUS was abnormal, EUS-guided fine-needle aspiration, endoscopic retrograde cholangiopancreatography (ERCP), and spiral computed tomography (CT) were performed. Patients with abnormalities suggesting neoplasia had surgery.

RESULTS

Thirty-eight patients were studied; 31 (mean age, 58 yr; 42% men) from kindreds with > or =3 affected with pancreatic cancer; 6 from kindreds with 2 affected relatives, 1 was a patient with Peutz-Jeghers syndrome. None had symptoms referable to the pancreas or suggestive of malignancy. Six pancreatic masses were found by EUS: 1 invasive ductal adenocarcinoma, 1 benign intraductal papillary mucinous neoplasm, 2 serous cystadenomas, and 2 nonneoplastic masses. Hence, the diagnostic yield for detecting clinically significant pancreatic neoplasms was 5.3% (2 of 38). The 1 patient with pancreatic cancer was treated and still is alive and disease-free >5 years after surgery. EUS changes similar to those associated with chronic pancreatitis were found, which were more common in patients with a history of regular alcohol intake (P = 0.02), but also occurred in patients who did not consume alcohol. Screening also led to a new diagnosis and treatment of symptomatic upper-gastrointestinal conditions in 18.4% of patients.

CONCLUSIONS

EUS-based screening of asymptomatic high-risk individuals can detect prevalent resectable pancreatic neoplasia but false-positive diagnoses also occur.

Dynamic infrared imaging for the detection of malignancy

The potential for malignancy detection using dynamic infrared imaging (DIRI) has been investigated in an animal model of human malignancy. Malignancy was apparent in images formed at the vasomotor and cardiogenic frequencies of tumour bearing mice. The observation of malignancy was removed by the administration of an agent that blocks vasodilation caused by nitric oxide (NO). Image patterns similar to those that characterize malignancy could be mimicked in normal mice using an NO producing agent. Apparently DIRI allows for cancer detection in this model through vasodilation caused by malignancy generated NO. Dynamic infrared detection of vasomotor and cardiogenic surface perfusion was validated in human subjects by a comparison with laser Doppler flowmetry (LDF). Dynamic infrared imaging technology was then applied to breast cancer detection. It is shown that dynamic infrared images formed at the vasomotor and cardiogenic frequencies of the normal and malignant breast have image pattern differences, which may allow for breast cancer detection.

Electromagnetic breast imaging: average tissue property values in women with negative clinical findings

Representative data are provided for three electromagnetic breast imaging techniques-near-infrared spectroscopy, electrical impedance spectroscopy, and microwave imaging spectroscopy-to serve as potential benchmarks for future investigation. The breasts of 23 women without clinical or mammographic findings of disease were imaged in the coronal plane with nonionizing radiation of varying frequencies. Average electromagnetic property values were reconstructed at each frequency on the basis of computational models of light diffusion, current flow, and microwave propagation. Electromagnetic properties were correlated with subject characteristics and between techniques. Each technique yielded information on breast tissue features (eg, conductivity, permittivity, light scattering, and absorption) that had not previously all been measured in the same individuals.

What Factors Are Associated with Diagnostic Follow-Up after Abnormal Mammograms? Findings from a U.S. National Survey

The purpose of this study was to identify factors associated with diagnostic follow-up after an abnormal mammogram in a national sample of women in the U.S. The sample was selected from the year 2000 National Health Interview Survey and included 1901 women aged 30 and above who reported ever having an abnormal mammogram. The outcome measure was receipt of at least some diagnostic follow-up after an abnormal mammogram. Bivariate and multivariate logistic regression analyses were used to explore the associations between sociodemographic characteristics, general health and health behaviors, cancer risk and risk perceptions, and health care utilization characteristics and follow-up. Approximately 9% of women who reported ever having abnormal mammograms reported not completing any additional diagnostic follow-up. Controlling for all other factors, women with less than a high school education were less likely to report follow-up after an abnormal mammogram than were women who had at least completed college (odds ratio = 0.56; 95% confidence interval: 0.32, 0.98). Younger women and women in poorer health were also less likely to report follow-up. Women who perceived a high versus low level of cancer in their family were more likely to report follow-up (odds ratio = 1.65; 95% confidence interval: 1.04, 2.62), controlling for all other factors. In a national sample of women with abnormal mammograms, a substantial number did not complete any diagnostic follow-up, potentially reducing the effectiveness of mammography screening programs in the U.S. Additional research on subsequent screening behaviors for women with incomplete follow-up and in-depth exploration of the roles of patient-provider interactions and health care system factors related to the index abnormal mammogram is warranted.

Decreasing Women's Anxieties After Abnormal Mammograms: A Controlled Trial

BACKGROUND

Few studies have evaluated interventions to decrease a woman's anxiety after she receives an abnormal mammogram (i.e., one with a recommendation for follow-up). We performed a controlled trial to compare the effects of both an immediate reading of mammograms (i.e., a radiology intervention) and of an educational intervention that taught skills to cope with anxiety on the psychological status of women whose mammograms were normal or abnormal.

METHODS

Eligible women (n = 8543) aged 39 years or older were recruited from seven mammography sites at the time of their scheduled mammography screening and assigned to receive no intervention, either the radiology or the educational intervention, or both interventions. We used the Impact of Events Scale (IES) and the Hopkins Symptom Checklist subscales for Anxiety (HSC-A) and Depression (HSC-D) in structured telephone interviews of 2844 women to assess the psychological status of all women with abnormal mammograms (excluding women diagnosed with breast cancer) and of a random sample of women with normal mammograms at 3 weeks and 3 months after their mammograms. All statistical tests were two-sided.

RESULTS

We obtained usable 3-week interviews for 2390 (84%) women. By the 3-week interview, 1037 (72.1%) of the 1439 interviewed women with abnormal mammograms had completed the recommended work-up and knew that their abnormal mammograms were false positives. Women with abnormal mammograms had higher IES and HSC-A scores (i.e., more anxiety) than women with normal mammograms (mean IES scores: 4.97 [95% confidence interval [CI] = 4.47 to 5.50] and 1.82 [95% CI = 1.51 to 2.14], respectively; P<.001; mean HSC-A scores: 1.14 [95% CI = 1.12 to 1.15] and 1.11 [95% CI = 1.09 to 1.13], respectively, P=.002). Among women with false-positive mammograms, those who had received the radiology intervention reported less anxiety than those who had not (mean IES scores: 4.42 [95% CI = 3.73 to 5.07] and 5.53 [95% CI = 4.82 to 6.28], respectively, P=.026). The educational intervention was not associated with any difference in psychological outcomes. Three months after the mammogram, by which time more than 80% of the women with abnormal results knew their mammograms to be false positives, anxiety levels of women with false-positive mammograms remained higher than those of women with normal mammograms (mean IES scores: 2.34 [95% CI = 1.99 to 2.69] and 1.15 [95% CI = 0.87 to 1.47], respectively, P<.001).

CONCLUSION

Immediate reading of screening mammograms, but not an educational intervention targeting coping skills, was associated with less anxiety among women with false-positive mammograms 3 weeks after mammography.

Cost-effectiveness analysis of interventions to enhance mammography compliance using computer modeling (CAN*TROL)

OBJECTIVE

Tailored telephone counseling and physician-based and clinic-based interventions have been shown to be cost-effective in enhancing utilization of mammography among nonadherent women. The objective of this study was to evaluate the costs and benefits of a broad implementation of these interventions from a health payer perspective.

METHODS

CAN*TROL computer modeling was employed in the cost-effectiveness analysis of interventions in a 2000 Texas female population. The estimated effects of the various interventions and their related costs derived from the literature were applied to a hypothetical scenario of a broad implementation of these interventions.

RESULTS

Seven studies were identified from the literature, six of them employed tailored telephone counseling (TC), whereas two used comprehensive physician-based (PB) or clinic-based (CB) interventions. The estimated intervention cost per women was 43 dollars for TC, 71 dollars for PB, and 151 dollars for CB. CAN*TROL model showed that after 15 years of implementation, TC, PB, and CB could reduce cancer mortality by 6.5, 2.2, and 10.7%, respectively. The cumulative net costs of interventions, mammography screening, and medical care costs were lower for TC (TC vs. PB vs. CB, 1.05 million vs. 1.06 million vs. 1.60 million). Nevertheless, CB resulted in more life-years saved (TC vs. PB vs. CB, 11,413 vs. 8515 vs. 14,559). The incremental cost-effectiveness ratio was more favorable for tailored telephone counseling interventions. One-way sensitivity analysis indicated that compliance rates and intervention costs had the most significant impact on the incremental cost-effectiveness ratio.

CONCLUSION

Tailored telephone counseling interventions may be the preferred first-line intervention for getting nonadherent women aged 50 to 79 years on schedule for mammography screening.

International variation in screening mammography interpretations in community-based programs

BACKGROUND

Variations in mammography interpretations may have important clinical and economic implications. To evaluate international variability in mammography interpretation, we analyzed published reports from community-based screening programs from around the world.

METHODS

A total of 32 publications were identified in MEDLINE that fit the study inclusion criteria. Data abstracted from the publications included features of the population screened, examination technique, and clinical outcomes, including the percentage of mammograms judged to be abnormal, positive predictive value of an abnormal mammogram (PPV(A)), positive predictive value of a biopsy performed (PPV(B)), and percentages of breast cancer patients with ductal carcinoma in situ (DCIS) and minimal disease (DCIS and/or tumor size < or =10 mm). North American screening programs were compared with those from other countries using meta-regression analysis. All statistical tests were two-sided.

RESULTS

Wide ranges were noted for the percentage of mammograms judged to be abnormal (1.2%-15.0%), for PPV(A) (3.4%-48.7%), for PPV(B) (5.0%-85.2%), for percentage diagnosed with DCIS (4.3%-68.1%), and for percentage diagnosed with minimal disease (14.0%-80.6%). The percentage of mammograms judged to be abnormal were 2-4 percentage points higher in North American screening programs than they were in programs from other countries, after adjusting for covariates such as percentage of women who were less than 50 years of age and calendar year in which the mammogram was performed. The percentage of mammograms judged to be abnormal had a negative association with PPV(A) and PPV(B) (both P<.001) and a positive association with the frequency of DCIS cases diagnosed (P =.008) and the number of DCIS cases diagnosed per 1000 screens (P =.024); no consistent relationship was observed with the proportion of breast cancer diagnoses reported as having minimal disease or the number of minimal disease cases diagnosed per 1000 screens.

CONCLUSION

North American screening programs appear to interpret a higher percentage of mammograms as abnormal than programs from other countries without evident benefit in the yield of cancers detected per 1000 screens, although an increase in DCIS detection was noted.

Is the promise of cancer-screening programs being compromised? Quality of follow-up care after abnormal screening results

Cancer screening has increased dramatically in the United States, yet in some populations, particularly racial minorities or the poor, advanced disease at diagnosis remains high. One potential explanation is that follow-up of abnormal tests is suboptimal, and the benefits of screening are not being realized. The authors used a conceptual model of access to care and integrated constructs from models of provider and patient health behaviors to review published literature on follow-up care. Most studies reported that fewer than 75 percent of patients received some follow-up care, indicating that the promise of screening may be compromised. They identified pervasive barriers to follow-up at the provider, patient, and health care system levels. Interventions that address these barriers appear to be effective. Improvement of data infrastructure and reporting will be important objectives for policy makers, and further use of conceptual models by researchers may improve intervention development and, ultimately, cancer control.

Realizing the promise of breast cancer screening: clinical follow-up after abnormal screening among Black women

BACKGROUND

Delayed or incomplete follow-up after abnormal screening results may compromise the effectiveness of breast cancer screening programs, particularly in medically underserved and minority populations. This study examined the role of socioeconomic status, breast cancer risk factors, health care system barriers, and patient cognitive-attitudinal factors in the timing of diagnostic resolution after abnormal breast cancer screening exams among Black women receiving breast cancer screening at three New York city clinics.

METHODS

We identified 184 Black women as having an abnormal mammogram or clinical breast exam requiring immediate follow-up and they were interviewed and their medical records examined. Bivariate and multivariate logistic regression analyses were used to assess the association between patient and health care system factors and diagnostic resolution within 3 months of the abnormal finding.

RESULTS

Within 3 months, 39% of women were without diagnostic resolution and 28% within 6 months. Neither socioeconomic status nor system barriers were associated with timely diagnostic resolution. Timely resolution was associated with mammogram severity, patients asking questions (OR, 2.73; 95% CI, 1.25-5.96), or receiving next step information (OR, 2.6; 95% CI, 1.08-6.21) at the initial mammogram. Women with prior breast abnormalities were less likely to complete timely diagnostic resolution (OR, 0.42; 95% CI, 0.20-0.85), as were women with higher levels of cancer anxiety (OR, 0.50; 95% CI, 0.27-0.92).

CONCLUSIONS

Interventions that address a woman's prior experience with abnormal findings and improve patient/provider communication may improve timely and appropriate follow-up.

Comparisons of three alternative breast modalities in a common phantom imaging experiment

Four model-based imaging systems are currently being developed for breast cancer detection at Dartmouth College. A potential advantage of multimodality imaging is the prospect of combining information collected from each system to provide a more complete diagnostic tool that covers the full range of the patient and pathology spectra. In this paper it is shown through common phantom experiments on three of these imaging systems that it was possible to correlate different types of image information to potentially improve the reliability of tumor detection. Imaging experiments were conducted with common phantoms which mimic both dielectric and optical properties of the human breast. Cross modality comparison was investigated through a statistical study based on the repeated data sets of reconstructed parameters for each modality. The system standard error between all methods was generally less than 10% and the correlation coefficient across modalities ranged from 0.68 to 0.91. Future work includes the minimization of bias (artifacts) on the periphery of electrical impedance spectroscopy images to improve cross modality correlation and implementation of the multimodality diagnosis for breast cancer detection.

Clinical and diagnostic value of preoperative MR mammography and FDG-PET in suspicious breast lesions

Dynamic enhanced magnetic resonance (MR) mammography and fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) of the breast were directly compared preoperatively in suspicious breast lesions. Forty-two breast lesions in 40 patients were examined with a three-dimensional dynamic MR imaging series and FDG-PET. The MR and PET examinations were evaluated separately and the results were compared with the histological findings. The sensitivity and specificity of each method were calculated. The diagnostic value of both modalities as single diagnostic tool and in combination was investigated. Nineteen malignant and 23 benign breast lesions were proven histologically. Magnetic resonance mammography and FDG-PET showed a sensitivity of 89 and 63%, respectively. The specificity was 74 and 91%, respectively. The combination of both imaging methods decreased the not-required biopsies from 55 to 17%. Only one false-negative finding-a patient pre-treated with chemotherapy-was observed in both methods. The combination of MR mammography and FDG-PET can help to decrease biopsies of benign breast lesions. Because of their high cost, these modalities should only be used in problematic cases to either rule out or to demonstrate malignancy. The best diagnostic strategy is achieved using MR mammography first. If the diagnosis is still questionable, FDG-PET can be performed.

Measuring the performance of screening mammography in community practice with Medicare claims data

BACKGROUND

Few studies have examined the outcomes of screening mammography in community practice, particularly the extent of false positive exams among older asymptomatic women.

RESEARCH DESIGN

Subjects were female Medicare beneficiaries, age 67 or older, residing in one of eleven SEER areas, with no evidence of breast cancer. Medicare claims data were used to identify their screening mammograms over two time periods, 1993-1995 and 1996-1998, and to measure their use of follow-up diagnostic testing (diagnostic mammography, breast ultrasound and breast biopsy) within three months of the screening mammogram.

RESULTS

There were significant differences among the rates of diagnostic testing for each age group (67-74; 75+ ) by year, but no clear trend toward higher or lower rates over time. Although rates of diagnostic testing differed significantly by geographic region in both time periods 1993-1995 and 1996-1998, estimates of specificity for all regions were within AHRQ clinical practice guidelines (specificity greater than 90%). Specificity significantly improved with the volume of the radiologist's practice for the latter time period (1996-1998) but not for the former (1993-1995).

CONCLUSION

Medicare claims offer an accessible population-based source of data for mammography performance indicators. As such, they offer a low cost method for evaluating individual mammography practices as well as monitoring the impact of reimbursement policies, practice guidelines and laws mandating requirements for accrediting facilities.

Clinical practice. Mammographic screening for breast cancer

A 44-year-old woman who is a new patient has no known current health problems and no family history of breast or ovarian cancer. Eighteen months ago, she had a normal screening mammogram. She recently read that mammograms may not help to prevent death from breast cancer and that “the patient should decide.” But she does not think she knows enough. She worries that there is a breast-cancer epidemic. What should her physician advise?

Frequency and predictive value of a mammographic recommendation for short-interval follow-up

BACKGROUND

A recommendation for short-interval follow-up of "probably benign finding" is associated with up to 11% of screening mammograms, but its predictive value for breast cancer is unclear. We examined the predictive values (i.e., the percentage of women with a diagnosis of breast cancer 2 years after a short-interval follow-up recommendation) and likelihood ratios (derived from the pretest and post-test odds of breast cancer in the Women's Health Initiative sample) for breast cancer that are associated with a recommendation for short-interval follow-up among postmenopausal women.

METHODS

We performed a longitudinal analysis of a prospective cohort of 68 126 postmenopausal women (aged 50-79 years) who were participating in clinical trials as part of the Women's Health Initiative at 40 centers across the United States. Eligible participants had screening mammograms at baseline and at least 2 years of follow-up that included a repeat mammography. Outcomes measured were breast cancer events at 1 and 2 years after baseline and the results of subsequent mammograms. All P values were two-sided.

RESULTS

A total of 2927 (5%) of the 58 408 eligible women had baseline mammograms that included recommendations for short-interval follow-up. The incidence of breast cancer for women with a short-interval follow-up recommendation was 1.0% at 2 years after the baseline mammogram compared with breast cancer incidences of 0.6% and 0.5% for women whose baseline mammograms were described as "benign" and "negative," respectively. Across the 40 participating centers, the prevalence of short-interval follow-up recommendations among baseline mammograms varied from 1.2% to 9.8% (P<.001), even when the analysis was adjusted for key variables in regression models. Centers reporting higher frequencies of such recommendations did not have lower positive predictive values for breast cancer than centers reporting lower frequencies. The likelihood ratio for breast cancer after a recommendation for short-interval follow-up on a subsequent mammogram was 2.20 (95% confidence interval = 1.65 to 2.86).

CONCLUSION

Having a mammographic recommendation for short-interval follow-up was associated with a low positive predictive value for breast cancer among postmenopausal women during a 2-year follow-up. This result suggests that the current criteria for this recommendation-repeat mammography within 6 months-should be reconsidered.

Breast lesions on sonograms: computer-aided diagnosis with nearly setting-independent features and artificial neural networks

PURPOSE

To develop a computer-aided diagnosis (CAD) algorithm with setting-independent features and artificial neural networks to differentiate benign from malignant breast lesions.

MATERIALS AND METHODS

Two sets of breast sonograms were evaluated. The first set contained 160 lesions and was stored directly on the magnetic optic disks from the ultrasonographic (US) system. Four different boundaries were delineated by four persons for each lesion in the first set. The second set comprised 111 lesions that were extracted from the hard-copy images. Seven morphologic features were used, five of which were newly developed. A multilayer feed-forward neural network was used as the classifier. Reliability, extendability, and robustness of the proposed CAD algorithm were evaluated. Results with the proposed algorithm were compared with those with two previous CAD algorithms. All performance comparisons were based on paired-samples t tests.

RESULTS

The area under the receiver operating characteristic curve (A(z)) was 0.952 +/- 0.014 for the first set, 0.982 +/- 0.004 for the first set as the training set and the second set as the prediction set, 0.954 +/- 0.016 for the second set as the training set and the first set as the prediction set, and 0.950 +/- 0.005 for all 271 lesions. At the 5% significance level, the performance of the proposed CAD algorithm was shown to be extendible from one set of US images to the other set and robust for both small and large sample sizes. Moreover, the proposed CAD algorithm was shown to outperform the two previous CAD algorithms in terms of the A(z) value.

CONCLUSION

The proposed CAD algorithm could effectively and reliably differentiate benign and malignant lesions. The proposed morphologic features were nearly setting independent and could tolerate reasonable variation in boundary delineation.

Mammography and computerized decision systems: a review

Computer-aided diagnosis (CAD) systems in mammography have been developed and investigated for several years and recently they have left the research stage to enter the clinical stage. The purpose of this article is to review the present situation of mammography for breast cancer detection and the role played by CAD systems. Results from the recent literature show that CAD systems have the potential to improve the sensitivities of radiologists in the detection of malignant clustered microcalcifications and masses, while keeping specificities at acceptable levels. This leads to the conclusion that CAD systems can be incorporated into clinical practice as a double reading option to radiologists. However, some issues have yet to be tackled for CAD systems to gain better acceptance and more widespread use worldwide.

Strategies for improving melanoma education and screening for men age >or= 50 years: findings from the American Academy of Dermatological National Skin Cancer Sreening Program

BACKGROUND

Recently, the Institute of Medicine (2000) and the Third United States Preventive Services Task Force (2001) called for studies to help clinicians identify patients, especially elderly patients, who are at high risk for melanoma. In the current study, the authors sought to identify factors associated with a high yield in skin cancer screening and to explore strategies for improving mass screenings for melanoma.

METHODS

The authors analyzed the data base of the 242,374 skin cancer screenings conducted on more than 206,000 Americans who attended the American Academy of Dermatology National Skin Cancer Screening Programs during the period 1992-1994.

RESULTS

Ninety-six percent of 3476 screenees with a presumptive diagnosis of melanoma or possible melanoma were contacted, and follow-up records were obtained for 73% of screenees. Of these, 363 screenees had histologically proven melanoma. Middle-aged and older men (age >or= 50 years) comprised only 25% of screenees but comprised 44% of those with a confirmed diagnosis of melanoma. The overall yield of melanoma (the number of confirmed diagnoses per the number of screenees) was 1.5 per 1000 screenings (363 diagnoses of 242,374 screenees) compared with a yield of 2.6 per 1000 screenings among men age >or= 50 years. The yield was improved further for men age >or= 50 years who reported either a changing mole (4.6 per 1000 screenings) or skin types I and II (3.8 per 1000 screenings). The predictive value of a screening diagnosis of melanoma was more than twice as high for men age >or= 50 years with either a changing mole or skin types I and II compared with all other participants.

CONCLUSIONS

The yield of mass screening for melanoma would be improved by outreach to middle-aged and older men, with particular focus on men with changing moles or with skin types I and II. Primary care physicians should be attuned to the risk factors among all of their patients but should be alerted in particular to the heightened risk of melanoma for men age >or= 50 years. Formal assessment of the impact of targeted screening on mortality warrants further study.

Screening mammograms by community radiologists: variability in false-positive rates

BACKGROUND

Previous studies have shown that the agreement among radiologists interpreting a test set of mammograms is relatively low. However, data available from real-world settings are sparse. We studied mammographic examination interpretations by radiologists practicing in a community setting and evaluated whether the variability in false-positive rates could be explained by patient, radiologist, and/or testing characteristics.

METHODS

We used medical records on randomly selected women aged 40-69 years who had had at least one screening mammographic examination in a community setting between January 1, 1985, and June 30, 1993. Twenty-four radiologists interpreted 8734 screening mammograms from 2169 women. Hierarchical logistic regression models were used to examine the impact of patient, radiologist, and testing characteristics. All statistical tests were two-sided.

RESULTS

Radiologists varied widely in mammographic examination interpretations, with a mass noted in 0%-7.9%, calcification in 0%-21.3%, and fibrocystic changes in 1.6%-27.8% of mammograms read. False-positive rates ranged from 2.6% to 15.9%. Younger and more recently trained radiologists had higher false-positive rates. Adjustment for patient, radiologist, and testing characteristics narrowed the range of false-positive rates to 3.5%-7.9%. If a woman went to two randomly selected radiologists, her odds, after adjustment, of having a false-positive reading would be 1.5 times greater for the radiologist at higher risk of a false-positive reading, compared with the radiologist at lowest risk (95% highest posterior density interval [similar to a confidence interval] = 1.17 to 2.08).

CONCLUSION

Community radiologists varied widely in their false-positive rates in screening mammograms; this variability range was reduced by half, but not eliminated, after statistical adjustment for patient, radiologist, and testing characteristics. These characteristics need to be considered when evaluating false-positive rates in community mammographic examination screening.

Confocal microwave imaging for breast cancer detection: localization of tumors in three dimensions

The physical basis for breast tumor detection with microwave imaging is the contrast in dielectric properties of normal and malignant breast tissues. Confocal microwave imaging involves illuminating the breast with an ultra-wideband pulse from a number of antenna locations, then synthetically focusing reflections from the breast. The detection of malignant tumors is achieved by the coherent addition of returns from these strongly scattering objects. In this paper, we demonstrate the feasibility of detecting and localizing small (<1 cm) tumors in three dimensions with numerical models of two system configurations involving synthetic cylindrical and planar antenna arrays. Image formation algorithms are developed to enhance tumor responses and reduce early- and late-time clutter. The early-time clutter consists of the incident pulse and reflections from the skin, while the late-time clutter is primarily due to the heterogeneity of breast tissue. Successful detection of 6-mm-diameter spherical tumors is achieved with both planar and cylindrical systems, and similar performance measures are obtained. The influences of the synthetic array size and position relative to the tumor are also explored.

Screening mammography: proven benefit, continued controversy

Screening mammography, despite its limitations, remains the best means for diagnosing breast cancer in asymptomatic women. Regarding the continuing controversies concerning the age at which screening should start, evidence supports beginning regular screening at age 40 in women at average risk . Similarly, evidence suggests that the screening interval should be yearly, especially in younger women. Rather than an arbitrary age at which screening should stop, the decision on screening elderly women should be made on an individual basis, taking into account level of health and life expectancy. More work needs to be done on determining the optimum screening strategies for high-risk women. As to the interpretation of screening mammography, a certain level of observer variability and of false-negative and false-positive readings are inherent in the process. These should be kept to a minimum through efforts by the interpreting radiologist to improve performance through auditing of individual results and continuing education. The impact of double reading and computer-aided detection in the interpretation of screening mammograms warrants further evaluation in terms of efficacy and cost-effectiveness. Despite these continuing controversies, mortality from breast cancer in the United States has been decreasing steadily for the past 25 years. The magnitude of the decrease has been reported to range from 8% to 25%. Although some of this decrease may be attributable to improvements in the treatment of breast cancer, early detection through screening mammography has undoubtedly played a role in this mortality reduction. The controversies that surround the issue of screening should not detract from the fact that screening mammography has proved to save lives.

Ultrasound as a complement to mammography and breast examination to characterize breast masses

This study was designed to determine if complementary ultrasound (US) imaging and Doppler could decrease the number of biopsies for benign masses. A total of 761 breast masses were sequentially scored on a level of suspicion (LOS) of 1-5, where 1 represented low, and 5 was a high suspicion of malignancy, for mammography, US, and color flow with pulse Doppler (DUS). After biopsy, the results were analyzed using 2 x 2 contingency tables and ROC analysis, for mammography alone and in combination with US and DUS. The addition of US increased the specificity from 51.4% to 66.4% at a prevalence of 31.3% malignancy. ROC analysis showed that the addition of US significantly improved the performance over mammography alone in women < 55 years old (p = 0.049); > 55 years old (p = 0.029); masses < 1 cm (p = 0.016) and masses > 1 cm (p = 0.016). These results show that the addition of US to mammography alone could substantially reduce the number of breast biopsies for benign disease.

Screening mammography: Is it suitably targeted to older women who are most likely to benefit?

OBJECTIVES

To determine whether screening mammography is suitably targeted to older women who are most likely to benefit.

DESIGN

Prospective cohort study.

SETTING

New Haven County, Connecticut.

PARTICIPANTS

Eight hundred forty-four community-dwelling older women were interviewed as part of the 1990 New Haven Established Populations for the Epidemiologic Study of the Elderly (EPESE) program.

MEASUREMENTS

Mammography use was ascertained from Medicare Part B claims data. A four-level prognostic mortality index was developed using items previously shown to be predictive of mortality. Mammography use and all-cause mortality were evaluated by prognostic stage over a 5-year period, January 1, 1991, to December 31, 1995.

RESULTS

Five-year mortality increased steadily with each prognostic stage (12% to 68%, P = .001), whereas the 5-year mammography use rate declined (48% to 7%, P = .001). Over half the women (53%) in the most favorable prognostic group did not receive a mammogram, whereas 13% in the two worst prognostic groups received at least one mammogram.

CONCLUSION

Screening mammography may be underutilized among older women who are the most likely to benefit and overutilized among those who are unlikely to benefit.

The impact of alternative practices on the cost and quality of mammographic screening in the United States

The decentralized structure of health care in the Unites States hinders population-based analysis of breast cancer screening. Our objectives are to model mammography in the United States as a whole, to identify the variables that most profoundly affect cost and efficacy, and to develop a strategy to improve mammography screening from a population perspective. A spreadsheet model was used to represent the variables of mammography screening in the United States. The population-based national screening program in Sweden provides a framework for comparison. The outcome measures are the aggregate cost and the number of cancers detected by mammography. We used deterministic sensitivity analysis to calculate the impact of variation in practice. Aggregate costs of screening in the United States are in the range of $3-$5 billion dollars. The percentage of women screened, cost per mammogram, cancer to biopsy ratio, recall rate, and cost of recall have the most profound effect on the quality and cost of a national screening program. Variance of these high-impact variables, based on the U.S. population, modifies the aggregate cost of screening by over $2 billion. As mammography screening in the United States increases to include all women over age 40, high-impact variables should be optimized to decrease costs and improve breast cancer detection. Our model establishes which parameters are most important.

Does timely assessment affect the anxiety associated with an abnormal mammogram result?

Anxiety following an abnormal mammogram result can be substantial. We examined whether the time to the first diagnostic test was associated with anxiety. We surveyed 449 women at 2 and 8 months after an abnormal mammogram result, and we reviewed their medical records. Twenty-six percent of women reported being very anxious about their abnormal mammogram result at the time of the two-month interview, and 22% reported persistent anxiety after 8 months. After adjustment, the number of days until the first diagnostic test was not associated with anxiety at the 2-month interview. By the second interview, women who received their first diagnostic test within the first week were significantly more anxious, as were women who did not receive their first test for at least 60 days after their results. Further work is needed to ascertain how to minimize the anxiety associated with the evaluation of an abnormal mammogram.

Mammography utilization after a benign breast biopsy among Hispanic and non-Hispanic women

BACKGROUND

In spite of the effectiveness of mammography screening for early detection of breast carcinoma, the use of screening mammography varies widely across racial and ethnic groups. Recently, concerns have been raised about the potential adverse effect a benign breast biopsy may have on subsequent mammography utilization, including subsequent use among minority women.

METHODS

Computerized health care claims data for 1991 through 1997 from a managed care organization were used to compare mammography use among Hispanic and non-Hispanic women who had had a mammogram followed by an incisional or excisional benign breast biopsy to women who had had a mammogram and no biopsy. Through survival analysis methods, the time-to-next mammogram was compared among these three groups.

RESULTS

The sample included 693 (3.2%) and 289 (1.3%) women who had had a mammogram followed by an incisional biopsy or an excisional biopsy, respectively, and 20,540 (95.4%) women who had had a mammogram and no biopsy. Both Hispanic and non-Hispanic women with a biopsy returned sooner for subsequent mammograms than women without a biopsy (P < 0.0001). Hispanic women without a biopsy returned later than non-Hispanic women without a biopsy (P < 0.0001). However, Hispanic women with an excisional biopsy returned sooner than non-Hispanic women (P < 0.05).

CONCLUSIONS

Within a managed care organization, both Hispanic and non-Hispanic women who had had a mammogram followed by a benign breast biopsy returned sooner for a subsequent mammogram than women who had had a mammogram and no biopsy. However, ethnic differences in time-to-next mammogram were observed for women without a biopsy and those with an excisional biopsy. Hispanic women without a biopsy returned later for a subsequent mammogram than non-Hispanic women in similar groups, but those with an excisional biopsy returned sooner.

Increased patient concern after false-positive mammograms: clinician documentation and subsequent ambulatory visits

OBJECTIVE

To measure how often a breast-related concern was documented in medical records after screening mammography according to the mammogram result (normal, or true-negative vs false-positive) and to measure changes in health care utilization in the year after the mammogram.

DESIGN

Cohort study.

SETTING

Large health maintenance organization in New England.

PATIENTS

Group of 496 women with false-positive screening mammograms and a comparison group of 496 women with normal screening mammograms, matched for location and year of mammogram.

MEASUREMENTS AND MAIN RESULTS

1) Documentation in clinicians' notes of patient concern about the breast and 2) ambulatory health care utilization, both breast-related and non-breast-related, in the year after the mammogram. Fifty (10%) of 496 women with false-positive mammograms had documentation of breast-related concern during the 12 months after the mammogram, compared to 1 (0.2%) woman with a normal mammogram (P =.001). Documented concern increased with the intensity of recommended follow-up (P =.009). Subsequent ambulatory visits, not related to the screening mammogram, increased in the year after the mammogram among women with false-positive mammograms, both in terms of breast-related visits (incidence ratio, 3.07; 95% confidence interval [CI], 1.69 to 5.93) and non-breast-related visits (incidence ratio, 1.14; 95% CI, 1.03 to 1.25).

CONCLUSIONS

Clinicians document concern about breast cancer in 10% of women who have false-positive mammograms, and subsequent use of health care services are increased among women with false-positive mammogram results.

Breast cancer policy as a paradigm for other health prevention issues: analysis of the Breast and Cervical Cancer Mortality Prevention Act of 1990

The public policy response to breast cancer mortality is examined through an analysis of federal legislation. Departing from the federal government's traditional role in health policy, the legislation funds states to provide directly some health services related to breast and cervical cancer. The legislation establishing a national program for breast and cervical cancer screening is used as an analytic model for policy development for preventive services for other public health issues. Increased collaboration between the public health community and the social work profession is advocated.

False-positive screening mammograms: effect of immediate versus later work-up on patient stress

PURPOSE

To compare the stress experienced by women who had false-positive screening mammograms and had undergone immediate on-site diagnostic imaging evaluation with that experienced by those who had been recalled for subsequent imaging.

MATERIALS AND METHODS

A retrospective survey was mailed to women with false-positive screening mammograms that had proved negative or benign at diagnostic imaging. The women were divided into (a) those who had undergone diagnostic imaging during the same appointment as their screening examination and (b) those who had returned at a later date for work-up. The survey included questions about stress that was related to the screening and diagnostic experiences, how subjects had been notified about screening results, and their breast health histories.

RESULTS

From the group that had undergone immediate work-up (n = 100), 50 eligible surveys were received; 71 were received from women who had undergone later work-ups (n = 176). The self-reported overall stress was significantly greater (P =.027) in the group recalled for subsequent diagnostic imaging. Among all respondents, stress from a false-positive screening result was greatest in women younger than 50 years of age with a positive first-degree family history of breast cancer.

CONCLUSION

Providing immediate on-site diagnostic evaluation can reduce the stress of a false-positive screening mammogram.

Mammography in 53,803 women from the New Hampshire mammography network

PURPOSE

To describe measures of mammography performance in a geographically defined population and evaluate the interpreter's use of the Breast Imaging Reporting and Data System (BI-RADS).

MATERIALS AND METHODS

Mammographic data from 47,651 screening and 6,152 diagnostic examinations from November 1, 1996, to October 31, 1997, were linked to 1,572 pathologic results. Mammographic outcomes were based on BI-RADS assessments and recommendations reported by the interpreting radiologist. The consistency of BI-RADS recommendations was evaluated.

RESULTS

Screening mammography had a sensitivity of 72.4% (95% CI: 66.4%, 78.4%), specificity of 97.3% (95% CI: 97.25%, 97.4%), and positive predictive value of 10.6% (95% CI: 9.1%, 12.2%). Diagnostic mammography had higher sensitivity, 78.1% (95% CI: 71.9%, 84.3%); lower specificity, 89.3% (95% CI: 88.5%, 90.1%); and better positive predictive value, 17.1% (95% CI: 14.5%, 19.8%). The cancer detection rate with screening mammography was 3.3 per 1,000 women, with a biopsy yield of 22.4%, whereas the interval cancer rate was 1. 2 per 1,000. Nearly 80% of screening-detected invasive malignancies were node negative. The recall rate for screening mammography was 8. 3%. Ultrasonography was used in 3.5% of screening and 17.5% of diagnostic examinations. BI-RADS recommendations were generally consistent, except for probably benign assessments.

CONCLUSION

The sensitivity of screening mammography in this population-based sample is lower than expected, although other performance indicators are commendable. BI-RADS "probably benign" assessments are commonly misused.

Integration of breast imaging into cancer management

This article reviews the use of breast imaging for screening, diagnosis, and staging. Its focus is on the ways in which imaging techniques can most effectively be integrated into clinical management.

Minimal access breast surgery

Minimal access procedures have great potential for providing patients with equal, if not superior, forms of breast cancer diagnosis and treatment. Many of these procedures are in a process of evolution. The reliability of each method probably depends heavily on the training, ability, and experience of the operator. Surgeons should be aware of the advantages and pitfalls of these techniques and exercise caution during the initial phases of their learning experience.

Is screening mammography effective in elderly women?

PURPOSE

Screening mammography is effective in reducing breast cancer mortality in women between the ages of 50 and 69 years. We sought to determine whether older women who undergo screening mammography have a decreased risk of metastatic breast cancer.

SUBJECTS AND METHODS

We studied 690,993 women aged 66 to 79 years who were California Medicare beneficiaries from January 1992 to December 1993, and who chose the fee-for-service plan. Health Care Financing Administration part B billing records were used to determine the use of screening mammography. The extent of breast cancer (in situ, local, regional, or metastatic) was ascertained for the 6,767 women who were diagnosed with the disease in 1993, using data from the California State Cancer Registry. For each type (extent) of breast cancer, the relative risk (RR) and 95% confidence (CI) of developing breast cancer was estimated by dividing the risk of its development in screened women by the risk in women who were not screened.

RESULTS

A total of 46% of women had mammography during the 2-year study period. In situ, local, and regional breast cancer were more likely to be detected among women who underwent screening mammography. For example, the relative risk of detecting local breast cancer in screened women was 3.3 (95% CI: 3.1 to 3.5). The risk of detecting metastatic breast cancer, on the other hand, was significantly reduced among women aged 66 to 79 years who underwent screening mammography (RR = 0.57, 95% CI: 0.45 to 0.72).

CONCLUSION

Screening mammography is associated with a decreased risk of detecting metastatic breast cancer among elderly women. Public health recommendations need to weigh the benefit of screening elderly women against the cost and potential harm from screening and treating early lesions that may have no effect on mortality.

Computerized analysis of lesions in US images of the breast

RATIONALE AND OBJECTIVES

Breast sonography is not routinely used to distinguish benign from malignant solid masses because of considerable overlap in their sonographic appearances. The purpose of this study was to investigate the computerized analyses of breast lesions in ultrasonographic (US) images in order to ultimately aid in the task of discriminating between malignant and benign lesions.

MATERIALS AND METHODS

Features related to lesion margin, shape, homogeneity (texture), and posterior acoustic attenuation pattern in US images of the breast were extracted and calculated. The study database contained 184 digitized US images from 58 patients with 78 lesions. Benign lesions were confirmed at biopsy or cyst aspiration or with image interpretation alone; malignant lesions were confirmed at biopsy. Performance of the various individual features and output from linear discriminant analysis in distinguishing benign from malignant lesions was studied by using receiver operating characteristic (ROC) analysis.

RESULTS

At ROC analysis, the feature characterizing the margin yielded Az values (area under the ROC curve) of 0.85 and 0.75 in distinguishing between benign and malignant lesions for the entire database and for an "equivocal" database, respectively. The equivocal database contained lesions that had been proved to be benign or malignant at cyst aspiration or biopsy. Linear discriminant analysis round-robin runs yielded Az values of 0.94 and 0.87 in distinguishing benign from malignant lesions for the entire database and for the equivocal database, respectively.

CONCLUSION

Computerized analysis of US images has the potential to increase the specificity of breast sonography.

Mammography use by elderly women: a methodological comparison of two national data sources

PURPOSE

Estimates of mammography utilization vary considerably, depending on the data source. Among women aged 65 years and older, recent estimates of annual mammography derived from the 1992 National Health Interview Survey (NHIS) were 50% higher than estimates from Medicare claims. We investigated possible reasons for the different estimates.

METHODS

We identified differences in the populations covered by the two data sources and made appropriate adjustments. Differences due to age were addressed by age restriction and age adjustment. Women in health maintenance organizations were eliminated from the NHIS sample so it more closely resembled the Medicare database, and estimates of mammography utilization by noninstitutionalized women were derived for Medicare to increase comparability with NHIS. By using the Medicare Current Beneficiary Survey to obtain individual-level comparisons between self-report and claims, we explored potential biases in self-reported data and missing claims.

RESULTS

Differences between the sample populations accounted for more than one-fourth of the rate difference. About half of the difference could be attributed to erroneous self-reports, biases in self-reported dates (forward and reverse telescoping) and missing Medicare claims.

CONCLUSIONS

Most of the discrepancy between the two data sources can be plausibly explained. However, caution must be used in using either data source alone, or both together, to represent the "true" mammography rate.

Diagnostic testing following screening mammography in the elderly

BACKGROUND

To provide some sense of the general frequency and timing of diagnostic testing following screening mammography in the United States, we investigated the experience of women screened in the Medicare population.

METHODS

By use of Medicare's National Claims History System, we identified a cohort (n=23172) of women 65 years old or older screened during the period from January 1, 1995, through April 30, 1995, and tracked each woman over the subsequent 8 months for the performance of additional breast imaging and biopsy procedures. Using two claims-based definitions for newly detected breast cancer, we also estimated the positive predictive value of screening mammography.

RESULTS

For every 1000 women aged 65-69 years who underwent screening, 85 (95% confidence interval [CI]=79-91) had follow-up testing in the subsequent 8 months; 76 (95% CI=71-82) had additional breast imaging, and 23 (95% CI=20-26) had biopsy procedures. Corresponding numbers for women aged 70 years or more were similar. Some women underwent repeated examinations; 13% of those receiving diagnostic mammograms had more than one; 11% of those undergoing biopsy procedures had more than one. About half of the women who underwent a biopsy had the procedure more than 3 weeks after the imaging test upon which the decision to perform a biopsy was presumably made. The estimated positive predictive value of an abnormal screening mammogram (defined as a mammogram that engendered additional testing) was 0.08 (95% CI=0.06-0.10) for women aged 65-69 years and 0.14 (95% CI=0.12-0.16) for women aged 70 years or more.

CONCLUSION

Additional testing is a frequent consequence of screening mammography and may require a considerable period of time to come to closure. The need for additional testing, however, is weakly predictive of cancer.

Outcomes of modern screening mammography

The University of California, San Francisco, Mobile Mammography Screening Program is a low-cost, community-based breast cancer screening program that offers mammography to women of diverse ethnic backgrounds (36% nonwhite) in six counties in northern California. Analysis of data collected on approximately 34,000 screening examinations from this program shows that the positive predictive value and sensitivity of modern screening mammography to be lower for women aged 40 to 49 years compared to women aged 50 and older. This lower performance is due to the lower prevalence of invasive breast cancer in younger women and possibly to age differences in breast tumor biology. Because of this lower performance, women in their forties may be subjected to more of the negative consequences of screening, which include additional diagnostic evaluations and the associated morbidity and anxiety, the potential for detecting and surgically treating clinically insignificant breast lesions, and the false reassurance resulting from normal mammographic results. Since the evidence is not compelling that the benefits of mammography screening outweigh the known risks for women aged 40 to 49 years, women considering mammography screening should be informed of the risks, potential benefits, and limitations of screening mammography, so that they can make individualized decisions based on their personal risk status and utility for the associated risks and potential benefits of screening.

The psychosocial consequences of mammography

Increasing numbers of mammograms being performed in the United States will be accompanied inevitably by an increasing number of false positives. According to reliable estimates from a survey of radiology facilities, U.S. women in their forties experience close to one million false positive mammograms every year. To determine the impact of false positive mammograms and the broader psychological impact of mammography, we conducted literature searches of Medline, CancerLit, and PsycInfo. We identified nine studies examining the impact of false positive mammograms. Most found short-term increases in such psychological measures as anxiety, distress, and intrusive thoughts. One study found substantial effects on these measures three months after an abnormal mammogram. Another study found an 18-month impact on anxiety. Few studies have used behavioral outcomes, but one reported overpractice of breast self-exam among women who had received false positive results. Another found no reduction in adherence to mammography among women who have had an abnormal test. The more general mammography literature suggests that many women are anxious about mammography before the exam; women with lower levels of education, African Americans, and women with a family history of breast cancer may be more vulnerable to distress. Unfortunately, this literature suffers major limitations, such as small sample sizes, inconsistent and sometimes inappropriate measures, variations in the time frames for measurement, few studies with women aged 40-49, and a paucity of U.S. research. More research is needed to characterize at-risk women and to test interventions designed to reduce the negative impact of abnormal mammograms. Improved communication is also needed throughout the entire mammography process.

Breast cancer screening among women in their forties: an overview of the issues

This article summarizes the issues prompting a recent NIH Consensus Conference on mammography screening for women in their forties. To date, eight randomized controlled trials of breast cancer screening have been conducted, and a reduction in breast cancer mortality has emerged after 10 to 15 years of follow-up among women offered screening in their forties. No effect appears for at least eight years, and the reason for the delay, compared to that seen in women aged 50-69, is not clear. Two possibilities include cancer-stage shift due to screening in younger women and the aging of women into their fifties during the course of screening. Possible adverse effects of screening include radiation risk, although this is low, false-negative and false-positive screening tests, and overdiagnosis due to detection of ductal carcinoma in situ (DCIS). In order to make appropriate decisions regarding mammography, women need age-related information about both the benefits and potential risks of screening.

Variation of benefits and harms of breast cancer screening with age

The critical issue in deciding whether to recommend breast cancer screening for women in their forties is to determine whether potential benefits are substantially greater than potential harms. Recent evidence from randomized clinical trials makes it likely that, after 10-12 years of follow-up, there is a real benefit from screening women ages 40-49, on the order of a 15-20% reduction in the relative risk of breast cancer death. This relative risk reduction translates into an absolute risk reduction of 1-2 women whose lives are extended from screening 1,000 women in their forties annually for 10 years (i.e., about one life extended per 5,000 mammograms). The absolute benefit of screening increases with age. Evidence about potential harms is less well established, but it is compelling that there are 15-40 times as many false positive as true positive mammograms (depending on the patient's age), and that at least some of the women with false positive mammograms have ongoing psychological distress as a result. Some 30% of all women who are screened annually during their forties will have at least one false positive mammogram and this probability likely decreases with advancing age. If the balance between benefits and harms is judged to be a "close call" for women in their forties, a blanket recommendation for all is inappropriate. Instead, each woman in her forties should be helped to understand the pros and cons of screening, to clarify her own values, and to consider with her primary care physician what decision would be best for her.

Ten-year risk of false positive screening mammograms and clinical breast examinations

BACKGROUND

The cumulative risk of a false positive result from a breast-cancer screening test is unknown.

METHODS

We performed a 10-year retrospective cohort study of breast-cancer screening and diagnostic evaluations among 2400 women who were 40 to 69 years old at study entry. Mammograms or clinical breast examinations that were interpreted as indeterminate, aroused a suspicion of cancer, or prompted recommendations for additional workup in women in whom breast cancer was not diagnosed within the next year were considered to be false positive tests.

RESULTS

A total of 9762 screening mammograms and 10,905 screening clinical breast examinations were performed, for a median of 4 mammograms and 5 clinical breast examinations per woman over the 10-year period. Of the women who were screened, 23.8 percent had at least one false positive mammogram, 13.4 percent had at least one false positive breast examination, and 31.7 percent had at least one false positive result for either test. The estimated cumulative risk of a false positive result was 49.1 percent (95 percent confidence interval, 40.3 to 64.1 percent) after 10 mammograms and 22.3 percent (95 percent confidence interval, 19.2 to 27.5 percent) after 10 clinical breast examinations. The false positive tests led to 870 outpatient appointments, 539 diagnostic mammograms, 186 ultrasound examinations, 188 biopsies, and 1 hospitalization. We estimate that among women who do not have breast cancer, 18.6 percent (95 percent confidence interval, 9.8 to 41.2 percent) will undergo a biopsy after 10 mammograms, and 6.2 percent (95 percent confidence interval, 3.7 to 11.2 percent) after 10 clinical breast examinations. For every 100 dollars spent for screening, an additional 33 dollars was spent to evaluate the false positive results.

CONCLUSIONS

Over 10 years, one third of women screened had an abnormal test result that required additional evaluation, even though no breast cancer was present. Techniques are needed to decrease false positive results while maintaining high sensitivity. Physicians should educate women about the risk of a false positive result from a screening test for breast cancer.