Study design in the evaluation of breast cancer imaging technologies.

RATIONALE AND OBJECTIVES: Bringing a new imaging technology to market is a complex process. Beyond conceptualization and proof of concept, obtaining U.S. Food and Drug Administration (FDA) approval for clinical use depends on the documented experimental establishment of safety and efficacy. In turn, safety and efficacy are evaluated in the context of the intended use of the technology. The purpose of this study was to examine a conceptual framework for technology development and evaluation, focusing on new breast imaging technologies as a highly visible and current case in point. MATERIALS AND METHODS: The FDA views technology development in terms of a preclinical and four clinical phases of assessment. With a concept of research and development as a learning model, this phased-assessment concept of regulatory review against intended use was integrated with a five-level version of a hierarchy-of-efficacy framework for evaluating imaging technologies. Study design and analysis issues are presented in this context, as are approaches to supporting expanded clinical indications and new intended uses after a new technology is marketed. CONCLUSION: Breast imaging technologies may be intended for use as replacements for standard-of-care technologies, as adjuncts, or as complementary technologies. Study designs must be appropriate to establish claims of superiority or equivalence to the standard for the intended use. Screening technologies are ultimately judged on their demonstrated effectiveness in decreasing cause-specific mortality through early detection, but they may be brought to market for other uses on the basis of lesser standards of efficacy (eg, sensitivity, specificity, positive and negative predictive value, and stage of disease detected).

Mammography in the 1990s: the United States and Canada.

PURPOSE: To evaluate trends in mammography quality before and after the implementation of the Mammography Quality Standards Act (MQSA) of 1992 and to compare technical data collected in the United States with corresponding data obtained from the first survey of mammography facilities conducted in 1994-1995 in Canada. MATERIALS AND METHODS: Data from MQSA inspections conducted in 1995-1997 were analyzed and compared with survey data on U.S. mammography facilities acquired before the MQSA. Technical indicators of mammography quality such as radiation dose phantom image score, film processing, and darkroom fog were analyzed. RESULTS: In the United States, phantom image scores, along with other technical measures of performance such as film processing, darkroom fog, and x-ray beam quality, have improved continuously since 1985. The U.S. mean glandular dose has increased to 1.6 mGy compared with the Canadian dose of 1.1 mGy. The mean total phantom image score with artifact subtraction was 11.1 in Canada in 1994-1995 and 11.8 in the U.S. in 1997. CONCLUSION: Mammography quality is better today than it has been at any other time in the United States. With the exception of radiation dose. Canadian technical measures of performance are comparable to measures before MQSA in the United States.

The impact of the Mammography Quality Standards Act on the availability of mammography facilities.

BACKGROUND: The Mammography Quality Standards Act (MQSA) became effective October 1, 1994, and requires all mammography facilities to meet quality standards as promulgated by the Food and Drug Administration (FDA). The FDA undertook an assessment of the MQSA federal certification requirements on the availability of mammography facilities. METHODS: A survey of states on mammography facility closures between October 1, 1993, and October 1, 1994, was conducted. MapInfo software was used to link zip codes to demographic databases. The characteristics of closed facilities were compared to certified facilities as of December 15, 1994. RESULTS: A total of 369 facilities (3.5%) had closed. This closure rate was comparable to previous years' rates (2.5-10%). As of December 15, 1994, 10,142 certified facilities were operating. Relative to their distribution in the United States, closures in rural areas were proportional, but there were more facility closures in the minority areas and in poverty areas. However, the relative distributions of facilities to these areas' populations were unchanged. CONCLUSIONS: Impact on facility availability has been minimal.

The impact of mammography quality improvement legislation in Michigan: implications for the National Mammography Quality Standards Act.

OBJECTIVES: This study examined the impact of state legislation on mammography quality and access in Michigan. METHODS: The impact of state legislation was analyzed with respect to utilization, numbers of machines and facilities, and image quality. RESULTS: The legislation had a positive effect on image quality improvement, had no impact on utilization by women aged 50 years and above, and resulted in few facility closures. CONCLUSIONS: Michigan's legislative intervention appears to have had a positive effect on efforts to improve mammography quality assurance with implications for other federal and state efforts to achieve quality assurance in health care delivery.

The Mammography Quality Standards Act and interventional mammography procedures.

The Food and Drug Administration (FDA) is in the early stages of developing regulations regarding mammographic interventional procedures. When implemented, the regulations have a significant impact on the way these procedures are performed. As part of the development process, the FDA is working with the American College of Surgeons (ACS), the American College of Radiology (ACR), and other interested professional and consumer groups. The goal is to ensure access to high-quality services for the diagnosis of breast cancer.

The influence of risk factors on breast carcinoma screening of Medicare-insured older women. National Cancer Institute Breast Cancer Screening Consortium.

BACKGROUND: It is not certain whether older women with additional breast carcinoma risk factors are adequately screened or whether they are more likely to undergo screening than other older women. This study was conducted to determine whether selected risk factors influence the breast carcinoma screening rates of Medicare-insured older women (i.e., age 65 years or older). METHODS: Self-reported rates of screening mammography and clinical breast examination in the previous year were compared for women with benign breast disease, women with a family history of breast carcinoma, and women lacking these risks, using samples of non-Hispanic white, Medicare-insured women surveyed at the 5 National Cancer Institute Breast Cancer Screening Consortium sites in 1991 (n = 5376, mean age = 69.7 years) and 1994 (n = 5086, mean age = 69.7 years). RESULTS: In 1993, rates of screening mammography reported in the previous year at the 5 Consortium sites had a range of 46-61% for women with a family history of breast carcinoma, 49-66% for women with benign breast disease, and 31-43% for women lacking these risks. Women with a positive family history or a personal history of benign breast disease were also more likely to report having had a clinical breast examination in the previous year and having received a physician's mammography recommendation. A substantial proportion of older women with a positive family history remain inadequately screened, however. Between 25% and 35% of women in this group had not had a screening mammogram in the previous 2 years, while at some Consortium sites more than 20% reported never having had a mammogram in their lives. CONCLUSIONS: Older women with additional risk factors are more likely to undergo screening mammography. This is due partly to more frequent physician recommendations for screening and partly to more frequent provision of clinical breast examinations. However, a substantial proportion of high risk older women remain inadequately screened, despite widespread clinical consensus that these women should be regularly screened. Interventions that target older women with risk factors and their physicians appear warranted. Understanding the mechanisms by which risk factors influence screening is an important area for future research.

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

OBJECTIVE: The purpose of this study was to gather from 50 community mammography practices that were included in the National Survey of Mammography Facilities data concerning abnormal findings on screening mammograms to determine the frequency of various recommendations made for patients who had abnormal findings and to compare these recommendations with the frequency with which the procedures were actually performed. We also determined the positive predictive value of screening mammograms (the number of cancers detected per 100 abnormal findings) and the yield (the number of cancers detected per 100 procedures done) of various diagnostic procedures done because of abnormal findings. MATERIALS AND METHODS: We identified 1717 screening mammograms done in the last half of 1991 that had abnormal findings. Radiologic recommendations and follow-up procedures, including repeat standard (screening) mammography, additional mammographic views, sonography, clinical breast examination, needle aspiration, needle biopsy, and open biopsy, were identified for all of the cases from the radiologic records, and follow-up data were obtained from referring physicians. The positive predictive value and yield in the National Survey of Mammography Facilities were compared with data from the mammography screening practice of the University of California at San Francisco (UCSF), a facility noted for its clinical efficiency. RESULTS: We estimate that 11% of all screening mammograms resulted in a recommendation for further diagnostic procedures. These 1717 mammograms with abnormal findings led to the following recommendations and procedures: repeat standard (screening) mammography, 610 (recommended)/635 (performed); additional mammographic views, 785/707; sonography, 400/345; biopsy, 189/229; and needle aspiration, 21/51. More procedures were done than were recommended in some cases because the results of certain procedures often led to the performance of other, additional procedures. The positive predictive value for screening examinations with abnormal findings was 3.5%, and the yield for open biopsy was 21%. In the UCSF data base, the positive predictive value for examinations with abnormal findings was 10%, and the yield for open biopsy was 34%. CONCLUSION: The positive predictive value for examinations with abnormal findings and the yield for diagnostic procedures performed as a result of abnormal findings in 50 community radiologic facilities were higher than those reported in some earlier studies, a fact that raised concern about the induced cost of screening mammography. However, these values were low compared with those in the UCSF data base. This fact was particularly true of repeat standard (screening) mammography.

The Mammography Quality Standards Act of 1992. History and philosophy.

The Mammography Quality Standards Act (MQSA) of 1992 established a precedent in the practice of mammography by creating federal quality standards for all parts of the mammography system. Heralded by some as crucial so all US women can reap the full benefits of early detection of breast cancer, MQSA implementation was delegated to the Food and Drug Administration (FDA) on June 2, 1993. In this article the major historical forces that surrounded MQSA's enactment as well as the FDA's philosophy on regulation development, inspections, and compliance under MQSA is summarized.

The association between alcohol and breast cancer: popular press coverage of research.

OBJECTIVES: This study was undertaken to examine popular press reports of the association between alcohol and breast cancer. METHODS: Articles from scientific journals and stories from newspapers and magazines published from January 1, 1985, to July 1, 1992, were retrieved from six on-line databases. Lay press stories were analyzed to determine which medical articles were publicized and what information was reported. RESULTS: Fifty-eight scientific articles on the relationship of alcohol and breast cancer were found, and 64 newspaper and 23 magazine stories were retrieved. The press cited 11 studies, 19% of those published during the study period. Three studies were featured in 77% of popular press stories. No scientific review articles were reported. Behavioral recommendations were given to the public in 63% of stories. CONCLUSIONS: The vast majority of scientific studies on alcohol and breast cancer were ignored in press reports. We encourage researchers and the popular press to give the public a broader understanding of public health issues.

Predictors of and satisfaction with bilateral prophylactic mastectomy.

BACKGROUND: Women with a first-degree relative with breast cancer are at increased risk of developing this disease. The optimal medical management of these women is unclear, with options including close breast cancer screening, bilateral prophylactic mastectomy, or participation in chemoprevention trials. Among women who undergo prophylactic bilateral mastectomy, very little is known about satisfaction with this surgery. Also, we know very little about variables related to prophylactic mastectomy decision making. METHODS: Participants were women at increased risk of breast cancer due to family history. These women were categorized by self-report as not interested in prophylactic mastectomy (n = 58), interested but deciding against surgery (n = 92), or subsequently having a bilateral prophylactic mastectomy (n = 14). Information on screening practices, risk perception, level of depression, and cancer-related worry was collected. Women completing prophylactic mastectomy reported on their satisfaction with the surgery and breast reconstruction. RESULTS: Women selecting surgery reported more breast cancer worry. The group expressing no interest in surgery reported fewer biopsies and lower risk estimates. Women completing surgery were satisfied with their decision, although satisfaction with reconstruction was mixed. CONCLUSION: Factors influencing surgical decision making may include breast-cancer-related worry, biopsy history, and subjective breast cancer risk.

The practice of prophylactic mastectomy: a survey of Maryland surgeons.

OBJECTIVES: Bilateral prophylactic mastectomy is a drastic breast cancer preventive option for which indications are not standardized and efficacy has not been proven. To estimate the magnitude of this controversial practice, surgeons were surveyed on their recommendations about and performance of prophylactic mastectomy. METHODS: A cross-sectional survey was sent to general surgeons (n = 522), plastic surgeons (n = 80), and gynecologists (n = 801) licensed to practice in Maryland in 1992. Proportions responding were 41.9%, 66.3%, and 54.9%, respectively. In addition, there were 30 respondents who identified "other" as their specialty. The respondents were asked about the role of bilateral prophylactic mastectomy and the number of times they had recommended and performed it in a year. RESULTS: Seven hundred forty-two surgeons responded (51.8%). More plastic surgeons (84.6%) than general surgeons (47.0%) and gynecologists (38.3%) agreed that bilateral prophylactic mastectomy has a role in the care of high-risk women. Eighty-one percent of plastic surgeons had recommended the procedure, compared with 38.8% of general surgeons and 17.7% of gynecologists. CONCLUSIONS: Indications and practice patterns reveal heterogeneity of medical opinion and practice of prophylactic mastectomy. This study raises the need for better evaluation of the efficacy and appropriateness of prophylactic mastectomy.

Quality assurance audits of community screening mammography practices: availability of active follow-up for data collection and outcome assessment.

OBJECTIVE: Routine and periodic mammography audit studies, the systematic evaluation of clinical follow-up procedures and outcomes subsequent to screening mammography reports of abnormal findings, have been advocated as an important component of quality assurance in screening mammography. This study assessed the degree to which mammography facilities in community practice maintain reporting and record-keeping systems and ascertain sufficient clinical follow-up data to facilitate the practice of mammography audit studies. MATERIALS AND METHODS: As part of a national survey of 1057 mammography facilities, data were collected from a stratified subsample of 50 facilities on facility information systems, and facility records were systematically abstracted to determine the degree of completeness of clinical follow-up data to screening mammography examinations with abnormal findings. Facilities were assisted in obtaining additional information through active data follow-up, and this information also was entered into the study's database. RESULTS: The nature of mammography information systems and the degree of data completeness varied widely. Computerized systems were used at relatively few facilities (12%). The organization of records and data varied widely and was generally not designed to accommodate routine systematic analysis. Screening examinations could be identified without reading the actual text of the mammography report at 94% of the facilities, but reports had to be read at the majority of facilities to identify examinations with abnormal findings (70%). Before active data follow-up, records were incomplete in about 40% of all cases. After active data follow-up, this decreased to 16%. Forty-two facilities achieved an average completeness of more than 90%, whereas the remaining eight lagged significantly behind this level. CONCLUSION: At the time of this study (late 1992 to early 1993), only about 20% of the facilities surveyed had informational systems and sufficient ascertainment of data to support the practice of mammography audit studies. After active data follow-up, more than 80% of the facilities were willing and able to achieve a high degree of data completeness with the assistance of our data abstracters. The results of this study suggest that, with the advent of standardized mammography data collection and analysis systems and increased emphasis on clinical outcomes assessment as a standard of care, the practice of performing mammography audits, although not currently widespread, is feasible for most facilities.

Current practice of screening mammography in the United States: data from the National Survey of Mammography Facilities.

PURPOSE: To describe the extent to which screening mammography (SCM) has been organized according to the public health concept of low-cost, high-quality, and population-based screening, selected indicators of U.S. mammography facilities were evaluated. MATERIALS AND METHODS: Data from the National Cancer Institute's phase I of the National Survey of Mammography Facilities were analyzed. This data base consists of questionnaire information obtained in 1992 from a 10% random sample of U.S. mammography facilities. RESULTS: Of 1,057 facilities, 634 (60%) distinguished SCM from diagnostic mammography (DXM). In facilities providing SCM (n = 535), 477 (89%) used the mediolateral oblique (MLO) view and/or the craniocaudal (CC) view. While 898 (85%) of all facilities requested clinical follow-up of abnormal mammograms, only 285 (27%) facilities actually received this information. Only 137 (13%) facilities operated at high volume (> or = 15 mammograms per day per machine), and 211 (20%) used batch interpretation. Average cost of a screening mammogram was $89 (range, $10-$225). CONCLUSIONS: While more facilities are distinguishing SCM from DXM and obtain MLO and CC views, SCM does not appear to be organized for high volume and low cost.