The present state of screening for breast cancer

Breast Microcalcifications Studied with 3d Contrast-enhanced High-field Magnetic Resonance Imaging: More Accuracy in the Diagnosis of Breast Cancer

Aims

To evaluate the reliability of magnetic resonance imaging (MRI) performed with three-dimensional (3D) sequences in mammographically detected breast microcalcifications.

Methods

During an 8-month period, a group of 28 patients with mammographically detected microcalcifications suspicious for malignancy underwent MRI. Their ages ranged from 33 to 65 years. Examinations were performed with a 1.5 Tesla MR unit and a 3D T1 weighted sequence. Images were interpreted on the basis of morphologic parameters and dynamic behavior in the uptake of contrast medium (Gd-DTPA). Histologic findings were considered as the gold reference.

Results

Histologic analysis revealed invasive carcinoma in 7 patients, 3 of which were associated with foci of lobular carcinoma in situ. Intraductal carcinoma was diagnosed in 8 patients, 1 of which was associated with a tubular carcinoma. Benign lesions accounted for 13 patients. All the neoplastic conditions showed enhancement on MR images (sensitivity, 100%), whereas early and intense enhancement was noted in 5 of 13 benign lesions (specificity, 61%). The positive predictive value was 75% and negative predictive value, 100%.

Conclusions

Although an overlap in the enhancement behavior of malignant and some benign lesions is clearly evident, a careful interpretation of MR images is helpful in detecting and mainly ruling out breast cancer combined with mammographically suspicious microcalcifications.

Patient compliance in mobile screening mammography

RATIONALE AND OBJECTIVES

We assessed the follow-up behavior of women who had abnormal results of screening mammograms taken on a mobile van.

METHODS

A retrospective cohort study was conducted between 1988 and 1991 of all women served by a mobile mammography van in rural North Carolina. Compliance with radiologist recommendations for follow-up was assessed through review of patient records and mail surveys of patients with incomplete records.

RESULTS

Compliance was 44% for negative or benign mammograms, 57% for indeterminate mammograms, and 62% for probably malignant or malignant mammograms. Women who had a previous mammogram or had a malignant finding were more likely to comply with follow-up recommendations (p < .0001) than women with normal or benign results and no history of mammography. Compliers and noncompliers did not differ with respect to family history of breast cancer or personal history of breast discomfort.

CONCLUSION

Compliance with recommendations in this setting was lower than expected. This may be because rural women using mobile van mammography have limited access to the resources needed for appropriate follow-up. Further research is needed to examine explanations for poor compliance in this setting.

Breast cancer in Canada: to screen or not to screen?

Lomas (1988) and Sabatier (1987) have suggested models by which to examine the roles that values, scientific knowledge, institutions, and the learning process play in the formulation of both national and clinical health-care policies. Utilizing their frameworks, this article offers an explanation for the development of high-volume screening mammography policies in Canada, despite the suggested inefficacy of screening technologies for 'unavoidable' illnesses such as carcinoma in the breast. The preliminary results of Canada's National Breast Screening Study further complicate this tissue. Inappropriate framing of the 'problem' in the policy-making process, by actors highly influenced by societal values and scientific evidence, is identified as the reason for present and planned policies and practices contradicting the first principles of health-policy analysis.

Trends in cervical and breast cancer in Iceland. A statistical evaluation of trends in incidence and mortality for the period 1955-1989, their relation to screening and prediction to the year 2000

The time trends in incidence and mortality from cervical cancer and breast cancer in Iceland, from 1955 to 1989, were analyzed by fitting curvilinear regressions to the age-standardized rates. The effect of the screening was evaluated by comparing the curvature of the fitted regression lines and changes in screening activity. The incidence and mortality rates for both cancer types were predicted up to the year 2000. At the commencement of cervical cancer screening in 1964, both the incidence and mortality rates were on the increase. After 1970, both rates decreased significantly. Assuming that regular attendance at screening will be 85%, it is predicted that the incidence and mortality rates will level out at about 7.5 and 2 cases per 100,000 women per year, respectively, by the year 1995 and remain at that level. The incidence of breast cancer has increased steadily since 1955. A sharp rise has been observed since 1987, due to screening with mammography. The mortality rate has shown small but significant fluctuations with time. The incidence rate is predicted to increase at the same rate as before 1987 (i.e. at 1.1 cases per 100,000 women per year), but at a slightly higher level and is predicted to reach 84 cases per 100,000 women per year by the year 2000. Breast cancer mortality is predicted to decrease to about 17 cases per 100,000 women per year by 1995 and to remain at that level.

Improved mammographic accuracy

Use of ancillary imaging studies to evaluate suspicious screening mammograms can improve their positive predictive value for detecting malignant lesions. In 1989 8181 screening mammograms were performed at the breast evaluation center at Memorial Hospital Medical Center in Long Beach. A total of 670 patients were called back for magnification views or ultrasonographic evaluation, and 92 of these patients underwent surgical biopsy. There were 42 cancers diagnosed, yielding an accuracy rate of 46%.

Screening mammography program of British Columbia

In an attempt to diagnose breast carcinoma as early as possible, a government-funded screening mammography program in British Columbia discovered 29 malignancies in the first 7,100 women screened. The program was carefully planned by a group consisting of representatives of all appropriate constituents. The screenees have demonstrated the anticipated increased frequency with increasing age and risk factors; in addition, the frequency of diagnosis is markedly lower in screenees who have had mammograms within the 2 previous years. Exclusive of equipment costs, amortization, and data processing, the cost per study is $33.81 (Canadian), resulting in a cost of $8,277.62 for each case diagnosed. This includes, for each study, an administrative fee of $1.00 as well as $1.00 devoted to continuing education for the reading radiologists. The success of the program has resulted in encouragement from the Health Ministry to expand rapidly throughout the Province, including use of a mobile van in more remote areas. Continued monitoring and peer review will ensure standard quality control in all of the screening facilities.

Participation in breast screening programs: a review

Despite recommendations by the American Cancer Society and other organizations for use of screening mammography, data on reported utilization of this procedure by American women show that these guidelines are not being met. We reviewed published studies that reported participation rates or that examined factors associated with participation in selected breast screening programs. In general, women at high risk due to age and family or personal history of breast disease were not more likely to participate in breast screening programs than women without those risk factors. The one group of variables that was fairly consistently associated with participation was the practice of other preventive health behaviors. Women who expressed more concern about their health and who were more knowledgeable about breast cancer screening and its benefits also were more likely to complete mammography. Approaches to increasing participation are discussed in the context of the literature on this subject.