Stephen A. Feig

Breast Cancer Screening With Imaging: Recommendations From the Society of Breast Imaging and the ACR on the Use of Mammography, Breast MRI, Breast Ultrasound, and Other Technologies for the Detection of Clinically Occult Breast Cancer

Screening for breast cancer with mammography has been shown to decrease mortality from breast cancer, and mammography is the mainstay of screening for clinically occult disease. Mammography, however, has well-recognized limitations, and recently, other imaging including ultrasound and magnetic resonance imaging have been used as adjunctive screening tools, mainly for women who may be at increased risk for the development of breast cancer. The Society of Breast Imaging and the Breast Imaging Commission of the ACR are issuing these recommendations to provide guidance to patients and clinicians on the use of imaging to screen for breast cancer. Wherever possible, the recommendations are based on available evidence. Where evidence is lacking, the recommendations are based on consensus opinions of the fellows and executive committee of the Society of Breast Imaging and the members of the Breast Imaging Commission of the ACR.

Staging and treatment of clinically occult breast cancer

Five hundred fifty‐seven biopsies were performed for clinically occult mammary lesions, detected by mammography as clustered calcifications or nonpalpable masses within the breast. One hundred seventy‐five cancers were demonstrated within this group, including 106 invasive carcinomas, 10 microinvasive carcinomas, 45 in situ ductal carcinomas, and 14 lobular carcinomas in situ (lobular neoplasia). No patient with in situ or microinvasive carcinoma had evidence of axillary node metastases in 33 specimens studied. However, a disturbingly high proportion of those patients with invasive carcinomas, approximately 35%, had histologically confirmed axillary node metastases, despite the small size of the primary tumors. These observations suggest that the use of the term “minimal” cancer is misleading when applied to invasive carcinoma. Staging systems for breast cancer have been imprecise when referring to nonpalpable lesions. Cancers detected as clustered calcifications only or as areas of parenchymal distortion without an accompanying mass are properly considered as T‐0 cancers, with a suggested T‐0(m) to indicate that the lesion was detected by mammography. However, when the mammogram indicates the presence of a mass that proves to be malignant, although the clinical examination may have been negative, the cancer should be staged according to the size of the mass on the mammogram, with the notation that it was detected by mammography, e.g., T‐1(m), T‐2(m), etc. The incidence of axillary node metastases even in these so‐called occult cancers is significant, so that recommendations for treatment for any invasive cancer, regardless of its size, must take these observations into account. Similarly, the incidence of multifocal sites of cancer within the breast, even in the noninvasive cancers encountered, must be remembered when treatment is suggested. Cancer 53:1379‐1384, 1984.

The pathology of breast cancer detected by mass population screening.

Breast cancer was detected in 156 of 17,526 asymptomatic women, (8.9/1000), aged 45‐64 years, screened by mammography, thermography, and physical examination. Twenty‐six percent of 149 pathologically reviewed cases metastasized to axillary nodes. Thirty‐six percent of tumors were in situ, minimally invasive, or low grade tubular carcinomas, none of which metastasized. Increased rates of detection were shown for intraductal and tubular types. Frankly invasive ductal and lobular carcinomas had a mean diameter of 2.3 cm., 46% of which had axillary lymph node metastases. Seventy‐percent of these were to only one to three nodes, however. Multicentricity with intraductal and lobular carcinoma in situ was frequently observed. Metastatic potential was related to tumor size, degree of stromal invasion, lymphatic permeation, and histologic grade. Few histological parameters other than size could be considered favorable. Forty‐two percent of tumors were not palpable, the majority being in situ, minimally invasive, and tubular types. Only five nonpalpable invasive carcinomas metastasized. While the initial results of mass screening appear favorable, prolonged follow‐up is needed to determine its impact on the population at risk.

Role and evaluation of mammography and other imaging methods for breast cancer detection, diagnosis, and staging

Mammographic screening of women age 40 and older can reduce breast cancer deaths by at least 30% to 40%. However, not all cancers are detected by mammography. Although a new supplementary modality for screening could, in theory, fill in this detection gap, such utilization must be based on rigorous demonstration of its ability to consistently and frequently find early cancers missed by mammography, such as those occurring in dense breasts or rapidly growing interval cancers that surface clinically between mammographic screens. After an abnormality is found at mammographic screening, supplementary mammographic views and/or ultrasound are now used to match the finding with an ACR BIRADS final diagnostic assessment category to indicate the relative likelihood of a normal, benign, or malignant diagnosis so that routine screening, short interval follow-up, or biopsy can then be advised. Appropriate categorization will maximize early cancer detection and minimize false-positive biopsies. Application of a new imaging method to this type of diagnostic evaluation requires well-designed studies to determine its effectiveness for this purpose.

Influence of Acute Variations in Hematocrit on the QRS Complex of the Frank Electrocardiogram

The influence of acute variations in hematocrit on the QRS complex of the Frank scalar electrocardiogram was studied in 31 patients with severe polycythemia secondary to cyanotic congenital heart disease and in eight patients with anemia due to thalassemia. Moderate reduction of the hematocrit in the polycythemic group resulted in a significant increase in the magnitude and a delay in both left maximal spatial voltage (LMSV) and maximal anterior force. Raising the hematocrit in the anemic group decreased the magnitude of LMSV and maximal anterior force. A change in the orientation of the spatial vector frequently accompanied induced variations in the hematocrit. Experimental and theoretical studies suggest that alterations in the hematocrit and, hence, intracardiac electrical resistivity distort the magnitude and orientation of the surface-recorded QRS voltages. It is postulated that the effect of high intracavitary blood hematocrit in polycythemia in reducing early QRS voltages is due to its influence on radial myocardial excitation propagated from endocardium to epicardium. Anemia, on the other hand, enhances the voltages due to radial spread of impulses in the myocardium, resulting in an increased magnitude of the LMSV and usually also of the maximal anterior force.

Brust-Imaging-Lexikon Mammografie

Zunachst sei ein lexikalischer Uberblick zu den Beurteilungskriterien vorangestellt (◘ Tab. 2.1)