1. Aetna considers annual mammography screening a medically necessary preventive service for women aged 40 and older. Annual screening is also considered a medically necessary preventive service for younger women who are judged to be at high risk by their primary care physician. Screening mammography for other women is considered experimental and investigational because its benefits in these other women are unproven.

2. Aetna considers screening mammography for men experimental and investigational, as the clinical benefits of such screening in men are unproven. Current guidelines from the U.S. Preventive Services Task Force and the American College of Radiology recommend such screening only for women. Aetna considers mammography medically necessary for surveillance of men with a prior history of breast cancer.

3. Aetna considers diagnostic mammography medically necessary for members with signs or symptoms of breast disease or history of breast cancer.

   Note: Diagnostic mammography is covered regardless of whether the member has preventive services benefits

4. Aetna considers digital mammography an acceptable alternative to film mammography.

5. Aetna considers computer-aided detection (CAD) a medically necessary adjunct to mammography.

6. Aetna considers xeroradiography for breast imaging experimental and investigational because this method of radiography is obsolete.

7. Aetna considers breast tomosynthesis imaging experimental and investigational because of insufficient evidence of its effectiveness.

See also CPB 105 - Magnetic Resonance Imaging (MRI) of the Breast; CPB 269 - Breast Biopsy Procedures and CPB 386 - Breast Transillumination and Electrical Impedance Scanning (EIS).

This policy is based on the recommendations of the American Cancer Society, American College of Radiology, and the American College of Obstetricians and Gynecologists.

A mammogram is an x-ray of the breast. A screening mammography is one of several tools that are used for early detection of breast cancer in asymptomatic women. Other screening tools include the clinical breast examination and breast self-examination. Diagnostic mammography is used to diagnose breast cancer in women who have signs or symptoms of breast disease.

Screening mammography aims to reduce morbidity and mortality from breast cancer by early detection and treatment of occult malignancies. There is extensive evidence from a variety of well-conducted, randomized controlled studies that annual or biennial mammography is effective in reducing breast cancer mortality by 30% in women aged 50-69 years. Data on women under age 50 are less clear. Results from the Canadian National Breast Screening Study (CNBSS) suggest that the contribution of mammography over good physical examinations to breast cancer mortality reduction may be less than has been assumed. This observation re-emphasizes a truism of screening - that it is not necessary to detect cancers as early as possible to obtain a benefit -- it is only necessary to detect them early enough. What is early enough in any individual case is uncertain because there are insufficient outcomes data. This has made it difficult for professional societies to develop specific mammography screening recommendations for high-risk women.

The U.S. Preventive Services Task Force (USPSTF) recommends screening mammography, with or without clinical breast examination, every 1-2 years for women aged 40 and older. The USPSTF also concluded that the evidence is insufficient to recommend for or against routine clinical breast examination (CBE) alone to screen for breast cancer.

The American Medical Association (AMA), the American College of Radiology (ACR), and the American Cancer Society (ACS), all support screening with mammography and CBE beginning at age 40. The American College of Obstetricians and Gynecologists (ACOG) supports screening with mammography beginning at age 40 and CBE beginning at age 19. The Canadian Task Force on Preventive Health Care (CTFPHC), the American Academy of Family Physicians (AAFP), and the American College of Preventive Medicine (ACPM) recommend beginning mammography for average-risk women at age 50. AAFP and ACPM recommend that mammography in high-risk women begin at age 40, and AAFP recommends that all women aged 40-49 be counseled about the risks and benefits of mammography before making decisions about screening.

A 1997 Consensus Development Panel convened by the National Institutes of Health concluded that the evidence was insufficient to determine the benefits of mammography among women aged 40-49. This panel recommended that women aged 40-49 should be counseled about potential benefits and harms before making decisions about mammography. In 2001, the CTFPHC concluded there was insufficient evidence to recommend for or against mammography in women aged 40-49.

Organizations differ on their recommendations for the appropriate interval for mammography. Annual mammography is recommended by AMA, ACR, and ACS. Mammography every 1-2 years is recommended by AAFP, ACPM, and the CTFPHC. ACOG recommends mammography every 1-2 years for women aged 40-49 and annually for women aged 50 and older.

Berg, et al. (2008) compared the diagnostic yield, defined as the proportion of women with positive screen test results and positive reference standard, and performance of screening with ultrasound plus mammography versus mammography alone in women at elevated risk of breast cancer.  A total of 2,809 women, with at least heterogeneously dense breast tissue in at least 1 quadrant, were recruited from 21 sites to undergo mammographic and physician-performed ultrasonographic examinations in randomized order by a radiologist masked to the other examination results. Reference standard was defined as a combination of pathology and 12-month follow-up and was available for 2,637 (96.8%) of the 2,725 eligible participants. Main outcome measures included diagnostic yield, sensitivity, specificity, and diagnostic accuracy (assessed by the area under the receiver operating characteristic curve) of combined mammography plus ultrasound versus mammography alone and the positive predictive value of biopsy recommendations for mammography plus ultrasound versus mammography alone. Forty participants (41 breasts) were diagnosed with cancer: 8 suspicious on both ultrasound and mammography, 12 on ultrasound alone, 12 on mammography alone, and 8 participants (9 breasts) on neither. The diagnostic yield for mammography was 7.6 per 1,000 women screened (20 of 2,637) and increased to 11.8 per 1,000 (31 of 2,637) for combined mammography plus ultrasound; the supplemental yield was 4.2 per 1,000 women screened (95% confidence interval [CI], 1.1 - 7.2 per 1,000; p = 0.003 that supplemental yield is 0). The diagnostic accuracy for mammography was 0.78 (95 % CI, 0.67 - 0.87) and increased to 0.91 (95% CI, 0.84 - 0.96) for mammography plus ultrasound (p = 0.003 that difference is 0). Of 12 supplemental cancers detected by ultrasound alone, 11 (92%) were invasive with a median size of 10 mm (range of 5 to 40 mm; mean [SE], 12.6 [3.0] mm) and 8 of the 9 lesions (89%) reported had negative nodes. The positive predictive value of biopsy recommendation after full diagnostic workup was 19 of 84 for mammography (22.6%; 95% CI, 14.2% - 33%), 21 of 235 for ultrasound (8.9%, 95% CI, 5.6% - 13.3%), and 31 of 276 for combined mammography plus ultrasound (11.2%; 95% CI. 7.8% - 15.6%). The authors concluded that adding a single screening ultrasound to mammography will yield an additional 1.1 to 7.2 cancers per 1,000 high-risk women, but it will also substantially increase the number of false positives.

Although digital mammography has not shown greater accuracy than film mammography, it has become standard of care. The FDA's initial market approval of digital mammography technology was based, in part, on studies that demonstrated its effectiveness in patients referred for further testing after an initial suspicious mammogram (FDA, 2004). In that setting, the FDA found the accuracy of digital technology was similar to that of screen film. Studies are currently underway to evaluate the effectiveness of digital mammography in screening of the general population.

Hendrick and colleagues (2008) retrospectively compared the accuracy for cancer diagnosis of digital mammography with soft-copy interpretation with that of screen-film mammography for each digital equipment manufacturer, by using results of biopsy and follow-up as the reference standard. The American College of Radiology Imaging Network Digital Mammographic Imaging Screening Trial (DMIST) collected screening mammography studies performed by using both digital and screen-film mammography in 49,528 women (mean age of 54.6 years; range of 19 to 92 years). Digital mammography systems from 4 manufacturers (Fischer, Fuji, GE, and Hologic) were used. For each digital manufacturer, a cancer-enriched reader set of women screened with both digital and screen-film mammography in DMIST was constructed. Each reader set contained all cancer-containing studies known for each digital manufacturer at the time of reader set selection, together with a subset of negative and benign studies. For each reader set, 6 or 12 experienced radiologists attended 2 randomly ordered reading sessions 6 weeks apart. Each radiologist identified suspicious findings and rated suspicion of breast cancer in identified lesions by using a 7-point scale. Results were analyzed according to digital manufacturer by using areas under the receiver operating characteristic curve (AUCs), sensitivity, and specificity for soft-copy digital and screen-film mammography. Results for Hologic digital are not presented owing to the fact that few cancer cases were available. The implemented design provided 80% power to detect average AUC differences of 0.09, 0.08, and 0.06 for Fischer, Fuji, and GE, respectively. No significant difference in AUC, sensitivity, or specificity was found between Fischer, Fuji, and GE soft-copy digital and screen-film mammography. Large reader variations occurred with each modality. The authors concluded that no statistically significant differences were found between soft-copy digital and screen-film mammography for Fischer, Fuji, and GE digital mammography equipment.

Pisano and associates (2008) retrospectively compared the accuracy of digital versus film mammography in population subgroups of the DMIST defined by combinations of age, menopausal status, and breast density, by using either biopsy results or follow-up information as the reference standard. For analysis, AUCs for each modality were compared within each subgroup evaluated (age less than 50 versus 50 to 64 versus greater than or equal to 65 years; dense versus non-dense breasts at mammography; and pre- or peri-menopausal versus post-menopausal status for the two younger age cohorts) while controlling for multiple comparisons (p < 0.002 indicated a significant difference). All DMIST cancers were evaluated with respect to mammographic detection method (digital versus film versus both versus neither), mammographic lesion type (mass, calcifications, or other), digital machine type, mammographic and pathologic size and diagnosis, existence of prior mammographic study at time of interpretation, months since prior mammographic study, and compressed breast thickness. A total of 33 centers enrolled 49,528 women. Breast cancer status was determined for 42,760 women, the group included in this study. Pre- or peri-menopausal women younger than 50 years who had dense breasts at film mammography comprised the only subgroup for which digital mammography was significantly better than film (AUCs, 0.79 versus 0.54; p = 0.0015). Breast Imaging Reporting and Data System-based sensitivity in this subgroup was 0.59 for digital and 0.27 for film mammography. AUCs were not significantly different in any of the other subgroups. For women aged 65 years or older with fatty breasts, the AUC showed a non-significant tendency toward film being better than digital mammography (AUCs, 0.88 versus 0.70; p = 0.0025). The authors concluded that digital mammography performed significantly better than film for pre- and peri-menopausal women younger than 50 years with dense breasts, but film tended non-significantly to perform better for women aged 65 years or older with fatty breasts.

Computer-aided detection and diagnosis (CAD) systems consist of computer programs that are designed to recognize patterns in images. CAD may be applied to digital mammograms or to plain film mammograms that have been digitized. CAD has been used for two different purposes: (i) to improve radiologists' ability to identify suspicious areas that may otherwise be overlooked on screening mammograms (detection), and (ii) to distinguish between benign and malignant lesions (diagnosis). The radiologist remains the reader and interpreter of the mammogram. CAD assists the radiologist by identifying areas warranting further review.

The American Cancer Society breast cancer screening guidelines (Smith, et al., 2003) indicate that for digital mammography and CAD there is “some clinical evidence for effectiveness or equivalence to screen-film mammography for screening” (Evidence Level B).

Bennett, et al. (2006) assessed current evidence to ascertain if the accuracy of single reading with CAD compares with that of double reading. These researchers performed a literature review to identify studies where both protocols had been investigated and compared. They identified 8 studies that compared single reading with CAD against double reading, of which 6 reported on comparisons of both sensitivity and specificity. Of the 6 studies identified, 3 showed no differences in either sensitivity or specificity; 1 showed single reading with CAD had a higher sensitivity at the same specificity; 1 showed that single reading with CAD had a higher specificity at the same sensitivity. However, 1 study, in a real-life setting, showed that single reading with CAD had a higher sensitivity but a lower specificity. The authors concluded that as the majority of the studies were not in a real-life setting, used test sets, lacked sufficient training in the use of CAD and simulated double reading (using a protocol of recall if one suggests), current evidence is therefore limited as to the accuracy, in terms of sensitivity and specificity, of single reading with CAD in comparison with the most common practice in the United Kingdom of double reading using a protocol of consensus or arbitration.

Fenton and colleagues (2007) stated that CAD identifies suspicious findings on mammograms to assist radiologists. Since the FDA approved the technology in 1998, it has been disseminated into practice, but its effect on the accuracy of interpretation is unclear. These investigators determined the association between the use of CAD at mammography facilities and the performance of screening mammography from 1998 through 2002 at 43 facilities in three states. They had complete data for 222,135 women (a total of 429,345 mammograms), including 2351 women who received a diagnosis of breast cancer within 1 year after screening. They calculated the specificity, sensitivity, and positive predictive value of screening mammography with and without CAD, as well as the rates of biopsy and breast-cancer detection and the overall accuracy, measured as the area under the receiver-operating-characteristic (ROC) curve. A total of 7 facilities (16%) implemented CAD during the study period. Specificity decreased from 90.2% before implementation to 87.2% following implementation (p < 0.001), the positive predictive value decreased from 4.1% to 3.2% (p = 0.01), and the rate of biopsy increased by 19.7% (p < 0.001). The increase in sensitivity from 80.4% before implementation of CAD to 84.0 % after implementation was insignificant (p = 0.32). The change in the cancer-detection rate (including invasive breast cancers and ductal carcinomas in situ) was insignificant (4.15 cases per 1,000 screening mammograms before implementation and 4.20 cases after implementation, p = 0.90). Analyses of data from all 43 facilities showed that the use of CAD was associated with significantly lower overall accuracy than was non-use (area under the ROC curve, 0.871 versus 0.919; p = 0.005). The authors concluded that the use of CAD is associated with reduced accuracy of interpretation of screening mammograms. The increased rate of biopsy with the use of CAD is not clearly associated with improved detection of invasive breast cancer. This is in agreement with Bazzocchi, et al. (2007) who noted that there is still considerable variation among different studies in the level of benefit deriving from CAD. Thus, the role of these systems in clinical practice is still debated, and their real contribution to the overall management of the diagnostic process is still unclear. < /p > < p > Screening film mammography has been shown to reduce the mortality rate from breast cancer; however, conventional mammography does not detect all breast cancers.  A significant factor contributing to the limitations of mammography is the structure overlap that results on a 2-dimensional mammogram.  Structure overlap not only obscures lesions, but can mimic abnormalities, thus contributing to reductions in both the sensitivity and specificity of mammography.  A number of new imaging techniques and enhancements for digital mammography have recently become available or are likely to become available in the near future.

Breast tomosynthesis is a 3-dimensional imaging technique that involves acquiring images of a stationary compressed breast at multiple angles during a short scan.  The individual images are then reconstructed into a series of thin, high-resolution slices that can be displayed individually or in a dynamic cine mode.  While holding the breast stationary, images are acquired at a number of different x-ray source angles.  Objects at different heights in the breast project differently for each angle.  The data are then reconstructed to generate images that enhance objects from a given height by appropriate shifting of the projections relative to one another.  Three important areas in tomosynthesis system requirements are: (i) detector efficiency and dose, (ii) field of view, and (iii) equipment geometry.  While holding the breast stationary, an x-ray tube is rotated over a limited angular range and a series of low-dose exposures are made every few degrees, creating a series of digital images.  The x-ray tube is rotated about +/-15 degrees, and 11 exposures are made every 3 degrees during a total scan of a few seconds.  These individual images are then reconstructed into slices.  There are 2 basic tomosynthesis system designs that differ in the motion of the detector during acquisition.  One method moves the detector in concert with the x-ray tube so as to maintain the shadow of the breast on the detector.  An altenate method is to keep the detector stationary relative to the breast platform.  The tomosynthesis reconstruction process consists of computing high-resolution images whose planes are parallel to the breast support plates.  These images are reconstructed with slice separation of 1 mm; thus, a 5-cm compressed breast tomosynthesis study will have 50 reconstructed slices.  The reconstructed tomosynthesis slices can be displayed similarly to computed tomography reconstructed slices.  Proponents of breast tomosynthesis hope it will resolve many of the tissue overlap reading problems that are a major source of recalls and additional imaging in 2-D mammography examinations (Smith, 2005).  Tomosynthesis is currently in clinical trials to evaluate its effectiveness.  The technique is neither clinically available nor approved by the U.S. Food and Drug Administration at this time.  Initial pilot studies suggested that breast tomosynthesis has comparable or superior image quality to that of film-screen mammography and has the potential to decrease the recall rate when used adjunctively with digital screening mammography (Good, et al., 2008; Chen, et al., 2007; Poplack, et al., 2007); however, further studies are needed to evaluate its effectiveness in clinical practice. 

Currently, there are no recommendations to screen men at risk for hereditary breast cancer with mammography. Robson (2002) explained “There are no established guidelines for screening of men at risk for hereditary breast cancer. It is reasonable to suggest periodic self-examination and evaluation by a provider experienced in clinical breast examination. The utility of screening mammography in men is unknown, although it is technically possible in at least some individuals.” However, diagnostic mammography may be indicated in men with a breast mass on clinical examination (American Cancer Society, 2003).

Xeroradiography (Xerox Corporation, Stamford, CT) is an outmoded X-ray imaging method that had been used especially in mammographic screening for breast cancer. With Xeroradiography, X-rays pass through the body to an X-ray-sensitive metal plate. The plate is then processed through a unique photocopying-type machine, and the X-ray image transferred to paper rather than X-ray film. Unlike photographically recorded X-ray images, Xeroradiographs produce a “positive” image in which the denser elements appear darker. Unlike X-ray films, the Xeroradiographic image is a mirror image of the object. The primary advantage of Xeroradiography over conventional plain film mammography is that the former produces instant radiographs. However, Xeroradiography has become outmoded because the radiation exposure required is much higher than with conventional radiographs, and the Xeroradiographic image has a number of defects, such as excessive contrast and edge enhancement.