Screening mammography is a low-dose x-ray examination of the breast that is performed on women with no complaints or symptoms of breast cancer (asymptomatic). The goal of screening mammography is to detect breast cancer when it is still too small to be felt by a physician or the patient. Research has shown that the early detection of small breast cancers by screening mammography greatly improves a woman's chances for successful treatment. For example, if breast cancer is caught and treated while it is still confined to the breast ducts (a type called ductal carcinoma in situ; DCIS), the cure rate is close to 100%. 

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Mammographic screening is key to the early detection of breast cancer

• Who Should Receive Screening Mammography?
• How Accurate is Screening Mammography?
• Comparing Different Breast Exams
• How Much Does a Screening Mammogram Cost?
• Additional Resources on Mammography

Who Should Receive Screening Mammography?

In addition, women younger than 40 who are at high risk of developing breast cancer (i.e., they have a strong family history of breast cancer or test positive from BRCA gene mutations), should ask their physicians about beginning annual screening mammograms earlier than age 40, as early as age 25 in some cases.

Screening mammography involves taking x-rays from two views from each breast, typically from above (cranial-caudal view, CC) and from an oblique or angled view (mediolateral-oblique, MLO). The procedure is discussed in detail in the Mammography and How it is Performed section. If women have questions about mammography during the procedure, they should feel free to ask the mammography technologist. If women have questions about their mammogram report or the radiologist’s letter to the woman about their mammogram, they should direct those questions to the radiologist.

For screening mammography each breast is imaged separately, typically from above (cranial-caudal view, CC) and from an oblique or angled view (mediolateral-oblique, MLO).

How Accurate is Screening Mammography?

Mammography is currently the only exam approved by the U.S. Food and Drug Administration (FDA) to screen for breast cancer in women who do not show any signs or symptoms of the disease. Mammography can detected approximately 85% of breast cancers. If a screening mammography indicates an abnormality, women will most likely be recommended for further breast imaging (i.e., with spot view mammography, ultrasound or other imaging tests). If further imaging confirms or reveals an abnormality, the woman may be referred for biopsy to determine whether she has breast cancer.

While screening mammography can detect most breast cancers, it can miss up to 15% of cancers. These cancers may not be visible on a mammogram film. If a physician detects a breast lump with physical examination but the mammography does not reveal any abnormality, he or she will mostly likely recommend other additional breast imaging (such as ultrasound) to further investigate the lump.

Breast cancer may not be visible on a screening mammogram if:

• The cancer is very small
• The cancer is in an area that is not easily imaged with mammography (such as in the axilla; the underarm region)
• The cancer is obscured by other shadows

While mammography can occasionally miss breast cancers, it can also detect cancer several years before a lump can be felt. Therefore, it is important for women 40 years of age and older to get a mammogram each year and have current mammograms compared with previous films to determine whether cancer is beginning to grow.

Clinical studies in the U.S., Sweden, and the Netherlands have suggested that deaths from breast cancer could be cut by between 36% and 44% if mammographic screening were performed annually on all women.

Mediolateral oblique (MLO) view mammogram showing the pectoral muscle, breast, nipple and breast ducts

 

Percent of American Women Who Have Had a Mammogram Within Past 2 Years
All Women Over 40 White, Non-Hispanic Women Over 40 Black, Non-Hispanic Women Over 40 Hispanic Women Over 40 Women Over 40 Below Poverty Level Women Over 40 Above Poverty Level	66.9% 68% 66% 60.2% 50.5% 69.3%

Comparing Different Breast Exams

Size of Tumors Found by Mammography and Breast Self-Exam
	Average-size lump detected with routine mammogram (0.43 inches / 1.1 cm)
	Average-size lump detected with first mammogram (0.59 inches / 1.5 cm)
	Average-size lump found by regularly practicing breast self-exam (0.83 inches / 2.1 cm)
	Average-size lump found accidentally (1.42 inches / 3.6 cm)

* These images were created for viewing at 800 by 600 resolution on a 16-inch monitor. They will appear larger or smaller depending upon display size and resolution. However, the relative size of the detected tumor will remain consistent.

How Much Does a Screening Mammogram Cost?

Screening mammography is a relatively low cost procedure. The average cost for screening mammography in the U.S. is about $100. Depending on a woman's health coverage program, there may be little or no "out of pocket cost" for screening mammography. Diagnostic mammography, which is often performed if an abnormality is detected on a screening mammogram, is more involved and time-consuming than screening mammography. Thus, diagnostic mammography is more expensive than screening mammography.

On January 1, 1998, the U.S. Congress expanded coverage for screening mammograms for Medicare beneficiaries 40 years of age and older. Donna E. Shalala, U.S. Secretary of Health and Human Services, reported that it is no longer necessary for Medicare beneficiaries to pay the annual deductible for screening mammograms (or Pap smears, pelvic exams or clinical breast exams). Previously, there was a small Medicare deductible of approximately $25 for screening mammography. Women younger than 40 who also have supplemental insurance such as Medigap or Medicaid may also have no out-of-pocket costs for screening mammography. Women are encouraged to call the Medicare Hotline at 1.800.638.6833 for questions on Medicare coverage of mammography.

Women who cannot afford the cost of annual screening mammography have a number of options:

• Determine whether they qualify for the National Breast and Cervical Cancer Early Detection Program, sponsored by the Centers for Disease Control (CDC). The CDC program covers the cost of annual screening mammograms and Pap smears for low-income women who do not have health insurance. To learn more about the CDC program, please visit http://www.cdc.gov/cancer/nbccedp/about.htm
• Contact the American Cancer Society (ACS) at 1.800.ACS.2345. The ACS maintains a list of facilities that offer free or reduced cost mammograms to eligible women. The American Cancer Society website is available at http://www.cancer.org/
• Make an appointment for a mammogram at a participating facility on National Mammography Day. Each year, the third Friday of October is designated National Mammography Day by the American College of Radiology. On this day, many facilities offer free or reduced cost mammograms.

Additional Resources on Mammography

Imaginis provides several resources on screening and diagnostic mammography to help women understand all aspects of the exams. Follow one of the links below for additional information on mammography:

• General Information on Mammography
• Mammography and How it is Performed: Imagining and Positioning
• Benefits of Receiving a Mammogram
• Key Steps for an Optimal Mammogram
• Mammogram Preparation and What to Expect During Mammography
• Find a Mammography Facility
• Mammography on Small Breasts
• Diagnostic Mammography
• Mammogram Interpretation: ACR/BI-RADS System
• Understanding the Mammogram Report
• Frequently Asked Questions About Mammography
• Mammography Quality Standards (MQSA) 
• Advances in Mammography and Breast Imaging
• Digital Mammography

Updated: July 2007

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