Definition and Overview

A mammography is a screening test that is strongly recommended for women with a history of breast cancer. It can detect the presence of the disease even when the tumours are too small to cause any noticeable symptoms, allowing patients to receive treatment as soon as possible.

Who Should Undergo and Expected Results

A mammography is strongly recommended for women particularly those who have a history of breast cancer. The ideal age on when they should start with the screening depends on the kind of history they have with the disease.

  • Breast cancer gene - If a woman has been confirmed to have breast cancer genes (BRCA1 and BRCA2), she should begin undergoing mammograms as early as age 25. If she is diagnosed at an even earlier age, she is advised to undergo breast MRI annually until she turns 25.

  • Strong family history - A strong family history of the disease means that a woman's mother or sister was diagnosed with breast cancer. In this case, the woman should undergo breast cancer screening between 35 and 40 years old or 10 years earlier from the age her relatives were diagnosed with the disease.
    A woman’s degree of risk depends on who on her family was diagnosed with the condition. This could either be a:

  • First-degree relative, usually a mother, sister, or daughter, but also possibly (although quite rare) the father or brother

  • Second-degree relative, such as a grandparent, an aunt or uncle, a grandchild, niece or nephew, or half-sibling <
    A woman is said to be at high risk of the disease if she has:

  • Two to four relatives diagnosed with breast cancer (at least one of whom is a first-degree relative) before age 50

  • One first-degree relative diagnosed with cancer in both breasts before age 50
    Moderate-risk individuals are those who have:

  • One first-degree relative diagnosed before age 40

  • Two first or second-degree relatives diagnosed after 50 *Three first or second-degree relatives diagnosed after 60

  • History of ovarian cancer or rare childhood cancers - A woman who has a family history of either ovarian cancer or rare childhood cancers is also considered to be at risk of breast cancer and should thus undergo regular screenings.
    Even if women have a strong history of breast cancer, it does not automatically mean that they will develop the disease. In fact, a greater number of women diagnosed with it do not have a breast cancer history. Nevertheless, doctors advise women with said history to undergo screenings so that if cancer develops, it will be caught and treated early, giving patients a better chance of complete recovery.

How the Procedure Works

A mammography is the recommended screening test for patients with breast cancer history. The test, which takes an x-ray of breast tissue using low doses of radiation, can detect breast cancer early. It can now be done using traditional method or the more advanced digital mammography method, which uses computer imaging. Regardless of the type of test, the entire process usually takes around 30 minutes.

In a standard mammography, the patient will be asked to remove her clothes on the upper half of the body, including the bra. Each of her breasts will then be placed on a clear plastic plate of the mammography machine. The breast will be pressed using another flat plate called a compression paddle, which helps keep breast tissue steady and spread out. This ensures that a better x-ray image of the entire breast will be obtained and that the resulting images are clear even with low amounts of radiation.

The procedure may be a bit painful or uncomfortable for most women. The scan takes only a minute, but it is normal for doctors to take two mammograms of each breast, usually asking the patient to change position to get a different angle of the said body part.

Both standard and digital mammography can detect breast cancer early in high and moderate risk patients of a certain age, usually at the age of menopause, but the digital version has an increased capability of detecting breast cancer even in younger patients and also in women whose breast tissue is denser than normal.

A mammography can detect cancers (malignant tumors), benign tumours and cysts. The results of the mammography will show if a woman has dense breast tissue, which may indicate either cancer or calcifications. Denser tissue will appear brighter and whiter than normal tissue, which appears darker.

In rare cases where a mammogram is not able to determine whether an abnormality in the scan results is cancer, the patient will be advised to undergo a breast tissue biopsy.

Possible Risks and Complications

Mammography is generally a safe, routine procedure. However, there are still some risks involved, the most important of which is radiation exposure.

Since the scan uses radiation, although at low levels, doctors use and prescribe mammograms with caution by taking into consideration the patient’s history of radiation exposure. Thus, patients are normally asked about their history of x-ray scans including those unrelated to mammography.

Also, radiation exposure has to be avoided completely in the case of pregnant women or patients who suspect they may be pregnant, as it can result in birth defects. If the patient really has to undergo a mammogram, some special precautions will be applied, such as wearing special equipment, during the test to minimize the fetus exposure to radiation.


  • American Cancer Society. American Cancer Society Recommendations for Early Breast Cancer Detection in Women Without Breast Symptoms. Last revised October 24, 2013. Available at:

  • American College of Obstetricians and Gynecologists (ACOG). ACOG practice bulletin no.122. Breast cancer screening. Obstet Gynecol. 2011;118:372-82. PMID 21778569

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