A mammogram is an X-ray examination of the breast, performed to detect breast cancer in its earliest stages, often before any signs or symptoms of the disease are present. Mammograms allow early detection of small tumors that are easier to treat than larger, more developed tumors. And it can also detect small abnormal growths in the milk ducts of the breast, called ductal carcinoma in situ (DCIS). Early removal of these growths helps to prevent the risk of future harm.

Reasons for a Mammogram

A mammogram can show abnormalities, such as tumors, in the breast tissue long before they can be felt on clinical or self-examination. Mammograms may be performed for screening or diagnostic purposes.

Screening Mammograms

Screenings involve producing images of both breasts in order to detect any tumors that cannot yet be felt under the skin. They can also detect calcium deposits that may, or may not, indicate breast cancer.

Diagnostic Mammograms

Diagnostic mammograms are performed after a lump or other sign of breast cancer has been detected, or after abnormalities have shown up on a previous mammogram. Diagnostic mammograms target a specific area of the breast, taking more detailed images from many more angles. Diagnostic mammograms are also useful in evaluating breast tissue that is unusually dense of tissue partially obscured by breast implants.

Both screening and diagnostic mammography can help diagnose breast diseases, lumps, cysts and benign and malignant tumors.

Candidates for a Mammogram

It is recommended that women between the ages of 40 and 75 have mammograms annually. Patients with certain risk factors should take extra care and may be advised to have screenings when younger or older than the typical age parameters. Such risk factors include:

  • Having a personal or family history of breast cancer
  • Being of Ashkenazi Jewish descent
  • Possessing breast cancer genes (BRCA1 and BRCA2)
  • Having abnormal changes in the breast
  • Having used hormone replacement therapy for a prolonged period
  • Having used alcohol excessively
  • Having had radiation to the chest
  • Having dense breast tissue

Men can also be diagnosed with breast cancer, but this occurs much more rarely. While only 1 percent of breast cancer patients are men, men should also be checked if they have symptoms or a strong family history of the disease, especially if they are between 60 and 70 years of age.

Preparing for the Procedure

Female patients should not schedule a mammogram the week before they have their period, as the breasts are usually tender at this time. They are instructed not to wear deodorant, powder, or lotions under the arms or on the breasts on the day of the mammogram. Pregnant women should not undergo mammograms because of the danger of exposing the fetus to radiation.

The Mammogram Procedure

During a mammogram, the woman stands with her breast against the mammogram plate. The professional administering the test positions each breast so that it will be appropriately compressed while exposed to a very low dose of radiation. Compression helps even out the thickness of the breast so that all breast tissue can be visualized, and it also holds the breast still to minimize blurring caused by patient movement. Images of the breast tissue once produced are displayed on a computer screen for the radiologist to view and analyze.

The mammogram procedure is uncomfortable for most patients, particularly if their breasts are sensitive, but the test does not take long and is usually well-tolerated.

Results of a Mammogram

While mammograms are very useful tests, and have saved countless lives, they are not foolproof. Both false positives and false negatives do occur. It is also possible for women to be overtreated and unnecessarily exposed to cancer treatments that may have adverse effects.

False-negative results are also possible. It is estimated that mammograms used for screening miss about 20 percept of breast cancers. This is especially true in women with dense breasts, who tend to be younger patients. In such cases, women who require treatment do not receive it and their cancer progresses without medical intervention.

Risks of a Mammogram

A mammogram is considered a safe procedure for most women, including those with breast implants. Patients should, however, always advise their doctors if they are pregnant or have any pre-existing medical conditions before participating in this diagnostic test.

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