Mammography is a specific type of medical imaging that uses low-dose X-rays to see inside the breasts for early detection of breast cancer — before symptoms occur — when it is most treatable. The resultant images are known as mammograms.


What are some common uses of mammograms?

Mammograms are used not only as a screening tool but also as a diagnostic tool.

  • Screening mammography: A screening mammogram is used to detect breast changes that could be cancerous in people experiencing no signs or symptoms. The goal is to detect cancer when it is small and treatment may be less invasive. Researches have shown that regular screening mammograms lead to early detection of breast cancers, when they are most curable and breast-conservation therapies are available.
  • Diagnostic mammography: A diagnostic mammogram includes additional mammogram images and is used to investigate suspicious breast changes (e.g. a new breast lump, breast pain, an unusual skin appearance, skin dimpling, nipple thickening or nipple discharge) found by the woman or her doctor as well as to evaluate abnormal clinical findings on a screening mammogram or to view breast tissue when it is difficult to obtain a screening mammogram. 


What are the risks and limitations of mammograms?

  • Mammograms expose you to low-dose radiation. The dose is very low, though, and for most people the benefits far outweigh the risks posed by this small amount of radiation. 
  • Having a mammogram may lead to additional testing due to a false-positive result (happens when a mammogram looks abnormal but no cancer is present). 

If your mammogram detects something unusual, the doctor or the radiologist who interprets the images will want to compare it with your previous mammograms. If you have had mammograms performed elsewhere, your radiologist will request them from you. To make a firm diagnosis, you may need additional mammograms or other tests which might include either a follow-up imaging test (such as an ultrasound) or a biopsy (a procedure to remove a sample of breast tissue for laboratory testing). 

5% – 15% of screening mammograms require more testing. However, most abnormal findings detected on screening mammograms turn out to be normal and are not cancer. It is estimated that a woman who has yearly mammograms between ages 40 and 49 has about a 30% chance of having a false-positive mammogram at some point in that decade and about a 7% to 8% chance of having a breast biopsy within the 10-year period.

  • Screening mammography cannot detect all breast cancers. Some cancers detected by physical examination may not be seen on the mammogram. A cancer may be missed if it is too small or is located in an area that is difficult to view by mammography, such as your armpit. Interpretations of mammograms can be difficult because a normal breast looks different for each woman. Also, the appearance of an image may be compromised if there is powder or salve on the breasts or if you have undergone breast surgery.

Not all of the cancers found by mammography can be cured. Some breast cancers are aggressive, grow rapidly and quickly spread or metastasise to other parts of the body.


How does it work?

During mammography, your breast will be positioned in a mammography machine.

The mammography machine will need to compress your breast to get a clear picture; this might feel uncomfortable, but it helps us get the best picture while using as little radiation as possible.


You will be asked to change positions between images. The routine views are a top-to-bottom view and an angled side view. The process will be repeated for the other breast. 


When the examination is complete, you may be asked to wait until the radiologist determines that all the necessary images have been obtained.


 The entire examination process should take about 15 minutes to 1 hour.



How often should you get a screening mammogram?

Experts and medical organisations do not agree on when to begin regular screening mammograms or how often the tests should be repeated. Talk with your healthcare provider about your risk factors, your preferences, and the benefits and risks of screening. Together, you can decide what screening mammography schedule is best for you.

Current guidelines from the Ministry of Health Malaysia (MOH) and the Academy of Medicine of Malaysia (AMM) recommend screening mammography once every two years for women aged 50 - 74 years in the general population. Women at high risk of breast cancer, however, are suggested to consider annual screening mammography beginning at age 30 and biennial mammography from 60 years of age onwards. Women who have had breast cancer should seek expert medical advice about when and how often screening mammography should be performed as well as the need for other types of screening.