What is a mammogram?
Mammography is a type of medical imaging that traditionally uses low-dose radiation or x-ray imaging to examine the breast for diseases, particularly lumps and bumps that may go undetected by touch. This method of breast examination began in the 1930s when a radiologist used this technique to detect breast tumors even before surgery.
More recently, digital mammography – which allows images to be viewed and stored in a computer – has started to replace x-ray mammography. One advantage of this technology is less exposure to radiation. Another is being able to store these images for a longer period of time, in case they need to be reviewed in the future.
In addition, Computer-Aided Detection (CAD) is an artificial intelligence system that can search these digital mammogram images for any abnormalities that are suspicious for cancer. These can include small calcifications and tumors. CAD increases the detection of cancers compared to the traditional x-ray mammogram.
Nowadays, the mammogram is regarded as the best screening tool for detecting breast cancer early. Mammograms can be done for screening or diagnostic purposes, which will be discussed further below.
Who needs a mammogram?
Guidelines recommend that women who are considered at average risk are advised to get their first screening mammogram at the age of 40, and following that, once a year. Those who have genetic mutations, genetic syndromes, or women who have a first-degree relative (such as a mother or sister) with a breast cancer diagnosis are considered high-risk. This specific group of women are recommended to start screening mammograms as early as 25 years old, or 10 years prior to the age where their first-degree relative had a breast cancer diagnosis.
Screening Mammograms are performed on women with no signs and symptoms of breast cancer. Your very first mammogram, which is usually advised starting at age 40, aims to detect the presence of any dangerous lumps or bumps early on.
A Diagnostic Mammogram on the other hand, is performed on women who are experiencing symptoms that are suspicious of breast cancer. A lump that can be felt by touch, breast pain, nipple discharge, or changes in the skin over your breast are among the symptoms which point to a need for diagnostic mammograms. This type of mammography tends to take a longer time and captures more images, especially if there are abnormal findings.
Early detection of breast cancer
The most significant benefit of having a mammogram is being able to detect breast cancer at an early stage – when cure is more likely and more treatment options are available. Experts have discovered that mammograms reach as high as 80 to 90% accuracy, making it the best method to screen for breast cancer.
Downsides of Mammography
Discomfort: Although most women can tolerate the procedure with fairly little discomfort, many will describe the procedure as uncomfortable, or even painful. This results from the pressure applied to the breast during compression between two flat plates of the machine.
Exposure to radiation: Thankfully, modern machines have further decreased the dose of ionizing radiation used during the procedure. The exposure remains insignificant, and the benefits of having a mammogram still outweigh this risk.
Interpretation of results: One recognized disadvantage of mammography is that some relatively harmless lumps can be overdiagnosed as breast cancer. Moreover, providers may have some degree of difficulty in reading results, especially in the young and in those with breast implants.
Machines used for mammography have two flat plates that compress the breast, spreading out the breast tissue. X-ray beams are directed into your breast and absorbed by the tissues depending on their density. Bone, which is very compact, would show up on a mammogram as white in color. Less dense tissues such as fat may appear dark gray.
Breast tumors are usually seen as a lighter shade of gray. Only your doctor can interpret if this is harmless or suspicious. Typical findings that can point to a malignant tumor include tiny calcifications, speculated (spiky) tumor edges, and irregular borders.
Radiologists are physicians who interpret your mammography results. Generally, they categorize your findings using a standard reporting system. The next steps depend on your category – in some cases, further testing such as ultrasound, magnetic resonance imaging (MRI), or biopsy may be required.
There is no special preparation prior to having your mammogram, but it is helpful to keep these things in mind:
#1 Schedule your mammogram during periods of least breast tenderness.
It is important to avoid having your mammogram a week before or after your period – this greatly affects the level of discomfort, as your breasts are tender and swollen during this time.
#2 Make sure to bring your past records.
Informing the technician of your medical history will be of great help, particularly if you are taking blood thinners, have breast problems or breast implants, or if you suspect you are pregnant. If you’ve had mammograms in the past, it is advisable to carry your results with you. Let your technician know if you have breast changes, if you’ve had prior breast surgery, or if you have a family history of breast cancer.
#3 Wear a separate top and pants or a skirt.
Wearing separate outfits makes it easier to remove your top and bra for the mammogram. Additionally, it is preferred to wear non-wire bras to increase comfort after the procedure.
#4 Avoid applying deodorant, antiperspirants, creams, or powder on your underarms before your appointment.
Some of these substances can show up as suspicious findings on the mammogram, leading to unnecessary false alarms. Make sure to wipe your underarms clean before the procedure begins.
Clear communication with the technician is key to a quick and safe mammogram. Be sure to follow their instructions, and tell your provider if you are feeling discomfort, or if you get lightheaded. A screening mammogram only takes about 20 minutes if there are no alarming findings.
If the images aren’t clear enough, you may need to repeat the procedure. As mentioned earlier, radiologists will read your results and categorize them. A negative mammogram means that your breast tissues are normal.
A benign result means that although there is a disease in your breast, it is less likely to be cancer. Suspicious or malignant means that you are likely to have breast cancer, and may need confirmation through additional diagnostic tests or a biopsy.
Keep in mind, though, that mammograms do not detect ALL breast cancers. There are some malignant lumps that can be missed. On the other hand, there might be non-cancerous tumors that can be interpreted as suspicious – also known as ‘false positive’ results.
Studies have shown that about 8 to 12% of positive results turn out to be non-malignant. However, further testing like breast ultrasounds or MRIs can help confirm the diagnosis, usually even before biopsy is done.
Your follow up and the need for biopsy also depends on the category that you are in. It is best to talk to your doctor about this.
Typically, having a mammogram doesn’t result in any long-term side effects. Some women report soreness after the procedure, which should resolve in hours or after taking an over-the counter pain reliever. Various factors affect the level of pain or sensitivity that you may feel after the mammogram.
Bruises may occur in those who are taking blood thinners. Lastly, exposure to low levels of ionizing radiation during the procedure is negligible and unlikely to cause harm.
What discomfort can be caused by mammograms?
Depending on several factors like pain tolerance, breast tenderness, and breast density, you might experience a degree of discomfort due to compression of breast tissue. Soreness may follow after the procedure, but typically resolves afterwards.
What are the limitations or accuracy of mammogram results?
Newer mammograms, especially those with Computer-Aided Detection (CAD) or 3D mammography have increased the test’s accuracy. Limitations include difficulty in interpretation, breast implants, and poor image quality.
What if I have undergone past breast surgery?
If you have had breast surgery in the past, let your technician and radiologist know. Surgery, even for reasons other than cancer, can distort the appearance of your breast tissue and skin on mammography, which may cause error in interpretation.
When should I have a mammogram screening test?
Annual screening by mammogram is recommended at the age of 40. If you have a history of genetic mutations that put you at higher risk, then annual screening begins at 25 years old. If you have family history, begin your annual mammography 10 years prior to the age of breast cancer diagnosis of a first-degree relative.
What happens if my mammogram shows cancerous tissue?
Depending on your radiologist and provider, further imaging using breast ultrasounds or breast MRIs may be required. A biopsy may be needed to confirm the diagnosis. It is important to communicate with your doctor about this to make sure you understand the next steps.