1.3 Diagnostic Testing

1.3.1 What is Diagnostic Testing?

Diagnostic tests help get a more accurate analysis of what is occurring.

Testing involves various procedures to determine whether the problem is cancer and the cancer stage (Canadian Cancer Society, n.d.r). These tests can include lab tests, imaging, and biopsies.

1.3.2 Mammography

Mammograms are a type of x-ray that looks for changes in the breasts that can occur with breast cancer, such as tiny lumps that cannot be felt during a clinical or self-examination (Canadian Breast Cancer Network [CBCN], 2022).

There are two types of mammograms: screening and diagnostic (CBCN, 2022). Screening mammograms monitor changes in breast tissue when there are no signs of breast cancer. Meanwhile, diagnostic mammograms take a closer look at a breast abnormality when breast cancer symptoms are present. This type allows your physician to understand what is happening in your breast.

Your healthcare technician will place your breast between two plastic plates that press together and flatten your breasts (CBCN, 2022). Flattening your breasts allows the machine to see as much tissue as possible. You will have front and side views of each breast taken.

Note that you should not apply any deodorant or body lotion on your breasts or arms before the mammogram as they can interfere with the accuracy of the test (CBCN, 2022). These products’ minerals and metallic substances may be mistaken for dense particles or calcification in the resulting images.

The risks involved with receiving a mammogram are minimal. Mammograms only use a small amount of X-rays, so they are considered safe (CBCN, 2022).

For more information on what to expect at your first mammogram, check out Video 5 (Screening BC, 2018), Video 6 (Screening BC, 2021), and Video 7 (Screening BC, 2016).

Each province and territory of Canada has different breast cancer screening guidelines.

The following resources are breast cancer screening guides specifically for those who live in British Columbia:

If you have any further questions or concerns regarding receiving a mammogram, make sure to talk to your healthcare team.

1.3.3 Ultrasound

Ultrasounds are non-invasive tests usually done as a follow-up to a mammogram that detects a lump in the breast (American Cancer Society, 2022b). These tests are also beneficial if you have dense breasts since abnormalities are difficult to detect using a mammogram.

An ultrasound allows your healthcare provider to closely examine the lump to determine if it is fluid-filled or solid (American Cancer Society, 2022b). Fluid-filled lumps are more likely to be cysts, while solid lumps need further testing to confirm whether they are cancerous.

1.3.4 Magnetic Resonance Imaging

Similar to ultrasounds, magnetic resonance imaging (MRI) can be used as a follow-up to a mammogram or ultrasounds with unclear results to confirm whether you have breast cancer (American Cancer Society, 2022a).

Unlike ultrasounds and mammograms, MRIs can help determine what stage of breast cancer you are in (American Cancer Society, 2022a). MRIs look at the size and location of the tumour, whether other tumours are present in that breast, or if there are tumours in the other breast.

1.3.5 Biopsy

Biopsies involve removing a small part of the breast tissue to be examined by a pathologist, who will determine if the lump is benign or malignant (CBCN, 2022). Two categories of biopsies are needle and surgical.

Needle Biopsies

Needle biopsies include fine needle and core needle aspirations (CBCN, 2022). Fine needle aspirations use a fine needle with a syringe to extract the fluid, tissue, or cells of the abnormal lump. On the other hand, core needle aspirations use a hollow needle with a syringe to remove a cylinder of tissue from the lump. Both types involve incisions, but leave no scarring.

Surgical Biopsies

Surgical biopsies can be excisional or incisional (Canadian Cancer Society, n.d.r). Excisional biopsies remove the whole lump along with some surrounding tissue, while incisional biopsies only remove a small part of the lump.

Unlike needle and incisional biopsies, excisional biopsies require either local anesthesia, sedation, or general anesthesia, and it may leave scarring (CBCN, 2022).

1.3.6 Ductography (Galatography)

Ductograms, or galactograms, are a type of X-ray that examines the breast ducts to find out why abnormal nipple discharge is occurring (Canadian Cancer Society, n.d.r).

See Image 5 for an example of a ductogram (Lange123, 2006).

Image 5: Ductography of a breast

1.3.7 Diffuse Optical Tomography

Diffuse optical tomography is a type of imaging used for breast cancer diagnosis (Altoe et al., 2019). This test is unique because it neither uses compression (like a mammogram) nor contrast dyes. During this test, low-intensity near-infrared light views both breasts simultaneously; it measures the breast tissue’s water percentage, hemoglobin, and oxygen levels.

The results of diffuse optical tomography show tissue metabolism and other characteristics that may link to breast cancer markers seen in another imaging test, such as a mammogram (Altoe et al., 2019).

See Image 6 for an example of a diffuse optical tomogram (DUCROS, 2016).

Image 6: Diffuse optical tomography of a breast

1.3.8 Blood Tests

Blood tests determine a baseline of your general health (Canadian Cancer Society, n.d.r). A standard blood test is a complete blood count, which measures the quantity and quality of red blood cells, white blood cells, and platelets in your body.

Another category of blood tests, called blood chemistry tests, can be used to stage breast cancer (Canadian Cancer Society, n.d.r). The three blood chemistry tests that can do this are blood urea nitrogen and creatine (kidneys), alanine aminotransferase and aspartate transaminase (liver), and alkaline phosphate (liver or bones).

1.3.9 Genetic Testing

Genetic testing can help you and your healthcare team identify if you are at risk of developing breast cancer (Lymphedema Working Group, 2012). Detecting this risk earlier could give you more time to consider your goals. This testing could also provide insight into what genes are contributing to breast cancer, which can help when deciding on a treatment method.

However, remember that genetic testing is not always the most accurate source of information (Lymphedema Working Group, 2012). Misinterpreted test results can lead to unnecessary worry.