Diagnosis & Staging
There is a small amount of fat between the skin and underlying muscle on the front of your chest. The breast grows in this fatty layer. Each breast has 15-20 lobes or sections. Lobes connect to ducts and ducts lead to the nipple.
Breast anatomy - female
The earlier a breast cancer is found, the better the chance of curing it with treatment.
If you find a lump, go and see a doctor or nurse practitioner right away.
Breast lumps are either malignant (cancer) or benign (not cancer).
- Not all lumps are cancer. Up to 90% (90 out of 100) of breast lumps are not cancer.
- It is common for breasts to feel tender and full before a period starts. These are not signs of cancer.
- There may be one or many benign breast lumps at one time. They are likely caused by the normal cycle of hormones in your body.
- Many benign lumps may change size during a menstrual cycle. Doctors may choose to keep an eye on a lump through a menstrual cycle to see if it gets smaller or goes away. If the lump goes away, it is not cancer.
These are some symptoms of breast cancer:
- A mass, a lump, a thickening or any change in your breast that is new or stays over time. Up to 90% (90 out of 100) of breast lumps are not cancer (benign).
- A lump in your breast gets bigger or your whole breast gets smaller or bigger. Painful lumps are less likely to be cancer.
- Your nipple starts to draw in (it sinks into your breast).
- There is dimpling or puckering of the skin of your breast.
- There is a change in the shape of your breast.
- You have bloody or watery discharge from your nipple.
- Redness, scaling or inflammation (swelling) of your nipple.
- Your breast is red, swollen or hot.
- A lump under your arm or in your armpit.
If you have any symptoms that you are worried about, please talk to your family doctor or nurse practitioner.
Male breast cancer is very rare. Each year, there are 10-30 new cases of male breast cancer diagnosed in B.C. [See note below]
Male breast cancer is very similar to female breast cancer, and it is treated in mostly the same way.
The main differences between male breast cancer and female breast cancer are:
- Male breast cancers are often diagnosed at later stages of disease (metastatic: cancer has spread to other parts of the body). This is likely because males ignore lumps in their breast tissue. Also, many males may not know that lumps in their breast tissue may be cancer.
- A high rate of male breast cancer cases are estrogen receptor positive (ER+). This means that the hormone estrogen helps the cancers grow.
- Males who develop breast cancer are more likely to have inherited a gene mutation (change) that raises their breast cancer risk.
Note: Available statistics do not have information about the inclusion of transgender and gender diverse participants. It is unknown how these statistics apply to transgender and gender diverse people. Patients are advised to speak with their primary care provider or specialists about their individual considerations and recommendations.
These tests may help diagnose breast cancer:
Diagnostic Mammogram (breast x-ray): If a lump is found in your breast by touch or from a screening mammogram, you may get a diagnostic mammogram. This type of mammogram takes more x-ray pictures. It can help find out if the lump is benign (not cancer) or if you need more tests.
Ultrasound: If a lump is found with a diagnostic mammogram, you may need an ultrasound. This can help determine if the lump is filled with fluid (a benign cyst that is not cancer) or is solid (possible cancer).
Magnetic Resonance Imaging (MRI): May help determine if the lump is cancer.
Biopsy: a small amount of tissue is removed. A specialist (pathologist) will look at the tissue.
- For information about how to understand your breast biopsy pathology report, read the
Pathology Report Patient Companion Guide.
Hormone receptor testing and Human Epidermal Growth Factor Receptor 2 (HER2) Testing: If the lump is cancer, pathologists will test your biopsy tissue to see if certain hormones help the cancer grow. This helps your oncologist (cancer doctor) decide on the best treatment for you.
- The hormones estrogen and progesterone may help some cancers grow. These are called estrogen receptor positive (ER+) or progesterone receptor positive (PR+) cancers.
- If these hormones do not help the cancers grow, they are called estrogen receptor negative (ER-) or progesterone receptor negative (PR-) cancers.
- HER2 is a common name for a gene that controls a protein on the surface of cells. This protein helps cells grow. If there is too much HER2 protein being made, it may help cancers grow.
For more information on tests used to diagnose cancer, see
BC Cancer Library screening and diagnosis pathfinder.
Breast cancers are either non-invasive or invasive:
Non-invasive: tumour is in one spot. Also called "in situ".
Invasive: tumour has grown into the breast fat around the ducts and lobules of the breast.
Almost all breast cancers are
adenocarcinomas. This means the cancer starts in the glandular parts of the breast. When a pathologist looks at the cancer under a microscope, they can tell exactly what part of the breast the cancer started in.
There are different types of adenocarcinomas, depending on where they started:
Ductal carcinoma: 75% (75 out of 100) of cases. Start in the ducts of the breast.
Lobular carcinoma: 15% (15 out of 100) of cases. Start in the lobules of the breast.
Medullary, tubular, scirrhous and
other rare types.
- The most common types of breast cancer.
- Invasive breast cancer means that cancer cells in the ducts or lobules of the breast have broken through the walls of these structures and grown into the surrounding cells.
- Breast cells are exposed to changing levels of hormones. This can cause cells inside the milk ducts to multiply. These cells result in a condition called intraductal hyperplasia. If the cells start to look abnormal, this is called hyperplasia with atypia.
- The extra cells may block the duct and begin to look like cancer cells. If this happens, this is called ductal carcinoma in situ (DCIS).
- In DCIS, the cancer cells are only in the milk ducts. If the cancer cells grow out of the ducts into the breast tissue surrounding the ducts, then it becomes an invasive cancer. DCIS is serious but very treatable and highly curable.
- DCIS is most often found by mammogram if calcium deposits start to form in the ducts.
- Pathologists may give the DCIS names depending on how they look under the microscope, such as papillary, cribriform and comedo.
- LCIS forms when too many cells grow in the lobules of the breast.
- If you have LCIS, this means that an invasive breast cancer can develop in the future in either breast, not just where the LCIS was found. LCIS isl less common than DCIS.
- If you have LCIS, you are at risk for future invasive breast cancer. Usually, the more LCIS you have, the higher your risk for future invasive breast cancer.
- LCIS is hard to see on a mammogram or ultrasound. It is often found when another lump is being checked by biopsy.
- If you have LCIS, the aim of any treatment is to stop invasive breast cancer from forming and to catch any cancers as early as possible. The options for treatment include:
- Regular screening and follow-up.
- Tamoxifen, a drug that can lower the risk of invasive breast cancer by half (50%).
- Removing both breasts, called prophylactic mastectomy. This is an extreme option and is rarely recommended. See "Can I help prevent breast cancer?" section below.
- This cancer shows up as inflammation (redness, swelling) of the skin over the tumour.
- It is a fast-growing (aggressive) type of adenocarcinoma.
- Very rare. Makes up 1% (1 out of 100) of cases in B.C.
- This cancer begins by looking like a skin disease, like dermatitis or reddening or scales on the nipple. It may look like eczema. These skin changes are caused by the cancer cells growing into the skin.
- Tumour is usually below the nipple.
- A health care provider may not feel the tumour on an exam.
- Very rare: 0.6% (less than 1 out of 100) of cases.
- Very rare: 0.5% (less than 1 out of 100) of cases
- Sarcomas start in the connective tissue of the breast.
- Lymphomas start in the lymphoid tissue of the breast.
Staging describes the cancer. Staging is based on how much cancer is in the body, where it was first diagnosed, if the cancer has spread and where it has spread to.
The stage of the cancer can help your health care team plan your treatment. It can also tell them how your cancer might respond to treatment and the chance that your cancer may come back (recur).
Stage 0: Tumour is non-invasive and usually small. Found with a mammogram. DCIS or LCIS.
Stage 1: Tumour is 2 cm (about 1 inch) or smaller. Cancer has not spread to lymph nodes.
Stage 2: Tumour is larger than 2 cm but less than 5 cm (2 inches) and/or cancer has spread to lymph nodes under the arm (armpit).
Stage 3: Tumour is larger than 5 cm. Cancer may have spread to many lymph nodes under the arm. Cancer has not spread to anywhere else in the body.
Stage 4: Tumour has spread outside of the breast and nearby lymph nodes to another part of the body, like the liver or bone. This is called metastatic breast cancer.
For more information on staging, see