What is Breast Cancer?
Cancer occurs when there are mutations in genes that regulate cell growth. The mutations let the cells divide and multiply in an uncontrolled, chaotic way. The cells keep multiplying, producing progressively more abnormal copies rather than reverting towards being healthy cells. This eventually forms a tumor in most cases.
Breast cancer is cancer that develops in breast cells. Usually, the cancer forms in the lobules or ducts of the breast. These are the glands that produce milk and the pathways that help bring the milk from the glands to the nipple. Cancer can also occur in fatty and fibrous breast tissue. This is known as stromal tissue.
The uncontrolled cancer cells start to invade healthy breast tissue and can travel to the lymph nodes under the arms. The lymph nodes are a primary pathway that helps the cancer cells move to other parts of the body.
How Is Breast Cancer Diagnosed?
To determine if your symptoms are caused by breast cancer or a benign breast condition, your doctor will want to conduct a thorough physical examination. They may also request one or more diagnostic tests to help understand what is causing the symptoms you are experiencing.
Tests that can help diagnose breast cancer include:
Breast exam. Your doctor will conduct a thorough breast exam, checking both breasts for abnormal spots or signs of breast cancer. Your doctor may also check other parts of your body to see if the symptoms you’re experiencing could be related to another condition.
Mammogram. Perhaps the best way to see below the surface of your breast is with an imaging test called a mammogram. Many women get annual mammograms to check for breast cancer. If your doctor suspects you may have a tumor or suspicious spot, they will also request a mammogram. If an abnormality is seen on your mammogram, your doctor may request additional tests.
Ultrasound. A breast ultrasound creates a picture of the tissues deep in your breast. The ultrasound uses sound waves to do this. An ultrasound can help your doctor distinguish between a solid mass, like a tumor, and a benign cyst.
Biopsy. If both a mammogram and an ultrasound are inconclusive, your doctor may wish to take a sample of the suspicious spot and have it tested. To do this, your doctor will remove a sample of the suspicious spot and send it to a laboratory. If the sample is positive for cancer, the lab can test it further in order to tell your doctor the type of cancer you have.
Breast cancer can be divided into stages based on how severe it is. Cancers that have grown and invaded nearby tissues and organs are at a higher stage than cancers that are still contained to the breast. In order to stage a breast cancer, doctors need to know:
if the cancer is invasive or non-invasive
how large the tumor is
whether or not the lymph nodes are involved
if the cancer has spread to nearby tissue or organs.
Breast cancer has five main stages. They are:
Stage 0 breast cancer is ductal carcinoma in situ (DCIS). DCIS is a type of pre-cancerous growth. Cancer cells in DCIS remain confined to the ducts in the breast and have not spread beyond the ducts and into nearby tissue.
Stage 1 tumors are no larger than 2 centimeters (cm). Lymph nodes are not impacted by stage 1 breast cancer.
Stage 2 breast cancers can be divided into two categories. The first type of stage 2 breast cancer has a tumor that is no larger than 2 cm, but the cancer has spread to lymph nodes. The second type of stage 2 breast cancer has a tumor that is between 2 and 5 cm, but the cancer has not spread to any lymph nodes or nearby tissue.
Several types of cancers can be at stage 3. The first is a tumor that is no larger than 5 cm, but this tumor has not spread to nearby lymph nodes or tissue. Breast cancer may be at stage 3 if the cancer has spread into the chest wall or skin but not the lymph nodes. Another type of stage 3 breast cancer can be a tumor of any size with lymph nodes in distant areas of the body having cancer, too.
Stage 4 breast cancer can have a tumor of any size, and the cancer has spread to nearby and distant lymph nodes, as well as distant organs.
How Is Breast Cancer Treated?
Your breast cancer’s stage, how far it has invaded, and how big the tumor has grown all play a large part in determining which treatments you will need. Once your doctor has determined your cancer’s size, stage, and grade, the two of you can discuss your treatment options. Surgery is the most common treatment for breast cancer. In addition to surgery, most women with breast cancer undergo a complementary treatment, such as chemotherapy, radiation, or hormone therapy.
Several types of surgery may be used to remove breast cancer, including:
This procedure removes only the suspicious or cancerous spot, leaving most surrounding tissue in place.
In this procedure, a surgeon removes an entire breast. In a double mastectomy, both breasts are removed.
Sentinel node biopsy.
This surgery removes some of the lymph nodes that receive drainage from the tumor. These lymph nodes will be tested, and if they don’t have cancer, you may not need additional lymph-removing surgery.
Axillary lymph node dissection.
If lymph nodes removed during a sentinel node biopsy test positive, your doctor may perform this procedure to remove additional lymph nodes.
Contralateral prophylactic mastectomy.
Even though breast cancer may be present in only one breast, some women elect to have a contralateral prophylactic mastectomy. This surgery removes your healthy breast to reduce your risk of developing breast cancer again.
High-powered beams of X-rays can be used to target and kill cancer cells. Most radiation treatments use a large machine on the outside of the body (external beam radiation).
Advances in cancer treatment have brought about the ability to radiate cancer from inside the body. This type of radiation treatment is called brachytherapy. To conduct brachytherapy, surgeons place radioactive seeds or pellets inside the body, near the tumor site. The seeds stay there for a short period of time each day and work to reduce cancer cells.
Chemotherapy is a drug that can destroy cancer cells. Some patients may undergo chemotherapy alone, but this type of treatment is often used in conjunction with other treatments, especially surgery.
In some cases, doctors prefer to give patients chemotherapy before surgery. The hope is that the medicine will shrink the tumor so the surgery will not have to be as invasive. Chemotherapy has many unwanted side effects, so discuss your concerns with your doctor before beginning treatment with this powerful drug.
If your type of breast cancer is sensitive to hormones, your doctor may start you on therapy to block hormones to help slow and possibly stop the growth of your cancer. Estrogen and progesterone, two female hormones, can stimulate breast cancer tumor growth. Taking medicines to stop or block the production of these hormones may help slow the growth of your cancer.
Certain medications are designed to attack specific abnormalities or mutations within cancer cells. For example, Herceptin (trastuzumab) can block the production of the HER2 protein. HER2 helps breast cancer cells grow, so taking a medication to slow the protein production may help slow cancer growth.