What is breast cancer?
Cancer occurs when changes called mutations take place in genes that regulate cell growth. The mutations let the cells divide and multiply in an uncontrolled way.
Breast cancer is cancer that develops in breast cells. Typically, the cancer forms in either the lobules or the ducts of the breast.
Lobules are the glands that produce milk, and ducts are the pathways that bring the milk from the glands to the nipple. Cancer can also occur in the fatty tissue or the fibrous connective tissue within your breast.
The uncontrolled cancer cells often invade other healthy breast tissue and can travel to the lymph nodes under the arms. The lymph nodes are a primary pathway that help the cancer cells move to other parts of the body.
Breast cancer screening
Having regular mammograms may not prevent breast cancer, but it can help reduce the chances that it will go undetected.
The American College of Physicians (ACP) provides the following general recommendations for women at average risk for breast cancer:
- Women ages 40 to 49: An annual mammogram isn’t recommended, but women should discuss their preferences with their doctors.
- Women ages 50 to 74: A mammogram every other year is recommended.
- Women 75 and older: Mammograms are no longer recommended.
The ACP also recommends against mammograms for women with a life expectancy of 10 years or less.
Signs and symptoms of breast cancer
In its early stages, breast cancer may not cause any symptoms. In many cases, a tumor may be too small to be felt, but an abnormality can still be seen on a mammogram.
If a tumor can be felt, the first sign is usually a new lump in the breast that was not there before. However, not all lumps are cancer.
Each type of breast cancer can cause a variety of symptoms. Many of these symptoms are similar, but some can be different. Symptoms for the most common breast cancers include:
- a breast lump or tissue thickening that feels different than surrounding tissue and has developed recently
- breast pain
- red, pitted skin over your entire breast
- swelling in all or part of your breast
- a nipple discharge other than breast milk
- bloody discharge from your nipple
- peeling, scaling, or flaking of skin on your nipple or breast
- a sudden, unexplained change in the shape or size of your breast
- inverted nipple
- changes to the appearance of the skin on your breasts
- a lump or swelling under your arm
If you have any of these symptoms, it doesn’t necessarily mean you have breast cancer. For instance, pain in your breast or a breast lump can be caused by a benign cyst.
Still, if you find a lump in your breast or have other symptoms, you should see your doctor for further examination and testing.
Types of breast cancer
There are several types of breast cancer, and they’re broken into two main categories: “invasive” and “noninvasive,” or in situ. While invasive cancer has spread from the breast ducts or glands to other parts of the breast, noninvasive cancer has not spread from the original tissue.
Breast cancer stages
Breast cancer can be divided into stages based on the size of the tumor(s) and how much it has spread. Cancers that are large and/or have invaded nearby tissues or organs are at a higher stage than cancers that are small and/or still contained in the breast. To stage a breast cancer, doctors need to know:
- if the cancer is invasive or noninvasive
- how large the tumor is
- whether the lymph nodes are involved
- if the cancer has spread to nearby tissue or organs
- Male breast cancer
- Although they generally have less of it, men have breast tissue just like women do. Men can develop breast cancer too, but it’s much rarer.
- According to the ACS, breast cancer is 100 times less common in white men than in white women. Its 70 times less common in black men than in black women.
- That said, the breast cancer that men develop is just as serious as the breast cancer women are diagnosed with. It also has the same symptoms.
Diagnosis of breast cancer
To determine if your symptoms are caused by breast cancer or a benign breast condition, your doctor will do a thorough physical exam in addition to a breast exam. They may also request one or more diagnostic tests to help understand what’s causing your symptoms.
Tests that can help diagnose breast cancer include:
- Mammogram. The most common way to see below the surface of your breast is with an imaging test called a mammogram. Many women ages 40 and older 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 abnormal area is seen on your mammogram, your doctor may request additional tests.
- Ultrasound. A breast ultrasound uses sound waves to create a picture of the tissues deep in your breast. An ultrasound can help your doctor distinguish between a solid mass, such as a tumor, and a benign cyst.
- Your doctor may also suggest tests such as an MRI or a breast biopsy.
Breast cancer treatment
Your breast cancer’s stage, how far it has invaded (if it has), and how big the tumor has grown all play a large part in determining what kind of treatment you’ll need.
To start, your doctor will determine your cancer’s size, stage, and grade (how likely it is to grow and spread). After that, you can discuss your treatment options.
Surgery is the most common treatment for breast cancer. Many people have additional treatments, such as chemotherapy, targeted therapy, radiation, or hormone therapy.
Several types of surgery may be used to remove breast cancer, including:
- Lumpectomy. This procedure removes the tumor and some surrounding tissue, leaving the rest of the breast intact.
- Mastectomy. In this procedure, a surgeon removes an entire breast. In a double mastectomy, both breasts are removed.
- Sentinel node biopsy. This surgery removes a few of the lymph nodes that receive drainage from the tumor. These lymph nodes will be tested. If they don’t have cancer, you may not need additional surgery to remove more lymph nodes.
- Axillary lymph node dissection. If lymph nodes removed during a sentinel node biopsy contain cancer cells, your doctor may remove additional lymph nodes.
- Contralateral prophylactic mastectomy. Even though breast cancer may be present in only one breast, some people elect to have a contralateral prophylactic mastectomy. This surgery removes your healthy breast to reduce your risk for developing breast cancer again.
With radiation therapy, high-powered beams of radiation are used to target and kill cancer cells. Most radiation treatments use external beam radiation. This technique uses a large machine on the outside of the body. Advances in cancer treatment have also enabled doctors to irradiate 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 and work to destroy cancer cells.
Chemotherapy is a drug treatment used to destroy cancer cells. Some people may undergo chemotherapy on its own, but this type of treatment is often used along with other treatments, especially surgery. In some cases, doctors prefer to give patients chemotherapy before surgery. The hope is that the treatment will shrink the tumor, and then the surgery will not need to be as invasive. Chemotherapy has many unwanted side effects, so discuss your concerns with your doctor before starting treatment.
If your type of breast cancer is sensitive to hormones, your doctor may start you on hormone therapy. Estrogen and progesterone, two female hormones, can stimulate the growth of breast cancer tumors. Hormone therapy works by blocking your body’s production of these hormones or by blocking the hormone receptors on the cancer cells. This action can help slow and possibly stop the growth of your cancer.
Certain treatments are designed to attack specific abnormalities or mutations within cancer cells. For example, Herceptin (trastuzumab) can block your body’s production of the HER2 protein. HER2 helps breast cancer cells grow, so taking a medication to slow the production of this protein may help slow cancer growth.