What is Breast Cancer?
Breast cancer is a cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, and fluid coming from the nipple, a newly-inverted nipple, or a red or scaly patch of skin.
Symptoms of Breast Cancer
Signs and symptoms of breast cancer may include:
• A breast lump or thickening that feels different from the surrounding tissue
• Change in the size, shape or appearance of a breast
• Changes to the skin over the breast, such as dimpling
• A newly inverted nipple
• Peeling, scaling, crusting or flaking of the pigmented area of skin surrounding the nipple (areola) or breast skin
• Redness or pitting of the skin over your breast, like the skin of an orange.
What are the different types of breast cancer? Where does breast cancer come from?
There are many types of breast cancer. Some are more common than others, and there are also combinations of cancers. Some of the most common types of cancer are as follows:
Ductal carcinoma in situ: The most common type of non-invasive breast cancer is ductal carcinoma in situ (DCIS). This early-stage breast cancer has not spread and therefore usually has a very high cure rate.
Invasive ductal carcinoma: This cancer starts in the milk ducts of the breast and grows into other parts of the surrounding tissue. It is the most common form of breast cancer. About 80% of invasive breast cancers are invasive ductal carcinoma.
Invasive lobular carcinoma: This breast cancer starts in the milk-producing glands of the breast. Approximately 10% of invasive breast cancers are invasive lobular carcinoma.
The remainder of breast cancers are much less common and include the following:
Mucinous carcinoma is formed from mucus-producing cancer cells. Mixed tumors contain a variety of cell types.
Medullary carcinoma is infiltrating breast cancer that presents with well-defined boundaries between the cancerous and noncancerous tissue.
Inflammatory breast cancer: This cancer makes the skin of the breast appear red and feel warm (giving it the appearance of an infection). These changes are due to the blockage of lymph vessels by cancer cells.
Triple-negative breast cancers: This is a subtype of invasive cancer with cells that lack estrogen and progesterone receptors and have no excess of a specific protein (HER2) on their surface. It tends to appear more often in younger women and African-American women.
Paget’s disease of the nipple: This cancer starts in the ducts of the breast and spreads to the nipple and the area surrounding the nipple. It usually presents with crusting and redness around the nipple.
Adenoid cystic carcinoma: These cancers have both glandular and cystic features. They tend not to spread aggressively and have a good prognosis.
Lobular carcinoma in situ: This is not cancer but an area of abnormal cell growth. This pre-cancer can increase the risk of invasive breast cancer later in life.
The following are other uncommon types of breast cancer:
• Papillary carcinoma
• Phyllodes tumor
• Tubular carcinoma
What causes breast cancer?
There are many risk factors that increase the chance of developing breast cancer. Although we know some of these risk factors, we don’t know the cause of breast cancer or how these factors cause the development of a cancer cell.
We know that normal breast cells become cancerous because of mutations in the DNA, and although some of these are inherited, most DNA changes related to breast cells are acquired during one’s life.
Proto-oncogenes help cells grow. If these cells mutate, they can increase the growth of cells without any control. Such mutations are referred to as oncogenes. Such uncontrolled cell growth can lead to cancer.
What are breast cancer risk factors? How do you get breast cancer?
Some of the breast cancer risk factors can be modified (such as alcohol consumption) while others cannot be influenced (such as age). It is important to discuss these risks with a health care provider when starting new therapies (for example, postmenopausal hormone therapy).
Several risk factors are inconclusive (such as deodorants), while in other areas, the risk is being even more clearly defined (such as alcohol use).
The following are risk factors for breast cancer:
Age: The chances of breast cancer increase as one gets older.
Family history: The risk of breast cancer is higher among women who have relatives with the disease. Having a close relative with the disease (sister, mother, and daughter) doubles a woman’s risk.
Personal history: Having a breast cancer diagnosis in one breast increases the risk of cancer in the other breast or the chance of additional cancer in the original breast.
Women diagnosed with certain benign (non-cancerous) breast conditions have an increased risk of breast cancer. These include atypical hyperplasia, a condition in which there is an abnormal proliferation of breast cells but no cancer has developed.
Menstruation: Women who started their menstrual cycle at a younger age (before 12) or went through menopause later (after 55) have a slightly increased risk.
Breast tissue: Women with dense breast tissue (as documented by mammogram) have a higher risk of breast cancer.
Race: White women have a higher risk of developing breast cancer, but African-American women tend to have more tumors that are aggressive when they do develop breast cancer.
Exposure to previous chest radiation or use of diethylstilbestrol increases the risk of breast cancer.
- Having no children or the first child after age 30 increases the risk of breast cancer.
- Breastfeeding for one and a half to two years might slightly lower the risk of breast cancer.
- Being overweight or obese increases the risk of breast cancer both in pre and postmenopausal women but at different rates.
Use of oral contraceptives in the last 10 years increases the risk of breast cancer slightly.
Using combined hormone therapy after menopause increases the risk of breast cancer.
Alcohol consumption increases the risk of breast cancer, and this seems to be proportional to the amount of alcohol used. A recent meta-analysis reviewing the research on alcohol use and breast cancer concluded that all levels of alcohol use are associated with an increased risk for breast cancer. This includes even light drinking.
Exercise seems to lower the risk of breast cancer.
Genetic risk factors: The most common causes are mutations in the BRCA1 and BRCA2 genes (breast cancer and ovarian cancer genes). Inheriting a mutated gene from a parent means that one has a significantly higher risk of developing breast cancer.
Types of breast cancer
There are several types of breast cancer, and they are 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.
These two categories are used to describe the most common types of breast cancer, which include:
Ductal carcinoma in situ. Ductal carcinoma in situ (DCIS) is a noninvasive condition. With DCIS, the cancer cells are confined to the ducts in your breast and haven’t invaded the surrounding breast tissue.
Lobular carcinoma in situ. Lobular carcinoma in situ (LCIS) is cancer that grows in the milk-producing glands of your breast. Like DCIS, the cancer cells haven’t invaded the surrounding tissue.
Invasive ductal carcinoma. Invasive ductal carcinoma (IDC) is the most common type of breast cancer. This type of breast cancer begins in your breast’s milk ducts and then invades nearby tissue in the breast. Once the breast cancer has spread to the tissue outside your milk ducts, it can begin to spread to other nearby organs and tissue.
Invasive lobular carcinoma. Invasive lobular carcinoma (ILC) first develops in your breast’s lobules and has invaded nearby tissue.
Other, less common types of breast cancer include:
Paget disease of the nipple. This type of breast cancer begins in the ducts of the nipple, but as it grows, it begins to affect the skin and areola of the nipple.
Phyllodes tumor. This very rare type of breast cancer grows in the connective tissue of the breast. Most of these tumors are benign, but some are cancerous. Angiosarcoma. This is cancer that grows on the blood vessels or lymph vessels in the breast.
What are the statistics on male breast cancer?
Breast cancer is rare in men (approximately 2,400 new cases diagnosed per year in the U.S.) but typically has a significantly worse outcome. This is partially related to the often late diagnosis of male breast cancer when cancer has already spread.
Symptoms are similar to the symptoms in women, with the most common symptom being a lump or change in the skin of the breast tissue or nipple discharge. Although it can occur at any age, male breast cancer usually occurs in men over 60 years of age.
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 women 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 women elect to have a contralateral prophylactic mastectomy. This surgery removes your healthy breast to reduce your risk of 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. Your doctor will tell you more about any specific treatment they recommend for you. Learn more about breast cancer treatments, as well as how hormones affect cancer growth.