Cancer begins when healthy cells in the breast change and grow out of control, forming a mass or sheet of cells called a tumor. A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can grow and spread to other parts of the body. A benign tumor means the tumor can grow but will not spread.
Breast cancer spreads when the cancer grows into adjacent organs or other parts of the body or when breast cancer cells move to other parts of the body through the blood vessels and/or lymph vessels. This is called a metastasis
Although breast cancer most commonly spreads to nearby lymph nodes, it can also spread further through the body to areas such as the bones, lungs, liver, and brain. This is called metastatic or stage IV breast cancer and is the most advanced type of breast cancer.
A risk factor is anything that increases a person’s chance of developing cancer. Although risk factors often influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do.
Most breast cancers are sporadic, meaning they develop from damage to a person’s genes that occurs by chance after they are born. There is no risk of the person passing this gene on to their children, as the underlying cause of sporadic breast cancer is environmental factors.
Inherited breast cancers are less common, making up 5% to 10% of cancers. Inherited breast cancer occurs when gene changes called mutations are passed down within a family from parent to child. These genes normally keep cells from growing out of control and turning into cancer. But when these cells have a mutation, it can cause them to grow out of control.
Multiple risk factors influence the development of breast cancer. This means that all women need to be aware of changes in their breasts.
The Following Factors May Raise a Woman’s Risk of Developing Breast Cancer:
The risk of developing breast cancer increases as a woman ages, with most cancers developing in women older than 50.
2. Personal history of breast cancer:
A woman who has had breast cancer in 1 breast has a higher risk of developing a new cancer in either breast.
Family history of breast cancer
Personal history of ovarian cancer
Early menstruation and late menopause
3. Timing of pregnancy:
Women who had their first pregnancy after age 35 or who have never had a full-term pregnancy have a higher risk of breast cancer.
4. Hormone replacement therapy after menopause:
Using hormone therapy with both estrogen and progestin after menopause, often called postmenopausal hormone therapy or hormone replacement therapy, within the past 5 years or for several years increases a woman’s risk of breast cancer.
5. Lifestyle factors:
As with other types of cancer, studies continue to show that various lifestyle factors may contribute to the development of breast cancer.
- Weight: Recent studies have shown that postmenopausal women who are overweight or obese have an increased risk of breast cancer. These women also have a higher risk of having the cancer come back after treatment.
- Physical activity: Lower amounts of physical activity is associated with an increased risk of developing breast cancer and a higher risk of having the cancer come back after treatment.
- Alcohol: Current research suggests that having more than 1 to 2 servings of alcohol, including beer, wine, and spirits, per day raises the risk of breast cancer, as well as the risk of having the cancer come back after treatment.
6. Radiation exposure at a young age:
Exposure to ionizing radiation at a young age may increase a woman’s risk of breast cancer. For example, therapeutic radiation to the chest for Hodgkin lymphoma may increase breast cancer risk in both breasts.
The very small amount of radiation a woman receives during a mammogram has not been linked to an increased risk of breast cancer.
Signs and Symptoms
The following signs and symptoms should be discussed with a doctor. Many times, the cause of a symptom may be a different medical condition that is not a cancer.
1. A lump that feels like a hard knot or a thickening in the breast or under the arm. It is important to feel the same area in the other breast to make sure the change is not a part of healthy breast tissue in that area.
2. Change in the size or shape of the breast
3. Nipple discharge that occurs suddenly, is bloody, or occurs in only 1 breast
4. Physical changes, such as a nipple turned inward or a sore located in the nipple area
5. Skin irritation or changes, such as puckering, dimpling, scaliness, or new creases
6. A warm, red, swollen breast with or without a rash with dimpling resembling the skin of an orange, called “peau d’orange”
7. Pain in the breast, particularly breast pain that does not go away. Pain is not usually a symptom of breast cancer, but it should be reported to a doctor.
Surgery is the removal of the tumor and some surrounding healthy tissue during an operation. Surgery is also used to examine the nearby axillary lymph nodes, which are under the arm. A surgical oncologist is a doctor who specializes in treating cancer with surgery.
Generally, the smaller the tumor, the more surgical options a patient has. The types of surgery for breast cancer include the following:
Removal of cancer in the breast:
Lumpectomy or partial mastectomy, generally followed by radiation therapy if the cancer is invasive. Mastectomy may also be recommended, with or without immediate reconstruction
This is the removal of the tumor and a small, cancer-free margin of healthy tissue around the tumor. Most of the breast remains.
This is the surgical removal of the entire breast.
- Lymph node evaluation:
Sentinel lymph node biopsy and/or axillary lymph node dissection.
Radiation therapy is the use of high-energy x-rays or other particles to destroy cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. There are several different types of radiation therapy:
- External-beam radiation therapy:
This is the most common type of radiation treatment and is given from a machine outside the body. This includes whole breast radiation therapy and partial breast radiation therapy, as well as accelerated breast radiation therapy, which can be several days instead of several weeks.
- Intra-operative radiation therapy:
This is when radiation treatment is given using a probe in the operating room.
This type of radiation therapy is given by placing radioactive sources into the tumor.
Therapies using medication:
The types of systemic therapies used for breast cancer include:
- Hormonal therapy
- Targeted therapy
A person may receive 1 type of systemic therapy at a time or a combination of systemic therapies given at the same time. They can also be given as part of a treatment plan that includes surgery and/or radiation therapy.