October is Breast Cancer Awareness Month. Breast cancer is the second leading cause of death in women. According to the American Cancer Society, 1 in 38 women will die from breast cancer. They also estimate that 42,170 women in the United States will die this year from breast cancer. But there is hope because there are more than 3.5 million survivors in the United States.
What is breast cancer?
Breast cancer is a type of cancer that starts in the breast. Cancer starts when cells begin to grow out of control. The type of breast cancer it will become depends on the type of cells affected.
Breast cancer usually forms a tumor that can be seen on an x-ray or felt as a lump. Not all forms of breast cancer form a lump. Breast cancer occurs almost entirely in women, but it can affect men.
Lumps can occur in breasts that are non-cancerous (benign). They are abnormal growths within the breast. They are not life-threatening, but some types of benign lumps can increase the risk of getting breast cancer. If you feel a lump in your breast, it is best to see your doctor.
Breast cancer can start in different parts of the breast. A breast is made up of 3 main parts: lobules, ducts, and connective tissue. Lobules are the glands that produce milk. Ducts are the tubes that carry the milk to the nipple. Connective tissue, which consists of fibrous and fatty tissue, surrounds and holds everything together. Most cancers begin in the ducts or lobules.
The most common types of breast cancer are:
• Invasive ductal carcinoma – Cancer cells grow outside of the ducts into other parts of breast tissue.
• Invasive lobular carcinoma – Cancer cells spread from the lobules to nearby tissue.
Both of the common types can metastasize meaning that they can spread via blood or lymphatic vessels to other parts of the body. There are several less common types like Paget’s disease, medullary, mucinous, and inflammatory breast cancer.
Knowing how your breasts look and feel normally is important so that you can detect any changes. Be sure to have regular mammograms and to perform home exams to look for any changes.
The most common symptom is a new lump or mass. A painless, hard mass with irregular edges is more likely to be cancer, but breast cancers can also be soft, tender, and round. Some may even be painful. You should see a health care professional immediately if you have any new lump, mass, or change. Other symptoms include:
• Swelling of all or part of the breast
• Skin dimpling
• Breast or nipple pain
• Nipple retraction (turning inward)
• Nipple or breast skin that is red, dry, flaking, or thickened
• Nipple discharge (other than breast milk)
• Swollen lymph nodes (sometimes breast cancer can spread to lymph nodes under the arm or collarbone before a lump is big enough to be felt in the breasts).
What are the stages of breast cancer?
Once a person is diagnosed with cancer, tests are performed to determine
if cancer cells have spread to other parts of the body. This is known as staging and is used to plan appropriate treatment. Stage is based primarily on the size and location of the primary tumor, the spread of cancer to nearby lymph nodes or other parts of the body, tumor grade, and whether certain biomarkers are present. Stages range from 0-4 with 4 being the most severe. The system used for staging is called the TNM system. TNM stands for:
• T – Tumor
• N – Lymph Node status (the number and location of lymph nodes with
• M – Metastases (whether or not the cancer has spread to other areas
of the body)
What are breast cancer hormone receptors?
When a biopsy is taken of breast tissue, cells will be tested for certain proteins that are estrogen and progesterone receptors. When estrogen and progesterone attach to these receptors, they fuel the cancer’s growth. Cancers are hormone-receptor positive or negative based on the presence or absence of these receptors.
Normal breast cells and some breast cancer cells have receptors that attach to hormones, estrogen and progesterone, and use these hormones to grow. Breast cancer cells may have one, both, or none of these receptors. Receptors include:
• ER-positive – Breast cancers that have estrogen receptors
• PR-positive – Breast cancers that have progesterone receptors
• Hormone-receptor positive – Cancer cell has one or both of the above receptors.
• Hormone-receptor negative – Cancer cells with no receptors.
Knowing the hormone receptor status is important because it helps your doctor decide how to treat the cancer. If a person is hormone-receptor positive, then medications may be prescribed to either lower estrogen levels or stop estrogen from acting on breast cells.
What are the risk factors that I cannot change?
• Being born female – This is the main risk factor for breast cancer. Men can also get breast cancer, but it is much more common in women.
• Getting older – As you age, the risk of breast cancer increases. Most breast cancer occurs in women age 55 and older.
• Genetics – About 5-10% of breast cancer cases are considered hereditary. The most common cause of hereditary breast cancer is an inherited mutation in the BRCA1 and BRCA2 gene. There are other gene mutations that can lead to breast cancer but are much less common.
• Family History – According to the American Cancer Society, most women who develop breast cancer do not have a family history. But women with close blood relatives with breast cancer have a higher risk. A first-degree relative (mother, sister, daughter) with breast cancer almost doubles a person's risk.
• Personal history of breast cancer – A woman with cancer in one breast has a higher risk of developing a new cancer in the other breast or in another part of the same breast.
• Race and ethnicity – Overall, white women are more likely than African-American women to develop breast cancer. However, for women under the age of 45, it is more common in African-American women.
• Height – Studies have found that taller women have a higher risk than shorter women.
• Dense breast tissue – Women with dense breast tissue have a 1.5-2 times higher risk than women with average breast density. Dense breast tissue can also make spotting cancer on a mammogram more difficult.
• Certain benign breast conditions – Women who have been diagnosed with certain benign breast conditions may have a higher risk. Some conditions are more closely linked than others.
Non-proliferative lesions - These don’t seem to affect risk or the affect is very low
• Fibrosis and/or simple cysts
• Mild hyperplasia
• Adenosis (non-sclerosing)
• Phyllodes tumor (benign)
• A single papilloma
• Fat necrosis
• Duct ectasia
• Periductal fibrosis
• Squamous and apocrine metaplasia
• Epithelial-related calcifications
• Other tumors (lipoma, hamartoma, hemangioma, neurofibroma, adenomyoepithelioma)
Proliferative lesions without atypica (cell abnormalities) – These conditions have an excessive growth of cells in the ducts or lobules, but the cells don’t look abnormal. These conditions are associated with a slightly higher risk.
• Usual ductal hyperplasia (without cell abnormalities)
• Sclerosing adenosis
• Several papillomas (papillomatosis)
• Radial scar
Proliferative lesions with atypia (cell abnormalities) – These conditions have an excessive growth of cells in the ducts or lobules, but some of the cells no longer look normal. Women with these changes have a 4-5 times higher risk.
• Atypical ductal hyperplasia (ADH)
• Atypical lobular hyperplasia (ALH)
• Starting menstruation early – Women who began menstruating before age 12 have a slightly higher risk. This increased risk may be due to a longer exposure of estrogen and progesterone.
• Going through menopause after age 55 – Women who have had more menstrual cycles because of going through menopause later (after 55) have a slightly higher risk.
• Having radiation to your chest – Women who were treated with radiation therapy for another cancer when they were younger have a significantly higher risk. Risk is dependent upon the age they received radiation. Risk is highest for teens and young adults who underwent radiation. Radiation treatment in women age 40 and above does not seem to increase risk.
• Exposure to diethylbesterol (DES) – From the 1940s to early 1970s, many pregnant women were given DES, an estrogen-like drug, to reduce their risk of miscarriage. These women have a slightly increased risk as well as their daughters.
What are the lifestyle risk factors of breast cancer?
• Alcohol – Alcohol can raise the risk of developing 6 different types of cancer: Mouth/throat, voice box (larynx), esophagus, colon/rectum, liver, and breast (women). Alcohol breaks down in our bodies to acetaldehyde. Acetaldehyde damages DNA and prevents your body from repairing the damage. DNA is the cell’s
“instruction manual” that controls a cell’s function and growth. When DNA is damaged, it can begin to grow out of control leading to cancer. According to the American Cancer Society, women who have 2 or more drinks a day have a 20% higher risk of developing breast cancer.
• Being overweight or obese – Being overweight or obese after menopause can increase your risk of breast cancer. Before menopause your ovaries make most of your estrogen, and fat tissue makes only a small part of the total amount. After menopause (when the ovaries stop making estrogen), most of a woman’s estrogen comes from fat tissue. Having more fat tissue after menopause can raise estrogen levels and increase your chance of getting breast cancer. However, the link between weight and breast cancer risk is very complex. Weight may also have a different effect on different types of breast cancer. For example, being overweight after menopause is strongly linked with an increased risk of hormone receptor-positive breast cancer.
• Physical inactivity – Evidence is growing that physical activity reduces breast cancer risk especially in post-menopausal women. The exact mechanism for how it
reduces risk is unknown, but it may be linked to the effect on weight, inflammation, hormones, and energy levels.
• Not having children – Women who have not had children or who had their first child after 30 have a slightly higher breast cancer risk.
• Not breastfeeding – Most studies suggest that breastfeeding may slightly lower risk especially if it’s continued for more than a year. This has been difficult to
study in countries like the United States where breastfeeding for that long is uncommon.
• Oral Contraceptives – Most studies have found that women using oral birth control pills have a slightly higher risk than women who never used them. However, once pills are stopped, risk levels return to normal within approximately 10 years.
• Birth Control Shot – Depo-Provera is an injectable progesterone that is given every 3 months. There are conflicting studies are whether this can increase risk.
• Birth control implants, intrauterine devices (IUDs), skin patches, vaginal rings – Some studies have found a link between IUDs and increased risk, but there
are few studies about implants, patches, and rings and breast cancer risk.
• Hormone therapy after menopause – Hormonal therapy has been used for years to help alleviate menopausal symptoms like hot flashes and vaginal dryness. However, certain types of breast cancer are made worse by hormones, so your doctor may recommend alternative treatments for menopause.
• Breast implants – Breast implants have not been linked with a higher risk of breast cancer.
There is no sure way to prevent breast cancer. However, there are steps you can take to reduce your risk. Steps include:
• Get to and maintain a healthy weight
• Be physically active
• Avoid or limit alcohol
If you are at an increased risk due to a genetic mutation or family history, there are some things you can do to help lower your chances or help you to find it early. Steps include:
• Genetic counseling and testing for breast cancer risk
• Close observation to look for early signs of breast cancer
• Medicines to lower breast cancer risk
• Preventive (prophylactic) surgery