With the exception of skin cancer, breast cancer is the most common cancer in American women, accounting for one in three cancers diagnosed in that demographic.
Breast cancer’s causes are not exactly clear. Studies have identified numerous risk factors for breast cancer in women, including hormonal, lifestyle and environmental factors that may increase the risk of the disease. Other factors include:
- Increasing age
- Personal history of breast cancer
- Early menstruation
- Late menopause
- Use of oral contraceptives
- Family history of breast cancer
- Inherited genetic changes
- History of radiation therapy to the chest
- Long-term use of combined hormone therapy
- Obesity after menopause
It's unclear why some people who have no risk factors develop cancer, while others with risk factors never do.
If you or a loved one is diagnosed with breast cancer, one of the first things you can do is educate yourself about the disease. Open communication between patient and doctor is extremely important. And asking questions of your doctor may help you make more informed decisions about your breast cancer treatment.
If you do not have breast cancer, but have a family history of the disease, you may consider asking your doctor about steps you may be able to take to lower your risk.
Here are the answers to some common questions patients ask about breast cancer, its causes, risk factors and available treatment options:
What is breast cancer?
Breast cancer is a common term for a cancerous (malignant) tumor that starts in the cells that line the ducts and/or lobes of the breast. Breast cancer is not one disease; rather it is several diseases that behave differently.
The most common types of breast cancer are:
Invasive lobular carcinoma: This disease, accounting for one in 10 breast cancers, begins in the lobules, or the glands of the breast that make milk.
Invasive ductal carcinoma: This cancer, accounting for about eight in 10 breast cancers, begins in the breast’s milk ducts, the thin tubes that carry milk from the lobules to the nipple.
Is my cancer invasive or noninvasive?
A tumor is an abnormal growth that may be benign or malignant. Benign breast tumors are not life-threatening and do not spread to other parts of the body. Malignant breast tumors are cancers that impact your health and may spread to other parts of the body. A malignant tumor that grows into surrounding tissue is considered invasive. Invasive tumors are more likely to spread to other parts of the body than non-invasive tumors. Non-invasive breast cancer cells remain in a particular area of the breast without spreading to surrounding tissue, lobules or ducts.
What stage is my cancer, and what does it mean?
Staging is a way to describe the severity or extent of your cancer. Knowing the stage of breast cancer will help your care team recommend a personalized treatment plan specific to your disease. Breast cancer diagnosed as stage 1 or stage 2 is considered early stage, while stages 3 and 4 are considered advanced.
What size is my tumor, and why does that matter?
Treatment options for breast cancer partly depend on how small or large your tumor is, if the cancer has spread to the lymph nodes and if the cancer is found in other parts of your body. The larger the tumor, the more likely it is that the breast cancer is lymph node-positive, meaning the axillary lymph nodes contain cancer. Sentinel node biopsy is the most common way to determine whether cancer cells have spread beyond the breast.
Should I get a second opinion?
A second opinion may confirm your original diagnosis and treatment plan, provide more details about the type and stage of your breast cancer, raise additional treatment options not considered, or lead to a recommendation for a different course of action. A second opinion may also help you feel more confident in your treatment decisions and help you find a doctor you feel comfortable with.
Has the cancer spread to my lymph nodes or other organs?
Cancer may spread from the site where it originated to other parts of the body. When cancer cells move away from a tumor, they may travel through the bloodstream to distant organs. If they travel through the lymph system, the cancer cells may end up in the lymph nodes. The lymph nodes in the underarm are the first place breast cancer is most likely to spread. Your doctor may perform a biopsy to check for the presence of cancer cells. The sample is examined by a pathologist who checks the nodes under a microscope. That exam determines lymph node status.
The spread of cancer to another part of the body is called metastasis. If breast cancer has metastasized to other areas of the body, it is categorized as stage 4 breast cancer. Breast cancer metastasizes primarily to the lungs, liver, brain, regional lymph nodes and bone.
Were HER2 tests performed on my tissue sample?
HER2 (which stands for human epidermal growth factor receptor 2) is a type of growth signal receptor, or antenna that may be present on your breast cancer cells. About 25 percent of breast cancers are HER2-positive, meaning the cancer cells make too much of a protein called HER2/neu, which indicates that the cancer may be more aggressive. If your breast cancer is HER2-positive, this helps doctors better predict whether the cancer may respond to certain targeted therapies.
Should I consider participating in a clinical trial?
Breast cancer treatment has improved tremendously over the years, thanks to advances made possible because of patients who have been willing to participate in studies exploring new treatment options, drug protocols or other approaches before they can be granted federal approval. These clinical trials may offer participants new treatment options that may have otherwise been unavailable to them, especially after exhausting conventional treatments. If you qualify for such a trial, ask your doctor about concerns or questions you may have about participating, so that you may determine if it’s a good fit for you.
I don’t have breast cancer, but am concerned about my risk. When should I begin screening?
The American Cancer Society (ACS) recommends the following early-detection screenings for women at average risk for breast cancer:
- Optional mammograms beginning at age 40
- Annual mammograms for women ages 45 to 54
- Mammograms every two years for women 55 and older, unless they choose to stick with yearly screenings
- MRIs and mammograms for some women at high risk of breast cancer
The ACS also recommends that women know the benefits and potential harms associated with breast cancer screening, as well as how their breasts normally look and feel and report any changes to their doctor right away.
What type of doctor should I see if I think I have breast cancer?
If you think you have breast cancer, you should talk to your primary care physician or OB/GYN. A number of doctors may play a role in your breast cancer treatment. The following is a list of doctors who may be involved in your care:
Medical oncologist: A physician who has special training in diagnosing and treating cancer using chemotherapy, hormonal therapy and targeted therapy
Radiation oncologist: A physician trained in cancer treatment using radiation to shrink tumors and destroy cancer cells
Surgical oncologist: A doctor who uses surgery to diagnose, stage and treat cancer and manage certain cancer-related symptoms, and who may perform biopsies and other surgical procedures such as removing a lump or a breast
Breast surgeon: A surgeon who is specially trained to perform surgery on the breast.
Reconstructive surgeon: A surgeon who uses surgery to restore the function or appearance of an affected part of the body.
Should I consider genetic testing?
Genetic testing may help determine if your cancer resulted from an inherited gene mutation. Genetic counseling may help you understand the risks, benefits and limitations of genetic testing in certain situations. A genetic counselor, doctor or other health care professional trained in genetics may help you and your family understand your test results and other findings, such as a genetic risk factor for another disease like diabetes or heart conditions.
Concerned about your cancer risk? Try our Risk Management Tool.