Basics & Overview
Breast cancer is a type of cancer that starts in the tissue of the breasts. Over a lifetime, one out of every eight women will develop breast cancer. Breast cancer can occur in both women and men, but it is considerably more common in women. If detected early, breast cancer is very treatable and increased public awareness has increased research and diagnosis of this condition.
Types of Breast Cancer
Breast cancer can start in any part of the breast. Breast cancer can be invasive – which means that the cancer has spread to a different part of the breast than where it started – and non-invasive or “in situ” cancer that is located only in the breast tissue of origin. There are several different types of breast cancer, but the two most common types are ductal and lobular cancer.
- Ductal cancer: This type starts in the ducts of the breast tissue and can be either invasive or in situ. Most breast cancers are ductal cancers. Early ductal cancer in situ has a high treatment success rate.
- Lobular cancer: The type starts in the milk-producing tissues (lobules) of the breasts and can also be invasive or in situ as well. The invasive form of this cancer may be difficult to diagnosis by mammogram.
There are other less common forms like inflammatory breast cancer (1 to 3 percent of all breast cancers), triple-negative breast cancer, Paget disease of the nipple, Phyllodes tumor and angiosarcoma.
Some breast cancers are sensitive to estrogen which means that exposure to estrogen causes the tumor to grow; these are called estrogen-receptor positive or ER-positive cancers. Other cancers may be HER2-positive. HER2 is a gene and if a cancer has too many copies of this gene, it may grow faster. HER2-positive breast cancer can be more aggressive and often has a higher chance of recurrence. Treatments targeted to this gene have improved outcomes of these cancers.
With routine screening, breast cancers can often be found at an early stage.
Early breast cancer does not have symptoms most of the time, but you may notice some of the following changes:
- A lump in the breast or an area of thickening
- Bloody or other types of discharge from the nipple
- Changes to skin of the breast, like dimpling
- Change in the size or shape of the breast
- Inversion of the nipple
- Redness of the breast skin
- Flaking or scaling of breast skin
Advanced breast cancer may have more significant symptoms.
- Bone pain
- Breast pain or discomfort
- Swelling of the armpit
- Skin ulcers
- Weight loss
Risks & Causes
There are risk factors that have been associated with breast cancer. Some are things that you can change while others are things that you have no control over.
Uncontrollable risk factors include:
- Family history of breast cancer: You have a higher risk of developing breast cancer if you have a close family (mother, daughter, or sister) who has had it. However, most women who develop breast cancer did not have any relatives who had the disease.
- Age and Gender: Your odds of developing breast cancer increase as you get older. While men can develop breast cancer, women have a significantly higher risk.
- Genetics: Certain genetic mutations increase the risk of developing breast cancer. The most common defects are found in the BRCA1 and BRCA2 genes. If you inherit one of these defects from your parents, your odds of developing breast cancer increases a lot; however, it does not make it inevitable.
- Menstrual cycle: If you started your menstrual cycle before the age of 12 or went through menopause after age 55, you have an increased risk of breast cancer.
Controllable risk factors include:
- Obesity: Obesity increases your odds of developing breast cancer because fat tissue produces estrogen which can promote the growth of some cancers
- Alcohol use: Drinking more than two glasses of alcohol a day may increase your risk.
Other risk factors include:
- Childbirth: Women who have not had children or had them after age 30 have an increased risk of breast cancer. Having children at an earlier age or being pregnant more than once lowers your risk.
- DES: Women who took the medication diethylstilbestrol or DES to prevent miscarriage in the 1940s to 1960s also have an increased risk of breast cancer after age 40.
- Radiation exposure: If you received radiation to the chest area as a child or young adult, your risk of developing breast cancer increases later in life.
- Hormone replacement therapy: Taking hormone replacement therapy containing estrogen and progesterone after menopause increases your risk of breast cancer.
Factors that have not been found to be associated with breast cancer include breast implants, use of antiperspirants, or tight bras or under-wire.
Just because you have one or more of these risk factors, it does not mean that you are going to develop breast cancer. Some women have no risk factors except being a woman.
Diagnosis & Tests
There are several procedures and tests that can help your doctor determine if you have breast cancer.
Screening looks for signs of breast cancer before there are any symptoms. Tests that can help with this are:
- Mammogram: This is a low dose x-ray of the breast to look for any abnormal areas. Women over age 40 are recommended to have mammograms every 1-2 years.
- Clinical breast exam: The doctor may perform a breast examination (clinical breast exam or CBE) which includes checking both breasts, both armpits, and the neck and chest area.
Self-examinations may also be helpful in finding lumps or changes in your breasts as well.
If a screening test or self-examination finds a suspicious area, your doctor will order further tests to make the diagnosis. Your doctor will take a thorough history from you and ask you information about risk factors too. Some of the tests that may help make the diagnosis include:
- Diagnostic mammogram
- Ultrasound examination
- Magnetic resonance imaging (MRI)
- Breast biopsy: This could include needle aspiration, ultrasound-guided procedures, stereotactic biopsies using mammograms, or open biopsy.
Once the diagnosis has been made, your doctor will order more tests to determine the extent or stage of your breast cancer. Breast cancer is staged from 0 to IV with 0 being very small and IV (metastatic) having spread to other parts of the body. These tests may include:
- Blood tests
- Mammogram of other breast
- Chest x-ray
- Breast MRI
- Bone scan
- CT scan
- PET scan
- Lymph node biopsy
Every patient may not need each one of these tests to figure out the disease stage.
Treatment & Management
Treatment is determined depending on your type of cancer (hormone-sensitive or not), stage of disease, your overall health, and your preferences. Treatments are also local (surgery or radiation) or systemic (chemotherapy, hormone or biologic therapy).
For most patients, there will be some type of surgery involved in the treatment of breast cancer. These operations include:
- Lumpectomy: Removing the tumor itself with a small rim of healthy tissue.
- Mastectomy: Removing all of the breast tissue and sometimes the muscle and overlying skin.
- Sentinel node biopsy: Checking one lymph node in the armpit to see if the cancer has spread. If this node is negative, it is unlikely that the cancer is in other lymph nodes.
- Axillary node dissection: Sometimes the doctor will remove more lymph nodes in the armpit if the sentinel node is positive for cancer.
Many women select breast reconstruction after the original surgery. You need to discuss this option with your surgeon upfront and may need to have an evaluation by a plastic surgeon first as well.
You may also need radiation therapy as a part of your treatment. This therapy uses high-powered energy beams like x-rays to destroy cancerous cells. This is often done after surgery. Side effects include a sunburn-like rash and fatigue.
In this therapy, your doctor will use drugs to kill cancer cells. The drugs may be given before surgery or after surgery depending on your situation. If the cancer has spread to other parts of the body, chemotherapy can be used.
There are many different types of drugs that can be used to treat breast cancer. The most common side effects of chemotherapy include nausea, hair loss, fatigue, hot flashes, and early menopause.
Hormone therapy is used to treat breast cancers that are sensitive to hormones like estrogen-receptor or progesterone-receptor positive tumors. Examples of these medications are:
- Selective estrogen receptor modulator (SERM): These medications block estrogen from attaching to the cancer cells. Tamoxifen is the most commonly used SERM and side effects include hot flashes, night sweats and vaginal dryness.
- Aromatase inhibitors: These medications block the conversation of androgens to estrogen and only work in postmenopausal women. Examples are exemestane (Aromasin), anastrozole (Arimidex), and letrozole (Femara). Side effects include joint and muscle pain and osteoporosis.
These therapies target specific characteristics like HER2 in the cancer cells. Those approved to treat breast cancer include:
- Lapatinib (Tykerb)
- Trastuzumab (Herceptin)
- Bevacizumab (Avastin)
You can also ask your doctor about available clinical trials that you may be able to sign up for.
There are no alternative treatments for breast cancer and some of these may cause bad interactions with your other treatments. However, some alternative therapies like yoga, tai chi, or muscle relaxation may help you cope with the side effects from other conventional therapies prescribed by your doctor. You should discuss any alternative therapies with your physician.
If you are at average risk for developing breast cancer, making some lifestyle changes may lower your risk of developing the disease.
- Reduce your alcohol intake
- Increase your exercise
- Reduce your use of HRT. You should discuss risks and benefits with your physician.
- Watch your weight
For women at higher risk of developing breast cancer, you can work with your doctor to create a plan to reduce your risk.
- Preventative medications: For some women, taking estrogen-blocking medications may help reduce the risk of breast cancer. Tamoxifen and raloxifene (Evista) are options and may have side effects like increased risk of blood clots. Tamoxifen also can increase the risk of uterine cancer. Your doctor will look at your situation and determine what may be helpful for you.
- Preventative surgery: Some women decide to have their breasts removed (prophylactic mastectomies) or even have their ovaries removed (prophylactic oophorectomies) to lower their risk.
Early Detection Is Key
While there are steps that you can take to lower your risk of developing breast cancer, the most important thing is to catch any disease early. Regular screening, mammograms and self-examinations can help you find breast cancer at its earliest stages when it is the most treatable. If you do develop breast cancer, you have multiple treatment options and it is also important to get support to deal with the diagnosis and treatment.