Breast Cancer: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Breast Cancer?
An oncologist, a doctor who treats cancer, leads care for breast cancer. A breast surgeon also treats it, and a primary care doctor often starts the workup. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is breast cancer?
Breast cancer is a cancer that starts in breast tissue. It happens when cells in the breast change and grow out of control. The extra cells can form a mass called a tumor. When the cancer stays in place, it is called in situ. When it spreads outside the breast, it is called invasive. Breast cancer is the second most common cancer in women in the United States. Rarely, it can also affect men.
Symptoms
Signs and symptoms include:
- A new lump or thickening in or near the breast or in the armpit.
- A change in the size or shape of the breast.
- A dimple or puckering in the skin. It may look like the skin of an orange.
- A nipple turned inward into the breast.
- Nipple discharge other than breast milk. It might happen suddenly, be bloody, or happen in only one breast.
- Scaly, red, or swollen skin in the nipple area or the breast.
- Pain in any area of the breast.
Causes and who gets it
Breast cancer happens when there are changes in genes. Often the exact cause is unknown. Some changes are inherited, meaning you are born with them. About 1 in 10 breast cancers are linked to inherited gene changes. Changes in the BRCA1 and BRCA2 genes are the most common inherited cause. About 1 in 2 women with these changes will develop breast cancer, compared with 1 in 8 women without them. Other genes such as PALB2, ATM, PTEN, and TP53 also raise risk.
Other risk factors include older age, dense breast tissue, more lifetime exposure to the hormone estrogen (starting periods early, starting menopause later, or taking hormone therapy for menopause), radiation therapy to the breast or chest, obesity, and drinking alcohol.
How doctors diagnose it
Your provider may use a physical exam of the breasts and armpits, a medical history, and imaging tests such as a mammogram, an ultrasound, or an MRI. A mammogram is an x-ray of the breast. A breast biopsy removes a small piece of tissue to check for cancer. If cancer is found, the cells are tested for hormone receptors and for a protein called HER2, which help decide the best treatment. Staging tests show whether the cancer has spread, and may include a sentinel lymph node biopsy, which checks whether the cancer has spread to the lymph nodes.
Treatment
Treatment options include:
- Surgery. A lumpectomy removes the cancer and some normal tissue around it but not the whole breast. A mastectomy removes the whole breast. These are two types of surgery.
- Radiation therapy.
- Chemotherapy.
- Hormone therapy, which blocks cancer cells from getting the hormones they need to grow. It helps lower the risk of the cancer coming back in certain types.
- Targeted therapy, which attacks specific cancer cells with less harm to normal cells.
- Immunotherapy.
Screening can find breast cancer early, when it is easier to treat. The U.S. Preventive Services Task Force recommends that women who are 40 to 74 years old and at average risk get a mammogram every 2 years. You may lower your risk by staying at a healthy weight, getting enough exercise, limiting alcohol, breastfeeding your babies if you can, and limiting hormone therapy. If you are at high risk, your provider may suggest medicines such as tamoxifen or raloxifene to lower the risk. Some women at very high risk choose preventive surgery to remove their healthy breasts or ovaries.
When to see a doctor
Tell your doctor about any changes you notice, such as a new lump, a change in the size or shape of the breast, skin changes, or nipple discharge. A breast that becomes warm, red, and swollen can be a sign of inflammatory breast cancer, a rare type in which cancer cells block lymph vessels in the skin of the breast.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. This kind of doctor can talk with you about which breast cancer screening tests are right for you and when you should have them. They can also examine any new lump you find and tell your doctor about any changes.
Common questions
Can breast cancer be prevented?
There is no sure way to prevent breast cancer. But staying at a healthy weight, exercising, limiting alcohol, and breastfeeding may lower your risk. Regular mammograms can find it early.
Who should get mammograms?
The U.S. Preventive Services Task Force recommends mammograms every 2 years for women 40 to 74 years old who are at average risk. Different plans may be used for women at higher risk.
Should I be tested for BRCA genes?
Genetic testing may be worth discussing if you have a strong family history of breast or ovarian cancer. Your doctor can help you decide.
Does breast cancer affect men?
Yes, but it is rare. Breast cancer is the second most common cancer in women, and men can get it too.
Sources
- MedlinePlus - Breast Cancer
- American Cancer Society - Breast Cancer Risk and Prevention
- Centers for Disease Control and Prevention - Screening for Breast Cancer
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
