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Breast cancer is a condition where cells in the breast grow uncontrollably, forming a mass called a tumor. It usually starts in the breast’s milk ducts—the thin tubes that carry milk to the nipple—or in the lobules, which are the glands that produce milk. When cancer cells stay within these ducts or lobules without spreading, it is called "in situ." If the cancer spreads beyond these areas into nearby breast tissue, it is called invasive breast cancer. Breast cancer can also spread to lymph nodes or other parts of the body through the blood or lymph system.
Breast cancer is one of the most common cancers, especially among women. Early detection through screening tests like mammograms can find breast cancer before symptoms appear, often leading to better treatment outcomes. Although breast cancer mainly affects women, men can also develop it, though this is rare. Understanding breast cancer helps patients and caregivers recognize warning signs and seek care promptly.
Symptoms that might lead someone to see a doctor include a new lump or thickening in the breast or underarm, changes in breast size or shape, dimpling or puckering of the skin, nipple changes such as inversion or unusual discharge, and redness or swelling. These signs do not always mean cancer but should be checked by a healthcare provider. Diagnosis usually involves a physical exam, imaging tests like mammograms or ultrasounds, and a biopsy where a small tissue sample is taken for testing. Additional tests may look for features of the cancer cells, such as hormone receptor status or genetic changes, to guide treatment.
Patients may hear terms like ductal carcinoma or lobular carcinoma, which describe where the cancer started. They may also hear about whether the cancer is invasive or non-invasive. Doctors use this information to decide on treatment options, which can include surgery, radiation, chemotherapy, hormone therapy, or targeted therapy. For men diagnosed with breast cancer, treatment often involves surgery to remove the breast tissue, sometimes followed by other therapies.
Hearing the term "breast cancer" does not always mean the cancer has spread or is life-threatening. Many types of breast cancer grow slowly and can be treated successfully. Also, not all breast lumps are cancerous; many are benign. It is important to understand the specific type and stage of breast cancer to know what it means for each person’s care.
Patients might ask: What type of breast cancer do I have? Is it invasive or non-invasive? What tests will I need? What are my treatment options? What symptoms should I watch for? How will this affect my daily life? Open communication helps patients make informed decisions and feel more confident about their care.
Breast cancer may be mentioned in pathology reports, treatment plans, visit notes, or educational materials. Understanding the type, stage, and test results helps patients and caregivers interpret what the diagnosis means. It is important to discuss any questions with your healthcare provider to get personalized information.
This information is educational and cannot replace advice from your healthcare provider. If you or a loved one has been told about breast cancer, the next step is to talk openly with your healthcare team. They can explain what the diagnosis means for you, discuss treatment choices, and provide support resources. Early and clear communication helps you make informed decisions and feel more confident about your care.
Public source information used for this glossary entry includes: