h1>What is Breast Cancer?
Breast cancer develops in the tissues of the breast, most often in the milk ducts or lobules. It can affect both women and men, though it is far more common in women. After skin cancer, breast cancer is the most frequently diagnosed cancer in U.S. women.
Types
- Invasive ductal carcinoma: Originates in a milk duct and invades surrounding tissue; the most common form.
- Ductal carcinoma in situ (DCIS): A non-invasive cancer confined to the ducts.
- Lobular carcinoma in situ (LCIS): Begins in the lobules and may increase future cancer risk.
- Triple-negative breast cancer: Lacks estrogen, progesterone, and HER2 receptors; tends to be more aggressive.
- Inflammatory breast cancer: A rare form that causes redness and swelling rather than a lump.
- Metastatic breast cancer: Cancer that has spread beyond the breast to other organs.
- Paget’s disease of the breast: Involves the nipple and areola, often with underlying ductal cancer.
Risk Factors
- Genetics: BRCA1 or BRCA2 mutations greatly increase risk.
- Hormonal factors: Early menstruation, late menopause, hormone therapy, and not having children.
- Lifestyle factors: Obesity, alcohol use, lack of exercise, and certain diets.
- Environmental exposures: Radiation and pollutants.
- Age: Risk rises after age 50.
- Breast density: Dense tissue both raises risk and makes detection harder.
- Family or personal history of breast or related cancers.
Symptoms
- A breast or underarm lump that feels different from surrounding tissue.
- Changes in breast size, shape, or appearance.
- Skin dimpling, redness, or thickening.
- Nipple inversion or discharge (especially bloody or clear).
- Persistent breast pain or discomfort.
Diagnosis
- Physical exam and clinical breast exam.
- Mammography for routine screening or evaluating lumps.
- Breast ultrasound to distinguish solid masses from cysts.
- Magnetic resonance imaging (MRI) in dense breasts or high-risk patients.
- Biopsy (fine-needle, core needle, or surgical) to confirm cancer.
- Hormone receptor and HER2 testing on biopsy samples.
- Staging with imaging (CT, bone scan, PET) if spread is suspected.
Treatment
Surgery
- Lumpectomy: Tumor removal with a margin of healthy tissue.
- Mastectomy: Removal of part or all of the breast.
- Sentinel lymph node biopsy and axillary dissection to assess spread.
Radiation Therapy
Targets remaining cancer cells in the breast area after surgery.
Chemotherapy
Systemic drugs to kill or slow cancer cell growth, given before or after surgery.
Hormone Therapy
For hormone receptor–positive cancers, uses drugs like tamoxifen or aromatase inhibitors to block estrogen’s effect.
Targeted Therapy
Drugs such as trastuzumab for HER2-positive cancers or PARP inhibitors for certain genetic profiles.
Immunotherapy
Helps the immune system recognize and attack cancer cells in select cases.
Prognosis
Early detection through screening and improved treatments have increased survival rates. Nearly 4 million U.S. women are breast cancer survivors.
Sources
- American Cancer Society. Cancer Facts & Figures 2023.
- National Cancer Institute. PDQ® Breast Cancer Prevention.
- National Comprehensive Cancer Network. Breast Cancer Guidelines.
- National Breast Cancer Foundation.