What Is It?
Breast cancer occurs when abnormal cells grow uncontrollably in the breast. It can start in ducts or lobules and may spread to lymph nodes or other parts of the body if not treated.
How Common Is It?
Breast cancer is the most common cancer in women in the United States. Average lifetime risk is about 1 in 8 women. Risk increases with age, but breast cancer can occur in younger people and in men.
Causes & Risk Factors
- Age (risk increases over time).
- Family history and inherited gene mutations (e.g., BRCA1/BRCA2).
- Personal history of breast cancer or certain high-risk breast lesions.
- Dense breast tissue (also makes mammograms harder to interpret).
- Radiation exposure to the chest at a young age.
- Hormonal and reproductive factors (effects vary by individual).
- Lifestyle factors (higher body weight after menopause, alcohol use, low physical activity).
Symptoms
- A new lump or thickening in the breast or armpit.
- Change in breast size or shape.
- Skin dimpling or “orange peel” texture.
- Nipple inversion that is new, nipple skin changes, or persistent crusting.
- Spontaneous, one-sided nipple discharge—especially bloody or clear.
- Persistent focal pain (less common as the only symptom).
When Should You See a Doctor?
- Any new breast lump or persistent change.
- Skin or nipple changes, especially if new and one-sided.
- Persistent spontaneous nipple discharge (bloody/clear).
- A lump during pregnancy or breastfeeding that persists for 2 weeks or more.
How Is It Diagnosed?
- Clinical exam and targeted history.
- Imaging: ultrasound, diagnostic mammography (often with tomosynthesis), and MRI for selected indications.
- Biopsy: core needle biopsy confirms diagnosis and determines tumor type and receptor status.
- Staging tests may be used depending on type and stage.
Treatment Options
- Surgery (lumpectomy or mastectomy; lymph node evaluation).
- Radiation therapy (commonly after lumpectomy; sometimes after mastectomy).
- Systemic therapy: endocrine therapy for hormone receptor–positive cancers; chemotherapy; targeted therapy (e.g., HER2-directed); immunotherapy for selected cancers.
- Reconstruction options may be available for those who choose mastectomy.
Can It Affect Fertility or Pregnancy?
- Some treatments (especially certain chemotherapies) can affect fertility; preservation options may be possible before treatment in selected patients.
- Breast cancer can be diagnosed during pregnancy or after delivery; imaging and treatment can often be adapted under specialist care.
Key Takeaways for Patients
- Breast cancer is common, but many cases are treatable—especially when found early.
- Do not ignore new lumps, nipple discharge, or skin/nipple changes.
- Diagnosis requires imaging and usually a biopsy.
- Treatment may include surgery, radiation, and medicines depending on cancer type and stage.