Breast cancer is a form of cancer that originates in the breast tissue and is characterized by the uncontrolled growth of abnormal cells. These cells can form tumors, invade nearby tissues, and potentially spread (metastasize) to other parts of the body. Breast cancer affects both women and men, though women are far more commonly diagnosed. In the United States, over 260,000 women and around 2,400 men are diagnosed annually.

Types of Breast Cancer

Breast cancer is classified based on the origin of the tumor and its behavior. The most common types include:

  • Ductal Carcinoma in Situ (DCIS): A non-invasive cancer that begins in the milk ducts and has not spread. DCIS has a high survival rate if treated early.
  • Invasive Ductal Carcinoma (IDC): The most common type, IDC originates in the ducts and invades nearby breast tissue. It can spread to other parts of the body.
  • Invasive Lobular Carcinoma (ILC): Starts in the lobules (milk-producing glands) and spreads to surrounding tissues.
  • Inflammatory Breast Cancer (IBC): A rare but aggressive cancer that causes the breast to appear red, swollen, and inflamed.
  • Male Breast Cancer: Though rare, men can develop breast cancer. Most male cases are ductal carcinomas.

Cancers are also classified based on hormone receptor status and genetic markers like HER2, which influence treatment decisions.

Common Symptoms

Breast cancer can present with various symptoms, though many people—especially in early stages—may notice no signs at all. Routine screening is essential for early detection.

Symptoms include:

  • A new lump in the breast or underarm
  • Swelling or thickening in part of the breast
  • Skin changes, such as dimpling, redness, or scaling
  • Nipple discharge (especially if bloody)
  • Nipple inversion or soreness
  • Pain in the breast or nipple area
  • Swollen lymph nodes near the armpit or collarbone

Becoming familiar with how your breasts normally look and feel can help you detect any changes early.

What Causes Breast Cancer?

Breast cancer develops when breast cells undergo genetic mutations and start growing uncontrollably. The exact cause is often unknown, but it is typically the result of a combination of genetic, hormonal, environmental, and lifestyle factors.

Risk Factors

General Risk Factors:

  • Age 50 or older
  • Obesity or being overweight
  • Personal or family history of breast or ovarian cancer
  • Inherited gene mutations (e.g., BRCA1, BRCA2)
  • Previous radiation therapy to the chest
  • Dense breast tissue
  • Smoking and alcohol use
  • Physical inactivity

Female-Specific Risk Factors:

  • Early menstruation (before age 12)
  • Late menopause (after age 55)
  • Having no children or having a first child after age 35
  • Not breastfeeding
  • Long-term use of hormone replacement therapy
  • Use of birth control pills (minor, reversible risk)

Male-Specific Risk Factors:

  • Klinefelter syndrome (extra X chromosome)
  • Liver disease
  • Estrogen-related medications or hormonal imbalance

Having one or more risk factors doesn’t mean you will develop breast cancer, but awareness and regular screening are vital.

 

How Breast Cancer Is Diagnosed

Early detection significantly improves outcomes. Diagnostic methods include:

  • Clinical Breast Exam: Performed by a healthcare provider to check for lumps or abnormalities.
  • Mammography: A specialized X-ray to detect breast tumors.
  • Ultrasound: Often used to determine if a lump is solid or fluid-filled.
  • MRI: Used for more detailed imaging, especially in high-risk patients.
  • Biopsy: The only definitive way to diagnose breast cancer. A sample of breast tissue is taken for laboratory analysis.

Further tests such as hormone receptor testing and HER2 testing help determine the cancer subtype and guide treatment.

Staging and Classification

Cancer staging determines the extent of disease:

  • Stage 0: Non-invasive (e.g., DCIS)
  • Stage I: Small tumor, localized
  • Stage II: Larger tumor or spread to nearby lymph nodes
  • Stage III: Further spread to lymph nodes and tissues near the breast
  • Stage IV: Metastatic; spread to distant organs

Tumor grade (how abnormal the cancer cells appear) and molecular subtypes (like HER2 status or hormone receptor presence) also affect treatment.

Treatment Options

Treatment depends on cancer type, stage, location, and individual health factors. Options include:

  • Surgery:
    • Lumpectomy: Removes only the tumor and some surrounding tissue.
    • Mastectomy: Removes one or both breasts, often used for larger or multiple tumors.
  • Radiation Therapy: Targets remaining cancer cells after surgery, or used in advanced stages.
  • Chemotherapy: Drugs administered orally or intravenously to kill cancer cells, especially for aggressive or late-stage cancer.
  • Hormone Therapy: Used when cancer is hormone receptor-positive; includes drugs that block estrogen/progesterone.
  • Targeted Therapy: Medications like trastuzumab for HER2-positive cancers.
  • Immunotherapy: Encourages the body’s immune system to attack cancer cells.

Some patients may also participate in clinical trials to access new therapies.

Prevention Strategies

There is no guaranteed way to prevent breast cancer, but you can reduce your risk by:

  • Maintaining a healthy weight
  • Exercising regularly (at least 150 minutes per week)
  • Limiting alcohol intake
  • Avoiding smoking
  • Breastfeeding, if possible
  • Limiting hormone replacement therapy after menopause
  • Getting regular screenings

Genetic and Preventive Testing

Genetic Testing: If you have a strong family history of breast or ovarian cancer, your provider may recommend genetic testing for mutations in BRCA1, BRCA2, or other genes.

Preventive Measures for High-Risk Individuals:

  • Prophylactic mastectomy (preventive breast removal)
  • Oophorectomy (removal of ovaries)
  • Use of medications like tamoxifen or raloxifene to reduce cancer risk

Breast Cancer Screening Guidelines

The U.S. Preventive Services Task Force recommends:

  • Starting mammograms every 2 years at age 40 for women at average risk
  • Annual screening or earlier if at high risk
  • Breast self-awareness to recognize changes

Screening recommendations may differ based on personal history and risk factors.

Living With Breast Cancer

A breast cancer diagnosis can impact physical health, emotional well-being, and lifestyle. Emotional support, counseling, and community resources can help individuals cope. Survivorship care plans may include:

  • Follow-up exams and imaging
  • Monitoring for recurrence
  • Managing side effects
  • Maintaining a healthy lifestyle

It’s important to stay engaged with healthcare providers for ongoing care and emotional support.