Breast cancer is a type of cancer that begins in the cells of the breast. It is the most common cancer among women worldwide, although it can also occur in men. Breast cancer can develop in different parts of the breast, including the ducts that carry milk to the nipple (ductal carcinoma), the glands that produce milk (lobular carcinoma), or other cells within the breast tissue. Early detection and advances in treatment have significantly improved outcomes for individuals diagnosed with breast cancer.

Types of Breast Cancer

• Ductal Carcinoma In Situ (DCIS): Early-stage breast cancer where abnormal cells are found in the lining of a breast duct but have not spread outside the duct.
• Invasive Ductal Carcinoma (IDC): The most common type of breast cancer, where cancer cells have spread beyond the ducts into surrounding breast tissue.
• Lobular Carcinoma In Situ (LCIS): Abnormal cells are found in the lobules of the breast but are not invasive.
• Invasive Lobular Carcinoma (ILC): Cancer cells have spread from the lobules into nearby breast tissue.
• Triple-Negative Breast Cancer: A subtype that lacks estrogen, progesterone, and HER2 receptors, making it more challenging to treat.
• HER2-Positive Breast Cancer: Characterized by overexpression of the HER2 protein, which promotes cancer cell growth.
• Hormone Receptor-Positive Breast Cancer: Relies on hormones like estrogen or progesterone to grow.

Causes and Risk Factors
Several factors may increase the risk of developing breast cancer, including:

• Gender: Women are much more likely to develop breast cancer than men.
• Age: The risk increases with age, with most cases occurring in women over 50.
• Family History: Having close relatives (mother, sister, or daughter) with breast cancer increases the risk.
• Genetic Mutations: Inherited mutations in BRCA1, BRCA2, and other genes can significantly increase the risk.
• Personal History: Having a previous breast cancer diagnosis or certain non-cancerous breast conditions increases risk.
• Radiation Exposure: Previous radiation therapy to the chest area, especially during adolescence, increases risk.
• Hormone Replacement Therapy (HRT): Long-term use of combined estrogen and progesterone HRT after menopause may increase risk.
• Reproductive History: Starting menstruation before age 12 or experiencing menopause after age 55 increases risk.
• Alcohol Consumption: Drinking alcohol is associated with an increased risk of breast cancer.

Symptoms
Symptoms of breast cancer may vary, but common signs include:

• A lump or mass in the breast or underarm area
• Swelling or thickening of breast tissue
• Changes in breast size or shape
• Skin changes on the breast, such as dimpling, puckering, or redness
• Nipple changes, such as inversion, discharge, or scaling
• Breast pain or tenderness
• Swollen lymph nodes under the arm

Diagnosis
Diagnosing breast cancer involves several tests and procedures, including:

• Breast Exam: Physical examination of the breasts and underarm area by a healthcare provider.
• Imaging Tests: Mammogram, ultrasound, and MRI help detect abnormalities in breast tissue.
• Biopsy: Removing a sample of breast tissue for laboratory analysis to determine if cancer is present and, if so, the type and characteristics of the cancer.

Treatment Options
Treatment for breast cancer depends on the type, stage, and other individual factors. Options include:

• Surgery: Lumpectomy (removal of the tumor and surrounding tissue) or mastectomy (removal of the entire breast), often combined with lymph node removal.
• Radiation Therapy: Uses high-energy rays to target and kill cancer cells, typically after surgery to destroy any remaining cancer cells.
• Chemotherapy: Drugs that kill cancer cells, often used before or after surgery to shrink tumors or destroy remaining cancer cells.
• Hormone Therapy: Drugs that block hormones like estrogen or progesterone to stop cancer cells from growing, used in hormone receptor-positive breast cancer.
• Targeted Therapy: Drugs that target specific molecules involved in cancer growth, such as HER2-targeted therapies.
• Immunotherapy: Boosts the body’s immune system to recognize and attack cancer cells, sometimes used in advanced breast cancer.

Prevention and Monitoring
Reducing the risk of breast cancer involves lifestyle changes and screening:

• Healthy Lifestyle: Maintaining a healthy weight, exercising regularly, limiting alcohol consumption, and avoiding smoking.
• Breast Self-Exams: Regularly examining the breasts for changes and reporting any concerns to a healthcare provider.
• Clinical Breast Exams: Regular examinations by a healthcare provider to check for breast abnormalities.
• Mammograms: Regular screening mammograms for women starting at age 40 or earlier if at higher risk.