The majority of breast cancer is associated with tumor growth in the epithelial cells of breast lobules (milk glands) and ducts responsible for taking milk to the nipple. In less frequent cases, it occurs due to growth in the connective tissue that provides structural support to the breast. 

Figure 1. Lobules and milk ducts. Wiki Commons.

Risk Factors for Breast Cancer 

  1. Age: Most common in females over 50
  2. Never having given birth or having first child after age 35: Hormonal changes during pregnancy help protect mammary glands from tumor growth. If a woman is having a child for the first time after age 35 she would have been exposed to more estrogen over her lifetime. That is because estrogen promotes breast cancer by binding to receptors on cancer cells. Another female hormone; progesterone has the same effect
  3. Genetic risk factors: Inheritance of the gene mutation BRCA1 or BRCA2 produces a 50-85% chance of getting breast cancer by age 70
  4. Family history: Increases risk by 5-10%
  5. Overweight or obesity after menopause: Due to production of estrogen by fat cells
  6. Diabetes: Due to increase insulin levels. Insulin has “anti-apoptotic” activity (ability to prevent cells from initiating cell death) which can cause cancer cells to persist
  7. Lack of physical activity: Exercise help to reduce fat cells (lower estrogen production) and regulate insulin production 
  8. Drinking alcohol: Alcohol causes blood estrogen levels to rise
  9. Having dense breasts: It’s easier to miss (not notice) tumor growth in denser breast 

Signs and Symptoms of Breast Cancer

  1. Swelling, lump or mass within the breast
  2. Skin irritation
  3. Redness
  4. Scaliness
  5. Thickening of nipples
  6. Discharge other than milk

Checking for Breast Cancer

Starting in their twenties, women should self-examine their breasts monthly for signs of cancer. Women in their twenties and thirties should have a clinical breast examination (CBE) done every 3 years and every year after age 40. After 50, they should have a yearly mammogram. A mammogram uses ionizing radiation to take a picture of the internal tissues of the breast to find any abnormality. If the image is unclear, your doctor may recommend an MRI which will provide a clearer image. A biopsy may be done afterwards to confirm cancer. This is done by removing and examining cells from the suspected area.

Cancer Treatment Options

  1. Surgery, called a mastectomy to remove part or the entire affected breast
  2. Radiation
  3. Chemotherapy
  4. Targeted drug therapy: The use of certain medication that targets biomolecules e.g. certain proteins that promotes cancer growth


The 5-year survival rate for breast cancer is 90%.

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Courtney Simons
Courtney Simons
Courtney Simons is a food science professor. He holds a BS degree in food science and a Ph.D. in cereal science from North Dakota State University.