There are many breast cancer causes and risk factors. Although studies and research have been done to prove some, some factors are still under investigation.

Causes Of Breast Cancer

Just like other types of cancer, the leading cause of breast cancer is unknown. However, several factors are linked to the causes of cancers of the breast. Furthermore,  researchers have identified hormonal, environmental and lifestyle factors that may increase your risk of getting breast cancer, and these include:

Inherited Breast Cancer: Some inherited mutated genes that may increase the chances of getting breast cancer is breast cancer gene 1 and 2 (BCRA 1 and BCRA 2). These are also the most common breast cancer causes. However, doctors estimate that about 5 to 10 percent of this cancer causes is due to inherited gene mutations. These gene mutations can also transfer from one family member to another.

Risk Factors For Breast Cancer

Several risk factors are likely to increase the chances of having breast cancer, and they are:

Age: Women of ages 60 and above are more likely to get breast cancer. Additionally, only a tiny percentage of women below the age of 45 are likely to have breast cancer.

Gender: The National Cancer Institute estimates that physicians diagnosed over 190,000 women with breast cancer annually. Although breast cancer can also occur in men, it is 100 times more common in women.

Obesity: Weight gain in adulthood and excess body fat around the waist may increase the risk of breast cancer. Furthermore, fat tissue usually constitutes too high levels of estrogen which is one of the leading breast cancer causes. (1)

Particular Breast Changes: Also, some benign (non-cancerous) breast conditions may increase the risk of breast cancer.

Menstruation: Women who start menstruation after menopause or at an early age also have a slightly higher risk of breast cancer.

Rare Genetic Conditions: There are some rare genetic conditions that experts have shown to be related to the increase in the risk of developing breast cancer. Experts have found the following factors to be the reason for an increase in the risk of breast cancer: (2)

  • Li-Fraumeni syndrome
  • Ataxia-telangiectasia (AT)
  • Cowden syndrome
  • Peutz-Jeghers syndrome
  • CHEK2 gene mutation
  • Exposure to ionizing radiation

Women, who at one point in life received radiation therapy to the neck, armpit, and chest known as mantle radiation field, have a higher risk of developing breast cancer. Doctors have also linked this to major breast cancer causes. Those who received ionizing radiation during the atomic bomb blast in the Second World War have a higher risk of developing breast cancer. (3)

Other risk factors for breast cancer may include the following:

  • Breastfeeding factors
  • Drinking alcohol
  • Having dense breast
  • Smoking


MAYO CLINIC. (n.d.). Retrieved July 16, 2017, from

American Cancer Society. (n.d.). Retrieved July 16, 2017, from

Breast Cancer Risk Factors. (n.d.). Retrieved July 16, 2017, from