Learn About the Causes of Breast Cancer

Understand Your Risk Factors

Breast cancer is the most common type of cancer among females. It is caused by the abnormal division of cells and subsequent formation of a mass of tissue called a tumor. Understanding the causes of breast cancer enables you to identify potential risk factors, which can lead to early detection and treatment.

  • Gender and age. Aging women are more likely than men to develop breast cancer.
  • Genetics. It is estimated that 5 to 10 percent of breast cancers are linked to inherited gene mutations.
    • Breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2) are the most well-known breast cancer genes. They are tumor suppressor genes that usually have the job of controlling cell growth and cell death. Changes to their structure may cause cancer tumors to grow.
    • Doctors may recommend that patients with a familial history of breast cancer undergo blood tests to identify possible BRCA mutations.
    • The PTEN gene helps control cell growth and death. Damage to this gene creates a higher risk for both cancerous and noncancerous breast tumors.
    • The TP53 gene tells cells to make a protein called p53, which helps stop the growth of abnormal cells. Changes in TP53 cause an increased risk of breast cancer, leukemia, brain tumors, and childhood sarcomas. Less than 1 percent of all breast cancer is thought to be related to this gene.
  • History of breast conditions. Previous breast conditions, specifically lobular carcinoma in situ (LCIS) or atypical breast hyperplasia, may be one of the causes of breast cancer. Also, women whose breasts have significant areas of dense tissue on mammograms are at increased risk for breast cancer.
  • History of breast cancer. Patients who have had cancer in one breast are at an increased risk to develop cancer in the other breast.
  • Radiation exposure. Radiation treatments to the chest during adolescence or young adulthood can be one of the causes of breast cancer.
  • Obesity. Being obese increases the risk of breast cancer.
  • Giving birth to a first child at an older age. Women who have their first child after age 30 may have an increased risk of breast cancer.
  • Beginning menstruation at a young age. Beginning menstruation before age 12 increases the risk of breast cancer.
  • Beginning menopause at an older age. Beginning menopause after age 55 increases the risk of breast cancer.
  • Pregnancy. Women who have never been pregnant are at an increased risk of developing breast cancer.
  • Post-menopausal hormone therapy. Estrogen and progesterone medications taken to treat the symptoms of menopause may increase the risk of breast cancer. Fortunately, the risk decreases when these medications are discontinued.
  • Alcohol use. Drinking alcohol excessively increases the risk of breast cancer.
  • Diethylstilbestrol (DES) exposure. Women who take this medicine while pregnant to lower the chance of miscarriage are at higher risk. Women whose mothers took DES during pregnancy may also have a higher risk.

What Is HER2-Positive Breast Cancer?

Patients who are newly diagnosed with breast cancer should be tested for HER2, a growth-promoting protein on the outside of all breast cells. Breast cancer cells that have higher than normal levels of HER2 are called HER2 positive, which indicates that cancer may grow and spread faster than other types of breast cancer. Fortunately, HER2-positive breast cancer is much more likely to respond to treatment with drugs that target the HER2 protein.

What Causes HER2-Positive Breast Cancer?

“What causes HER2 positive breast cancer?” is a frequently asked question by recently diagnosed patients. Although the cause is not fully known, there are genetic, lifestyle, and environmental factors that may contribute to the diagnosis. It is currently believed that HER2 positive breast cancer risk may increase for:

  • Women
  • Obese patients
  • Patients who give birth after age 30
  • Patients with a family history of breast cancer
  • Patients who have undergone previous radiation therapy
  • Patients who smoke

Newly diagnosed breast cancer patients, especially those who have identified risk factors, should be tested for HER2 breast cancer. Identifying HER2 breast cancer early may increase the chances of treatment success.

To schedule an appointment with one of New Jersey’s best breast cancer specialists call 844-CANCERNJ or 844-226-2376.

Patient Stories

  • "I feel very comfortable that going forward that I am under the best care."

    Ferlie
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  • The Mental Health treatment helped me to deal with the Cancer.

    Sonia
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  • “Should I kick myself for not getting it checked earlier, well sure, however the battle is here, right now,”

    Willa
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Patient Stories

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