The role of genes in breast cancer

MANILA, Philippines - A female breast represents life. 

Every mammal was once nurtured and nourished by its mother’s breasts. However, this life-giving female embodiment is also a cause of concern due to the rising breast cancer incidence. The 2010 Philippine Cancer Facts and Estimates reported that among Filipinos, breast is the number one cancer site with an estimated 12,262 cases for every 100,000 population. This represents 28 percent of Filipino women who have been diagnosed with breast cancer.

Women with higher risks of breast cancer, as cited by the DOH and the Philippine Cancer Society in the report, include those who experienced early menarche and/or late menopause, those who never had children, and those whose first pregnancy occurred after the age of 30.

A new development in breast cancer research points at the role of gene mutations that can adversely affect the predisposition of women for breast cancer.

Among genetic mutations that impact breast cancer risk, BRCA1 and BRCA2 genes are the most common. BRCA1 and BRCA2 are human genes that belong to a class of genes known as tumor suppressors. In normal cells, BRCA1 and BRCA2 help ensure the stability of the cell’s genetic material (DNA) and help prevent uncontrolled cell growth. Mutation of these genes has been linked to the development of hereditary breast and ovarian cancer.

A woman’s risk of developing breast and/or ovarian cancer is greatly increased if she inherits a harmful BRCA1 or BRCA2 mutation. Men with these mutations also have an increased risk of breast cancer. Both men and women who have harmful BRCA1 or BRCA2 mutations may also be at increased risk of other cancers The names BRCA1 and BRCA2 stand for breast cancer susceptibility gene 1 and breast cancer susceptibility gene 2, respectively.

Another gene mutation that can impact breast cancer risk is HER2, a protein called human epidermal growth factor receptor 2 (HER2), which promotes the growth of cancer cells. Normal breast cells contain two copies of the HER2 gene and produce appropriate amounts of HER2 receptors to enable normal cell growth and division. Some breast tumor cells, however, contain many more copies of the HER2 gene and in turn produce too many HER2 receptors  the receptors are overexpressed. In about one of every five breast cancers, the cancer cells make an excess of HER2 due to a gene mutation. This gene mutation and the elevated levels of HER2 that it causes can occur in many types of cancer  not only breast cancer.

For more information on gene mutations that affect breast cancer risk, visit www.cnetwork.org.ph For more information on cancer prevention, visit www.cnetwork.org.ph.

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