One in every ten women in the United States will develop breast cancer sometime during her life. (Breast Care). More than six percent of these cases are linked to hereditary. There are many measures that can be taken to detect breast cancer early in its stages. Women who believe they have a higher risk should have the breast cancer gene testing.
In order for a woman to consider her case of breast cancer to be hereditary, she must contain either the BRCA1 or BRCA2 gene mutation in her genetic make up. Hundreds of mutations have been found in both genes and almost all of the mutations identified are primitive mutations found in only a single family. Most of the mutations result in a miss-formed protein product; thus the nature of these mutations is easily interpreted. Two successive acquired mutations occurring in a single cell are necessary for the development of cancer. Mutations anywhere along either gene are associated with an increased risk for breast cancer. (Transmed Network-Breast Cancer-Characteristics of Hereditary Breast Cancer, 1997).
More than six hundred different mutations have been identified on the BRCA1 gene. (Gene Clinics, 2000). The number of mutations found on the BRCA1 gene is different than those found on the BRCA 2 gene. The prevalence of cancer predisposing BRCA1 mutations in the general population is estimated to be between one out of five hundred and one out of a thousand cases. BRCA1 and BRCA2 mutations indicate that elevated breast cancer risks begin in the late twenties and early thirties. Doctors normally recommend that women began yearly mammograms at the age of fifty. If the gene can be detected as early as the age of twenty, women should take advantage of the extra precaution and have the test done in addition to the mammograms to prevent late diagnosis of cancer. (Gene Clinics, 2000).
Virtually all individuals with a cancer predisposing mutation in BRCA1 and BRCA2 have inherited it from a parent. (Gene Clinics, 2000). The parent may or may not have had a cancer diagnosis depending upon the penetrance of the mutation, the gender of the parent, the age of the parent with mutation and other variables. It is appropriate to offer mutation analysis to both parents of an individual with a BRCA1 or BRCA2 cancer predisposing mutation. (Gene Clinics, 2000).
In inherited forms of cancer, the parent passes on the gene mutations through a loss of either the maternal or paternal allele within the egg or sperm from which an individual is conceived. Thus every child that is conceived thereafter has a possibility of passing it on to his or her child. (Transmed Network-Breast Cancer-Characteristics of Hereditary Breast Cancer, 1997). The off spring of an individual identified as having either the BRCA1 or BRCA2 mutations have a fifty percent chance of inheriting the mutation themselves. (Gene Clinics, 2000). If the mutation exists in someones genetic makeup it is considered a dominant trait and can be passed down generation to generation as long as it remains dominant. The mutation may also be passed down as a recessive gene in the genetic makeup.
The risk that a sibling will inherit the cancer predisposing BRCA1 and BRCA2 mutation is fifty percent if at least one parent had the BRCA1 or BRCA2 cancer predisposing mutation as well. If one sibling inherited the mutation it does not mean that the other siblings will also inherit the mutation. However, the risk of developing the cancer depends upon the kind of mutation, the gender of the individual, and the persons age. (Gene Clinics, 2000) Studies showed that the BRCA1 cancer predisposing gene is linked to forty five percent of site specific related breast cancer and thirty five percent of site specific cases were related to the BRCA2 gene. (Transmed Network-Breast Cancer, 1997). A person who has the modified gene, labeled BRCA1, has an eighty five percent lifetime risk for developing breast cancer, as well as a higher risk of ovarian cancer. (National Action Plan on Breast Cancer, 1996).
Genetic testing benefits both sporadic and hereditary cases. The test only identifies weather the gene is present in the persons genetic makeup, not if it is hereditary. The gene can be present in any woman. Environmental things such as radiation and chemicals that a woman can come in contact with can cause the mutation in her genetic make up. (Understanding Gene Testing).
Finding out that a gene mutation is present does not mean that a woman will develop the cancer. Women who test positive for the BRCA1 mutation gene have an eighty percent chance of developing the cancer. The risk is high, but not definite.
People who test negative for the BRCA1 mutation still have a risk of developing the cancer. Although, a negative response to the test will give a woman a sense of relief, she should still be checked regularly. A negative result may also lower the amount of checkups and tests that are required for families with a higher risk of developing the cancer.
If a woman does not contain the genetic mutations, a woman can still develop breast cancer. Out of 180,000 cases annually, ninety four percent are not linked to being hereditary and are considered sporadic. Even if you contain the BRCA1 or BRCA2 gene mutation you have an eighty five percent chance of having breast cancer. This gives women a fifteen percent chance to hope that she does not develop breast cancer.
Genetic mutation testing has become another easy way for women to detect breast cancer early. A woman will never truly know if she will definitely develop breast cancer. Test such as genetic mutation testing will definitely help in early detection and prevention against spreading.
Gene Clinics. (March 4, 2000). BRCA1 and BRCA2 Hereditary Breast/Ovarian Cancer. Retrieved November 19, 2000 from the World Wide Web: Http://www.geneclinics.org/profiles/brca1/
National Action Plan on Breast Cancer. (September 5, 1996). State of the Science on Hereditary Breast Cancer and Genetic Testing. Retrieved November 19, 2000 from the World Wide Web: http://www.napbc.org/napbc/state.htm
Transmed Network. (1997). Breast Cancer-Characteristics of Hereditary Breast Cancer. Retrieved November 19, 2000 from the World Wide Web: http://www.breastdiseases.com/genebr3.htm
Transmed Network. (1997). Breast Cancer-Genetic Epidemiology. Retrieved November 19, 2000 from the World Wide Web: http://www.breastdiseases.com/genebr2.htm
Transmed Network. (1997). Hereditary Breast Cancer. Retrieved November 19, 2000 from the World Wide Web: http://www.breastdiseases.com/genebr1.htm
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