Wednesday, 16 May 2012

Recent Advance Genetic in Breast Cancer

Breast cancer arises with the involvement of genetic and non-genetic factors. Breast cancer is well-born from breast tissues with unregulated growth of cell and mutation of genes. There is approximately 214,000 breast cancer cases were diagnosed (Boris Pasche 2008) and 50,000 women died in US due to breast cancer by 2006. From research in 1994 and 1995, it was found two types of genes that cause breast cancer called BRCA1 and BRCA2.

BRCA1 and BRCA2 have different in structure and cellular roles. BRCA1 gene is larger than BRCA2 and it is located on chromosome 17. On the other hand, BRCA2 is found on chromosome 13. BRCA genes are involved in cell division, cell growth and DNA damage response. Mistake spelling in gene sequence causes DNA damage and damage of DNA will cause BRCA genes to change. In addition, modification of BRCA genes increases the risk of breast cancer.

Detection of BCRA1 and BRCA2 mutation can be done by analysing blood or saliva sample from an affected subject. From this sample, changes of DNA which indicates the mutation of these two genes can be detected. Thus, result can be obtained in several weeks. Positive result means an individual carry the mutation of BCRA genes. Besides, negative result means an individual does not carry the risk of BCRA mutation. Having a negative result does not mean an individual will not develop cancer. Risk from mutation is increased by increasing of women age, for example, 17% risk at the age of 40 years, 39% by age of 70 and increase to 54% when women reach to age 80.

Implementation of breast cancer invention is very important for prevention of cancer in the early stage. Prevention of cancer can be done by several methods such as cancer screening (mammography, MRI, and ultrasound), surgery and chemoprevention. Mammography method should be used for women at the age 40. MRI is more sensitive compared to mammography where 81% : 40%. MRI is widely used than mammography due to the sensitivity will give an accurate detection or results. Furthermore, it is used when breast cancer cannot be detected using mammography and ultrasound. Surgery occurs where healthy breast tissue is removed, therefore, it can reduce the risk of breast cancer by 97%. Chemoprevention is involved the use of natural substance. Tamoxifen and raloxifene are examples of the natural substance. These two substances were approved by the U.S. Food and Drug Administration (FDA) as a breast cancer treatment.

In conclusion, BRCA1 and BRCA2 are hazardous genes that cause cancer from the mutation process. Mutation can be detected by analysing blood or saliva sample of an individual. Moreover, early prevention for breast cancer is done by some methods such as, cancer screening, surgery and chemoprevention.

Andrew Tutt, Alan Ashworth 2008, ‘Can genetic testing guide treatment in breast cancer?’, European Journal of Cancer, vol.44, pp.2774-2780.
Boris Pasche 2008. ‘Recent Advance in Breast Cancer Genetics’, Cancer Treat Res, vol.141, pp:1-10.
Srila Samphao, Amanda J. Wheeler, Elizabeth Rafferty, James S. Michaelson, Michelle C. Specht, Michele A. Gadd, Kevin S. Hughes, Barbara L. Smith 2009, ‘Diagnosis of breast cancer in women age 40 and younger: delays in diagnosis result from underuse of genetic testing and breast imaging’, The American Journal of Surgery, vol.198, pp.528-543.
Steven S Coughlin, Muin J Khoury, Karen K Steinberg 1999, ‘BRCA1 and BRCA2 gene mutations and risk of breast cancer: Public health perspectives’, American Journal of Preventive Medicine, vol 16, pp.91-98.

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