Genetic Testing Disease Risk Profiling Cancer

Scientists continue to struggle to discover what exactly causes cancer and how the disease progresses. Fortunately, some advances have been made in understanding the relationship between genetics and cancer. Researchers estimate that between 5 and 10 percent of all of those who get cancer develop the disease because of inherited factors. Therefore, it is important to understand the link between genetics and cancer.

Cancer Genetics Research

The root of cancer genetics lies with the genes of an individual’s chromosomes. Genes consist of DNA, or deoxyribonucleic acid. When DNA changes, or mutates, a cell may turn cancerous.

Research has shown that two types of genetic changes might lead to cancer: random gene mutations and inherited gene mutations. Random gene mutations might be caused by environmental factors, such as exposure to radiation or chemicals.

Inherited gene mutations are passed from parents to children. If you inherit a cancer gene, you may not automatically develop cancer. However, you are considered to be at higher risk of getting the disease than the “normal” population.

Genetics have been linked to several types of cancers, including some forms of ovarian, thyroid and pancreatic cancers.

Breast Cancer Genetics

Breast cancer is another cancer that can have its roots in genetics. Scientists have been able to isolate several mutations on genes that can increase the possibilities of developing this type of cancer. These genes include:

  • BRCA1 and BRCA2, both of which belong to the tumor suppressor gene class
  • CDH1, a gene that is normally responsible for making a protein that helps cells adhere together to form tissue
  • PTEN, STK11, and TP53, which are other types of genes that also help with tumor suppression.

While breast cancer in men is rare, studies have indicated that men with mutated BRCA1 or BRCA2 genes are more likely to develop this type of cancer than men without a mutation. In addition, the mutation can be passed on to the man’s children, even if he himself does not develop breast cancer.

Genetic Connection to Breast Cancer - Genetics and Cancer

Genetics and Childhood Cancer

Experts estimate that less than 5 percent of childhood cancers are genetically related. Genetic considerations stand out the most with retinoblastoma, a cancer of the eye’s retina. Roughly 40 percent of diagnosed cases with this cancer are attributed to genetic factors.

Wilm’s tumor, a kidney cancer, can also be associated with genetics, although to a lesser degree than retinoblastoma.

Cancer Genetics and Screening

Not everyone needs to get genetic screening. However, if someone in your immediate family has had cancer that might be genetically related, or if you or someone in your immediate family has had an unusual cancer, you might want to investigate screening.

In addition, someone in your family having more than one type of cancer can also be a red flag. The age at which you or someone in your immediate family develops cancer can also indicate an inherited risk. Developing cancer after the age of 50 is much more “normal” than developing cancer before you turn 50.

Immediate family includes:

  • aunts and uncles on both sides of your family
  • grandparents on both sides of your family
  • parents
  • siblings.

A positive result from genetic screening does not automatically tell you that you will absolutely get cancer. However, it will help you make certain decisions such as:

  • deciding to be monitored more frequently for any indications that cancer is developing
  • having preventative surgery
  • making lifestyle changes, such as stopping smoking and eating a healthier diet.

Resources

Cancer Research UK (2005). Genetic factors — childhood cancer. Retrieved September 17, 2008, from the Cancer Research UK Web site: http://info.cancerresearchuk.org/cancerstats/childhoodcancer/geneticfactors/.

Genetics Home Reference (2008). BRCA1. Retrieved September 17, 2008, from the Genetics Home Reference Web site: http://ghr.nlm.nih.gov/gene=brca1.

Genetics Home Reference (2008). BRCA2. Retrieved September 17, 2008, from the Genetics Home Reference Web site: http://ghr.nlm.nih.gov/gene=brca2.

Genetics Home Reference (2008). Breast cancer. Retrieved September 17, 2008, from the Genetics Home Reference Web site: http://ghr.nlm.nih.gov/condition=breastcancer

Genetics Home Reference (2008). PTEN. Retrieved September 17, 2008, from the Genetics Home Reference Web site: http://ghr.nlm.nih.gov/gene=pten

Genetics Home Reference (2008). STK1. Retrieved September 17, 2008, from the Genetics Home Reference Web site: http://ghr.nlm.nih.gov/gene=stk11

Genetics Home Reference (2008). TP53. Retrieved September 17, 2008, from the Genetics Home Reference Web site: http://ghr.nlm.nih.gov/gene=tp53.

Genetics Home Reference (2008). CDH1. Retrieved September 17, 2008, from the Genetics Home Reference Web site: http://ghr.nlm.nih.gov/gene=cdh1.

National Cancer Institute (2006). Genetic testing for breast and ovarian cancer risk: It’s your choice. Retrieved September 17, 2008, from the NCi.Nih.Gov Web site: http://www.nci.nih.gov/cancertopics/Genetic-Testing-for-Breast-and-Ovarian-Cancer-Risk.

Petre, Rich (2008).Genetics screening program. Retrieved September 17, 2008, from the Froedtert Web site: http://www.froedtert.com/SpecialtyAreas/CancerGeneticsScreeningProgram/.