Is there genetic testing that can indicate cancers that are hereditary?
In the ongoing battle against cancer, medical science has recently identified specific genes, which, if defective, are likely to result in the onset of particular types of hereditary cancers. As a means of early detection, genetic testing is becoming more widely used to identify those who may be at risk for certain types of cancer through inherited genetic mutations.
Breast Cancer
Scientists have identified two genes in the DNA sequence, coded as BRCA-1 and BRCA-2 for “Breast Cancer”, in which if mutations are present a woman is up to 7 times more likely to develop breast or ovarian cancer than the general population without the genetic defect. As this mutation can be hereditary, potential cancer patients who have a family history of either disease are genetically tested for the mutation to determine a preventative course of treatment. While the cancer primarily affects women, there is also a growing number of hereditary breast cancer cases in men also.
Colon Cancer
The genome CA has been scientifically identified as the primary source of mutation in hereditary colon cancer. If a patient has a family history of colon cancer, or personally has an early (before age 50) or numerous incidents of colon polyps, genetic testing for the CA mutation may be effective in determining a predisposition to cancer.
Upon positive screening in any of the above cases, the patient can then decide on preventative measures. The options range from having more frequent checkups for cancer to undergoing a surgical procedure to remove the colon or breasts. Another determining factor in course of treatment will be the extent to which will be covered by health insurance.
In all cases of genetic testing for cancer, the patient, and possibly the patient’s family, will be required to go through genetic counseling prior to genetic testing. The genetic counselor will explain the procedures and post testing options if it is determined that a patient has a predetermination for a particular hereditary cancer. Since the cost of the testing is extensive, and the test results are complicated to interpret, many times a family member who already has cancer will be tested for the genetic mutation, to determine if the source is hereditary, before testing other family members. In many cases, health insurance will not cover the cost of genetic testing unless a source of heredity in a current patient is determined.
Sources
healthatoz.com from the article: Genetic Testing for Cancer Last updated Feb. 2007
macgn.org from the article: Genetic Testing for Cancer Risk Published Feb. 2005
