Genetic Cancer
Genetic cancer at a glance
- Genetic cancers represent a line of cancers that are caused by genetic mutations passed on to the child through its parents’ DNA during conception.
- Common genetic cancers include breast, ovarian and colorectal.
- About 5-10 percent of all cancers are caused by genetic defects.
- Treating genetic cancer depends upon the type and stage of the cancer, and may involve radiation, surgery or chemotherapy.
What is genetic cancer?
Genetic cancers are mutations within deoxyribonucleic acid (DNA) that are present before birth. A person’s genetic makeup is comprised of 46 chromosomes; 23 from the mother and 23 from the father. Across the chromosomes are thousands of genes containing DNA that are responsible for producing protein and essential substances for life. When that production is compromised, the genes are considered mutated, which increases the risk of cancer.
The more common genetic cancers include breast, ovarian, colorectal (which likely leads to endometrial cancer) and prostate cancer. Everyone has the chance of developing sporadic cancers (those that arise after birth), and these represent the most common cancers. Genetic cancers only represent 5-10 percent of all cancers diagnosed. And just because a person carries a hereditary mutation does not ensure that the cancer associated with that mutation will occur.
Causes of genetic cancer
Genetic cancers arise from a mutation in the genes that occurs when the DNA cells divide too quickly and become mismatched. Although it’s not known why these specific actions happen within the DNA, most genes that contribute to cancer fall under three main, identifiable categories:
- Tumor suppressor genes – When functioning normally, these genes limit cell growth by regulating the speed at which new cells divide. When these genes are not functioning properly, they become mutated, cells grow out of control and, in some cases, lead to cancer.
- Oncogenes – These are genes that transform a healthy cell into a cancerous one. Common oncogenes include the specialized protein HER2 that is found on some breast and ovarian cancer cells, as well ras genes, a family of genes that include a protein that can become overactive.
- DNA repair genes – These genes fix replicated DNA. If the repair genes aren’t working properly, they may fail to fix the copy and lead to the mutation and possible cancer.
Testing for & treating genetic cancer
Those with a family history of genetically-linked cancers may opt to be screened for genetic cancer mutations. Genetic testing is usually conducted by taking a blood, saliva or skin cell sample. A genetic testing laboratory then analyzes the sample and returns the results to the doctor or genetic counselor who requested the test. Several weeks are usually required to receive the results.
Read more about genetic cancer testing
Treating genetic cancer depends on the specific type of cancer diagnosis and will be treated according to patient health, cancer stage and personal preferences. These traditional treatments might include chemotherapy, radiation or surgery. Physicians are currently studying gene therapy as a way to locate and treat defective genes that may cause cancer or increase a person’s chances for getting cancer.
Gene therapy essentially replaces the defective gene with a healthy, fully-functional gene. These genes may be gathered in a blood or bone marrow extraction. A lab then mixes the genes with genetic material believed to combat the mutation. This mixture is injected back into the body either through tissue or a vein. The only way to participate in this experimental treatment right now is in a clinical trial.
Gene therapy may eliminate the need for any type of surgery, radiation or chemotherapy, as well as increase preventive measures for cancer. Researchers are also studying additional therapies, such as special gene injections that cause the tumor to be more receptive to cancer treatment. These are currently only in the preliminary research stages.