Genetic testing helps to examine the changes in the DNA and helps to estimate your chance of cancer disease in your lifetime. Basically, Deoxyribonucleic Acid (DNA) is a chemical database that carries instructions in their staircase like the pattern for the human body’s function. In this test, doctors examine the changes in the genes, chromosomes, or protein. Moreover, it can also help to provide information for diagnosing, treating, and preventing illness. There is a limitation in the genetic testing means, in case of a positive result of the test doesn’t mean you have cancer and vice versa.
Genetic tests are available for some types of cancers are listed below:
- Breast cancer
- Ovarian cancer
- Colon cancer
- Thyroid cancer
- Prostate cancer
- Pancreatic cancer
- Melanoma
- Sarcoma
- Kidney cancer
- Stomach cancer
Types of Genetic Testing for Cancer
Genetic testing is an important test for determining the risk of developing cancer as well as for screening and treatment purposes. Many types of tests of genes for different purposes. Some genetic testing types are listed below:
Diagnostic Testing
This type of genetic testing can be done if you have symptoms of the disease that can be the outcome of genes mutations. Diagnostic testing can be done if have a suspected disorder. Hence, genetic testing can be done to confirm a diagnosis of cystic fibrosis or Huntington’s disease.
Presymptomatic and Predictive Testing
If you suspected to be a family history of a genetic condition, this genetic testing can help out to identify the risk of developing the condition and will be helpful to prevent those conditions. Mostly this test is very beneficial for the cancer patients to have past family background suffered from this disease. This type of test can be very beneficial for identifying your risk of certain types of colorectal cancer.
Carrier testing
In the case of family history genetic disorder, such as sickle cell or cystic fibrosis, you should choose genetic testing before having children. An expanded carrier screening test can detect genes that could be responsible of genetic diseases and mutations. Moreover, this test also has the ability to identify the carriers of your partner for the same condition.
Parental testing
If you’re pregnant, tests can detect some types of abnormalities in your baby’s genes. Down syndrome and trisomy 18 syndrome are two genetic disorders that are often screened for as part of prenatal genetic testing. Traditionally this is done looking at markers in blood or by invasive testing such as amniocentesis. Newer testing called cell-free DNA testing looks at a baby’s DNA via a blood test done on the mother.
Newborn Screening
This is the most common type of genetic testing. In the United States, all states require that newborns be tested for certain genetic and metabolic abnormalities that cause specific conditions. This type of genetic testing is important because if results show there’s a disorder such as congenital hypothyroidism, sickle cell disease, or phenylketonuria (PKU), care and treatment can begin right away.
Preimplantation testing
Also called preimplantation genetic diagnosis, this test may be used when you attempt to conceive a child through in vitro fertilization. The embryos are screened for genetic abnormalities. Embryos without abnormalities are implanted in the uterus in hopes of achieving pregnancy.
Risk factors for Heredity Cancers
Hereditary cancer is any cancer caused by an inherited gene mutation. An inherited gene means it is passed from parent to child within a family. The following factors suggest a possible increased risk for hereditary cancer:
- Family History of Cancer
- Cancer at an early age
- Multiple Cancers
- Rare Cancer
Reason to Consider Genetic Tests for Cancer
Genetic testing has limitations and emotional implications. These may include:
- Family History suggests being a heredity disease
- Depression, Anxiety or Guilt
- Family Tension
- False Sense of Security
- High Cost
- Unclear Results
- Discrimination and Privacy cost
What to Expect during Genetic Testing for Cancer
There can be several steps or procedures that are associated with the genetic testing for cancer. In this section, we are going to discuss expected procedures in detail.
Risk Assessment
A genetic counselor will look at your family medical history along with your personal medical history. It is compulsory to determine for health care professionals whether you are good candidate for genetic testing or not.
Genetic Counseling
A professional genetic counselor will work on your personal and family medical history and provide you additional information. This information will help you to decide if you want to get genetic testing. Information can be varying but the most important information, that a genetic counselor will provide you as listed below:
· How cancer can be inherited within families?
· How gene mutations can be enhancing the risk of developing cancer cells?
· How genetic testing works?
· What is the limitation of genetic testing?
· Pros and Cons of genetic testing?
· How your genetic test result can affect your mental health and relationship with your family members?
It is important to attend counseling of healthcare professionals. They play an important role in interpret results and discuss the future strategy after genetic testing.
Informed consent
You have to sign a informed consent document, if you decide to get tested. In this document, you’ve been told about things like:
- What is the purpose of genetic test and why you are being tested?
- Accuracy and the limitation of test
- Detailed pros and cons of testing
- Potential implications of the genetic testing results
- What can be the alternatives to genetic testing
- Your rights to privacy and refuse testing.
Sample collection and analysis
The testing procedure typically involves collecting a blood sample from a vein in your arm. However, it may also be a sample of:
- blood
- saliva
- cheek cells
The sample is then analyzed by a lab that specializes in genetic testing. It’s possible that it can take several weeks for results to be ready.
Receiving the results
Genetic counselor will contact you to discuss plan for the next steps after the receiving of genetic testing results. Following tests that you can receive are:
- Positive
- Negative
- Unknown Significance
When you receive positive result, means you have a gene variant that can increase the risk of cancer. Your health professional will tell you about the risk level and potential steps. Genetic counselor will ask you to getting screened for cancer more frequently, implement lifestyle changes, that can help to reduce your cancer risks, and medication for lowering the cancer risk. In case of negative result, you wouldn’t have any gene variant that can cause cancer. It is important to note that, negative result doesn’t mean you’ll never develop cancer in your whole life in future. However, in case of unknown significance, gene variant is detected but its significance as far as cancer risk is currently unknown.
What are the benefits of the Genetic Testing for Cancer?
There are several potential benefits of genetic testing for cancer. Some benefits include:
- Clear-conscience. If your family members having certain types of cancer, you should do genetic tests. Negative results will give you peace of mind, that you are not inherited the certain types of variants that can cause gene mutations.
- Protective Measures. If your result is positive and you contain certain types of variants that increase the risk of cancer, can help you to take precautionary measures early. It can look out for potential cancer symptoms before the development of cancer cells.
- Family Testing. It’s possible that immediate family members can learn about their cancer risk from your results. It may also encourage them to get tested.