Every cancer, like every patient, is different. Genomics or genetic testing is the scientific testing of a person’s genes. Genetic testing is usually undertaken when someone is at high risk of having inherited a changed gene, based on a strong family history of cancer. It helps to estimate the chances of developing cancer in your lifetime. It does this by searching for specific changes in genes, chromosomes, or proteins. These changes are called mutations.
The introduction of genomics has resulted in doctors being able to recommend screening or other specific interventions. Analysis of the "gene signatures" of different cancers—i.e. which genes are more active in cancerous cells compared to normal ones. This provides doctors insight into what tumors will respond to a certain type of medication, giving them greater understanding while planning a line of treatment.
Dr. Deni Gupta, the senior Oncologist at Dharmashila Medical Institute New Delhi, states: “The rise in “radiation genomics” has brought healthcare providers to a place where, for some cancers, doctors will be able to predict and identify patients who may be more responsive to radiation therapy.”
Benefits of Gene Testing To Detect Cancer
A common misconception is that genetic testing can tell for sure whether a patient will develop cancer. It can, however, detect whether a person is more likely to develop cancer at later stages in their life. It is recommended for patients who are at a higher risk of having inherited a changed gene, based on a strong family history of cancer.
For the moment, genetic tests are available for some types of cancer. These include breast, ovarian, colon, and thyroid cancers.
Benefits of genetic testing:
- Predicts your risk of particular diseases like cancer early in your life
- Provides information to help your doctor plan your treatment
- Detects early predisposition of passing cancer to offspring
Important Note: Someone who inherits a cancer-predisposing mutation present in the family doesn’t necessarily mean they will develop cancer. There are several other factors that influence the outcome in a given person with the mutation.
Who should consider genetic testing for cancer risk?
Medical experts believe that gene testing should be done if the following criteria are met:
- Close relatives who have had the same type of cancer
- Family members who have had cancer linked to a gene mutation, such as breast or ovarian cancer
- Family members who had cancer at a younger age than normal for that type of cancer
- Cancer screening results that may point to genetic causes
- Family members have had genetic tests and had a positive result
Gene Testing Procedure
You will first need to have an assessment to determine the level of risk. A Vaidam Health Consultant can help you order the test after talking with you about your health and needs.That way you can decide whether testing is right for you.
How the testing works:
- A small sample of body fluid or tissue is taken-usually blood, but sometimes saliva, cells from inside the cheek, skin cells, or amniotic fluid (the fluid surrounding a developing fetus).
- Samples are sent to a lab that specializes in genetic testing. It can take several weeks to get the results.
- Once you get the results, consult a Genetic Oncologist who will provide accurate information about what a particular genetic test means for your health and care.
Genetic Tests for Cancer Risks
Gene changes linked to cancer can be detected with the help of Predictive genetic testing. This test is used to look for inherited gene mutations that might put a person at higher risk of getting certain kinds of cancer. Doctors generally advise this testing under three conditions:
- Strong family history:
- Gene Tests: BRCA1, BRCA2
- Related cancer types: Female breast, ovarian, and other cancers, including prostate, pancreatic, and male breast cancer
- Inherited Cancer mutation:
- Gene Tests: TP53
- Related cancer types: Breast cancer, soft tissue sarcoma, osteosarcoma (bone cancer), leukemia, brain tumors, adrenocortical carcinoma (cancer of the adrenal glands), and other cancers
- Early Detection:
- Genes: MSH2, MLH1, MSH6, PMS2, EPCAM
- Related cancer types: Colorectal, endometrial, ovarian, renal pelvis, pancreatic, small intestine, liver, and biliary tract, stomach, brain, and breast cancers
Note: This list is non-exhaustive. There are over 50 inherited cancer syndromes for which genetic testing is available.
Other cancers linked with genetic mutations:
- Adrenal Gland
- Small intestine
- Renal Pelvis
- Liver or Biliary Tract
- Pituitary Gland
Understanding Your Test Results
It is best to consult a Genetic Oncologist or a healthcare professional trained in genetics to help understand test results. The healthcare specialist will include discussing recommendations for preventive care and screening with the patient. In some cases, a Genetic Healthcare specialist may recommend other family members consider being tested for specific gene changes that indicate an increased risk of cancer. However, this is a very personal decision and one that is largely left to the family members.