We all know the benefits of being forewarned about any impending problem because we can then be forearmed for tackling the problem. So the idea that we can somehow predict cancer by having a test conducted is an appealing one: it brings with it the promise of early detection and immediate and effective treatment.
What is genetic testing for cancer?
Certain inherited genes may be the sorts that do not function properly, they are mutated or altered genes that are known to be one of the factors involved in cancer. The BRCA1 and BRCA2 (BReast CAncer Gene 1 and BReast CAncer Gene 2) are an example of altered genes that can be responsible for breast cancer for instance.
These can be inherited from either side of the family; maternal as well as paternal and for the purposes of calculating one’s cancer risk, ones parents’ brothers and sisters, and both sets of grandparents as well as one’s own siblings have to be taken into account.
Genetic testing for cancer involves a mutation search that usually is performed on the person who has been diagnosed with cancer in the family.
If the mutation is found, others in the family are seen to be at risk of that cancer, and may be candidates for genetic testing. These other family members may then be offered predictive or predispositional testing.
This will predict a person’s chances of developing cancer, and they could then follow guidelines about more rigorous and frequent testing for cancer. It can clarify cancer risk and help one make lifestyle and medical alterations. One can contemplate getting risk reducing surgery and also offer useful information to others in the family.
What are the limitations of genetic testing for cancer?
Genetic tests cannot predict whether an individual is likely to get cancer or not. The genetic test merely predicts whether a person is likely to have cancer or not.
Further this kind of testing is no use for those who don’t have a family history of cancer – which means two or more close family members who have been diagnosed with cancer, or a family member who has been diagnosed with cancer early in life.
Things to keep in mind about genetic testing for cancer
It is important to remember that there are many other factors that contribute to the development of cancer and only 5 to 10% of cancers are hereditary. It is recommended that a person be offered testing only if there is a family history of cancer, if the genetic test can be adequately interpreted and if the test results have accepted clinical utility.
One also needs to keep in mind the difference that a positive test could make to one’s life: it could affect relationships and also impact insurance, and so on. There is also a psychological impact of a positive test that one will have to contend with. One will also have to decide what to do with those results, make lifestyle alterations, share the information with others in the family, and so on.