Hereditary cancers are those cancers that occur across generations. They are caused by certain genetic mutations that can be transmitted to the offspring. They constitute about 5- 10 % of all cancers.
These tend to present at an early age. The carriers of the mutation have a higher risk of developing more than one particular cancer.
The first step to understanding your hereditary cancer risk is a genetic counseling session. There is a stepwise approach to suspected hereditary cancer susceptibility.
Genetic tests use a patient’s blood sample to look for genetic mutations that may lead to an increased risk for some cancers.
Diagnosis is made by a genetic test. A genetic test is done on a blood sample or even a cheek swab.
History and physical examination: A detailed personal and family history of at least three generations is taken. A family tree - pedigree chart is created. A physical examination is done to look for certain tell tale signs. Based on these, a risk assessment about the possibility of a hereditary cancer is made.
Pre Test Counselling: If suspected to be at a higher risk, a pre test counselling is offered to understand the need, scope, outcome, limitations, implications, and cost of the genetic test. Based on willingness and consent of the patient, genetic testing is advised. It takes about 3 – 4 weeks for the report.
Post Test Counselling: A post-test counselling is scheduled, to discuss the report and understand the way forward.
A personalised care plan is laid out for each patient based on his/her mutation status.
Preventive health checkups, lifestyle changes, prophylactic surgeries and chemo prevention are discussed as and when required.
Are all cancers hereditary?
All cancers are not genetic/ hereditary. A small percentage of them are and they have the aforementioned features.
If I have a genetic mutation, will all my children have them too?
Hereditary cancers have an autosomal dominant inheritance. This means that there is a 50 % chance that the mutation can be passed on to the next generation and vice versa.
Who should be referred to a hereditary cancer clinic?
If there is a strong history of cancer in your family you may want to discuss it with the genetic counsellor. Carry as much information of cancer in your family (up to three generations).
What is genetic testing?
Genetic testing is a test done on a blood sample or a cheek swab with the intent of identifying a gene alteration (change) that is known to increase cancer risk.