The genetic evaluation importance on cancer patients has grown a lot. However, these are expensive tests and do not always have specific management and / or effective prophylactic treatments. For this reason, it is important that the test is requested in the more suitable cases. Who, when and how to test?
The answer: It depends!
Who should we test?
What should be taken into account when indicating this type of test:
- The patient tumor type and its specific characteristics (pathological anatomy and immunohistochemistry);
- Family history with cancer cases, taking into account the family members tumor types, as well as the diagnosis age and kinship degree with the patient / probing that is being evaluated.
With the information above it is possible to indicate whether or not there is a risk of the evaluated patient having a genetic predisposition syndrome to hereditary tumors. This way we can determine that who should be tested are all patients at risk for genetic predisposition syndrome to hereditary tumors.
When should these patients be tested?
When the risk is identified and when there is a diagnostic suspicion (taking under consideration the patient’s data and which syndrome is suspected). If there is a family case cluster, we start testing for patients who already have a confirmed cancer diagnosis.
How to test patients?
In the first family case, the most current indication for evaluation is a gene analysis panel most associated with the genetic predisposition syndrome to suspected hereditary tumors. If no changes are found in this evaluation, we follow it with tests for major genomic rearrangements.
Once the mutation associated with the genetic predisposition syndrome to hereditary tumors is identified, it is indicated that first-degree relatives are also tested, this time, only by the test that exclusively evaluates the family mutation.
OBS: Nowadays, there is already a strand in literature that indicates the genetic evaluation for all breast cancer cases. In this type of tumor, some studies have applied the “Polygenic Risk Score”, calculated based on the variants accumulation that have no identified pathogenic effect.
About the author:
Taisa Manuela Bonfim Machado Lopes has a PhD in Sciences at Oswaldo Cruz Foundation and studied biology at the Federal University of Bahia. She is currently the coordinator of the Molecular Biology sector at the Laboratory of Immunology and Molecular Biology at the Institute of Health Sciences (UFBA).