Comment by ufo
4 days ago
Genetic tests for cancer are a different kind of genetic test. They test the tumor itself for mutations that are present only in the tumor, not in the rest of the body.
4 days ago
Genetic tests for cancer are a different kind of genetic test. They test the tumor itself for mutations that are present only in the tumor, not in the rest of the body.
Oh interesting. I didn’t know that. Thank you for the clarification.
Are you sure? BRCA testing is just a genome test, not the tumor. I may be misunderstanding your statement.
BRCA is one risk factor for certain cancers. You can get genetic counseling to understand your cancer risk looking at this and other markers.
In this context, though, we're talking about measuring the actual cancer (including the tumor's mutations) to determine what therapies it is likely to be responsive to.
e.g. this: https://www.cancer.gov/about-cancer/treatment/types/biomarke... not this: https://www.cancer.gov/about-cancer/causes-prevention/geneti...
I don't think anybody in this thread moved to talking about tumor sequencing.
I'm just responding to:
"""Genetic tests for cancer are a different kind of genetic test. They test the tumor itself for mutations that are present only in the tumor, not in the rest of the body."""
Strictly speaking, BRCA is a genetic test for cancer (even if it's only a "risk factor"), and it's done on the regular genome, not on the cancer.
(None of this is important or really relevant)
1 reply →
Indeed, there are some cancers with a hereditary predisposition. But they are quite rare and such genetic counseling is usually only indicated when there is a family history of the disease.
For the vast majority of cancer patients, generic testing means somatic testing for tumor markers.