Welcome, and thanks for joining me! I'm assuming you have some knowledge of Hereditary Breast and Ovarian Cancer (HBOC) and BRCA1 and BRCA2 genetics testing but will include links to further information at the end for anyone who might one day be reading this and have no idea what I'm on about.
My family history - the background
I'm female, 33 years old, living in the UK, and have a family history of breast and ovarian cancer. My mother was diagnosed with breast cancer aged 47, her mother was diagnosed with breast cancer aged 59 and her mother died from ovarian cancer aged 58. These are the only 3 women in my family across those three generations - and I am the only woman (and person) in my generation. It's a small family, so the numbers are small, but the reality is breast and ovarian cancer have killed 100% of the women in the 3 generations of my family before me, and I feel very much like I'm next.
I talked to my GP about it and was referred to the Family History Service, and referred on by them to the Genetics Clinic. The Genetics Clinic confirmed that this is a significant family history which suggests a genetic fault in the family causing these cancers. I was offered a genetic test to see if I have a BRCA 1 or BRCA 2 gene mutation.
My genetic test
Ideally, when there is a family history of breast and ovarian cancer, the first genetic test in that family will be done on someone who has / has had one of these cancers. They look at the whole of the BRCA1 and BRCA2 genes and see if they can find a mutation.
If a mutation is found then they know exactly what the problem is in that family. Other family members can then have a genetic test which checks specifically for this mutation. If that mutation is there then they know they have an increased risk of developing breast and ovarian cancer. If that mutation is not there then they know they have not inherited it and they do not have an increased risk of developing breast or ovarian cancer.
If a mutation is not found then it is likely that the family has HBOC caused by something other than a mutation in the BRCA1 or BRCA2 genes. There is a whole world of research about this.
In my case there was no-one alive with cancer to test first. So the test I had looked at the whole of my BRCA1 and BRCA2 genes to see if there was any mutation.
My test result - uninformed negative
I received my test result - and it's negative! No BRCA1 or BRCA2 mutation found! Good news! Right?! Wrong.
My test result tells me that I do not have a mutation in my BRCA1 or BRCA2 genes. It does not tell me whether this is because:
- There was a BRCA1 or BRCA2 mutation in my family which caused the history of breast and ovarian cancer and I did not inherit it. Or,
- There is another cause of the history of breast and ovarian cancer in my family other than a BRCA1 or BRCA2 mutation (for example a mutation in another gene, or something else affecting the BRCA1 or BRCA2 genes from a distance) which can't yet be tested for.
- I am not an increased risk of developing breast or ovarian cancer. Or,
- I am at a significantly increased risk of developing breast or ovarian cancer.
This is why I am an "uninformed negative" - I am uninformed as to whether the BRCA1 and BRCA2 genetic test result was negative because there was a mutation and I didn't inherit it so am in the clear, or because the problem in my family lies outside of those 2 genes.
So what next?
I'll write a bit about that in my next post!
Further information about HBOC and BRCA genes
A few places where you can read about hereditary breast and ovarian cancer and BRCA - but I will be creating a more comprehensive list of further information and resources later.
Family History (Breakthrough Breast Cancer)
Breast cancer in families (Breast Cancer Care)
FORCE website (Fighting hereditary breast and ovarian cancer)
NICE guidelines on familial breast cancer (for people in the UK)
Breast cancer genes (Cancer Research)
OPERA online tool to check risk of hereditary breast and ovarian cancer (Macmillan)
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