Hi @maryp,
I can give you my experience with this.
I have stage 4 HGSOC, was diagnosed in late October 2022. In my case, blood sample (germ line) BRCA testing was done at the time of diagnosis - it took about a month to get results - and it came back negative. I have four adult children, two of them daughters, so I had mixed feelings about the result - on the one hand disappointed, because I knew that a BRCA mutation would improve my prognosis. and on the other hand, relieved that I would not be passing the mutation and the increased risk of cancer to my children.
.
Tissue testing was done at the time of surgery (January) - it also took about a month to come back - and it came back positive for a somatic BRCA1 mutation. I am currently receiving Bevacizumab (trade name Avastin) along with the usual carboplatin/paclitaxel doublet for the 6 post-surgery chemo rounds, and will be getting Avastin and Olapararib (trade name Lymparza) for the maintenance phase of treatment.
Olaparib is the parp inhibitor that has shown greatest efficacy for patients with both BRCA 1 and 2 mutations, regardless of whether they are germline or somatic mutations. Clinical trials using Olaparib for maintenance treatment have shown significant improvements in progression free survival times (PFS) compared to patients with BRCA mutations that receive a placebo, as well as increased outcome survival times (OS).
The way I see it, it was the best possible outcome in terms of BRCA.
I felt exceedingly lucky to be in the very low percentage of patients with ovarian cancer to have a somatic BRCA mutation (in the order of 3-5%). And very happy to not be passing a deleterious mutation on to my kids. I get the benefit of the BRCA sensitivity to treatment and my kids don't have to have BRCA in their DNA.
I can't speak to the testing situation in Ontario, as I am in Manitoba.
Not only was I offered the the blood test and the tissue test, I have also been referred to genetic counseling to help me to understand the results. At the time of the counseling, they will review my family history of cancer and will likely offer a genetic screening panel and further consultation once those results are in. It's going to take a while to move up the queue for the genetics consult, but I'm grateful for it having been offered.
To the topic of germline testing: From my reading, and in discussion with my very knowledgeable oncologist, it is very unlikely for a person with a somatic BRCA mutation to also have a germline mutation.
That being said, I can completely understand your desire to find out whether that is true in your mom's case. If I were you, I would be wanting to know for certain about that as well. And I'm surprised that the blood test wasn't done, as it seems to me to be standard of care these days for advanced ovarian cancer, given that the percentage of patients with BRCA (or other HRD mutations) is quite high, and given that treatment decisions would be affected by that information.
However, now that they have the somatic tissue results for your mom, the oncologists would not be incentivized, from a medical or treatment perspective to do the blood testing on your mom, as the results would not affect their treatment decisions. She would be getting Olaparib regardless of whether it was germline or somatic.
The blood test results would really only affect you and other family members.
There are labs that you can pay to do genetic testing - something to consider if it that is an option for you financially, and if you can't get the province to pay for testing on your mom.
I don't have any links, but if you search genetic testing Ontario in google you will find private lab options.
I hope that info was helpful, please feel free to ask questions if I missed anything.
I hope treatment is going well for your mom. How is she faring?
Petra