Guardant 360

[ron_bucher]

I’m interested in hearing about anyone using Guardant 360 test results for their treatment decision.

[RJAMSG]

Hello Ron, I’ve not heard of the Guardant 360 yet? Genetics? Link to more information?

[ron_bucher in reply to RJAMSG]

ncbi.nlm.nih.gov/pmc/articl...

[MoonRocket]

Do you suspect a HRR mutation or are you curious? Liquid biopsies have a pretty large false findings. Something to consider. I think the saliva testing is pretty solid though.

[ron_bucher in reply to MoonRocket]

Can you share the “false finding” data you refer to? What is HRR?

[MoonRocket in reply to ron_bucher]

Not to be curt, if you don't understand what HRR you need to do a little research on the purpose of these tests. It can help guide treatment decisions but only in the hands of people who understand the results.I'm not even sure this liquid biopsy is approved for prostate cancer. I suggest the Foundation One CDX liquid biopsy instead.

[ron_bucher in reply to MoonRocket]

saliva tests are for mutations we are born with. Guardant 360 is for mutations developed after birth.

[MoonRocket in reply to ron_bucher]

My comments were regarding liquid biopsies. The germline test should be okay, but of little value IMHO absent a positive tumor or liquid biopsy test.

[PCaWarrior]

My MO likes the test. I've had 4 of them. The test reads out various mutations and metrics. Tumor mutational burden, MSI status, and over 100 genetic mutations. Somatic.

FDA.gov:

"Both Guardant360 CDx and FoundationOne Liquid CDx are approved for people with any solid cancer (e.g., lung, prostate), but not for those with blood cancers. While FDA has approved other blood tests that check for the presence a single gene mutation in tumor DNA, these are the first approved blood tests that check for multiple cancer-related genetic changes."

[ron_bucher in reply to PCaWarrior]

Did your test results factor into treatment decision(s)?

[PCaWarrior in reply to ron_bucher]

We started testing two years ago expecting AR changes. AR amplification is a sign that my current therapy is not working as well as desired and that CRPC is brewing. We know exactly what we will try if this is the case. So far, nothing. When my PSA started going up we suspected mets since Guardant reported that I have no mutations and that my ctDNA has dropped to undetectable. So I had a PSMA scan and am now going through SBRT (5 treatments).

[Seasid in reply to PCaWarrior]

Could you add olaparib parp inhibitor during the SBRT of your cancer?

[dico]

The Guardant360 pointed my husband to Keytruda due to a MSI-HI result. My husband was a super responder and his cancer has been undetectable since June 2022 after only one infusion of Keytruda.

[EdBar]

I’ve had a few genetic test run over the last few years, the first was a Guardant 360 run by Snuffy Myers several years ago to test for neuroendecrine cancer which thank goodness was negative. Since then Dr. Sartor has run an another Guardant 360 which again showed nothing. He has also ran a couple of Caris genetic tests which turned up 2 germ line genetic mutations, one being CHEK2 which may fall into the category of HRR mutations and make it an option to treat with a Parp Inhibitor and enzalutamide which was recently approved by the FDA. He said there is a current study taking place to refine what is considered a HRR mutation since currently that field is very wide. If CHEK2 falls in that category then I’ve got another bullet in the holster. He has also run a Tempus genetic test recently to check for somatic mutations but it came up negative.

Ed

[j-o-h-n]

Guardant360 is just another way of saying 4 o'clock.......

Good Luck, Good Health and Good Humor.

j-o-h-n Tuesday 10/31/2023 7:12 PM DST

[PCaWarrior]

If you have children, a germline test is good.