How important is genetic testing

[Islandboy2021]

Should I get a genetic test done to confirm the type of cancer I have.

Thanks

[Tall_Allen]

Definitely take a germline genomic test, like Color Genome Dx.

Idk if you can get a somatic genomic test in Canada- they are very expensive. You would have to have metastases big enough to get enough biopsy tissue.

[Islandboy2021 in reply to Tall_Allen]

I will definitely look into the genomic test. I know I had the biopsy done on my prostate at diagnosis in 2017 and they collected 12 cores. Not sure if these are available. I would assume not.

[Tall_Allen in reply to Islandboy2021]

That would not be useful.

[dhccpa in reply to Tall_Allen]

I had that same question. My biopsy was in July 2018. Scans done shortly afterward showed bone Mets in a number of places. You're saying the original prostate tumor tissue no longer serves any useful purpose? Or simply isn't useful for analyzing the bone Mets?

Thanks

[Tall_Allen in reply to dhccpa]

Yes, both. For germline - saliva or blood - it is cheap and should be done for everyone; for somatic- a recent large met is best - it is expensive. There are somatic blood tests too - but they are very expensive and often tell you less than a tissue test. Genomics usually are not actionable, but sometimes they are. Histology and IHC can also provide clues.

[dhccpa in reply to Tall_Allen]

Thanks

[tango65]

The best information about the cancer is to study the genome of the cancer, since it could be different of your genome. My cancer has PTEN loss but my genome does not have it.

If direct biopsies can not be done, it may be possible to get a liquid biopsy to look for cell free DNA, but with your PSA the yield of a liquid biopsy will be negligible.

You can get a genetic study of your genome which could show mutations like BRCA, PTEN etc. which will be also present in the cancer and they may be actionable mutations which could be treated with specific drugs.

[Seasid]

Are they biopsying the prostate in Canada?

Do you have some saved samples?

My 4 years old prostate biopsy sample was rejected by PeterMac quality control. They can't genetically test it. It was maybe too small.

The sample is also too old now as it is always preferable to biopsy a new mets as the cancer always change and reinvents itself.

It looks like it is not so easy to get a good quality biopsy sample for genetic testing.

I believe that even with a PSMA PET scan they would have difficulty finding mets to biopsy.

[EdBacon in reply to Seasid]

Prostate biopsies aren't useful for this purpose. You need to have tissue from active metastases.

[Seasid in reply to EdBacon]

I agree, and i know that, but my MO did send my 4 years old prostate biopsy sample to Peter Mac, but Peter Mac did reject the sample.

Should I find a new place for treatment?

Did they biopsy your prostate in order to determine your Gleason score?

[EdBacon in reply to Seasid]

They don't biopsy the prostate at stage 4 as far as I know. Gleason scores are for prostate biopsies. I did initially get a biopsy of a lesion on my pelvis.

I don't think you should necessarily find a new place for treatment. Just see if you can get genetic sequencing done. They might find a treatable somatic mutation like BRCA 1, BRCA 2 or ATM.

You can't always get a tissue sample so in those cases, liquid biopsy (blood test) can be used. It's less sensitive though.

[Seasid in reply to EdBacon]

Are they determining a Gleason score at stage 4?

Why did my MO sent my biopsy (original greason score biopsy sample) to Peter Mac for genetic testing? And previously he wanted to send the same sample to the USA for the same purpose?

Do you believe that it is a proper way? If it is ok, than why everyone is here now screaming that prostate biopsy is not good.

I am confused.

[EdBacon in reply to Seasid]

From what I know, Gleason scores are generally only done with prostate biopsies. It's also useful to do genetic testing on the prostate, but the cancer evolves and the mutations evolve over time. These are called somatic mutations. For example, the cancer may not have a BRCA 2 mutation in the early stages, but develop one later. In this case, it's possible to treat the cancer with a PARP inhibitor. It's best to get tissue from newest active mets to evaluate.

Once the horses get out of the barn so to say, we're not as interested in what's in the barn.

[Seasid in reply to EdBacon]

So it was a mistake sending my old prostate biopsy samples to Peter Mac for genetic testing? Can I rely on such a team to treat me?

[Seasid in reply to EdBacon]

Could you please fill out your profile? It would help to other members to respond to you.

[EdBacon in reply to Seasid]

I did it.

[Chugach]

I’d be dead years ago without it

[HopingForTheBest1]

A genetic test will also let you know if Keytruda can be an effective treatment. You need to be MSI and have a high tumor burden, which a genetic test will identify.

The test results can also determine whether any of your siblings, children, or other relatives should be tested as well. It could potentially save their lives.

[Rocketman1960]

Absolutely do it. If you are lucky it will open up other treatment options.

[SteveTheJ]

More information is better than less information. As for knowing what type of cancer you have, that's probably not the correct question to ask.

I got a spit-in-a-test tube test from Invitae, I think. There are other types of tests like blood tests. I was told that if my test results were meaningful that my brothers could both get free tests ... but the results weren't meaningful. I would do the same thing again though.