How can you have different results from gene testing?

[benninger]

Counsyl reliant cancer screen came back negative for ATM {blood draw} tested in 04/18. Foundation one came back positive for ATM L807* {slide} tested in 06/18. How can we have two different results and what does this mean.

[Tall_Allen]

The blood test was from circulating tumor cells. The other test was of a specific tumor. Cancer cells undergo genetic breakdown as they evolve. The positive slide was probably a later tumor from the ones that sloughed off into your bloodstream.

[benninger in reply to Tall_Allen]

The slide one (Foundation One ) the positive one was from the tumor that was removed in July 2017. The blood one (Counsyl) was done 4/18 and it tested negative .Does this mean the gene is gone now or could there be a mix up.

[Tall_Allen in reply to benninger]

It just means that the biopsied tumor did not contribute much to the circulating tumor cell burden. They only look at tumor cells in 7.5 ml of blood, so if the cells from that tumor didn't happen to be in that blood sample it wouldn't show up there.

[benninger in reply to Tall_Allen]

Thank You that makes sense. He is doing great now with the loupron and zytiga . Just want to tell you how much you are appreciated.

[j-o-h-n in reply to benninger]

Don't applaud... just throw money...😃😃😃😃😃

Good Luck and Good Health.

j-o-h-n Wednesday 08/29/2018 7:11 PM EDT

[benninger in reply to j-o-h-n]

Would if we had any left...I have learned more from this site than I have from his Doctors.

[j-o-h-n in reply to benninger]

I'm in the same boat, suffering with that Italian disease "mefundsarelow". You're correcto dectecto he (and they) really knows his (their) stuff.

Good Luck and Good Health.

j-o-h-n Thursday 08/30/2018 6:41 PM EDT

[benninger in reply to j-o-h-n]

Thank you and good luck to you too

[CalBear74 in reply to Tall_Allen]

Wow. Nice work on this problem!