4 replies to this topic

[Taylor]

The nurse at my onc's office called with my first BCR-ABL results on Sprycel. Previously I had been undetectable for about 2.5 years on Tasigna (PCRU in 7 months).

She didn't know exactly how to read the results so she was going to ask my onc, but she said the test says

"Detected. Abnormal." For the percentages, she said there were two on the main sheet:

International Scale: 0.011.

The other, I can't remember if it just said quantitative or standard testing, but it was much lower, something like 0.009.

I'm not too worried, as that's still MMR, correct? This is the first time that I've received numbers on the IS.

It's technically not the start of a trend since it's the first on Sprycel, but I hope Sprycel can hold me down because I really like the drug.

One thing though is I got the blood drawn on a Friday, and I'm not sure how quickly they tested. I know the sample can degrade, but can it give false positives? I would have thought false negatives.

Thank you.

[Marnie]

Hi, Taylor.. ..

Your results seem just fine to me.  I'm on Sprycel and have been bouncing in and out of PCRu for awhile now.  My latest came back as <.02 IS, which is the limit of the test sensitivity.  Neither my doc nor I are worried.  Your results are even better.

My blood is always drawn on a Monday or Tuesday morning, and is only shipped across town, so it's probably pretty accurate, though sometimes it is stored.  However I talked to the phlebotomist (how do you spell that?) and he told me that they extract what they need and treat it appropriately so that when they run a batch the results are accurate. 

Anyway. . .I don't think there's any need for you to be concerned.  Your numbers are probably statistically not much different than .000.  Glad to hear that Sprycel is working well for you.

Marnie

[Happycat]

Taylor,

PCRU doesn't mean completely gone, zero, zilch, nada. It simply means the number was too low to be detected with standard instrumentation. There are two changes here.  You switched drugs - that's change #1.  Change #2 is the lab switching to IS. it sounds to me like they gave you both numbers. 0.011 is the IS number, and the 0.009 is the lab's old scale number. When there are multiple changes, it is much harder to pinpoint cause and effect.

Most instruments seem to have detection limits around 0.002 or 0.004. Some can go lower, but I'm not sure how reliable the numbers are.  That said, a number like 0.009 is pretty close to the detection limits. You're getting into the noisy baseline with that.  Think of it as trying to spot a few blades of grass that are an inch higher than all the other ones on your lawn. Not very easy, and thus more error prone.

I wouldn't worry too much about sprycel not working for you yet. You should be within the same order of magnitude if the detection limit is 0.002 or 0.004.  A little variation is to be expected.

HTH,

Traci

[Trey]

It's a 4 log reduction and close to limits of sensitivity.  If this is the first IS then maybe the lab changed equipment or it could be a new lab.

[Taylor]

Thank you all for the help and words of encouragement. I'll keep trucking along!