Advanced Member
Posted 02 June 2016 - 11:29 AM
I was wondering if anyone has found a good explanation online of the meaning of PCR test values. I notice that many people here are posting percentages. My FISH test at diagnosis had a percentage (87), but my PCR test has a numeric value. It is listed as 1.2X10*5 (or 120,000). I have not been able to find a good explanation of how to convert this value to a percent.
Thank you in advance for any help.
-Adam
3/23/2016 Dx PCR 93.4399% IS, FISH 87%
3/30/16 Sprycel 100mg
4/15/2016 liver toxicity and a brief stint on Tasigna 600mg book-ended by drug breaks
6/6/2016 resumed Sprycel at 50 mg increased to 70 one month later followed by 100mg
6/17/2016 FISH Test 2%
8/22/2016 PCR 0.0035% IS
11/7/2016 PCRU
12/29/2016 PCRU
4/5/2017 PCRU
6/28/2017 PCRU
10/26/2017 PCRU
Advanced Member
Posted 02 June 2016 - 11:53 AM
PCR is expressed as a percent (or should be). Specifically it is a ratio of bcr-abl proteins (produced by the CML cells) to the normal abl control protein. bcr-abl/abl is what is reported. The value you cite above: 120,000 makes no sense as a PCR lab test result.
FISH is a percentage of CML cells observed under the microscope. Eighty Seven percent of your cells under the microscope were CML at diagnosis. Many patients start out with 100% of their observed cells as CML - or FISH = 100%.
FISH is a true number of cells measure. PCR is a molecular measure and roughly correlates to number of cells.
During successful treatment, FISH will fall to zero (i.e. cytogenetic remission). This is a very important result to achieve. When FISH falls to zero, PCR is usually around 1%.
Diagnosed 11 May 2011 (100% FiSH, 155% PCR)
with b2a2 BCR-ABL fusion transcript coding for the 210kDa BCR-ABL protein
Sprycel: 20 mg per day - taken at lights out with Quercetin and/or Magnesium Taurate
6-8 grams Curcumin C3 complex.
2015 PCR: < 0.01% (M.D. Anderson scale)
2016 PCR: < 0.01% (M.D. Anderson scale)
March 2017 PCR: 0.01% (M.D. Anderson scale)
June 2017 PCR: "undetected"
September 2017 PCR: "undetected"
Advanced Member
Posted 02 June 2016 - 12:23 PM
Thank you for the explanation. I wonder if the lab is using its own type of scale. I agree that the value does not make sense to me. Based on what I had found the PCR has some type of logarithmic scale and I was hoping that there was some way to convert this value using some function or formula, but if it is generally reported in a percentage then this must have some other meaning.
3/23/2016 Dx PCR 93.4399% IS, FISH 87%
3/30/16 Sprycel 100mg
4/15/2016 liver toxicity and a brief stint on Tasigna 600mg book-ended by drug breaks
6/6/2016 resumed Sprycel at 50 mg increased to 70 one month later followed by 100mg
6/17/2016 FISH Test 2%
8/22/2016 PCR 0.0035% IS
11/7/2016 PCRU
12/29/2016 PCRU
4/5/2017 PCRU
6/28/2017 PCRU
10/26/2017 PCRU
Advanced Member
Posted 02 June 2016 - 01:59 PM
Ask your lab what your PCR result is in the "international scale". They should be able to provide that to you.
The log scale is used to compare one result to the next. So assume for example, that your PCR was 100% at diagnosis. And then at your next test your PCR was 1% - you would have a two log drop in PCR. It's just another way of comparing one response to the next.
Using the example above - a three log drop would be 0.1% and a four log drop would be 0.01% PCR. Any thing lower than 0.01% (I.S. scale) is within the limits of the test.
Diagnosed 11 May 2011 (100% FiSH, 155% PCR)
with b2a2 BCR-ABL fusion transcript coding for the 210kDa BCR-ABL protein
Sprycel: 20 mg per day - taken at lights out with Quercetin and/or Magnesium Taurate
6-8 grams Curcumin C3 complex.
2015 PCR: < 0.01% (M.D. Anderson scale)
2016 PCR: < 0.01% (M.D. Anderson scale)
March 2017 PCR: 0.01% (M.D. Anderson scale)
June 2017 PCR: "undetected"
September 2017 PCR: "undetected"
Advanced Member
Posted 02 June 2016 - 03:33 PM
When is a PCR test usually administered? I was diagnosed about 9 weeks ago and I had a BMB and FISH test while I was at the hospital, but I don't believe I had a PCR test performed. Is that normal?
DX 3/30/2016 WBC 484.2 FISH 95.3
took Hydrea 3/30-4/11
taking Sprycel 100 mg since 4/5
10 day break from Sprycel for platelet count of 12 4/26-5/8
7/07/2016 1.47% (IS)
9/30/16 BMB PCR .1259 switched to new onc
12/30/16 PCR .1569
4/7/17 PCR .0904 MMR
7/14/17 PCR .0520
12/1/17 PCR .0148
Advanced Member
Posted 02 June 2016 - 04:21 PM
When is a PCR test usually administered? I was diagnosed about 9 weeks ago and I had a BMB and FISH test while I was at the hospital, but I don't believe I had a PCR test performed. Is that normal?
At diagnosis the BMB and FISH are most important. PCR is often done at the same time (and may be in your bone marrow report), but is not necessary. The condition of your bone marrow (cytogenetics) and how many cells as a percentage under the microscope (FISH) which are CML cells is most important in the beginning.
Only when FISH drops to very low percentages eventually to zero in response to treatment does PCR then become relevant as a continuing indicator of residual CML disease at the molecular level.
Diagnosed 11 May 2011 (100% FiSH, 155% PCR)
with b2a2 BCR-ABL fusion transcript coding for the 210kDa BCR-ABL protein
Sprycel: 20 mg per day - taken at lights out with Quercetin and/or Magnesium Taurate
6-8 grams Curcumin C3 complex.
2015 PCR: < 0.01% (M.D. Anderson scale)
2016 PCR: < 0.01% (M.D. Anderson scale)
March 2017 PCR: 0.01% (M.D. Anderson scale)
June 2017 PCR: "undetected"
September 2017 PCR: "undetected"
Advanced Member
Posted 02 June 2016 - 09:44 PM
1.2X10*5 (or 120,000)
120,000 would not be possible. Max theoretical PCR would maybe be about 200% IS. It could be 1.2 x 10 -5th, which is .000012 which sounds too low for that FISH result, but I don't know. Ask for a copy of the report.
Advanced Member
Posted 03 June 2016 - 04:25 AM
120,000 would not be possible. Max theoretical PCR would maybe be about 200% IS. It could be 1.2 x 10 -5th, which is .000012 which sounds too low for that FISH result, but I don't know. Ask for a copy of the report.
Trey, I do have a copy of the report and 1.2 x 10*5 is what is listed on it. Unfortunately most of the report is written in Japanese. I was told it was a PCR report and assumed thta it would be easy to figure out how to interpret the number, but it seems unlikely. I will ask more questions about it the next time I see my onc.
Scuba, thanks for your input as well. I was concerned that not having my PCR value from before taking any TKIs would be a problem in the future, which was why I was trying to interpret it. At least I now know that I don't need to worry so much if I can't convert the value to the IS. In the future, I believe they will do the PCR from my blood instead of the BMB. Hopefully at that time they will give me proper percentages.
3/23/2016 Dx PCR 93.4399% IS, FISH 87%
3/30/16 Sprycel 100mg
4/15/2016 liver toxicity and a brief stint on Tasigna 600mg book-ended by drug breaks
6/6/2016 resumed Sprycel at 50 mg increased to 70 one month later followed by 100mg
6/17/2016 FISH Test 2%
8/22/2016 PCR 0.0035% IS
11/7/2016 PCRU
12/29/2016 PCRU
4/5/2017 PCRU
6/28/2017 PCRU
10/26/2017 PCRU
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