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Shared care and Q-PCR

I have now got the reeferal for a second opinion/shared care at a CML centre of excellence, which I asked for.As you may remember I was on a reduced dose of Glivec for 8 weeks, reduced to 200mg from 400mg. The reason my doctor reduced the dose was because of my almost intolerable side efects. I now know this is below the recommended dose level. Having had excellent advice from this site (thanks Sandy)I began to question my treatment and find out more. It has been 1 year since dx.

My two hospitals are now comminicating! As I am due a bone marrow biopsy (one hospital forgot this & I had to remind them!) The prof has asked for a Q-pcr biopsy. Does anyone know what the "Q" stands for? I shall have to wait the resuts of this befor I can see him, so another few weeks of awfull side effects as I am back on 4oomg, which is what I should be on. I put my faith in the Drs at my local hospital & feel very sad that I have had to question them.

Perhaps they will change my drug for Dasatinib or Nalotinib. I know that these both have different side effects but cant find out what they might be..can anyone fill me in here please? I hope they might be more managable. I know the PCT in this area are reluctant to fund it and also I dont think its NICE approved in this area either.
Thanks for your time in reading my post kind regards to you all.

Hi Ali,

Not sure if this helps, I'm very much learning all this stuff myself.

I found a telephone interview from Dr Druker (assisted getting Glivec on the market) kindly referred to by someone on the forum.

In the transcript he mentions that his preference for monitoring the PCR value is a "quantitative PCR" because it gives him a number that he can monitor.

I hope all goes well. My son is having his first "quant PCR (BCR-ABL) test on Tuesday.

Kindest Regards
Michelle

For more information on PCR's go to the FAQ section on the left hand menu.

Here is a snip from the info on there which explains what PCR's are and what you should expect:

.....polymerase chain reaction tests or PCR tests. This test has the capability to look for a needle in a haystack, namely, 1 leukaemic cell in as many as 1 million normal ones. It is molecular testing and so the response by PCR is described as molecular response. When patients reach this level, when they are zero by all other tests except PCR, they are said to have minimal residual disease.(MRD)

Like we watch the cancer marker decrease as in reduction of Ph percentage from bone marrow cytogenetics or FISH, we now have a technique, the PCR, where the cancer marker can indeed be tracked at low level of disease. For some years, qualitative PCRs have been used for post-SCT patients to track for molecular relapse which usually heralds cytogenetic and hematological relapse. Qualitative PCRs are those that give a positive or negative without giving numbers.

More useful are quantitative PCRs which give a number. To us laypeople, what exactly is this number? PCR tracks the BCR-ABL transcripts and the number that is churned out is a percentage ratio of leukaemic cells to total cells. In order to be sensitive and correct for degradation of RNA, a housekeeping gene is used as a control. And therefore, the PCR result is expressed as the percentage ratio of BCR-ABL (cancer marker gene)in leukaemic cells to housekeeping gene which is expressed in all cells. This ratio is necessary to cancel out errors in the PCR measurements and give a reliable marker of the disease status.

Nowadays, real-time quantitative PCRs are used in most of the top centers to track low-level disease. However, even in this low-level disease, there are sub-levels. Patients in CCR can have high PCR values or low PCR values. Therefore, the CML experts have come up with two stages of response in the molecular category. Major molecular response (MMR) is a 3 log reduction of the disease from diagnosis(1000-fold reduction) and complete molecular response is when there is no cancer marker present from the PCR tests.

Sandy

Ali,

Reducing the Gleevec dose to 200 mg daily should never be done unless you had serun level testing to confirm that the 200 mg dose for your body is the same as the 400 mg dose for the rest of the population.

The experts will stop Gleevec completely, wait for the side effects or low counts to return to normal and then restart Gleevec at the 400 mg dose.

The reason for this is that if you take a suboptimal dose of Gleevec, your body will become resistant to Gleevec.

Zavie

Ali,

Reducing the Gleevec dose to 200 mg daily should never be done unless you had serun level testing to confirm that the 200 mg dose for your body is the same as the 400 mg dose for the rest of the population.

The experts will stop Gleevec completely, wait for the side effects or low counts to return to normal and then restart Gleevec at the 400 mg dose.

The reason for this is that if you take a suboptimal dose of Gleevec, your body will become resistant to Gleevec.

Zavie