hi matt,
your doctor is right about your pcr results being the same.... when the % ratio is figured out, the size of the sample AND the number of ABL (housekeeping) genes in the sample are crucial to the interpretation of the figure you get at the end.
remember that pcr % represent very small amounts of disease...
i would say that it is early days to switch to another drug. if you had a mutation your bcr/abl % would be rising rather than sticking. also you have been tested every 2 months rather than every 3-6 months as at most other centres.
i think you are on the standard dose (400mg)is that right?
if so then you would increase the dose to 600mg or 800mg before changing drugs.
it may be that you just need some more time and/or a higher dose.
do read anjana's layperson's explanation of PCR testing etc. on the FAQ/Glossary page... here is an extract
'....Firstly, at diagnosis, a bone marrow test is done to count how many Philadelphia chromosomes a patient has. This is the CML cancer marker. However, this test is done only on 20 marrow cells, there are millions and millions of cells so obviously this is not a sensitive test. However, for diagnosis, this is fine, since most patients are diagnosed 100%Ph+, that is all 20 marrow cells have the cancer marker. With Interferon treatment, this sometimes sufficed because majority never gained a complete cytogenetic remission when all 20 cells examined are free of the disease. However, with IM, the situation is quite different. 82% of patients achieve CCR on Glivec at 2.5 years follow-up and for most, this CCR comes quickly in the space of months. However, having no cancer marker in 20 cells does not mean you do not have disease so obviously more sensitive tests are needed. FISH is one such test that can detect the cancer marker in from 200-500 marrow or blood cells. This is an improvement on the 20 cells.
However with Glivec therapy, in 6-9 months, many patients show no disease by cytogenetics and FISH. This still means there is disease except we cannot see it. We do need to see it in order to measure Glivec's continued efficacy so in comes 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)............'
this was written some time ago so the figure for newly diagnosed CCR's to glivec is even higher now, well over 90% (see 60 month IRIS data published at ASH this year) and with ever decreasing rates of relapse year on year.
Sprycel...
the SMC (scottish medicines constortium) has approved sprycel for the NHS in scotland so there would be no problem in you changing over to that drug.
nilotinib is showing great promise too and a list of trial centres in the UK is on the news section under ENACT....... the updated list from november should be there.
try to forget about ratios/logs/percentages for a while and have a good xmas.
i am sure all will be well ;o))
love,
sandy C ;o)
