Hi Naomii,
I think it's a good idea to push for the PCR results after 4 or 5 weeks. PCR tests do not take 3 months to do. In a busy hospital lab like Hammersmith they usually have them back within 4 weeks. In fact the blood needs to be tested within 72 hours of the sample.
The current ELNet Guidelines are:
CHR- Complete Haematological Response by 3 months all blood cell counts return to normal ranges)
CCyR- Complete Cytogenetic Response by 12 months - PH+ cells reduced by around 100 times from level at diagnosis.
*FISH test would fail to show PH+ cells visible in marrow-
**a PCR result should read below 1.5% bcr/abl
MMR- Major Molecular Response by 18 months (bcr/abl is lowered by 1000 times from the level at diagnosis) which might be shown as a 3 log drop or 0.1% remaining bcr/abl.
CMR- Complete Molecular Response can be achieved before or after 18 months and is described as a 4 - 5 log reduction or >0.01% - 0.001% bcr/abl on the international scale (IS)
If you don't meet the goals you could discuss an increase in dose or a change to another TKI (currently nilotinib in 2nd line), although some people meet the goals later or earlier than others... the earlier you reach a goal the better it is thought to be.
I don't think you should be overly worried, and your doctor might well be right, you might find that in 3 months you have reached CCyR or lower, but the current thinking is that the earlier you reach CCyR the better it is for the longer term stability of your response.
There is currently no difference in price between nilotinib or imatinib so if you think you could manage the different administration regime (from one dose a day with food for imatinib - to 2 doses a day away from food for nilotinib) then I think it is a discussion worth having with your consultant.
Hope this is helpful,
Sandy