Please read the interesting paper in the link provided below. It is from research being done at both the Mayo Clinic and in Portugal and it is recent, 2009. They have a very positive hypothesis which they have worked out in virtual models of CML patients, which substantiates, in part some of the findings that may be happening with the patients in the STIM trials in Europe. So, in fact they are saying and this is directly quoted from the paper: Leukemic stem cell extinction: We evaluated the natural history of a million virtual patients following their disease over time from the appearance of the first LSC. Figure 3A shows the probability of extinction of the LSC lineage as a function of fitness advantage, illustrating that this probability is maximized precisely in the case of CML in which LSC and hematopoietic stem cells are neutral. Figure 3B displays the increase of the extinction probability as a function of time under neutral evolution. The simulations portray a remarkable and unexpected result in the context of CML: in the vast majority of cases, clonal extinction of LSC occurs. More importantly, by the time the disease is diagnosed (~5 years after the appearance of the first LSC), most patients - 84% - no longer have LSC . Closer inspection of the results shows that LSC extinction is an early event: after 1 year already 50% of the patients no longer have LSC. For those patients in whom LSC are still present, we observed that the average clone size increases by one LSC per year (R2=0.9999). Moreover, since the current model treats certain parts of the hematopoietic tree stochastically, some patients may never be diagnosed with CML, despite initially carrying LSC (see below). - this is from the paper and substantiates what I said a few days ago....
This paper actually illustrates a comment that I made earlier, that there is a finite set of LSC, that do become extinct. The paper goes on to say that treatment with a TKI should probably be for about 9 years, as long as the patient is having a good response to the TKI, in order to ensure that all cells that could cause repopulation of the disease are in fact eradicated.
I do realize that this is research, but you will note from reading the paper that there are some very interesting references to results that substantiate some of what these researchers are saying so that this all makes a plausible sense.
All quite positive and happy thoughts for a Sunday....
The paper is titled:
Tyrosine kinase inhibitor therapy can cure chronic myeloid leukemia without hitting leukemic stem cells