Sunday, January 4, 2009

What is CML ?

Happy New Years everyone ! I'm super hopeful for great results this coming year. Tyler is getting some good results, which puts him on track for the transplant in the end of January. He is seriously due for some good news !
I wanted to give some info on what CML is, and how they measure progress. There are some great resources out there, just do a search on CLM and Leukemia will give you some great resources. Here is how I would best describe it.
What is Chronic Myelogenous Leukemia (CML)
CML is a type of Leukemia, which inflicts about 4800 people in the US every year. A vast majority of cases occur in middle age and older people, with only a few percent of the cases inflicting children. The average age of patients diagnosed with CML is 66 year old.
There are 3 phases of CML, with Chronic being the least advanced and often occurring without any symptoms. I've actually learned of two cases where the person didn't even suspect anything, but went into the dr. office for some other injury or symptom. Accelerated is the next phase, with Blastic being the third and most severe phase. These phases are determined by how many blast cells (immature blood cells that never mature) are found in the blood. This is measured as a percentage. Usually chronic is from 0 to 15%, I was 8% when I first went in at about 12,000 blast cells. At my last visit, I had 1200 blast cells out of 62k, so that is roughly 2%. Ideally you are at 0%.
The reason this is all occurring, is that in a vast majority of CML patients, two positions on the chromosome switch place, position 9 and 22. This is also called the Philadelphia Chromosome. Now here is where an expert would have to give you a more detailed and scientific description, but basically as I've understood it, this results in a protein being created in the body, that causes the white blood cell creation to go to town.
As most of you know who have read either my own blog, or Tyler's blog, the first line of treatment is a drug called Gleevec. What the drug does which is different than Chemo drugs in the past, is that it binds to the protein that is created by the Philadelphia chromosome, and prevents the chain reaction of white blood cell creation. The drug itself doesn't kill any cells, thus it's a breakthrough in how they attack CML.
Remission Definitions
There are 3 types of milestones that they look for. They are :  Hematologic Remission (blood), Cytogenetic Remission (cell level), and Molecular Remission. Virtually all patients get to Hematologic Remission. The goal is to get to Cytogenetic remission, where the Philadelphia Chromosome becomes undetectable. This occurs in about half the patients using Gleevec.
This is where I find a lot of opinions, but here are some general guidelines that I've seen.
  • A Hematologic response is expected within 3 months. This means that your blood level numbers return to normal within 3 months.
  • The next milestone is looking for a Cytogenetic response within 6 month (reduction in leukemia cells) s, and major Cytogenetic response within 12 months (Major Cytogenetic response means that less than 35% of the cells in the bone marrow or the blood have the Philadelphia Chromosome).
  • Molecular response is when even the most sensitive tests cannot detect any evidence of leukemia. I'm not really sure how important the molecular response is, if someone shows a complete Cytogenetic response (0% of the cells in the marrow/blood show the Philadelphia Chromosome).
So what does all this mean
My first goal will be to have a hematologic response by 3 months. We're already seeing major movement in the right direction after just 12 days on Gleevec (we're really curious about this upcoming blood work since it will be after 28 days on Gleevec). After that we'll be looking for a cytogenetic response. My ultimate goal of course is a molecular response, with no evidence of any leukemia in the blood or marrow, and maybe even one day they'll tell people that it's ok to go off Gleevec, once they get enough information on how the long terms responses are.
Next Dr. Appointment is this coming week, Wednesday 1/7/09.

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