Do we have remission with CML?
For anyone facing a cancer diagnosis, remission is a much sought after thing - a "safe haven." For those with Chronic Myelogenous Leukemia (CML), the word "remission" may often be replaced with the word "response" when discussing the disease with fellow survivors or medical teams** The reason being that remission is often times perceived in the general public, or perhaps thought of, as a state in which the disease has been eradicated or brought under complete control so that NO ADDITIONAL therapy/treatment (chemotherapy, biological therapy, radiation, surgery, etc.) is necessary.
Some in the CML community have had family, friends and acquaintances become very concerned or alarmed to discover that they are STILL taking treatment. Questions such as "I thought you were in remission?" or "Has your cancer come back?" are asked frequently. With CML, patients are currently required to take a therapy drug indefinitely in order to keep the disease from reappearing. It is thought that the leukemic stem cell (LSC) that initiates the disease actually goes into hiding when therapy drugs (Tyrosine Kinase Inhibitors - TKIs) are introduced into a patient's system. These "hiding" cells are referred to as Quiescent LSCs. In most cases, TKI therapy will keep the disease from progressing to an accelerated or blast phase, yet does not eliminate the LSCs.
There are three categories of response CML patients experience.
- Hematologic Response - blood counts return to the normal ranges.
- Cytogenetic Response - the disease has been greatly reduced, or no longer appears in the bone marrow.
- Molecular Response - the disease as been decreased to a point that it is no longer detectible in the marrow, or it is no longer detectible utilizing Polymerase Chain Reaction (PCR) testing.
NOTE: Being found "CMR", "undetectible" or "PCRU" does not indicate cure as there is no way to know whether every cell in your body is free of the Philadelphia Chromosome.
** More on remission vs response:
Merriam Webster defines remission as: "a state or period during which the symptoms of a disease are abated <cancer in remission AFTER treatment>." Another source* defines remission as "diminution or abatement of the symptoms of a disease; the period during which such diminution occurs." As you can see, CML DOES fit some definitions of remission, yet if you were to survey 100 people, you might find many different definitions.
*Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. (c)2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
Do most people become resistant to Gleevec?
No, in fact, only a small percentage of individuals develop resistance to Gleevec® or other TKIs. You Hematologist/Oncologist will order the appropriate tests to determine if resistance has developed but only based on significant changes in your blood work.
What is a Log Reduction?
"Log reduction" is a mathematical term used to show the relative number of cells, germs, microbes, etc., reduced in or on something. When the term log reduction is used in CML, it refers to the reduction one's CML, or specifically BCR-ABL.
For example, a "5-log reduction" means the number of Philadelphia Chromosome positive cells have been reduced 100,000-fold.
1 log reduction means the number of CML cells is 10 times smaller
2 log reduction means the number of CML cells is 100 times smaller
3 log reduction means the number of CML cells is 1000 times smaller
4 log reduction means the number of CML cells is 10,000 times smaller
5 log reduction means the number of CML cells is 100,000 times smaller