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Monitoring and Adherence in CML

Posted Aug 24 2008 1:49pm

ANNOUNCER: Treatment for many patients with chronic myelogenous leukemia or CML can be so effective experts say it can now be managed as a chronic condition.

PATRICIA JAKEL, RN, MN, AOCN: It's like having diabetes, it's like having heart disease, that you need treatment for long periods of time. We may not cure you, but we're going to keep your disease in check and in remission.

MICHAEL MAURO, MD: When the disease is in remission, there's very little to remind you that you even have leukemia. Many of my patients will say, "If I didn't have to take that pill once a day, I wouldn't remember, really, that I had leukemia." On the flip side, our task is to make sure that we do whatever we can to help patients remember and to understand that compliance is crucial to maintaining response.

ANNOUNCER: The pill is imatinib or Gleevec, a targeted anti-cancer drug. While imatinib will keep the CML in check for most patients for many years, infrequently, relapse can occur.

CAROLYN BLASDEL, RN, FNP, OCN: Cancers are notorious for developing resistance to treatment, and it's thought that by suboptimal dosing -- in other words, by having inadequate levels of Gleevec in your blood that this gives the cancer a chance to figure out ways to get around the drug, and we call that resistance.

ANNOUNCER: It is important for patients to take imatinib as prescribed by their doctor to fight the disease and to guard against resistance. Regularly scheduled monitoring helps doctors and patients know if the medicine is working and if patients are reaching treatment goals.

JORGE CORTES, MD: The issue of monitoring has become more and more relevant, because the better treatment options you have for a patient, the more critical it is that you make sure that the goals that you want for a patient are met, and if not, that you do something to improve that.

CAROLYN BLASDEL, RN, FNP, OCN: Typically when people are diagnosed with CML, their white blood count's quite high. It could be 50,000, it could be 300,000. But normally within the first month, those counts go back to normal.

ANNOUNCER: Blood tests should be conducted every week or two until patients achieve a complete hematologic response. When blood counts normalize doctors will continue to monitor patients' progress every six months with cytogenetic testing to check what impact the treatment is having on the underlying disease.

CAROLYN BLASDEL, RN, FNP, OCN: The gold standard for CML is a bone marrow biopsy and aspiration, and with a bone marrow, we can look at what's actually going on inside the marrow, where blood is produced, and in particular cytogenetics. And CML is caused by a translocation between chromosomes 9 and 22. So when we do a bone marrow biopsy, we're looking for that. Is it present?

ANNOUNCER: Cytogenetists examine 20 marrow cells to check for the phildelphia chromosome, which results from the translocation. Any decrease in the percentage of cells containing the Philadelphia chromosome is called a cytogenetic response. At one year, doctors have a specific target.

NEIL SHAH, MD: When we move out to 12 months, we're expecting a deeper level of response, so we're expecting the bone marrow to show no more than 35% of cells to contain the Philadelphia chromosome in metaphase analysis. And this is termed a major cytogenetic response.

ANNOUNCER: CML is still present after a cytogenetic response. Another more sensitive test is used to measure the remaining percent of cml cells. It is called fish or fluorescence in situ hybridization. It is performed on the blood or bone marrow and detects the presence of the abnormal BCR-ABL gene, which results from the translocation of chromosomes 22 and 9.

STEPHEN NIMER, MD: We take the cells and we look under the microscope, using a fluorescent probe that allows us to distinguish between a normal cell and a CML cell. And when we do this analysis, we look at 500 cells and then we can say whether half of the cells or 250 of the cells are the leukemia cell or if 10 out of the 500 are the leukemia cell or if 1 out of the 500 is a leukemia cell.

ANNOUNCER: The most sensitive techniques are molecular tests known as PCR or polymerase chain reaction.

STEPHEN NIMER, MD: What PCR allows us to do is to take 100,000 cells and, even one of them has this BCR/ABL in it, we can amplify that to the point where we can detect a positive result and then we know that there are CML cells still in the patient.

ANNOUNCER: Many doctors order PCR testing every three to six months. In many cases, results show an ever decreasing percentage of white blood cells with the Philadelphia chromosome.

JORGE CORTES, MD: The goal of therapy has become to achieve what people call a major molecular response, which has been equated to what's been defined as a 3-log reduction in the levels of transcripts, product of the Philadelphia chromosome.

STEPHEN NIMER, MD: Whatever level the patient started out with, if that patient's disease goes down to 1/1000th of the amount that they started with, we say they've had a 3-log reduction.

JORGE CORTES, MD: The reason why achieving this major molecular response or 3-log reduction is important is because what we've shown is that it correlates with the best outcome.

STEPHEN NIMER, MD: 94% of the patients who have had this 3-log reduction are still doing marvelously well with no sign of the disease getting worse.

CAROLYN BLASDEL, RN, FNP, OCN: But even when we can't find any evidence of CML with our most sensitive test, it's still possible that because of there being something like a trillion cells in the bone marrow and our sensitivity is only 1 in a million, there could still be up to a million CML cells. We can't tell.

JORGE CORTES, MD: What about the fact that we identify low levels of disease in many patients, most patients still? You can still find a little bit of disease. But let's assume that 40 years go by and it never comes back. Is that a cure or not? Dr. Goldman and Dr. Talpaz coined this term of operational cure, meaning, you're not really cured, but you're really -- you're looking like you're cured. I mean, you're functioning just as if you were cured. And, you know, I always like to quote a small part of this book, Don Quixote, where Don Quixote says, "You know, until death, all is life."

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