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Published on October 30, 2020
Doctor Explains Diagnostic Steps and Induction Therapy Options for AML
How is acute myeloid leukemia (AML) diagnosed? What are the typical diagnostic tests for AML? After a diagnosis is reached, what are the next steps? What is induction therapy for AML? Is there more than one type?
There are many questions that may run across our minds in terms of how different types of cancer are diagnosed, tested and treated. Tune in as Dr. Elizabeth Bowhay-Carnes, MD, director of programs related to hematology and young adult oncology at UT Health MD Anderson Cancer Center, a blood cancer specialist, and physician explains the process of diagnosing AML in detail as well as the purpose of induction therapy.
This program is sponsored by AbbVie Inc. and Genentech Inc. These organizations have no editorial control. It is produced by Patient Power, and Patient Power is solely responsible for program content.
Transcript | AML 101: Diagnosis and Induction Therapy
What is AML?
Dr. Bowhay-Carnes: A diagnosis of acute leukemia is extremely overwhelming. We realize and understand it is a shock. As the name acute implies, frequently patients were feeling healthy with no other serious medical problems just two weeks before they can develop some kind of symptom. And then suddenly their whole life is turned upside down, not just the patient, their family members, their loved ones, their whole care community. And it's very important to verbalize that.
How is AML diagnosed?
So, talking about diagnosis first, the very first step, is you first have some sort of vague symptom of not feeling good, bruising, fever, something wrong, and then someone gets a complete blood count. This is a simple routine blood test where we just take blood from the vein in the arm and look at the blood cells. That will give us information about white blood cells or the immune system, red blood cells, and platelets. And we see first from those initial tests that something is not right. Either the immune system cells will sometimes be extremely high, extremely low, or normal, but problems with the other blood cells, the red blood cells and the platelets.
So, from that initial complete blood count, the next step, and usually done quite quickly, is a bone marrow biopsy. A bone marrow biopsy is a test where, as it implies, we need to look inside the bone marrow. The bone marrow is where our body makes these cells. It makes the majority of our immune system cells, our red blood cells, platelets. And so, from that complete blood count, we know something's wrong and we need to go directly into the source of the bone marrow to look and see, "Okay. What's wrong?" The bone marrow test is done with a hollow needle, usually in the back part of the hip bone.
We're able to then use that very small sample, look at it under the microscope, and perform a vastly different number of tests that are needed from that small sample to first get the diagnosis. So, there are different kinds of leukemia. The word leukemia means cancer of the immune system and cancer of the bone marrow. And so acute myeloid leukemia (AML) is this particular type of these myeloid cells. And throughout this talk, you'll hear us sometimes interchange the word blast. A blast is a term we use describing the number of cancer cells in leukemia and how many are present.
So, the patient presents with some sort of symptom, they're told their blood counts, something doesn't look right, they have a bone marrow biopsy, and within short order, a blood cancer specialist or a specialist is coming in to talk about a diagnosis of acute myeloid leukemia.
What is Induction Therapy?
So now we have the diagnosis and the treatment team is coming in to talk to you about your treatment options. The patient's asking, "Okay. Doc, okay, I'm ready to fight this. What are we going to do?" And so medically, we use the term choosing induction therapy. The word induction means simply trying to kill off as many leukemia cells as possible, as quickly as possible. And there are different kinds of induction therapy. There is no one path that every patient takes. And so, when we're choosing induction therapy and giving our first recommendations, we look at many different factors. First the age of the patient, their overall health, whether they have any underlying heart, kidney problems, how they're feeling at that moment, how far they live from the cancer center. And all of these things get brought in to making the best-personalized treatment decisions for each individual patient.
What is 7 and 3 Chemotherapy?
So, when we're talking about induction, one option is what we call standard induction chemotherapy. Standard induction chemotherapy has usually used a combination of chemotherapy drugs, an anthracycline and cytarabine (Cytosar-U). And we abbreviate that and call that 7+3. It's called 7+3 because one of the chemos, cytarabine, is given over seven days, and the anthracycline is given three days. In this 7+3 induction chemo, the usual path is a patient is admitted into the hospital and they're getting chemo every day for seven days in a row. Before that, they would have already had the bone marrow biopsy, heart tests, liver tests, kidney tests, CAT scans, special IV lines.
They receive induction chemotherapy over seven days. The first week may also come along with other care, such as antibiotics, blood transfusions, medicine to treat nausea, pain, everything that we call supportive care. Within that first week of chemo, again, it's overwhelming, but patients are starting to settle into who their treatment team is, understanding the routine of what's going to happen in the hospital for that next week. Two weeks after that chemotherapy finishes, patients usually remain in the hospital and need to continue to receive supportive care, blood transfusions, antibiotics, medicine to try to make them feel better, but they usually do not feel very well. They have decreased appetite, possibly some mouth sores, so there are lots of things that we need to do as a care team to get someone through that process.
Then after about three to four weeks after the first dose of chemotherapy was given, the patient's blood counts start to recover, and we do another bone marrow biopsy to determine how did the treatment work. Again, standard induction chemo that's given in the hospital over this month process. The purpose of that treatment is to kill off as many cancer cells as we possibly can during that period of time. And so that bone marrow biopsy that is repeated, approximately 30 days from the beginning, tells us, how did it work? So, going through some different options and branches and treatment, if we repeat this bone marrow biopsy after standard induction chemo, and it's showing no residual blast or very minimal blast, cancer cells, we all can celebrate, breathe a sigh of relief for that moment. Usually, patients can be discharged from the hospital and then talk about what their next steps are.
Is There Another Type of Induction Chemotherapy?
There is another very commonly used induction therapy, azacitidine (Vidaza) and venetoclax (Venclexta). So, this other arm of induction therapy is given a little bit differently. So, one of the medicines is given usually as a subcutaneous injection for seven days in a row. And then the venetoclax is a pill that's taken every day by mouth. Sometimes it's given in the hospital, sometimes it's given in clinic out of the hospital setting. So, it's a different process of logistics of treatment.
It still does have side effects, but it does have less side effects in the beginning upfront. That being said, the time it takes to best response, or working, is a little bit longer, but that's not necessarily a bad thing. So, if your treatment team thinks that the second type of induction is a better fit for you, then it's important to know that on average it takes a few number of months for people to get the best response to the treatment, know it's working. And so, it's a different setup from focusing on the first 30 days induction therapy to this induction therapy that lasts through a good number of months.