For acute myeloid leukemia (AML), test results play a vital role in determining the most appropriate treatment option. Expert Dr. Ellen Ritchie reviews key tests used to pinpoint a patient’s specific AML, how the test results are utilized, and important questions patients should ask their doctor about AML testing.
Dr. Ellen K. Ritchie is assistant professor of medicine and a member of the Leukemia Program at the Weill Cornell Medical College of Cornell University and the New York Presbyterian Hospital. More about Dr. Ritchie, here.
So, let’s help our audience be clear about basic testing. What tests are necessary to help understand a patient’s specific disease at diagnosis?
I mean certainly it’s important to do a physical exam and to find out what the general health of the patient is. In order to evaluate an AML, or any other leukemia, I look at the peripheral blood smear. To look at what I think the type of leukemia might be that I am dealing with. There are some leukemias that have particular way that they look like acute promyelocytic leukemia for which there is a designated therapy which works.
And you can tell that just by looking at a peripheral blood slide. The next test is always a bone marrow biopsy. Patients are not delighted that that is a test, but it is a test that can be done in the office, usually within 15 to 20 minutes. And that test gives us a lot of information. It gives us information about what type of AML it is, what are the markers on the outside of the cell, it gives us information about the chromosomes inside the leukemia cell. Are there missing chromosomes, or rearranged chromosomes? And if there are, that can be very relevant to the prognosis. And lastly, it’s sent for a particular mutations or markers. So, we look for IDH3 mutations, we look for FLT3 mutations, we look for IDH1 and IDH2 mutations, and we do an entire myeloid panel. Which is about 44/45 genes that are most commonly mutated in patients with AML. So that’s the initial work-up for any AML patient.
You mentioned markers, Dr. Ritchie. What is genomic, or biomarker testing?
So, we’re looking really at most specifically at mutations inside individual genes that might be in your leukemia cell. So, there are some mutations actually that confer a better prognosis. Like NPM1 or CEPBA, those can be more positive type of prognosis than some of the others.
But we’re also looking for markers that might be targetable with certain therapies that we have. So, if you have a FLT3 ITD or TKD, we actually have particular drugs which can target those particular mutations. There are also drugs that are FDA approved to treat IDH1 and IDH2 mutations.
There are certain mutations that have a relatively poor prognosis, like TP53 for which there are clinical trials which are available, which specifically are meant to target patients who have those sorts of mutations. And there’re other clinical trials using the FDA-approved drugs that I just mentioned, for FLT3, for IDH1 and IDH2 and combining it with other agents to try and improve outcome in AML patients.
Some patients may not know if they’ve received these important tests, so what key questions should they be asking their physician about testing?
So, physicians, they – financial coverage of the mutational testing is not uniform across the country and across insurances. So, Medicare and different Medicare insurances and some of the private insurances all vary in their coverage.
So, in my clinic, I am asking – I prefer the test that we do in house at Cornell. But it’s important that I ask, what will their insurance cover. And make sure that I send the appropriate testing that will be covered by insurance. There are some insurances that will not cover this type of testing. So, it is a real question for the patient, when you go to see the doctor to say, are you going to do mutational NGS testing?
And, will my insurance cover this? Hopefully most – if Medicare adopts the coverage of these types of mutational testing, it’s often true that private insurance will eventually pick this up. But it’s a murky field, and it’s really important to talk to your doctor about this. The cost of the bone marrow biopsy, and the chromosomal evaluation is nearly always covered by insurance.
What tests should follow an AML diagnosis and why? Dr. Hetty Carraway, an AML specialist from Cleveland Clinic, outlines key testing for patients with AML, how the results impact treatment choices, and provides advice on advocating for yourself, stressing the importance of including a caregiver as part of the conversation.
Dr. Hetty Carraway is Director of the Leukemia Program at Cleveland Clinic. Dr. Carraway cares for patients with acute leukemia and bone marrow failure states. Learn more about Dr. Carraway, here: https://my.clevelandclinic.org/staff/18591-hetty-carraway
Welcome to Empowered, a podcast by the Patient Empowerment Network. I’m your host, Katherine Banwell.
Today we’ll discuss how you can be proactive by insisting on better AML care and personalized treatment options. Joining me is Dr. Hetty Carraway. Welcome. Would you please introduce yourself?
Hi. My name is Dr. Hetty Carraway. I’m one of the physicians at the Cleveland Clinic. I work as the Director of the Leukemia Program, and I spend most of my time caring for patients with acute leukemia and bone marrow failure states.
Thank you. Let’s start with the basics. What essential testing should AML patients undergo following a diagnosis?
This is a pretty standard workup for patients that have this diagnosis of acute leukemia.
For most of our patients we always evaluate with a peripheral blood count including a complete blood count with differential, typically a comprehensive metabolic panel, and looking at a test called a uric acid, which looks at the cell turnover and the cellular debris in terms of the burden on the kidney. We often will get a bone marrow biopsy with aspirate for patients, and in the diagnosis of leukemia typically that’s already been done.
There are tests that are sent off of that aspirate called a test for chromosomes, whether it’s comprehensive cytogenetics or FISH, for fluorescence in situ hybridization. We’re often testing using a study called NGS or next generation sequencing looking for specific mutations of genes known to be important in the pathogenesis of leukemia.
Furthermore, we often get a test called flow cytometry from that aspirate looking at the markers on top of the leukemia cells that help us to identify the blast population. So, I would say those by and large are the tests in the bone marrow biopsy that we get, which are innumerable and detailed.
They often take some time to get back, so at the time of the diagnosis patients know that they have a diagnosis of leukemia, but those additional chromosome tests or mutation testing that can take up to two weeks if not longer to get back. And so, it’s important to follow up on that information later on and say, has that testing come back? If so, how does that change any of what the decisions are moving forward?
Genetic testing can often be confused with molecular testing. What’s the difference between the two, and why should patients undergo the testing?
The chromosome testing and the mutational testing help us to really classify the risk in terms of the leukemia itself, whether or not that leukemia is responsive to chemotherapy alone, or if it means that there’s a higher likelihood of that leukemia not being controlled with leukemia only.
In that setting, we often then move towards transplant for curative intent in addition to the chemotherapy. The reasons to get the information is to really help us better tailor the therapy for each individual patient. That information really does help us guide not only the upfront therapy for some patients but even the long-term therapy. It can be incredibly overwhelming to have too much information at the get-go, so in some senses it’s better to have these pieces as they unfold over time.
For other patients, they want to know what exactly the plan is going to be A to Z from day one. That is of course more challenging now that it just takes time to get this information. I think what they need to know is that we’re working hard to get that information.
As soon as we get it, we don’t hold back. We reveal and share that information and come together to say, this is what this data or information means, and these are some of the choices that we either recommend that you consider, and these are the risks and benefits to those considerations.
Let’s look at something that is similar to what you’ve just been talking about. How do test results impact treatment and overall care?
When you asked me how come chromosome or genetic information is different than mutational information, the chromosomes can help us to figure out where patients land in terms of prognosis. That information is different than the mutational testing. Both of those pieces can help us figure that out.
The mutational test, I will tell you, does help us figure out are there targets on the leukemia that allow us to use therapy that’s directed to that mutation. The key example I’ll give is a mutation in a gene called FLT3. That particular mutation has an agent now that is F.D.A. approved called Midostaurin, and so once we know that a leukemia harbors a FLT3 mutation we often add a drug called Midostaurin to the backbone therapy that is used for patients.
Now, that’s important, and now there are more and more genes that when mutated we have novel therapies that direct against that specific tag that’s on the leukemia and helps to improve eradication of the disease or control of the disease if you will.
That’s different than the genetic information when we’re looking at chromosomal changes that may allow us to say in the rare instances of favorable cytogenetics like a translocation of chromosome 15 and 17 consistent with ATL, the treatment for that type of leukemia, acute promyelocytic leukemia, is very different than what we do for the majority of other leukemias. The prognosis for that leukemia is also very different. It helps to tailor the regimens, and it helps to select specific therapy that may be helpful to each individual patient.
Dr. Carraway, you just mentioned FLT3. Would you tell us about the common mutations in AML and how these may impact treatment options?
There’s a multitude of mutations that we’re now following in patients. The way that we follow them is by doing this next generation sequencing test at the upfront time at diagnosis.
The reason why we’re doing that is because those mutations can regress with therapy, or they can progress where you gain additional mutations that happen as the disease progresses. Even if it’s responding to therapy or as it loses response to therapy and reemerges, it may reemerge with different mutations. As a result of that, it may change what therapy we select. Our ability at this point in being to recommend exactly at what time points we are checking the next generation sequencing we’re still learning right now as to what are the key times to do that testing.
In general, most institutions are doing that next generation sequencing at the time of diagnosis, and then also for some patients before they go to bone marrow transplant and even after bone marrow transplant.
For some of those patients that unfortunately relapse, we’re also making sure to retest the next generation sequencing mutation testing to see are there new mutations that have come about that weren’t there before?
I understand there’s something called IDH.
You were also asking about what other mutations besides FLT3 happen in patients with AML. FLT3 is one such mutation. NPM1 is another mutation that often it frequents patients that have AML. Those two mutations happen in about 30 percent of patients with AML. There are other mutations such as DNMT3A, ASXL1, and TET2 that we typically see in patients with MDS or even a pre-leukemia state called CHIP. For other patients, we have mutations that are targetable like IDH1 or IDH2.
Those two mutations happen in probably 10 percent to 15 percent of patients diagnosed with AML. Why are those important? They’re important because we have oral medications that are pills that patients can take. In the relapse setting for many patients after induction or intensive chemotherapy, they can use these oral therapies to try and control their leukemia. These are pretty exciting.
All of these oral therapies have been approved in the last two to three years in the space of leukemia, so it’s been a game-changer in terms of identifying these mutations and then identifying drugs that target those mutations. It’s really changed the landscape for patients with AML. It’s new information, and that’s why as patients you want to hear about this so you know what questions to ask and you know, can you tell me, am I a candidate for one of these oral medications that is now available for patients with AML?
What advice do you have for patients when it comes to asking for appropriate testing and speaking up in their own care?
This is so important. I think patients are leery to stir the pot or be difficult. I think coming from a place of inquiry, teach me about this, that, or the other thing, help me understand this, that, or the other thing – I would like you to show me why this decision or talk with me about why this decision versus another decision might be better for me compared to somebody else.
I can’t underscore the importance of advocating for yourself and asking questions about why am I getting this drug? What are the side effects to this drug? What is my prognosis? What is different about my case versus somebody else’s situation? How do I best prepare myself in getting ready for the therapy that I’m about to go through?
Those are all important questions that patients should ask. They should certainly have people, if possible in their family be advocates for them. I welcome that, and I think that that’s a really important part of going through this type of therapy for any patient. Your physician should welcome having your involvement in that. Don’t be shy about that. It’s your health, and any investment in that the most important people in that is inclusive of you and your caregivers. They should be a welcome part of the team.
Dr. Carraway, thanks so much for joining us today.
Thank you for the opportunity to be here.
And thank you to our listeners for joining us for Empowered. Visit PowerfulPatients.org to access resources to help you be a proactive patient in your care decisions. I’m Katherine Banwell.
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After an acute myeloid leukemia (AML) diagnosis, additional tests must follow to determine prognosis and treatment options. Dr. Pinkal Desai explains key tests that aid in choosing optimal care for each patient.
Dr. Pinkal Desai is Assistant Professor of Medicine at Weill Cornell Medical College and a hematologist specializing in acute myeloid leukemia (AML) at Weill Cornell Medicine. Learn more about Dr. Desai, here.
Other than a complete blood count, what additional testing should take place following an AML diagnosis?
So, a blood count or CBC is just a hint that there might be AML. It’s certainly not diagnostic.
But when you see that there are some abnormalities in blood count, and there might be the presence of these immature cells or blasts in circulation, there is suspicion that this is acute myeloid leukemia. The diagnosis, the gold standard for diagnosis, is a bone marrow biopsy, which is a procedure that can be done out-patient or in the hospital, depending on where the patient is. It takes about 15 minutes, where we take a sample out of the hip bone and look at the cells. This is where bone marrow is being made, so you’re going to exactly where the problem lies, and seeing if the blast count is increased.
So, the diagnosis of AML is established when the blast count is over 20 percent in the bone marrows. And normally, it needs to be less than 5 percent.
And if it’s over 20 percent, that’s the diagnosis of AML. Whether it’s over 20 percent in the bone marrow or in the peripheral blood.
It doesn’t matter, one way or the other. This is a diagnosis of AML, but you do need a bone marrow biopsy to confirm diagnosis of AML.
What about genetic or molecular testing? Is that done?
AML diagnosis is just one part or the first step of saying somebody has leukemia. There is a slew of other tests that are important, and we generally consider, within the genetic tests, we generally consider two kinds of testing. One is the cytogenetics, or the karyotype analysis, which looks at the chromosomes in our bodies.
So, leukemia can be associated with big chromosomal changes, and that’s important to recognize. And the second one is the molecular testing, and we’ll go over both of them.
The chromosomes, or the karyotypic analysis, the vast majority of leukemia patients have a normal chromosome type, but there are certain recurrent abnormalities in chromosomes that we see in leukemia, and that’s important to know for a variety of reasons: treatment decisions, prognostication.
And the second part of it, the molecular, these are actually genetic routine analysis, and this is not somebody – it doesn’t mean, when we say genetic testing, it’s not the patient’s own normal genetic type. So, we’re not looking for what they have inherited. Most of leukemia is actually a random event, and it’s not inherited. We’re talking about genetic damage that the leukemia cells have within themselves.
It gives us the signature of the leukemia, and it helps us understand what genetic abnormalities are present in the leukemia. There are several panels, 50 to 100 genes, but there’s usually recurrent genetic damage that leukemia cells have.
And you want to know that, because again, like karyotype, this is important in treatment decisions, and also in the prognostication and prediction in the future.