Childhood Leukemia: Most Common Childhood Cancer

MD Anderson Cancer Center
Date: 12-12-11


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Lisa Garvin: Welcome to Cancer Newsline, a podcast series from the University of Texas MD Anderson Cancer Center. Cancer Newsline helps you stay current with the news on cancer research, diagnosis, treatment and prevention, providing the latest information on reducing your family's cancer risk. I'm your host, Lisa Garvin. Today, we're going to talk about leukemia in children. And our guest is Dr. Patrick Zweidler-McKay. He's an associate professor of pediatrics here at MD Anderson and also the section of chief of the pediatric leukemia and lymphoma unit here at MD Anderson. Dr. Zweidler-McKay, let's talk about leukemia first. It's a--what we call hematologic or blood-borne disease.

Dr. Patrick Zweidler-McKay: That's right. And so cancer is come in many types. So you can get a cancer, basically, starting anywhere in your body. And leukemias which are the most common form of cancer in children, but not in adults, starts in your blood and where your blood is made which is was within your bones.

Lisa Garvin: And so this is a disease that cannot be treated by surgery, obviously, a lot of cancers are treated by surgery, but leukemia is a systemic disease, so you have to attack the system.

Dr. Patrick Zweidler-McKay: That's right. So many times we hear about other cancers are metastatic or they spread throughout the body. Since this is cancer is in your blood and it's circulating around your body all the time, it's actually metastatic from the very beginning. It spreads throughout every part of your body, anywhere where there's blood there are leukemia cells. So there is no therapy that can be done to get rid of most of it that isn't systemic. So chemotherapy has to be given throughout your whole body.

Lisa Garvin: Now lymphoblast, let's talk about what the trigger is. I mean these are cells that are immature. Is that what's happening, they're released before they mature?

Dr. Patrick Zweidler-McKay: Right. So as in many cancers, it's often a problem that in normal cell doesn't do it what it supposed to be doing. It gets stopped at in early stage. And often at those early stages, it has the ability to grow more quickly than it would if it had done its normal thing which is to mature completely and then stop growing. And so leukemia is the same thing. Many of the cancer cells start out as normal cells that have some mistakes that occur inside those cells. They stopped developing on their normal path. And those immature cells continue to grow, and grow, and grow. And eventually just like any other cancer they start taking over your body by having too many of these leukemia cells.

Lisa Garvin: Now there are many types of leukemia. What are the most common in children?

Dr. Patrick Zweidler-McKay: Right. So a little differently have been adults, the most common type of leukemia is ALL or Acute Lymphoblastic Leukemia. All leukemias come from your immune system. This particular one comes from cells that are normally calls T-cells or B-cells, and they make your antibodies in your immune system, and they attack the bacteria or viruses that you might become sick with. Now they are not able to function in that way when their leukemia cells. They're stopped too early on their development to do that. But they resemble them and they continue to grow and these lymphoblastic leukemia cells are about 8 out of every 10 leukemias that we see in children. Much--It's much more rare in adults. Other types of leukemia are much more common and we do have some interaction in that ALL that we see. It transitions through the adolescent years and early adult years into the ALL that seen by adult oncologist.

Lisa Garvin: What is the typical age of onset at--you know, being at MD Anderson as long as I have, it seems like leukemia patients are pretty young.

Dr. Patrick Zweidler-McKay: Yes. And again, particularly in pediatrics are formed of ALL has a peak incidence or the age that children usually get it between 2 and 4 years of age. Unfortunately, it's those very young kids, most of them, who have a very good chance of fighting their cancer.

Lisa Garvin: Let's talk about leukemia often manifests as flu-like symptoms. I mean it seems like the symptoms would be pretty subtle especially in a young baby. What would parents be looking for?

Dr. Patrick Zweidler-McKay: Right. So, you know, cancer in particular leukemia is often very subtle. It often makes you not feel well, you may have some fevers, you may be flushed. You may have rashes. You may have lymph nodes or bumps that increase in size. But for the most parts, those symptoms are gonna be anything but cancer, anything but leukemia, because every child has those symptoms at one point or another. So we are very careful not to make parents and pediatricians overly concerned about leukemia. But that if somethings wrong, and their child isn't getting better or that their pediatrician examines them and things that it might one thing and it doesn't turn out to get better, when something like that happens we encourage parents to bring them back to the pediatrician and that pediatrician is then to think, at least on their list of things, they're thinking about of cancer, of leukemia, because it does affect about 1 in 300 children during their childhood. And so a pediatrician will likely see several children with cancer during their career.

Lisa Garvin: It's fairly easy to diagnose, is it not? What are some of the diagnostic tools that you use? I think a blood sample is one.

Dr. Patrick Zweidler-McKay: Yes, so that's actually one of the nice things about leukemia is that because it is in your blood and it's--the bad cells leukemia or cancer cells are circulating in your blood, all you need is a regular blood count, something that many people have, many women have on a regular basis, many people have when they're sick and in the hospital. It's a simple test with one needle sick and we're able to see what cells are in the blood, and typically we can see the leukemia cells just with our naked eye in a microscope and say, "This is suspicious for leukemia." Now to prove that there's leukemia we have to look where the blood cells are made and this is where the leukemia cells hide and that's within the bones. And so we do something called a bone marrow aspirate. And this is a test were used a slightly bigger needle to take a little bit of blood from within a bone to be able to make the diagnosis of leukemia.

Lisa Garvin: So once that happens and of course there are acute and chronic types, obviously children are in affected with chronic types of leukemia, but is time of the essence once you--let's--let me ask another question first. How often do you catch it early and how important is it for them to get immediate treatment?

Dr. Patrick Zweidler-McKay: Okay. So leukemias typically present--the patients will typically be sick enough to come to the hospital, when the leukemia is already circulating in their blood. And at that point, there isn't a distinction between early, catching it early or catching it late. If we look in the bone marrow of patients, a new patient with leukemia, usually 80 to 90 percent of the bone marrow was already filled up with leukemia. And it doesn't really make a difference whether or not they only have 20 or 30 percent or whether or not that 80 or 90 percent. The treatment is the same. And the outcomes are the same as well. So the important thing is simply to identify it. Because what happens is when leukemia is in your bone marrow it stops your normal blood cells from being made. So patients will become anemic or they'll become pale, will have low blood counts. They'll be more prone to infection. So it's not uncommon for us to get a child who went to a normal hospital and had a pneumonia and when they go to a blood test they saw at the immune cells were gone and that these cancer cells were present instead. So it can also decrease your ability to clot to stop bleeding. And so another common story is--here's a child who's active, who all of the sudden starts getting very large bruises or having nosebleeds and is brought to the pediatrician and when a blood test is done, the diagnosis is made.

Lisa Garvin: Let's talk about treatment. There're a lot of agents out there. And actually there's been a lot of success with new chemotherapies and targeted therapies. Let's talk about the standard treatment for children.

Dr. Patrick Zweidler-McKay: Right. ALL in particular in children is one of the great cancer success stories. So in my lifetime, a child who was diagnosed with cancer when I was born has essentially no chance of surviving. They were a few drugs that we're able to hold off leukemia for a few months or so. But ultimately, those children with all die from their leukemia. Now, we have a success rate of almost 80 to 90 percent depending on the age of the child and specific things about their leukemia. But a 90 percent cure rate in a type of cancer is something that almost on here have been most adult cancers. But we've worked up to within the last few decades in improving the treatments. And we can talk a little bit more about the specifics. But we used many different medications, many different drugs to treat childhood leukemia. The goal is to try to kill the leukemia cells for many different angles rather than using one big sledgehammer. And we've been very successful using that combination approach. Unfortunately, there are some kids who don't respond to that combination approach. There are some kids who will respond but then unfortunately relapse. And even though we have a great success rate at the beginning, once leukemia comes back, it's more like what you would think of another cancer which is it's very difficult to cure at that point. And then we really need to use much more intense treatments including something called the bone marrow transplant.

Lisa Garvin: Now Gleevec was a big success story for adult leukemia patients, was that also true for children?

Dr. Patrick Zweidler-McKay: Well, yes. So the situation where it was such a big success story or continues to be a success is in CML or Chronic Myelogenous Leukemia. This is a form of leukemia that's much more common in adults, although we do have children as early as the age of 2 that have--that get CML as well. That particular disease has a DNA change in it which causes those cells to be susceptible or sensitive to this drug, Gleevec, which was specifically designed to target that DNA change. So for that disease, it's been great a success. There is also type of ALL that we've been talking about that also has that type of DNA change. In children, it's only 3 to 5 percent of patients, in adults it's above 25 percent of patients. So actually in pediatric patients we have been leading the way in using these target drugs for those very few patients in pediatric ALL that have this DNA change. And we've been able to show that from 10 years ago when they had maybe 25 percent chance of living for 2 to 3 years. Now they're closer to 70 to 80 percent chance, which has flips completely on its head so that now it's more likely that your child would live at least for several years with this cancer than before.

Lisa Garvin: Now how often do you have to do a bone marrow or what we call now a stem cell transplant?

Dr. Patrick Zweidler-McKay: Unfortunately not very often. At least for ALL, we're now very successful with most patients without using a bone marrow transplant. We used them either when they have DNA changes particularly that we know historically are not gonna respond to just chemo by itself. And those patients particularly if they have a sibling, or a family member who is a close match as we say we might use that for their treatment of leukemia. But typically its only one when they relapsed when we have more difficult in treating them that we'll use a bone marrow transplant. But here at MD Anderson where we often treat many of the relapsed patients, we used bone marrow transplant often for these ALL patients.

Lisa Garvin: And as far as long term outlook, obviously anybody who gets a cancer at young age there will be some long term of effects and not only from a cancer but from the chemotherapy. What sorts of things should parents be looking out for in the long term?

Dr. Patrick Zweidler-McKay: Alright. Well, of course we're very happy to say that most of our leukemia patients are long term survivors. And they have typically received between a year and 3 years of chemotherapy treatment. And during that time they been exposed to many poisons, many of these chemotherapy drugs are simply poisons. And they've caused damage to different parts of their body. In addition for some patients, although less and less with time now, we're using radiation, and particularly radiation to the brain. And for a young child, it's not a good idea to use radiation to their brain because we know that it has many long term side effects including learning difficulties and growth difficulties. So an important feature now we're curing so many of these children is long-term followup. And the pediatrics program has had a long-term followup program for decades now. And we've been following these children who are now adults and we as well as others throughout in the country have found that problem seem to crop up 10 years, 20, 30 years out from having their cancer. And this is now well documented. And it really shows that long-term followup. Meaning returning to an oncologist for the rest of your life is a very important thing to do when you had--you've been exposed to these poisons or radiation.

Lisa Garvin: In typical although at certain drugs, but cardiotoxicity is always an issue or, you know, heart problems, is that limited to certain drugs?

Dr. Patrick Zweidler-McKay: It's worse with certain drugs but it can be result of this high dose chemotherapy of any drug. But we typically think of its specific drugs. We're trying to use less and less of dose drugs. Unfortunately, they're an important part of that mixture, that combination that we used for most of our high risk patients. They're still most to the high risk leukemia patients do get exposed to drugs that we know very well have a heart damaging effects and those effects can be decades in the making the child now who likely not have any problem because children hearts are resilient. But as the age and normal ware and tear occurs on their hearts, the damage that's done from these agents will often make that worse. And we do see a significant number of patients in the future having heart issues, and again, another reason to keep close to your oncologist for followup.

Lisa Garvin: I think in--this is just based on my personal experienced working at MD Anderson is that children with leukemia have to be tough. Like you said they go through a few years of chemotherapy I mean with a lot of childhood diseases, surgery, boom, you're done. With leukemia it's a long hard--I shouldn't say long and hard, but it is, it's a difficult road for them. How do your patients seem to take as your young patients?

Dr. Patrick Zweidler-McKay: Right. Well, you know, often the children do the best. It's the families. It's the parents. It's the other siblings who typically have a very difficult times especially at the very beginning. Children get used to the frequent visits, the hospitalizations, being stuck with a needle, getting medications, being sick all the time in a way that most adults including ourselves would not be able to tolerate. But it does take a toll. It interferes with their school, interferes with their social life, it interferes with their ability to feel normal, and so--

Lisa Garvin: And they may be bald as well from the treatment?

Dr. Patrick Zweidler-McKay: During the treatment often there're periods when they're bald. This can cause problems with other kids asking questions. And so we have a child life program and a school program here at MD Anderson and what we do is try to normalize the fact that they're--they have a diagnosed of cancer and not they're getting treatment. And we try to provide services including an independent charter school that we set up here at MD Anderson so the kids can have normal classes. They can keep up with their grades and that when they ready to go back into the normal school environment, we have a liaison that works with their school and provides education to their fellow classmates and their teachers so that they can go back into their school environment as easily as possible. But no one ever comes out to this process the same that they went in. And often we see children are really more resilient because of everything that they have been through. So we've been quite happy with the successes. Unfortunately, we're not always successful in that causes even more damaging and pain for the families of course.

Lisa Garvin: Are there any final thoughts or advice you can give to parents?

Dr. Patrick Zweidler-McKay: Well, I think most of the parents wanna hear that cancer and particularly leukemia something that we can identify. It's something we know a lot about. It's something where we know what is the best standard treatment for it. And if anything comes up along the treatment, we have alternative ways of treating this as well. So although it's a rare type of cancer, it's a type of cancer that we have established a very successful treatment for. And so although you'll never wanna hear that your child has cancer, this is a cancer that we can treat and can be very successful with. And since that's what we do here all the time, we'll take you through it day by day, year by year, and hopefully watch your children grow up as many of other patients have.

Lisa Garvin: Great. Thank you very much. If you have questions about anything you've heard today on Cancer Newsline, contact askMDAnderson at 1-877-MDA-6789 [background music] or online at Thank you for listening to this episode of Cancer Newsline. Tune in next week for the next podcast in our series.

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