Leukemia Explained - Healthline
Leukemia Explained - Healthline
, Brian J. Druker MD, Neil Shah MD, PhD, Gabrielle Morris MD
A routine check-up may find that you have too many white blood cells, a sign of leukemia. What can be done? Learn about leukemia and how new treatments are providing hope.
ANNOUNCER: Leukemia, a cancer of white blood cells is diagnosed in about 29,000 adults and 2,000 children each year in the US.
NEIL SHAH, MD: Leukemia is really defined as the overproduction of white blood cells; it's a blood disorder caused by, essentially, an abnormality in cells in the bone marrow. What makes it a cancer is that the cells have a failure to become normal. So they accumulate in an immature stage and they don't serve any useful function.
ANNOUNCER: The types of leukemia are categorized by how quickly the disease develops: chronic leukemia, which develops slowly; and acute leukemia, which quickly worsens, and is a more aggressive form of the disease.
BRIAN DRUKER, MD: When I think about chronic leukemia I like to explain it as there are too many blood cells. They generally function normally, but what they often do is they crowd out the normal cells from the bone marrow. With acute leukemia, however, not only are there too many blood cells, but they don't mature normally. So you accumulate in the bone marrow immature blood cells that don't function very well at all.
ANNOUNCER: Leukemia is also grouped by the types of white blood cells affected. The disease can arise in the myeloid cells or the lymphoid cells.
NEIL SHAH, MD: We have chronic myeloid leukemia, chronic lymphocytic leukemia, acute myeloid leukemia and acute lymphoblastic leukemia. So we consider those four categories of leukemia.
ANNOUNCER: Each form of leukemia occurs at different rates in the population. Chronic lymphocytic leukemia, the most common form strikes about 10,000 people a year. Acute myeloid leukemia, 8000 a year. Chronic myeloid leukemia about 5000 a year. And acute lymphocytic leukemia about 4000 a year. Adult leukemia can affect any age group but is most common in older patients.
Adult leukemia can affect any age group but is most common in older patients.
BRIAN DRUKER, MD: With chronic myeloid leukemia, the average age of onset is 50 to 60 and it's quite similar with all of the other types of acute leukemia.
The most common leukemia in children is acute lymphocytic leukemia and there are about 2,000 cases per year of that in children, and also about 2,000 cases per year in adults. In the children, it affects younger children, generally between ages 2 and 4.
ANNOUNCER: What causes leukemia? While there isn't an exact cause, there are some known factors.
NEIL SHAH, MD: We know that there are some risk factors for the development of leukemia, such as exposure, sometimes to chemotherapy, sometimes exposure to radiation. The vast majority of patients, however, don't have any clearly identifiable risk factor.
BRIAN DRUKER, MD: It's certainly not thought to be inherited. It's an acquired disorder that you pick up an abnormality in the bone marrow.
With acute myeloid leukemia, there are some chemical exposures such as benzene that can predispose. Besides that there are really no clear factors environmental or otherwise that are known to cause leukemia.
ANNOUNCER: There are a number of symptoms that can occur with this disease.
BRIAN DRUKER, MD: The symptoms of chronic leukemia can be pretty nonspecific: low grade fevers, fatigue, night sweats, occasionally some abdominal discomfort from an enlarging spleen, occasionally some loss of appetite or decreased weight, but usually they're pretty nonspecific.
The symptoms of acute leukemia are symptoms of very serious illness.
There are often times very high fevers associated with infection, bleeding disorders and sometimes in very serious cases the immature white blood cells will block blood vessels and that could actually lead to a stroke and in some occasions, difficulty breathing.
ANNOUNCER: When a person displays a number of symptoms suggesting leukemia, a blood test is done. Sometimes chronic leukemia is diagnosed during a routine checkup.
BRIAN DRUKER, MD: The symptoms are usually nonspecific, patients oftentimes will have symptoms for three, four, six months of just some mild fatigue, maybe a low-grade fever, occasionally some night sweats.
With acute leukemia the diagnosis is often some acute illness, an infection, a bleeding episode, something that patients notice very prominently.
ANNOUNCER: Often when a blood count reveals signs of leukemia the next test is a bone marrow biopsy.
NEIL SHAH, MD: The bone marrow biopsy is very useful because that allows us to analyze the factory in which the cells of the blood are being made and we can sometimes see abnormal changes in the bone marrow environment.
Additionally, we perform what we call cytogenetic analysis, which looks for evidence of kind of gross mutations, things that are grossly wrong with the chromosomes of these cells.
ANNOUNCER: There are various treatment options available for leukemia.
NEIL SHAH, MD: They range the full gamut from watchful waiting in some cases of chronic lymphocytic leukemia to bone marrow transplantation, which can be a very aggressive but can cure some of these leukemias. Additionally, there are some new, exciting treatments, which involve targeted therapy of the underlying genetic changes of these frequently with oral pills.
BRIAN DRUKER, MD: Acute leukemias are treated with chemotherapy and/or a bone marrow transplant. The chronic lymphocytic leukemia is treated with a variety of chemotherapy treatments plus an antibody called Rituxan has moved into the mainstay of therapy. Chronic myeloid leukemia, the current standard treatment is a targeted therapy called Gleevec. And some younger patients will undergo a bone marrow transplant as a curative therapy.
ANNOUNCER: There have been great strides in treating leukemia, particularly in children.
BRIAN DRUKER, MD: In the 1950s and 60s, children lived no more than about six to twelve weeks after the diagnosis acute lymphoid leukemia. Now the cure rate approaches 75 to 80 percent with combinations of chemotherapy.
The biggest problem is that in all leukemia is based on our understanding of what drives the growth of leukemia cells and being able to target those with specific drugs. And as we understand more and more about what drives the growth in each and every leukemia, it's very likely that in the near future we'll have many, many more of these targeted drugs that are going to be more effective and better tolerated.