May 3, 2014 | by Kim Proescholdt
Editor's Update: Ravi Bhatia has since left City of Hope. He joined the University of Alabama at Birmingham in January 2015.
City of Hope Every four minutes, someone is diagnosed with a blood cancer. More than 156,000 new cases in the U.S. are expected this year alone, with more than 52,000 of those diagnosed as leukemias. Causes of these cancers remain relatively unknown, but advances in treatment, some of which resulted from research at City of Hope, are increasing survival rates.
Recognized internationally for its breakthrough treatments for leukemia and other blood disorders, City of Hope is one of the most successful treatment centers for leukemia in the country and has had some of the consistently best survival outcomes. Here, Ravi Bhatia, M.D., director of the Division of Hematopoietic Stem Cell and Leukemia Research and co-leader of the Hematologic Malignancies Program, explains that the focus of doctors and others at City of Hope is not just cancer remission, but to cure patients altogether.
What is leukemia, and are there any symptoms?
Leukemia is a cancer of the blood cells. It usually begins in the bone marrow – the soft material in the center of most bones where blood cells are formed. Normally, blood cells are made in an orderly, controlled way. In a person with leukemia, the bone marrow makes abnormal white blood cells, called leukemia cells. As more leukemia cells are produced, they crowd out the healthy blood cells, making it hard for normal blood cells to do their work, which is to fight infections, carry oxygen and prevent bleeding.
Common symptoms of leukemia include headache, anemia, weight loss, pain in the bones or joints, swelling or discomfort in the abdomen (from an enlarged spleen) and swollen lymph nodes, especially in the neck or armpit. Some of the symptoms of leukemia are similar to those caused by the flu or other common diseases, so it is important to see a doctor if you have these symptoms. Only a doctor can diagnose and treat leukemia.
What are the most common leukemias?
There are four common types of leukemias. Two are chronic – chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML) – meaning they get worse over a longer period of time, and the other two are acute – acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) – meaning they progress quickly. CLL, CML and AML are diagnosed more often in older adults. Of these, CLL is the most common and can be quite mild, such that patients may live with it for a long time and not require treatments. ALL is the most common leukemia in children but can also occur in adults.
Are there any known causes or risk factors for leukemia? Can it be inherited?
In many cases, no one knows why some people develop leukemia and others do not. There have been some studies that have identified certain factors associated with increased risk for leukemia. These include being older, working with certain chemicals, smoking, exposure to very high levels of radiation, certain health conditions, and past treatment with chemotherapy or radiation therapy.
But most people who have known risk factors do not get leukemia, while many who do get the disease have none of these risk factors. More than 65 percent of people diagnosed with leukemia are over 55 years of age. Leukemia occurs more often in men than women and is more common among white people than other races.
In terms of inheritance, other than a small number of patients where leukemia may run in the family, there is very little evidence that these diseases are inherited. There are genetic components to the diseases and often there are alterations in the DNA. But the cause of these changes is unknown.
What new basic research and/or treatments should patients be aware of in the area of blood cancers?
One area of research that has evolved over the last five years is the use of genomics. This is allowing us to examine the molecular basis of leukemia and identify the genes that are contributing to its development. Understanding the genetic basis allows us to better understand who needs more treatment and who can get by with less treatment.
Our area of research also focuses on leukemia stem cells. There is a small population of leukemia stem cells that generate the rest of the leukemia cells. It turns out you can get rid of the bulk of leukemia cells, but if the leukemia stem cells aren’t removed as well, they will “hang around” and regenerate the leukemia after treatment is finished. Here at City of Hope, we are studying the properties of leukemia stem cells and developing treatments to target and destroy them.
Immunotherapy is also another area of burgeoning research. One way we are harnessing immunotherapy is using T cells, which are immune cells that directly bind to the cancer tumor and kill it. We are also using genetically engineered antibodies to directly attack and destroy the tumor.
Scientifically, this is a very exciting time to be a hematologist. There is so much new knowledge emerging that is actually resulting in development of new, effective and less toxic treatments for patients with leukemia. We are really starting to see improvements in outcomes for our patients. Remission for our patients is what we always strive for, but curing them altogether is our real goal.
What advice do you have for patients recently diagnosed with leukemia?
For someone who has just been diagnosed with leukemia, I would tell them to first learn as much as they can about the type of leukemia they have so that they can be informed participants in the decisions about their care. Knowledge is power. A diagnosis of leukemia doesn’t mean that all is lost and nothing can be done. Many leukemias are curable, and for the others there are many excellent treatments that allow patients to resume living a normal life.
I would also suggest that patients seek out a knowledgeable, experienced and trusted team of experts, particularly at a comprehensive cancer center like City of Hope where there is access to the latest treatments and clinical trials.
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Learn more about leukemia and other blood cancers treatments at City of Hope.