November 4, 2007
In July, Jason Blake signed a $20 million, 5-year deal to play forward for the Toronto Maple Leafs. A few months later, at this high point in his career, he was diagnosed with CML. He plans to continue playing this season. So what is CML anyway? How did Jason get it? And why is he still playing hockey if he's sick?
What is CML?
CML stands for chronic myelogenous leukemia. Leukemia is cancer of the blood cells, while chronic means that compared with other types of cancer, it's slow growing, and may take years to develop. Myelogenous refers to the type of cell affected — "myeloid" cells, which are a type of white blood cells coming from the bone marrow.
CML is a rare type of cancer that can occur in any age group, but especially in middle-aged adults and the elderly. Less than 500 new cases are diagnosed in Canada each year.
You probably know that smoking increases your risk of lung cancer, and spending too much time in the sun increases your risk of skin cancer. But with CML, and many other types of cancer, no one knows for sure what causes it.
The dirt on genetics of CML
All human cells have DNA, the genetic code that tells them how to grow and what their role is in the human body. Cancer is caused by mutations (changes) in the genetic code, making cells grow and divide much faster than they should. Often the result is a tumor. If this happens to a blood cell, it usually doesn't form a tumor because these cells are constantly moving around in the blood and tissue.
Did You Know?
cancer is caused by mutations, or changes, in the DNA of our cells DNA is made up of genes, the blueprints for all the proteins our cells make. The mutation that causes CML is actually two genes fused together to make one mutant gene, called BCR-abl. As a result, a mutant protein is made that tells the cell to divide faster than it should.
Did You Know?
cancer cells divide faster than normal cells What does all this mean for Jason Blake?
Jason is lucky, because in the last few years there's been a breakthrough in treatment of CML. A drug called imatinib, taken as a pill, sticks to the mutant protein and stops it from speeding up cell division. Because imatinib sticks only to this one protein and leaves the others alone, it doesn't usually have a lot of unpleasant side effects, unlike many types of cancer therapy.
Because of this drug, the survival rate for people diagnosed with CML is now 85-90%. Before imatinib was approved, CML would have been fatal within a few years! It's a pretty amazing drug, and scientists are working hard to find drugs like this to treat other types of cancer.
Did You Know?
symptoms of CML sometimes include low fever, feeling tired, bruising easily, and generally feeling sick. But especially in early stages of the disease, there might be no symptoms at all Hockey players have a full physical exam every year — a great idea for all of us! For Jason, this means his CML was most likely caught early, and he's probably still feeling healthy. With his doctor's ok, he can keep patrolling the right wing for the Maple Leafs.
CML Society of Canada
Leukemia & Lymphoma Society
CML — Merck Manual
Kim Paulson works in a laboratory where she studies heart disease. She keeps her own heart healthy by jogging. She also loves climbing things, exploring new places, and reading a good book.