Note, 9/2003: The facts about leukemia detailed below are still pertinant. However, in the mere 6 years since my son't diagnosis, many more prognostic factors have entered the arena of ALL treatment. These include the molecular description of the leukemias and in some cases the results of more sensitive assays for leukemia cells referred to as MRD - for minimal residual disease - assays. I am leaving this current page "as is", while I keep another page as up-to-date as possible:
James had acute lymphocytic leukemia, or ALL. His cell type is B-cell; his white blood cell count (WBC) at diagnosis (dx) was 7,800; there were no leukemia cells in his spinal fluid at diagnosis (although they found a couple, it was below the critical limit and his doctor felt they may have been from blood contamination), and he was in remission at day 7 after treatment, meaning he was an "early responder" (RER).
Those are "just the facts". I know that my family and friends don't know what these things mean, nor do they want to spend the hours surfing the Web that I have done (see my links page). Plus, the hospital gave us all these lovely little pamphlets, and I have the Mayo Health Clinic CD ROM. Using these sources, I am going to provide a mini-review of my readings for those who are interested.
Blood consists of three types of cells:
There are several different types of white blood cells:
RBCs, platelets, and WBCs are all made in the bone marrow. In fact, they all derive from one cell type, called a stem cell, which then differentiates into one of the three types.
Leukemia is a cancer characterized by uncontrolled growth of one of the types of WBC. The most common kinds of leukemia are:
If these leukemias progress quickly, they are further denoted acute. If they progress slowly, they are called chronic. Acute leukemias are most prevalent in children and are therefore often called "childhood leukemias".
ALL, acute lymphocytic leukemia, means that the blood contains abnormal, immature lymphocytes. These abnormal cells can resemble either a B-lymphocyte or a T-lymphocyte or neither at all. These abnormal cells are called lymphoblasts or blasts or leukemia cells. (We like to call them blasts, as in "blast the blasts.") What these blasts do is best described in the following quotation from "You and Luekemia":
"What the blasts do is something like this. Imagine that your and your family are at home, living your normal lives. One day, a little rabbit walks in the front door and won't leave. That doesn't upset your lives too much. But then a few more rabbits show up. Then more and more, until the whole house is full of rabbits. Now, that's a problem. It would be really hard to live a normal life with rabbits all over the place. Just by being there, they would cause trouble.
That's what leukemic blasts do. They start out in your bone marrow and they fill that up. But then they go other places, too. They can go to your lymph nodes or to your spleen or liver. Actually, they can go anywhere blood goes - and that's everywhere. Just as if the rabbits were not only in your house, but in every building in your city. Blasts also cause trouble by forgetting to grow up. They stay immature and keep dividing when they shouldn't . Because they are so immature, they can't do their work."
Basically, blasts crowd out the good cells. Since they crowd out the red blood cells, a person with ALL is anemic, without enough red blood cells to carry the necessary oxygen or energy to the body. That's why fatigue is a sign of leukemia. The blasts also crowd out the platelets, so if a person with ALL is cut, the bleeding does not stop as readily. They also bruise easier. Since the blasts are immature, non-functioning infection fighting cells, a person with ALL is easily susceptible to infection. What a mess!
Any child entering a treatment protocol for ALL in 1997 is given a 70% chance of cure. This means that two years after treatment has ceased, there is a 70% chance that blast cells will not be detected and this the doctors call a cure. Certain factors lend to higher and lower risk factors. These factors are used by the oncodocs to determine which direction the treatment will take. Some factors count more than others.
towards low risk*** towards high risk under 10 years old at dx over 10 years old at dx girls boys low WBC at dx (<50,000) high WBC at dx (>50,000) blasts not found in spinal fluid at dx blasts found in spinal fluid at dx pre B-cell T-cell no blasts detected in marrow day 7 blasts detected in marrow day 7
***Prognostic factors have been updated to include other factors, such as cytogenetics. Please see www.acor.org/ped-onc/diseases/ALL.html and click on prognosic factors for current information (2003).
By day 28, 95% of the children treated for ALL are in remission, meaning that blast cells are not detectable in the bone marrow. James was in remission at day 7, and is still in remission.
So, now you know what I mean when I say that James leukemia is ALL, and why the pre B-cell and no blasts in spinal fluid at dx and WBC of 7,800 at dx and no blasts detected in marrow day 7 are important! Four out of six ain't bad!