This is bogus...
Here's a link to Acute Lymphocytic Leukemia. Interesting to note: It typically occurs in YOUNG CHILDREN. There are other forms of leukemia that occur in adults.
The symptoms include (among other things) an INCREASE in white cells; NOT a decrease of them. A complete workup is usually performed before a diagnosis is given. A simple blood test can raise suspscion of leukemia, but, blood tests ALONE aren't sufficient to diagnose the cancer.
Acute lymphocytic leukemia - MayoClinic.com