Joe, you are absolutely correct that looking at one number is a dangerous game. So too is taking the evidence from one disease and applying it to another. If you remember, last week when I wrote about beta-2-microglobulin, I was careful to refer to multiple myeloma. It has been reasonably proven that the B2M is predictive in patient with MM. It has not be proven to work the same way in CLL - which is strange since they are both B cell lymphoproliferative disorders. Apparently though there is sufficient difference between the two that little from one can be assumed about the other.
Just looking at the doubling time is also not a good idea. Some people have a slow build-up of cells but the cells themselves get "younger" and more dysfunctional. In that situation, looking at the white count would be just as misleading as a reliance on CD status or B2M levels. There is no one test that is applicable to everyone. How many times have people written about the individuality or uniqueness of their CLL when contrasted with someone else's CLL. I know that it is tedious to keep track of all the numbers and I know that you do so want to enhance the importance of the good numbers in relation to some not-so-good values but we can't
The terms" lymphocyte doubling time" and absolute lymphocyte doubling time" are essentially synonymous. One never uses the percentage lymphocyte count for much at all in people with CLL.
As to when to start treatment, that is a decision that is never based on only 1 reason. So, for some folks a doubling time of less than 1 year is associated with additional signs and symptoms and that grouping triggers the decision. For others, the single sign of a fast doubling time may just mean more close follow up since there are no other reasons to start treatment.
Here are the two major staging systems in use today
RAI STAGING SYSTEM
0 Lymphocytosis in blood and bone marrow
I Lymphocytosis and enlarged lymph nodes
II Lymphocytosis with organomegaly
III Lymphocytosis and anemia (Hb < 11.0 g/dl)
IV Lymphocytosis and thrombocytopenia (platelet count < 100 x 109/L)
BINEY STAGING SYSTEM
A Hb > 10.0 g/dl Platelet count > 100 x 109/L < 3 lymph node areas enlarged
B Hb > 10.0 g/dl < 3 lymph node areas enlarged Platelet count > 100 x 109/L > 3 lymph node areas enlarged
C Hb < 10.0 g/dl or Platelet count < 100 x 109/L