Alkylator Score and Leukemia in Childhood Cancer Survivors

 

The first step is to identify each alkylating agent (including procarbazine) that the patient received.

 

The second step was to tally the total dose for each alkylating agent received and to standardize as mg per square meter BSA).

 

The third step was to determine the total dose distribution for each alkylating agent and to divide it into thirds (lower, middle, upper). If the distribution of doses shows a Gausian distribution then the middle third would be the mean +/- 0.41 SD.

 

An assumption would be that the dosage ranges have been standardized and are not exceeded.

Distribution	Points
not given	0
lower third of doses	1
middle third of doses	2
upper third of doses	3

 

total alkylator score =

= SUM(points for all alkylating agents received)

 

Interpretation:

• minimum alkylator score: 0

• maximum alkylator score: 12 (assumes exposure to a maximum of 4 alkylating agents)

• The higher the score the greater the risk of developing leukemia.

• The risk of developing leukemia was impacted by the total radiation dose.

• The risk of developing leukemia was impacted by exposure to the vinca alkaloids and to doxorubicin.

 

Alkylator Score	Aprroximate Relative Risk for Leukemia (Adjusted for Radiation)
<= 2	1.0 (low)
3 or 4	8.0 (moderate)
5 or 6	18 (high)
>= 7	23 (high)

from Table 3 page 462.