CML latency time T. T is here considered as a random variable, that is, a quantity described by a probability density because it may fluctuate from case to case in a way not (yet) fully predictable. In light of an early report56 on the Japanese atomic bomb survivors, clinically oriented quantitative CML models predict or assume a density that is narrow (has small SD), for example, the red curve. However, more recent LSS results indicate broader curves, having substantially larger SD and extended upper tails, for example, the blue curve. This curve is based on male CML incidence in the LSS database up to 1987, for doses between 0.01 and 4 Sievert (Sv; 1 Sv is defined as that dose which has the same biologic effect as 1 Gy of hard x-rays, where 1 Gy = 1 Joule/kg), with ∼ 15 of 22 total cases believed to be radiation-induced.48 As discussed in the paragraph before this figure and the paragraphs below it, other current radiobiologic estimates are even broader than the blue curve and their right tails extend out even farther. Details on latency time estimates in many different CML models and on the methods used to calculate the curves shown are in supplemental Section 2.2.
