Malignant cell growth in advancing leukemia

An exponential function is proposed to describe cell growth, which incorporates the parameter signifying the population's proliferative index (f). This growth function could describe with precision the increase of peripheral blasts registered in one case of untreated CML at blast crisis, in which it revealed a pattern of growth characterized by f maintained constant at 0.5. The specific rate of blast growth remained unchanged throughout CML blast crisis. Based on the proposed growth expression and the calculation of progenitor cell presence in blood, a similar pattern of growth, in which f = 0.5, became apparent for AML progenitors in two cases of relapsing AML. The presence of leukemic progenitors in blood was quantified by adopting an indirect approach. The estimated fs compared closely with 3H-thymidine indexes previously obtained (literature data) for leukemic blasts and their progenitors. It is considered that the pattern of proliferation that maintains f = 0.5 may characterize the mode of cell growth that pertains in stages of advancing leukemia. Transfer of cells from quiescence to the state of proliferative activity is assumed as controlled, viewed in the line of a model of cell growth that requires f = 0.5 and constant specific rate of growth.