Prognostic value of serial measurements of leukocyte thymidine uptake in well-controlled chronic myelocytic leukemia

Abstract

Twenty-nine patients with well-controlled Ph 1-positive CML were followed with peripheral blood and bone marrow thymidine uptake determinations ( 3H-TdR) at approx. six-month intervals over periods of eight to 48 months (median 30 months). Median peripheral blood 3H-TdR of individual patients varied considerably, ranging from 0.6 to 18 dpm/10 3 WBC. However, increases in sequential studies of individual patients were usually less than two-fold. More than four-fold increases (4.1-16-fold, median 7.5-fold) in blood 3H-TdR were recorded in 11 patients. At the time of 3H-TdR increase, there was no or minimal evidence of clinical or hematologic deterioration; chromosome analysis showed new abnormalities in four out of 10 patients. Ten of these 11 patients exhibited criteria of the terminal phase of CML two to six months after the increase in 3H-TdR; the eleventh died of another cause at five months. In contrast, only two of 18 patients without such change in 3H-TdR entered the terminal stage at five and six months and three at seven to 12 months ( p < 0.002). The bone marrow 3H-TdR did not provide significant prognostic information in these patients. Periodic measurement of thymidine uptake by circulating leukocytes may be useful in the follow-up of patients with well-controlled CML, to provide early warning of disease progression.