Leucocyte doubling time is a useful predictor of progression-free survival in chronic lymphocytic leukaemia.

Abstract. Objective. To assess leucocyte doubling time (LDT) in relation to progression-free survival in patients with chronic lymphocytic leukaemia (CLL). In addition, to define the impact of a second LDT in both untreated and treated patients. Design. Retrospective study of LDT in previously untreated patients with CLL. Subjects and setting. Sixty patients diagnosed over a 13-year period at a county hospital. In forty-five of the 60 patients, an LDT could be defined. These patients were included in the final analysis. Main outcome measures. LDT below and above 12 months, progression-free and overall survival. Results. Patients in Binet stages B and C had a median LDT of 4 months as compared to 26 months in stage A patients (P < 0.01). The projected progression-free survival at 3 years was 24% in patients with an LDT of < 12 months. The corresponding figure for the remaining patients was 68% (P < 0.01). The overall 5-year survival did not differ significantly between patients with an LDT below and above 12 months, respectively. In seven untreated patients, a second LDT could be calculated which was shorter than the first recorded LDT. A second LDT was also identified in five patients post treatment that was consistently shorter than their first LDT. Conclusions. Measurement of LDT is a simple complement in predicting progression-free survival in patients with CLL. Thus, monitoring of LDT may add to the clinical evaluation and therapeutic decision making for the many elderly patients with this often indolent disease.