High incidence of chronic lymphocytic leukemia (CLL) diagnosed by immunophenotyping: A population-based Canadian cohort

Incidence and outcomes of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) are not well established at the population level, especially since the widespread use of immunophenotyping. We studied the epidemiology of CLL in Manitoba (Canada) by combining data from a centralized flow cytometry facility and the provincial cancer registry for the period 1998-2003. Of 616 cases identified, 27% of patients identified by flow cytometry were not on the cancer registry. The age-adjusted incidence of 7.99/100,000 is substantially higher than the reported incidence in registry reports. We also noted differences in relative survival based on age and gender.