Changes in the incidence, pattern of presentation and clinical outcome of early chronic lymphocytic leukemia patients using the 2008 International Workshop on CLL guidelines

Objectives: Before 2008, diagnosis of chronic lymphocytic leukemia (CLL) relied on 1996 National Cancer Institute Working Group criteria which required an absolute lymphocyte count of 5.0 × 109/l or higher. The up-dated 2008 International Workshop on CLL (IWCLL) guidelines recommend using the B-cell count as a basis for the diagnosis of CLL and indicate a B-cell threshold of 5.0 × 109/l. The objective of this study was to assess the effects of these changes on the pattern of presentation and clinical outcome of early CLL. Methods: For this purpose we analysed 414 patients with previously untreated, Binet stage A CLL diagnosed between January 2006 and December 2010 and registered prospectively at a national database. Results: After patients were reclassified according to updated 2008 IWCLL guidelines, 130 Rai stage 0 CLL patients were reclassifed as clinical monoclonal B-cell lymphocytosis, resulting in a 31.4% decrease (from 414 to 284) in the diagnosis of early stage CLL. Moreover, a shift towards a more...