Poor age-corrected survival of chronic lymphocytic leukaemia patients with trisomy 12

Analyses on the prognostic impact of cellular markers in chronic lymphocytic leukaemia is hampered by the strong influence of age on survival. We have therefore used a ratio between the observed survival (or observation time) and the expected survival of age- and sex-matched healthy Swedes to eliminate the age dependence. Log rank analysis of the observed/expected survival time ratio demonstrated that CLL-patients with trisomy 12 had a poorer age-corrected survival than other patients.