A. Incidence of laboratory tumour lysis syndrome (LTLS) and clinical tumour lysis syndrome (CTLS) associated with initial lactate dehydrogenase (LDH) values. LDH <2x upper limit of normal (ULN)vs. LDH ≥2x ULN, p = 0.005 (Fisher’s exact test). B. Incidence LTLS or CTLS by treatment group and LDH values. C. Incidence of LTLS, or CTLS at any time prior to the initiation or following chemotherapy (COP-R; cyclophosphamide, vincristine, prednisone, rituximab).