Chronic Lymphocytic Leukemia in Younger Adults: Preliminary Results of a Study Based on 454 Patients-IWCLL/Working Group.

Whether all younger adult patients with chronic lymphocytic leukemia (CLL) should be offered intensive and/or experimental treatments is currently undecided. In order to investigate the natural history and prognosis of CLL in younger adults, information on 454 B-CLL patients less than 50 yrs old, from 13 different International groups was collected and analyzed. The male/female proportion is 1.46 (270/184) and the median age is 46 yrs (range, 20-49). Number of cases increases with age: nine patients (2%) are <30 yrs; 70 (14%) are 30 to 40 yrs; and 375 (84%) are 41 to 49 yrs. Clinical stages distribution is as follows: Rai O, 113 (25%), Rai I, 98 (21.5%), Rai II, 182 (40%), Rai III, 25 (5.5%), and Rai IV, 36 (8%); Binet's A, 235 (52%), Binet's B, 160 (35%), Binet's C 59 (13%). Bone marrow biopsy was available in 251 cases, being nodular in 46 (18.5%), interstitial in 76 (30%), mixed in 60 (24%), and diffuse in 69 (27.5%). Clinical characteristics of these patients do not differ from those described for entire series of CLL patients including all ages. The majority of patients (93%) were diagnosed between 1975 and 1989 and at the time of this analysis 138 (30.3%) have died. Infection accounts for the large majority of deaths (48%). Overall median survival is 12 yrs. Survival probability (±SD) is 73.55 ± 2.47% at 5 yrs, 51.04 ± 3.46% at 10 yrs, and 45.53 ± 4.08% at 15 yrs. Prognostic parameter identified in whole series of patients with CLL are also useful when applied to this special subset. Thus, patients in stage A, B, and C have, at 10 yrs after diagnosis, survival probabilities of 72.4%, 33.7%, and 21.2%, respectively. Rai stages also discriminate different risk-groups with a survival probability at 10 yrs of 76% for patients in stage 0, 45% for those in stage I + II, and 24% for patient in Stage III + IV. Patients with non-diffuse bone marrow pattern have a survival probability of 76% at 10 yrs compared to 28% for those with a diffuse pattern. Further analysis will refine both the prognostic assessment and the optimal treatment approach for these patients.