Adolescent and adult acute lymphoblastic leukemia: Prognostic features and outcome of therapy. A study of 293 patients

The case histories of 293 adolescent and adult patients with acute lymphoblastic leukemia (ALL) first seen and treated between 1969 and 1979 are reviewed. A complete remission (CR) was achieved in 79% of cases. Male sex, advanced age (≥30 yr old), and early CNS involvement were the major determinants of remission failure. Median duration of first CR was 16 mo, with 23 patients (actuarial proportion 25%) alive and relapse-free at 5 yr. The major determinant of first CR length was white blood cell (WBC) count (best cut-off value at 35 x 109/liter). First CR length was also negatively affected by early CNS involvement, morphological FAB L3 subtype, and B-cell (Smlg+) leukemia, but these features were significantly associated with a high WBC count. First CR length in patients 11-15 yr old did not differ significantly from that of patients 16-59 yr old. The negative prognostic value of T-cell (E+) leukemia was not confirmed in this adult series. CNS prophylaxis provided an effective protection against CNS relapse. Maintenance chemotherapy was apparently more effective when 4 or more than 4 drugs were employed. 'Low risk' patients WBC count <35 X 109/liter still relapsed rather frequently (32% at 1 yr, 49% at 2 yr), with 33% of them alive and relapse-free at 5 yr. 'High risk' patients (WBC count ≥35 X 109/liter ± early CNS involvement ± morphological L3 subtype ± B-cell leukemia) relapsed very quickly (50% at 6 mo, 70% at 1 yr), with only 6% of them relapse-free at 5 yr.