Prognostic factors for survival of 194 patients with low infiltrate leukemia

Prognostic factors were identified from the histories of 194 patients diagnosed as having low infiltrate leukemia (LIL) between 1973 and 1981, when the policy was to delay treatment until there was evidence of progressive disease or life-threatening morbidity. Their median age was 59 yr; 63% were male; 30 had had a malignant disease previously. Presenting symptoms included anemia, 82%; infections, 15%; and hemorrhage, 16%. The group's median survival was 42 weeks, with high marrow cellularity and percentage of blasts, impairment of bone marrow, liver or renal function, age over 65 yr and performance status less than 80% associated with poorer survival. Cytogenetic changes associated with poor survival included loss of chromosome 5 or 7, additional chromosome 8, karyotypic instability, and presence of 100% abnormal metaphases. A regression model including terms for blood and bone marrow features, and age at hospital admission was able to stratify patients into prognostic groups in the same population and in an independent population admitted prior to 1973. Further prospective testing of the model is required. Twenty-six of the 78 patients who were eventually treated with combination chemotherapy achieved complete remission. The presence of Auer rods, diagnosis of acute leukemia or refractory anemia with excess blasts, rapid increase in marrow infiltrate and favorable cytogenetic karyotype were associated with response. Delaying treatment in all patients was found to have improved only modestly the survival of patients with LIL.