An analysis of risk factor and survival in childhood acute lymphoblastic leukemia

To study the survival and prognostic factor of childhood acute lymphoblastic leukemia, 78 newly-diagnosed cases between January 1982 and June 1987 in National Taiwan University Hospital were reviewed and analyzed. They were stratified into two groups, i.e. standard-risk (SR) and high-risk (HR), according to their pre-treatment leukocyte count and age. Following induction therapy, 97% of the SR patients and 80% of the HR patients attained complete remission. In the SR group, the 2- and 3-year failure-free survival rates were 37% and 24%, with a median survival of 16 months. In the HR group, failure-free survival at the second and third year were 11% and 4%, respectively, with a median survival of 5.3 months. Three factors are strongly related to induction failure, i.e. high leukocyte counts (greater than 50*10(9)/1), massive hepatomegaly and large lymph nodes. Univariate analysis of failure-free survival showed six variables with significant detrimental effects on eventual outcomes, i.e. high leukocyte counts (greater than 50*10(9)/1), meningeal leukemia, marked lymphadenopathy, age younger than 2 years and older than 10 years, massive hepatomegaly (greater than 6 cm), and high LDH level (greater than 800 u/1). However, statistical survival models should also determine the joint effects of the prognostic factors so that the relative importance of each factor can be assessed. High initial leukocyte count, disclosed by multivariate analysis, was the single most important factor detrimental to the continuance of complete remission (P = 0.0004). Preliminary results also revealed poor compliance and early relapse in this study. Possible causes of early failure are discussed. Conceptual education for family members, as well as management with effective cytoreductive therapies are urgently needed.