Distribution of pretreatment serum LDH concentrations (logarithmic scale) according to stage of disease. (○) Patients surviving event-free; (□) toxic death; (▴) patients suffering from progress; (*) patients who developed second malignancy. From 16 patyients (2, 7, 2, 1, and 4 of stage I, II, III, IV, and B-ALL, respectively) the LDH values are lacking. One of these patients (stage IV) relapsed, and 2 B-ALL patients died of acute cell lysis syndrome. One patient (stage III) with LDH less than 100 U/L and 3 patients (B-ALL) with LDH greater than 10,000 are not depicted; 1 of them (B-ALL) died of acute cell lysis syndrome.