[Early evaluation of therapeutic response in acute lymphoblastic leukaemia. A study of cytoreduction in blood and bone marrow (author's transl)].

Cytoreduction was evaluated during the first week of induction treatment in 29 adult patients with acute lymphoblastic leukaemia. In 25 patients a slope of decrement of circulating blasts between the 1st and 7th days of treatment could be drawn on a semilogarithmic scale. The fall of the medullary blast index was calculated in bone marrow obtained by aspiration in 17 cases and by aspiration plus biopsy in 11 cases. The diminution of circulating and medullary blasts was more pronounced in patients who achieved complete remission than in those who failed to respond (p less than 0.001), irrespective of the induction treatment. Early therapeutic cytoreduction, as measured by these simple mathematical methods, therefore has a bearing on the prognosis, and the induction treatment should be reinforced in cases where cytoreduction is insufficient.