抄録
This controlled study of children with acute lymphocytic leukemia was designed to test the efficacy and toxicity of different mode of administration of 6-mercaptopurine and methotrexate during remission and whether more increased dosage of these drugs prolongs remission in patients with features associated with a particular poor prognosis such as initial high white cell count.
After inducing remission with prednisolone and vincristine, patients received cranial irradiation and IT methotrexate, and were randomized to receive intermittent cyclic maintenance therapy (Regimen A, B, and C) during May 1976 and April 1977, and concomitant conbination therapy (Regimen AA, BB, and CC) during May 1977 and June 1978. Total dosage of each antileukemic drugs was designed to be equal between Regimen A and AA, B and BB, and C and CC.
Of the 71 patients entering this study between May 1976 and June 1978, 66 (93%) attained complete remission and were randomized to receive continuation chemouherapy of Regimen A (13 cases), B (12), C (8), AA (12), BB (12), and CC (8). In Regimen A+B+C and AA+BB+CC, the results were eqivalent but 6 patients (AA: 2, BB: 2, CC: 2) died with complication of pneumocystis carinii pneumonia and varizella-zoster infection associated with severe neutropenia and mucositis during complete remission. The maintenance therapy with concomitant use of 6-MP and MTX increased toxicity and complication without demonstrably increasing the leukemocidal effect. In 16 patients with initial high white cell count over 25,000/mm3 (Regimen C and CC), the duration of complete remission and survival were inferior to those with low initial white cell count, inspite of increased dosage of 6-MP and MTX.
These data suggested that the maintenance therapy with intermittent cyclic fashion of 6-MP and MTX might be effective and less toxic than that with concomitant conbination of these drugs, and that the additional combination chemotherapy to 6-MP and MTX might be necessary for patients with features associated with a poor prognosis such as initial high white cell count.
