EPIPODOPHYLLOTOXIN-RELATED ACUTE MYELOID-LEUKEMIA - A STUDY OF 35 CASES

To define better the risk of epipodophyllotoxin-related acute myeloid leukemia (AML) after extended follow-up and to assess responses to int ensive salvage therapy, all patients who developed this complication a fter treatment for acute lymphoblastic leukemia (ALL) or non-Hodgkin l ymphoma (NHL) in consecutive clinical trials at St Jude Children's Res earch Hospital from 1979 to 1994 were studied. Cases with 'lineage swi tch' or 'clonal selection' were excluded. Epipodophyllotoxin-related A ML developed in 32 of 1140 patients treated for ALL and in three of 33 2 treated for NHL; it was a first adverse event in 25 and two cases, r espectively. The complication was diagnosed at 12-130 months (median 3 4 months) after the initiation of treatment with epipodophyllotoxins; all but one of the cases occurred within 73 months, indicating that th e risk is negligible after 6 years. The predominant karyotypic feature was 11q23 translocations (71% of cases); 21q22 rearrangements were ra re. In a stepwise Cox regression analysis, two factors increased the r isk of this complication: weekly or twice weekly administration of epi podophyllotoxins (P < 0.001); and the administration of asparaginase i mmediately before epipodophyllotoxin therapy (P < 0.001). Initial resp onses to salvage therapy were comparable to those reported for de novo AML: 92% of the evaluable patients entered complete remission after c ombination treatment. Single-agent therapy with 2-chlorodeoxyadenosine induced complete or partial remissions in one-half of the patients tr eated. The long-term survival rate was dismal. Of the 17 evaluable pat ients treated exclusively with chemotherapy, only one is alive at 84 m onths, compared to three of 16 patients who underwent bone marrow tran splantation (alive at 10, 23 and 73 months), Cases of epipodophyllotox in-related AML constitute a unique clinical syndrome that will require innovative strategies for cure.