Recurrent Adult Acute Myeloid Leukemia
A subset of relapsed patients treated aggressively may have extended disease-free survival (DFS); however, cures in patients following a relapse are thought to be more commonly achieved using BMT.[Level of evidence: 3iDii] A retrospective study from the International Bone Marrow Transplant Registry compared adults younger than 50 years with AML in second complete remission who received HLA-matched sibling transplantation versus a variety of postremission approaches. The chemotherapy approaches were heterogeneous; some patients received no postremission therapy. The transplantation regimens were similarly diverse. Leukemia-free survival appeared to be superior for patients receiving BMTs for two groups: patients older than 30 years whose first remission was less than 1 year; and patients younger than 30 years whose first remission was longer than 1 year.[Level of evidence: 3iDii]
Allogeneic BMT from an HLA-matched donor in early first relapse or in second complete remission provides a DFS rate of approximately 30%.[Level of evidence: 3iiiA] Transplantation in early first relapse potentially avoids the toxic effects of reinduction chemotherapy.[3,17,18] Allogeneic BMT can salvage some patients whose disease fails to go into remission with intensive chemotherapy (primary refractory leukemia). Nine of 21 patients with primary refractory AML were alive and disease free at 10 years following allogeneic BMT.[Level of evidence: 3iiiA] Randomized trials testing the efficacy of this approach are not available. Autologous BMT is an option for patients in second complete remission, offering a DFS that may be comparable to autografting in first complete remission.[19,20,21]
Patients who relapse following an allogeneic BMT may undergo an infusion of lymphocytes from the donor (Donor Lymphocyte Infusion or DLI), similar to the therapy patients with relapsing chronic myelogenous leukemia (CML) undergo. (Refer to the Relapsing Chronic Myelogenous Leukemia section of the PDQ summary on Chronic Myelogenous Leukemia Treatment for more information.) There are no published studies of any prospective trials examining the role of DLI for patients with AML who relapsed following allogeneic BMT. A retrospective study of European patients found that, out of 399 patients who relapsed after an allogeneic BMT, 171 patients received DLI as part of their salvage therapy. A multivariate analysis of survival showed a significant advantage for the 171 DLI recipients, who achieved a 2-year overall survival from the time of relapse of 21%, compared to 9% for the 228 patients who did not receive DLI (P < .04; RR=0.8; 95% confidence interval, 0.64-0.99).[Level of evidence: 3iiiA] The strength of this finding is limited by the retrospective nature of the study, and the possibility that much of the survival advantage could have been the result of selection bias. Furthermore, the remission rate of 34% reported in this study was considerably less than the 67% to 91% reported for CML. Therefore, even if the survival advantage conferred by DLI is real, the fraction of relapsed AML patients who might benefit from this therapy appears to be quite limited.