Optimal time-points for minimal residual disease monitoring change on the basis of the method used in patients with acute myeloid leukemia who underwent allogeneic stem cell transplantation: a comparison between multiparameter flow cytometry and Wilms' tumor 1 expression.

Minimal residual disease (MRD) of 30 adult AML patients was monitored by multiparameter flow cytometry (MFC) and WT1 expression before and after allogeneic stem cell transplantation (allo-SCT). Diagnostic performance of pre-transplant MRD measured by MFC was higher than that obtained by WT1 expression. Comparable results were displayed at day +30 post-transplant, while better values by WT1 compared to MFC were found at day +90. Positive MRD by MFC predicted a shorter disease free survival (DFS) before and 1 month after transplant (p=0.006 and p=0.005), while only high WT1 levels at 1 month from the transplant significantly impacted on DFS (p=0.010). Our results support the idea that MRD monitoring by MFC should be suggested before and 30 days after the transplant, while WT1 expression should be preferred after this procedure. The assessment of MRD at day +30 from allo-SCT is recommended as post transplant check-point for the predictive role displayed, independently of the method used.

Minimal residual disease after allogeneic stem cell transplant: a comparison among multiparametric flow cytometry, Wilms tumor 1 expression and chimerism status (Complete chimerism versus Low Level Mixed Chimerism) in acute leukemia.

Relapse represents the main cause of treatment failure after allogeneic stem cell transplant (allo-SCT). The detection of minimal residual disease (MRD) by multiparametric flow cytometry (MFC), chimerism, cytogenetics and molecular analysis may be critical to prevent relapse. Therefore, we assessed the overall agreement among chimerism (low level mixed chimerism [LL-MC] vs. complete chimerism [CC]), MFC and Wilms tumor 1 (WT1) mRNA to detect MRD and investigated the impact of MRD obtained from the three methods on patient outcome. Sixty-seven fresh bone marrow (BM) samples from 24 patients (17 acute myeloid leukemia [AML], seven acute lymphoblastic leukemia [ALL]) in complete remission (CR) after allo-SCT were investigated at different time points. A moderate agreement was found among the three techniques investigated. A higher concordance between positive results from MFC (75.0% vs. 32.7%, p = 0.010) and WT1 (58.3% vs. 29.1%, p = 0.090) was detected among LL-MC rather than CC samples. Relapse-free survival (RFS) and overall survival (OS) were found to be higher in MRD negative patients than in MRD positive patients analyzed with MFC and WT1. Our results discourage the use of low autologous signals as the only marker of MRD, and suggest the usefulness of MFC and WT1 real-time quantitative polymerase chain reaction (RQ-PCR) in stratifying patients with respect to risk of relapse.

Bortezomib (Velcade) for progressive myeloma after autologous stem cell transplantation and thalidomide.

Twenty-one patients with multiple myeloma, all relapsed after frontline autologous stem cell transplantation and all relapsed again after or resistant to thalidomide (employed as second line treatment) received bortezomib (1.3 mg/m(2) body surface twice weekly for 2 weeks followed by an interval of 10-12 days) without adjunct of steroids as third line therapy. Three patients died of progressive disease during the first 2 cycles with bortezomib. Eighteen patients received at least 2 cycles and were evaluated for response. According to EBMT criteria, two complete (negative immunofixation) and seven partial (reduction of M-component > 50-75%) remissions were achieved (ITT response rate 42.8%). Duration of response lasted from 2 to 14+ months. Grades 3-4 toxicities (thrombocytopenia, leucopenia, peripheral neuropathy and vasculitis) were observed in seven patients, but no patient interrupted the treatment due to side effects. We conclude that bortezomib alone may induce high quality responses as third line salvage therapy with acceptable toxicity in a significant proportion of homogeneously pre-treated myeloma patients with progressive disease after autologous transplantation and thalidomide.

Autologous stem-cell transplantation for patients with acute myeloid leukemia aged over 60 yr.

OBJECTIVES: Preliminary reports have suggested that autologous stem-cell transplantation (ASCT) is feasible in elderly patients with acute myeloid leukemia (AML). The objective of this study was to describe the disease characteristics and treatment results from a series of 22 elderly AML patients undergoing ASCT. METHODS: The median age was 64 yr (range 61-71). Twenty patients were in first complete remission (CR1), two in CR2, and all were in performance status 0-1. The median interval between CR achievement and ACST was 3 months (range 2-5). In 20 cases peripheral blood stem cells were infused, in two bone marrow. RESULTS: All patients had a successful engrafment. One patient (5%) died from transplant-related complications. The median number of days to granulocytes > 500 mm-3 and platelets > 20 000 mm-3 was 11(range 9-15) and 13 (range 9-20), respectively. Non-hematologic toxicity included WHO grade III-IV stomatitis in 32% patients and grade IV nausea and vomiting in one (4.5%). Seven patients had fever of unknown origin, while in 14 a documented infection was diagnosed. Median duration of hospitalization was 31 d (range 16-60). CONCLUSIONS: After a median follow-up of 12 months from ASCT, nine patients are alive in continuous CR and 13 died from AML relapse. Median survival from diagnosis and disease-free survival (DFS) was 19 and 14 months, respectively. Our data show that ASCT with a standard conditioning regimen is feasible in AML patients aged more than 60 yr. Toxicity and hemopoietic recovery do not substantially differ from those observed in young adults. DFS and overall survival (OS) duration are encouraging, but a longer follow up is needed on a larger series of patients.