Outcome of a multicenter treatment program including autologous or allogeneic bone marrow transplantation for de novo acute myeloid leukemia

Correlation analysis of p53 protein isoforms with NPM1/FLT3 mutations and therapy response in acute myeloid leukemia

The wild-type tumor-suppressor gene TP53 encodes several isoforms of the p53 protein. However, while the role of p53 in controlling normal cell cycle progression and tumor suppression is well established, the clinical significance of p53 isoform expression is unknown. A novel bioinformatic analysis of p53 isoform expression in 68 patients with acute myeloid leukemia revealed distinct p53 protein biosignatures correlating with clinical outcome. Furthermore, we show that mutated FLT3, a prognostic marker for short survival in AML, is associated with expression of full-length p53. In contrast, mutated NPM1, a prognostic marker for long-term survival, correlated with p53 isoforms β and γ expression. In conclusion, p53 biosignatures contain useful information for cancer evaluation and prognostication.

Use of biological assignment in hematopoietic stem cell transplantation clinical trials

BACKGROUND

When comparing treatments for a specific illness, it is sometimes impractical or impossible to conduct a randomized clinical trial (RCT). Biological assignment trials are one alternative design. In hematopoietic stem cell transplantation (HCT) trials, a human leukocyte antigen (HLA)-matched sibling donor is considered optimal, but such donors are available for only 20-30% of otherwise eligible patients. Rather than randomizing only those with a matched sibling donor, in a recent multiple myeloma trial, the type of HCT each patient received was biologically based, i.e., chosen according to whether or not the patient had a matched sibling donor.

PURPOSE

This article describes the design and implementation of biological assignment trials as well as their advantages and disadvantages.

METHODS

We focus on several aspects of such trials, including efficiency of trial duration, ethical issues, and potential sources of bias. Statistical issues are considered including sample size calculations, monitoring for biased enrollment, and adjustments for imbalances in patient characteristics. A multiple myeloma trial is used as an illustration.

RESULTS

Although they often require a larger sample size, biological assignment trials can provide substantial efficiency in terms of study duration over randomized trials when accrual to a randomized trial would be slow. Determination of sample size requires consideration of the anticipated proportion of patients with a biologically favored (HLA-matched sibling) donor. An add-on randomization of patients without a matched sibling donor may alleviate ethical concerns about applicability of study results to all patients regardless of whether the biological assignment groups differ with respect to outcome.

LIMITATIONS

Prognostic factor imbalance and enrollment bias can occur in a biological assignment trial. Statistical adjustment for potential imbalance in prognostic factors is important, as is monitoring center accrual for enrollment bias and performing an appropriate intention-to-treat analysis.

CONCLUSIONS

A biological assignment trial can be a reasonable way to compare treatments which are biologically based, such as HLA-matched sibling transplants, when the gold-standard randomized trial design is impractical or impossible. Implementing such a trial requires careful consideration of the ethical issues and potential biases.

Meta-analysis of autologous bone marrow transplantation versus chemotherapy in adult patients with acute myeloid leukemia in first remission

In the present study, we have conducted a meta-analysis comparing autologous bone marrow transplantation (ABMT) and intensive chemotherapy in adult acute myeloid leukemia (AML) patients in first remission. Combined results of the six appropriate randomised controlled studies indicate that ABMT had no advantage over chemotherapy or no further treatment concerning death rate (overall rate ratio (RR)-0.95, 95% CI, 0.81-1.11), while was superior to chemotherapy concerning event rate (overall RR--0.82, 95% CI, 0.71-0.94). In conclusion, ABMT did not improve survival but it improved event-free survival (EFS) when compared with chemotherapy or no further treatment in patients with AML in first complete remission.

Consolidation therapy with autologous bone marrow transplantation in adults with acute myeloid leukemia: a meta-analysis

BACKGROUND

The optimal consolidation therapy for adults who are in first remission of acute myeloid leukemia after induction chemotherapy and who do not have a histocompatible donor is poorly established. We conducted a meta-analysis to compare the efficacy of autologous bone marrow transplantation with that of non-myeloablative chemotherapy alone (or no further treatment).

METHODS

Eligible studies were identified by searching electronic databases and by examining the reference lists of relevant studies and review articles. Eligible studies were those that prospectively enrolled adults with acute myeloid leukemia and randomly assigned patients who were in first remission and who did not have a matched sibling donor to one of the two consolidation therapies. Two reviewers independently assessed all studies for relevance and validity. We used a fixed-effects model to calculate the ratio of probabilities for disease-free and overall survival at 48 months or at the nearest recorded assessment point for each study and for all studies combined. All statistical tests were two-sided.

RESULTS

We identified 587 potentially relevant studies, 36 of which were retrieved for detailed evaluation. In the six studies eligible for this meta-analysis, a total of 1044 patients were randomly assigned to receive autologous bone marrow transplantation or non-myeloablative chemotherapy (five studies) or autologous bone marrow transplantation or no further treatment (one study). Compared with patients who received chemotherapy or no further treatment, patients who received autologous bone marrow transplantation had a better disease-free survival (ratio of disease-free survival probabilities = 1.24, 95% confidence interval [CI] = 1.06 to 1.44; P =.006) but a similar overall survival (ratio of overall survival probabilities = 1.01, 95% CI = 0.89 to 1.15; P =.86).

CONCLUSION

Our results do not support the routine use of autologous bone marrow transplantation in adult acute myeloid leukemia patients in first remission.