The early reduction of leukemic blasts in bone marrow on day 6 of induction treatment is predictive for complete remission rate and survival in adult acute myeloid leukemia; the results of multicenter, prospective Polish Adult Leukemia Group study

Prognostic and Therapeutic Value of Day 14 Bone Marrow Aspiration in Adult Acute Myeloid Leukemia Patients

BACKGROUND

Early blast clearance to induction chemotherapy in acute myeloid leukemia (AML) is an important prognostic indicator of treatment outcome in addition to genetics and molecular genetics. We evaluated the prognostic value of bone marrow aspiration (BMA) at day 14 (D14) and impact on outcome to asses the timing of a second induction.

PATIENTS AND METHODS

This retrospective study included 303 adult AML patients managed at the National Cancer Institute, Cairo University, from the beginning of 2010 to the end of 2014.

RESULTS

Median age was 34 years (range, 18-67 years). Sixty-six percent had early blast clearance with < 5% blasts and 34% had ≥ 5% blasts at BMA D14; 38 patients died early during or shortly after induction. Initial blast load (bone marrow and peripheral blood) and initial platelet count were significantly higher in those with disease that did not respond to therapy compared to those whose disease did respond to therapy at D14 (P < .001, .035, and .006, respectively). The median disease-free survival for early blast clearance at D14 was 18.5 months, versus 18.7 months for those with late response to therapy (day 28), and was only 1.3 months for patients who received immediate second-line therapy on the basis of BMA D14 (P < .001). The median overall survival for early blast clearance was 13.6 months, versus 7.2 months for those with late response to therapy, and only 1.3 months for patients who received immediate second-line therapy on the basis of BMA D14 (P < .001).

CONCLUSION

BMA D14 has a significant prognostic impact on the therapeutic outcome of AML patients (complete remission, disease-free survival, and overall survival); however, a second induction in patients with BMA D14 blasts > 5% should be delayed until neutrophil recovery to minimize death in aplasia.

Comparison of Peripheral Blast Clearance and Day 14 Bone Marrow Biopsy in Predicting Remission Status and Survival After 7+3 Induction in Acute Myeloid Leukemia

INTRODUCTION

Induction chemotherapy with cytarabine and an anthracycline (7+3) remains the standard of care for acute myeloid leukemia (AML).

PATIENTS AND METHODS

We retrospectively analyzed 183 newly diagnosed AML patients to compare the utility of rapid peripheral blast clearance (PBC), day of peripheral blast disappearance, residual blasts, and cellularity at day 14 bone marrow biopsy (D14BM) in predicting clinical response to 7+3 induction, overall survival (OS), and relapse-free survival (RFS).

RESULTS

In multivariable logistic regression analysis, day 2 PBC > 85% [P = .0016] was the only predictor of remission status, with sensitivity and specificity of 75%. Peripheral blast disappearance within 5 days after induction and < 10% cellularity in D14BM predicted superior OS and RFS in multivariate analysis. Median follow-up of patients was 28 months since diagnosis. Two-year OS and RFS for patients with ≤ 10% versus > 10% cellularity at D14BM was 60.6% [95% confidence interval (CI), 50.8%-72.2%] versus 32.5% [95% CI, 23.0%-45.8%], and 51.9% [95% CI, 41.9%-64.3%] versus 28.8% [95% CI, 19.1%-43.4%], respectively [P = .0003 for OS and .002 for RFS].

CONCLUSION

Rapid PBC after 7+3 induction showed a significant improvement in specificity compared with D14BM, with similar sensitivity. Neither of these methods were reliably specific tools for the decision of early reinduction, despite their prognostic value. Our findings indicate that morphological cellularity in D14BM is an independent prognostic factor for OS and RFS, regardless of blast percentage, and that ≤ 10% cellularity defines D14BM hypoplasia.

Peripheral blood blast clearance is an independent prognostic factor for survival and response to acute myeloid leukemia induction chemotherapy

In patients with acute myeloid leukemia (AML), rapid reduction of circulating blasts with induction chemotherapy may serve as an in vivo marker of chemosensitivity. We performed a retrospective analysis of 363 patients with untreated AML who received induction chemotherapy in order to determine the relationship between day of blast disappearance (DOBD) and complete remission (CR) rates, event-free survival (EFS), and overall survival (OS). DOBD ≤ 5 vs. >5 was identified as the most discriminating cutoff for OS. DOBD > 5 was observed in 35 patients (9.6%). The CR rate for patients with DOBD ≤ 5 vs. >5 was 74.0 and 28.6%, median EFS was 9.4 and 1.8 months, and median OS was 17.1 and 5.8 months, respectively (P < 0.001 for all). DOBD > 5 was independently associated with a lower CR rate and shorter EFS and OS (P < 0.001 for all). DOBD > 5 retained prognostic significance for EFS and OS when patients were stratified by cytogenetic risk group, de novo vs. secondary or therapy-related AML, European LeukemiaNet-based risk groups, and whether CR was achieved. We propose DOBD > 5 as a simple and early marker of disease resistance that identifies patients with poor prognosis who otherwise may not be identified with existing risk stratification systems. Am. J. Hematol. 91:1221-1226, 2016. © 2016 Wiley Periodicals, Inc.

Routine interim disease assessment in patients undergoing induction chemotherapy for acute myeloid leukemia: Can we do better?

The presence of >5% blasts at "day 14" (D14), in patients undergoing induction chemotherapy for acute myeloid leukemia (AML) is problematic. It is unclear if a second course of chemotherapy for early persistent disease will alter outcome in these patients. We conducted a retrospective study of AML patients undergoing induction chemotherapy where diagnostic, interim (around day 14), and recovery (days 21-42) bone marrow (BM) evaluations were available for review. Of the 113 patients included in the final analysis, 99 (87.6%) achieved CR at hematologic recovery. At D14, 90 patients (79.6%) had <5% blasts and of these, 87 (96.7%) ultimately achieved CR. At D14, Twenty-three (20.4%) patients had residual leukemia (>5% blasts). Of these, 11 (47.8%) received a second course of chemotherapy (double induction [DI]) and 12 (52.2%) were observed until count recovery (single induction [SI]). No significant difference in CR rates was observed between these two groups (58.3% DI group vs. 45.5% SI group, P value = 0.684). In our analysis, D14 BM evaluation did not uniformly identify patients with primary induction failure. To unequivocally determine the value of a D14 marrow assessment in AML, prospective studies in the context of large cooperative group trials are required. Considering our findings and similar reports from others, we propose that D14 marrow assessment should be individualized, and that other factors, such as cytogenetics and early peripheral blood blast clearance should be considered, to identify patients most likely to benefit from interim disease assessment during AML induction therapy.

Should acute myeloid leukemia patients with actionable targets be offered investigational treatment after failing one cycle of standard induction therapy?

PURPOSE OF REVIEW

Therapeutic failure in acute myeloid leukemia remains common. It may be advantageous to identify patients with suboptimal treatment responses early as they may benefit from timely care strategy changes. Here, responses portending failure of standard induction therapy are reviewed and therapeutic options examined, including use of investigational, targeted agents for suitable patients.

RECENT FINDINGS

Patients entering complete remission without minimal residual disease early, that is, with one cycle of standard induction chemotherapy, have a lower relapse risk and live longer than other similarly-treated patients, supporting the proposition of early complete remission without minimal residual disease as a criterion for induction therapy success. Investigational small molecule drugs are appealing for patients who fail standard therapies, but complete remission rates as a single agent are typically modest.

SUMMARY

The relative value of different treatment strategies if a first standard induction therapy cycle fails to produce complete remission is unknown. However, retreatment with the same therapy often leads to complete remission and provides a benchmark against which other approaches should be compared. Addition of investigational small molecule drugs to standard reinduction therapy in patients with actionable targets could offer an attractive therapeutic strategy in this situation that might improve outcomes and facilitate clinical drug testing.

Is the D14 bone marrow in acute myeloid leukemia still the gold standard?

PURPOSE OF REVIEW

Early bone marrow evaluation on day 14 of induction is common practice assisting in decision making regarding reinduction need in acute myeloid leukemia (AML). Studies exploring day 14 bone marrow false positive and negative rates yielded diverse data, and a highly specific method for early bone marrow evaluation is warranted. Given the improved induction-associated death rate, the risk of redundant reinduction administered to patients anticipating remission with one induction cycle may be outweighed by the benefit from the potential reduction in the falsely interpreted nadir bone marrow. The purpose of this review is to analyze current evidence on ways to optimize early bone marrow evaluation during induction in AML.

RECENT FINDINGS

Day 14 bone marrow blast count is affected by patient's age, leukemic risk, and induction regimen, and its remission prediction power is enhanced if more stringent cutoffs are used to define significant residual blast numbers or if morphologic bone marrow evaluation is performed on day 5 of induction.

SUMMARY

Early bone marrow evaluation has a potential to personalize the induction regimen, but because of limitations of day 14 bone marrow results, earlier bone marrow evaluation or the use of flow cytometry to detect minor blast populations may improve remission prediction in AML.

Prospective comparison of early bone marrow evaluation on day 5 versus day 14 of the "3 + 7" induction regimen for acute myeloid leukemia

Evaluation of early response during induction therapy for acute myeloid leukemia (AML) is used for prognostication and re-induction strategy, yet the optimal evaluation time point is unknown. Clearance of bone marrow (BM) blasts by day 14 of therapy does not ensure remission; thus, some patients requiring re-induction are neglected. This study aimed to examine the role of earlier BM evaluation during induction for predicting remission and overall survival. Results of BM testing on the 5th and 14th day of intensive induction were prospectively compared in 127 adult patients with AML. Re-induction was given, based on Day 14 results, to 25 patients. Reduction of the BM blast count to <5% as early as by the fifth day of induction was more specifically associated with the achievement of remission compared to Day 14 (88.2% vs. 60%, respectively). Rapid responders have a better 3-year overall survival (OS). Day 5 results are a stronger predictor of OS by multivariate analysis and better segregate long-term survivors than the Day 14th BM count (66% vs. 30%, P = 0.0001 and 48% vs. 37%, respectively, P = 0.04). The Day 5 evaluation of BM carries significant clinical information. The benefit of prescribing re-induction based on such early evaluation should be prospectively studied.