**4. ASCT for acute lymphocytic leukemia**

ALL is divided into tumors of B cell and T cell lineage and it is the most common cause of leukemia in children however up to 20% of the cases of ALL occur in adults. Despite of the developments of induction chemotherapy regimen, relapse rates and mortality still remain high in this century. Most of studies were designed according to risk stratification and categorized patients into standard, intermediate or poor risk. Poor risk criteria are cytogenetic abnormalities t(9;22), t(4;11), or t(1;19); pro–B-cell immunophenotype; high WBC (i.e., > 30 × 109 /L in case of B-ALL; > 100 × 109 /L in case of T-cell ALL [T-ALL]) at the time of diagnosis. Although the introduction of more aggressive chemotherapy regimens has reduced the need for allo-HSCT in patients younger than 35 years of age, allo-HSCT remains the standard of care for high-risk patients and relapse after CR1. SCT is still a debate in ALL patients without poor-risk features however Allo-SCT is highly recommended in poor risk ALL patients in CR1. Allo-SCT is not certainly suggested in ALL patients without poor risk to avoid the unnecessary risks of transplantation procedure-related mortality and GVHD to patients, who may be cured with chemotherapy alone and to postpone allo-SCT to an eventual relapse. The standard risk patients rather than the high-risk patients, older patients and the patients who are not eligible for Allo-SCT may be the ones who are most likely to benefit from ASCT in first remission. MRD has emerged as a prognostic marker that can define patients to high-risk, making them candidates for Allo-SCT.

Several studies have been published about the experience of ASCT in ALL. The results of some recent trials are summarized in **Table 2**. Data from three prospective trials of the French group have failed to demonstrate any significant superiority of ASCT over chemotherapy, even in a subset of high-risk patients [39–41]. Conversely, it has been reported that ASCT may be an effective treatment for ALL patients who experienced an isolated extramedullary relapse. A recent randomized study of 433 adult standard risk ALL patients showed that LFS at 5 years was significantly better in patients who underwent allo-HSCT compared with ASCT (60% vs. 42%, *P* = 0.01). In a large study which is comparing chemotherapy and autologous transplantation in ALL patients, the LFS and OS were found superior for chemotherapy group [34]. In the LALA-87 trial, results in standard-risk ALL were similar for Allo-SCT [37] and for chemotherapy or ASCT and then the same group reported no benefit of ASCT for ALL in all risk groups [42].

The Philadelphia chromosome (Ph) translocation (9; 22) is the most common chromosomal abnormality seen in adult patients with ALL. The t(9;22) is observed


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**Author details**

patients without poor risk.

in Ph + ALL [47, 48].

**5. Conclusion**

Fatma Keklik Karadağ, Fahri Şahin and Güray Saydam\*

\*Address all correspondence to: guraysaydam@gmail.com

provided the original work is properly cited.

Ege University, School of Medicine, Hematology, Izmir, Turkey

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

*Consolidation: Autologous Stem Cell Transplantation in Acute Leukemia*

in 2 to 5% of children with ALL and 30% percent of adults. Historically, Ph-positive ALL (Ph + ALL) was considered a very high-risk subtype and Allo-SCT was highly recommended for all eligible patients. After the introduction of tyrosine kinase inhibitors (TKIs) (first TKI, imatinib; second-generation TKIs such as dasatinib or nilotinib; the third-generation TKI, ponatinib) which could be successfully used both as salvage therapy and upfront in combination with intensive chemotherapy, complete remission is achieved in 90% of Ph + ALL patients [43]. The critical role of MRD prior to ASCT was already confirmed in Ph-negative ALL and may also be important in the Ph + setting [44]. Results of ASCT for Ph + ALL improved markedly in recent years with more than half of patients being alive and leukemia-free at 2 years [43, 45, 46]. The role of biologic response modifiers such as α-interferon (α-IFN and interleukin-2) in Ph + ALL is analyzed and it was reported that combination of α-IFN with maintenance chemotherapy and ASCT improves the outcomes

According to NCCN guidelines; Patients with good-risk AML are recommended

to undergo high-dose cytarabine-based chemotherapy. Patients with poor-risk AML are recommended to undergo allogeneic stem cell transplantation (alloSCT). However, the best post remission therapy for patients with intermediate-risk AML in first complete remission (AML/CR1) is still uncertain. ASCT would be an option in CR1 and MRD negative. ASCT is a kind of standard treatment of CR2 in APL patients. There is no benefit of ASCT in Ph negative ALL patients however ASCT is a therapeutic option for relapsed Ph + ALL. Although the main disadvantages of ASCT are the possibility of contamination of leukemic cells in the stem cell product and the absence of graft-versus-leukemia effect, which lead to a higher relapse rates than that of Allo-SCT, ASCT should be considered a standard therapy in acute leukemia patients who are not eligible Allo-SCT and MRD negative in CR1 and the

*DOI: http://dx.doi.org/10.5772/intechopen.94424*

#### **Table 2.**

*Summaries of studies on autologous stem cell transplantation in ALL.*

#### *Consolidation: Autologous Stem Cell Transplantation in Acute Leukemia DOI: http://dx.doi.org/10.5772/intechopen.94424*

in 2 to 5% of children with ALL and 30% percent of adults. Historically, Ph-positive ALL (Ph + ALL) was considered a very high-risk subtype and Allo-SCT was highly recommended for all eligible patients. After the introduction of tyrosine kinase inhibitors (TKIs) (first TKI, imatinib; second-generation TKIs such as dasatinib or nilotinib; the third-generation TKI, ponatinib) which could be successfully used both as salvage therapy and upfront in combination with intensive chemotherapy, complete remission is achieved in 90% of Ph + ALL patients [43]. The critical role of MRD prior to ASCT was already confirmed in Ph-negative ALL and may also be important in the Ph + setting [44]. Results of ASCT for Ph + ALL improved markedly in recent years with more than half of patients being alive and leukemia-free at 2 years [43, 45, 46]. The role of biologic response modifiers such as α-interferon (α-IFN and interleukin-2) in Ph + ALL is analyzed and it was reported that combination of α-IFN with maintenance chemotherapy and ASCT improves the outcomes in Ph + ALL [47, 48].
