Peripheral blood examination characteristically shows anemia, thrombocytopenia, and neutropenia (Table 20.2) although the total white blood cell count (WBC) is variable. The reduction in the level of hemoglobin is mild to moderate, but nearly one-third of the patients have a hemoglobin level below 8 g/dl. Although clinical bleeding due to thrombocytopenia is not very common, about half of the patients have a platelet count below 50  ×  10⁹/L. The proportion (30 %) of adult ALL patients having had some history of hemorrhage corresponds well with the 30 % of patients with a platelet count below 25  ×  10⁹/L. The proportion of patients with a granulocyte count below 0.5  ×  10⁹/L, usually associated with high risk of infection, was only one-fifth in this series. Only a small minority of patients had clotting defects and of these 5 % had an initially decreased fibrinogen level, which might be of relevance if an immediate l-asparaginase treatment is anticipated. The WBC was reduced in 27 %, normal or modestly elevated in 60 %, and 16 % had a marked leukocytosis (WBC count >100  ×  10⁹/L) at presentation. However, even in the cases where the WBC was reduced or normal, characteristic lymphoblasts could be identified on a well-stained blood smear in more than 90 % (Table 20.2).

Bone marrow examination provides further material for diagnostic assessment including morphology, cytochemical stains, immunological markers, and cytogenetic and molecular analysis. Smears of the bone marrow aspirate show markedly hypercellular particles. The majority of cells are leukemic lymphoblasts. A total of 97 % of the adult ALL patients had a bone marrow infiltration with leukemic lymphoblasts above 50 % (Table 20.2). The normal hematopoietic elements are greatly reduced or absent but, in contrast to AML, they have essentially normal morphology. The trephine biopsy of the bone marrow will further demonstrate marked hypercellularity with replacement of fat spaces and normal marrow elements by infiltration with leukemic cells. A slight increase in marrow reticulin is seen in a small proportion of patients with ALL but much less commonly than with AML. If an adequate bone marrow aspiration is available, it remains open whether an additional biopsy should be done. In our hands a biopsy was necessary when aspiration was not possible due to heavily packed leukemic cells or increased reticulin fibers, which was the case in 16 % of patients.

The laboratory investigations that should be performed at the time of diagnosis (Table 20.1) will serve as a baseline for subsequent studies during the induction period, and may also document metabolic abnormalities that require correction before the start of treatment or modification of drug dosage. Renal impairment, hyperuricemia, and electrolyte imbalance should be corrected if possible before treatment is begun. Serum lactic dehydrogenase (LDH) levels are markedly elevated in most patients with ALL. A full hemostatic profile should be performed to detect the very occasional adult ALL patients with disseminated intravascular coagulation or with an incidental clotting abnormality related to preexisting liver disease or liver infiltration. Besides cultures from any clinically infected site, surveillance cultures from the nose, throat, axillae, groin, vagina, perianal area, and of sputum and urine are taken to detect clinically occult infection and to provide useful information about microbiological etiology if septicemia or severe infection subsequently develops. An aliquot of serum should be stored that can be used to provide baseline antibody titers in the assessment of infection during the induction phase. In patients with a past medical history of heart disease and in elderly patients where treatment with an anthracycline is anticipated, an echocardiogram with myocardial function, including the ejection fraction, should be carried out.

The examination of the cerebrospinal fluid (CSF) is an essential diagnostic procedure in ALL to exclude or confirm initial CNS disease. There are different opinions as to when the first lumbar puncture should be done. Early recognition of CNS disease is clinically important because more aggressive CNS therapy is required for such patients. Therefore a diagnostic puncture should be done if possible before initiation of systemic chemotherapy. This procedure is restricted to patients with an adequate platelet count (>20  ×  10⁹/L), an absence of manifest clinical hemorrhages, and without a high WBC. For safety reasons such patients should receive intrathecal methotrexate at the first lumbar puncture. Clearly this procedure necessitates an atraumatic lumbar puncture and should only be performed by experienced physicians since in childhood ALL blood contamination of the CSF was associated with a higher relapse risk. In pediatric studies nowadays CNS disease at diagnosis is classified into four groups: CNS1 (no blasts in CSF), CNS2 (<5 WBC/μl with blasts), CNS3 (≥5 WBC/μl with blasts), and TLP+ (traumatic lumbar puncture with  ≥10 RBC/μl with blasts) [2]. CNS involvement in adult ALL is generally defined as CNS3 or the presence of signs of CNS involvement in CT or MRT or neurological symptoms not otherwise explainable, e.g., cranial nerve palsies.

Bone marrow aspirates and blood smears are stained with Wright’s or Wright’s-Giemsa stain and the blast cells may be classified according to the French–American–British (FAB) classification. Clinical relevance of FAB subtypes is limited to the detection of the L3 FAB subtype which is characteristic for mature B-ALL. This subtype is important to identify since different treatment approaches are used. In the new WHO classification ALL is classified together with lymphoblastic lymphoma into B-precursor lymphoblastic leukemia/lymphoma, T-precursor lymphoblastic leukemia/lymphoma, and Burkitt’s leukemia/lymphoma [3]. The further subclassification is of less relevance for management of ALL.

The cytochemical stains to discriminate between AML and ALL are Sudan black, myeloperoxidase, and chloracetate or nonspecific esterase. These reactions are negative in ALL, negativity being usually defined as less than 3 % of leukemic blast cells positive. Cytochemical stains to confirm ALL are periodic acid-Schiff (PAS) and acid phosphatase. The PAS stain will show coarse granules or block positivity in at least some cells of most patients with adult ALL of the L1 or L2 type, the incidence of positivity being approximately 60–70 % in both groups. The acid phosphatase reaction is positive in 20–30 % of all ALL being more specific for T-ALL. About 70 % of patients with T-ALL will show strong and localized paranuclear staining with acid phosphatase. PAS or acid phosphatase reactivity is, however, not restricted to ALL and since it can be positive in some cases (M5) of AML the additional reactions for peroxidase and acetate esterase must be negative.

The main aim of immunophenotyping of leukemic blast cells is to distinguish between AML and within the ALL between B- or T-lineage ALL by using monoclonal antibodies to pan-B (CD19), pan-T (CD7), and pan-myeloid surface antigens (CD13, CD33, CDw65). To detect early lymphoid or myeloid differentiation, lineage-specific markers which are first exhibited in the cytoplasm (cy) of B- (cyCD22), T-cell (cyCD3), and myeloid precursor cells (myeloperoxidase) are used. To define further maturational stages within the B- and T-cell lineages, markers more specific for particular maturational stages are used: for B-lineage CD20, cy immunoglobulin μ heavy chain (cyIgM) and surface immunoglobulin (sIg), and for T-lineage CD1, CD2, CD4, CD8, and surface sCD3. The maturation stages are not identified by the presence or absence of a single antigen but by a pattern of antigen expression. One widely used classification system for immunologic subtypes in ALL has been proposed by the EGIL group [4]. For further details on immunobiology of ALL refer to Chap. 17.

With the availability of more specific monoclonal antibodies 98–99 % of the acute leukemias can now be reliably classified by immunological marker analysis. In addition, ALL can be subdivided according to various maturational stages of B or T lineage, whereby it is assumed that they are in differentiation arrest corresponding to normal maturational stages. Immunological classification of ALL subtypes is summarized in Table 20.3.

Cytogenetic and molecular genetics abnormalities are independent prognostic variables for predicting the outcome of adult ALL (Chap. 18). In several multicenter studies, clonal chromosomal aberrations could be detected in approximately 62–85 % of adult ALL patients. The most frequent numerical chromosomal aberrations are hypodiploid karyotype with less than 46 chromosomes (4–8 %), hyperdiploid karyotype with 47–50 chromosomes (7–15 %), or greater than 50 chromosomes (7–8 %). The most frequent structural aberration is the translocation t(9;22)/Philadelphia chromosome (Ph+ ALL). Other translocations occur less frequently and are mostly associated with distinct immunological subtypes such as t(4;11) (3–4 %) in Pro-B-ALL, t(8;14) (5 %) in mature B-ALL, t(1;19) (2–3 %) in pre-B-ALL, and t(10;14) (3 %), 9p– (5–15 %), 6q– (4–6 %), and 12p aberrations (4–5 %) mainly in T-ALL.

The Ph chromosome t(9;22)(q34;q11) results from a translocation involving the breakpoint cluster region of the BCR gene on chromosome 22 and the ABL gene on chromosome 9. One-third of adult ALL patients with a Ph ­chromosome show M-BCR rearrangements (resulting in a 210-kDa protein), similar to patients with CML, whereas two-thirds have m-BCR rearrangements (resulting in a 190-kDa protein).

The most frequent form of 11q23 abnormalities in ALL is t(4;11)(q21;q23). The translocation is frequently detected in infant leukemia and in patients with the pro-B ALL subtype (CD10 negative). The overall incidence in adults is approximately 5 %. Typical molecular aberrations in ALL with associated cytogenetic translocations and immunological subtypes are summarized in Table 20.3.

The role of cytogenetic analysis in adult ALL has to be re-evaluated critically. The most frequent cytogenetic aberrations and those with the largest prognostic impact can also be detected by the corresponding molecular genetic abnormalities, as mentioned previously. These techniques are more reliable and have a greater sensitivity, e.g., a detection level of more than 10^–6 for BCR–ABL. They are, therefore, more useful for initial detection of the aberrations and for follow-up analysis of minimal residual disease (see next section). In addition, the observed incidence of the majority of cytogenetic aberrations is very low and therefore a correlation to clinical outcome and even more therapeutic consequences are limited. Nevertheless, cytogenetic analysis is still recommended as a routine diagnostic method in ALL.

Conventional microscopic evaluation of bone marrow smears has a detection limit of 1–5 %. With new methods for detection of MRD, residual blast cells can be detected and measured quantitatively below this level with a sensitivity of 10⁻⁴–10⁻⁶. With these methods individual follow-up analyses can be performed in patients with clinical and morphological CR. ALL is an “ideal” disease for detection of MRD since more than 90 % of the patients show individual clonal markers. Most experience has been accumulated with MRD detection by flow cytometry and PCR (overview in [6]).

MRD detection by flow cytometry targets individual leukemia-specific combinations of surface antigens and reaches a sensitivity of 10⁻⁴. PCR detection may target leukemia-specific fusion genes such as bcr–abl or mll-af4, which may be detected in 30–40 % of adult ALL cases. A more widespread applicability is reached with detection of clonal rearrangements of immunoglobulin heavy chain (IgH) or T-cell receptor (TCR- β, -δ, -γ) gene rearrangements. This method reaches a sensitivity of 10⁻⁴–10⁻⁶ and combinations of two or more target structures can be identified in more than 80 % of ALL patients. For this method the best level of standardization has been reached regarding methodology [7] and reporting and interpretation of results for clinical trials [8]. MRD detection with any method should be restricted to experienced laboratories, which participate in quality control rounds taking place on an international level.

A few general measures can be started at once. Sufficient fluid intake to guarantee urine production of at least 100 ml/h throughout induction therapy reduces the risk of uric acid formation. This may require parenteral fluid administration when the patient’s oral intake is inadequate because of nausea or difficulty in swallowing. If the venous system does not offer an easy approach, access by catheter or port is advantageous when anticipating a longer period of induction therapy or when part of the therapy will be carried out on an outpatient basis.

Hyperuricemia is frequently present at diagnosis; it may worsen following the initiation of chemotherapy and, if not treated, can lead to renal failure. Adequate doses of allopurinol (300–600 mg/day) should be given and the urine alkalinized before chemotherapy. Allopurinol has to be reduced when 6-­mercaptopurine is given. In patients with high risk of tumor lysis, uratoxidase may be used for prevention of hyperurikemia [9].

In patients presenting with renal impairment, an attempt must be made to reestablish renal function before chemotherapy is started. Renal failure is often observed in patients with Burkitt’s lymphoma or B-ALL with abdominal tumor masses and can be resolved by a gentle pretreatment with cyclophosphamide (C) combined with prednisone (P) or dexamethasone (DX) alone.

The acute tumor lysis syndrome is most frequently seen in patients with B-ALL or T-ALL but may also occur in other subtypes with high WBC or large tumor mass. Massive and rapid tumor cell lysis leads to hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia, which can largely be prevented by the C  +  P/DX treatment in B-ALL or by a gentle therapy with steroids, vincristine (V), or C in the other subtypes.

Approximately one-third of adult ALL patients present with infections at diagnosis. Fever or infection at the time of admission is mainly caused by severe granulocytopenia, especially if the granulocyte count is less than 5  ×  10⁹/L but may also be due to immunological deficiency (e.g., CD4 lymphopenia) or mucosal lesions. Combination chemotherapy causes additional hematological toxicity and at least 50 % of adults undergoing induction treatment will experience severe or life-threatening infections. The incidence of infections with gram-positive bacteria has increased—especially those due to more frequent use of indwelling catheters. Fungal infections also occur more frequently.

Much attention has been paid to prophylactic measures against infection. They include oral hygiene using antiseptic soaps and mouthwashes and disinfection of the anogenital region. Other precautions include reverse protective isolation and air filtration, if available, which can reduce especially the risk of Aspergillus infections. Simple precautions that can always be carried out are: no live plants in the room, no humidifiers, no i.m./s.c. injections if avoidable, no uncooked vegetables, no unpeeled fruits, and no visitors having any kind of infection. Prevention and management of infections is discussed in detail in Chaps. 51–10.1007/978-1-4614-3764-2_53.

The use of hematopoietic growth factors (HPGFs) such as colony-stimulating factor–granulocyte (G-CSF) is a valuable component of supportive therapy during the treatment of ALL. There is no indication that these CSFs stimulate leukemic cell growth in a clinically significant manner. The majority of clinical trials demonstrate that the prophylactic administration of G-CSF significantly accelerates neutrophil recovery [10–13] and several prospective randomized studies also showed that this is associated with a substantially reduced incidence and duration of febrile neutropenia and of severe infections [10, 12, 13]. The enhanced marrow recovery allows closer adherence to the dose and schedule of chemotherapeutic regimens. However it still remains open whether the increased dose intensity translates into an improved leukemia-free survival.

The advantage of G-CSF administration is particularly evident in patients at high risk for prolonged granulocytopenia. Furthermore, scheduling appears to be important. When CSFs are first given at the end of a 4-week chemotherapy regimen, potential benefits are limited. Therefore it is noteworthy that G-CSF may be given in parallel with chemotherapy without aggravating the myelotoxicity of these specific regimens [10, 12, 13] and that this scheduling is an important determinant of the clinical efficacy.

The thrombocytopenia present in one-third of the patients at diagnosis will worsen following chemotherapy, requiring transfusion of platelet concentrates. Platelet transfusions should be given for bleeding and to prevent bleeding when platelet counts are below 20  ×  10⁹/L especially during febrile periods, which interfere with platelet function. When a long induction period is anticipated and there is a likelihood that a patient will need frequent platelet transfusions it might be preferable to start with HLA-matched platelets immediately, if this is logistically possible (technical facilities, costs), to avoid refractoriness to random platelets. The issue of platelet transfusions is discussed in detail in Chap. 56.

l-Asparaginase treatment leads to a decrease in fibrinogen and ATIII. So far no standards have been defined for substitution of both factors although it is done in many trials.

In patients with a large leukemic cell burden, that is, a high WBC and/or massive organomegaly, cell reduction with a cautious preinduction therapy is recommended. In patients with high WBC count (>100  ×  10⁹/L), where hyperviscosity due to leukostasis with cerebral impairment may occur, leukopheresis may be considered. However, such technical facilities may not be available and these patients can also be managed with a gentle prephase chemotherapy consisting of V or C and P or DX in nearly all cases without complications. Prephase treatment is suitable anyway in order to stabilize the patients and complete all diagnostic procedures before start of induction treatment.

Standard induction therapy for ALL includes prednisone, vincristine, anthracyclines, mostly daunorubicin, and also l-asparaginase. Further drugs, such as cyclophosphamide, cytarabine (either conventional or high dose), ­mercaptopurine and others, are added in many protocols, sometimes named as early intensification.

Steroids such as prednisone and prednisolone have been most frequently administered. Dexamethasone shows a higher anti-leukemic activity in vitro and a better penetration of the cerebrospinal fluid [14]. Extensive use of DX may, however, be associated with an increased risk of septicemias and fungal infections, which may be circumvented if treatment time and dose are reduced.

The most frequently used anthracycline is daunorubicine (DNR). Several study groups have replaced the usual weekly applications, as in the BFM-based protocols, by higher doses of DNR (45–80 mg/m²) on subsequent days. Expectedly promising results of smaller trials could not always be reproduced. The Italian GIMEMA group evaluated a previously published regimen with high-dose DNR. The CR rates were 93 % and EFS 55 % in the originally published small population compared to 80 % CR and 33 % OS in the larger multicenter trial [15]. Thus it remains open whether intensified anthracyclines are beneficial for adult ALL at all, for all subgroups and age groups. Intensive anthracycline therapy may be associated with an increased induction mortality. Therefore, intensive supportive care and probably the use of growth factors are recommended with these types of protocols.

Asparaginase (A) does not affect the CR rate but improves LFS. If not used during induction therapy, it is often included as part of the consolidation treatment. Three different A preparations with significantly different half-lives are available: native E. coli A (1.2 days), Erwinia A (0.65 days), and pegylated E. coli A (PEG-L-A) (5.7 days). The availability may vary between different countries. In order to reach equal efficacy, the application schedule has to be adapted and is generally daily for Erwinia, every second day for E. coli and 1–2 weeks for PEG-L-A. The latter asparaginase preparation has the advantage of less frequent administrations and more even activity distribution. In a considerable proportion of adult ALL patients A induces laboratory changes, e.g., coagulation disorders, liver transaminases with unclear clinical impact [16] and in fewer patients severe complications such as hepatopathies or pancreatitis. A-induced toxicities are not predictable and may lead to treatment delays in individual patients. On the other hand, ASP is recognized as an extremely important drug for the treatment of ALL due to its unique mechanism of action and resistance. Several studies have demonstrated that effective asparagine depletion is associated with better outcome [16]. Optimization of A therapy is therefore a major aim for management of adult ALL.

The role of cyclophosphamide (C)—generally administered at the beginning of induction therapy—has been evaluated in several studies. A randomized study by the Italian GIMEMA group comparing a three-drug induction with or without C did not show a difference in terms of CR rate (81 % vs. 82 %) [17]. However, in several nonrandomized trials, high CR rates (85–91 %) were achieved with regimens ­including C pretreatment [12, 18]. In BFM-based regimens for adult ALL, CP is part of prephase treatment and of phase II of induction together with cytarabine and mercaptopurine.

When in ALL CR is achieved treatment has to be continued in order to eliminate residual leukemia after induction chemotherapy and thereby prevent relapse as well as emergence of drug-resistant cells because a high percentage of patients show MRD after induction therapy. Continuation or postremission therapy consists of intensification or consolidation and maintenance. Consolidation/intensification refers either to high-dose therapy, the use of multiple new agents, or readministration of the induction regimen (reinduction). SCT is also included in postremission therapy in many trials. Maintenance is usually a less intensive therapy. In most studies that involve repeated consolidation cycles over the entire treatment period, it is difficult to analyze critically the effect of the different treatment phases on outcome.

Intensive consolidation is standard in the treatment of ALL although consolidation cycles in large studies are very variable and it is impossible to evaluate their individual efficacy. In general it seems that intensive application of high-dose methotrexate (HDMTX) is beneficial. However, in adults dosages are probably limited at 1.5–2 g/m² if given as 24 h infusion. Otherwise toxicities, particularly mucositis, may lead to subsequent treatment delays and decreased compliance. From pediatric ALL trials there is increasing evidence that intensified application of asparaginase leads to improved overall results. In adult ALL this approach appears to be useful particularly in consolidation, where less toxicity can be expected compared to induction. Several studies have also demonstrated that a reinduction improves outcome. The role of HD anthracylines, podophyllotoxins, and HD cytarabine in consolidation remains open.

The most important feature of consolidation is probably to administer rotating cycles with short intervals. However after several consolidation cycles some adult patients tend to develop prolonged cytopenias, which lead to delays of subsequent chemotherapies. Therefore a balance between bone marrow toxic and less toxic cycles may be important. For future studies in adult ALL stricter adherence to protocols with fewer delays, dose reductions, and omissions would be an important contribution to therapeutic progress.

Maintenance up to a total treatment duration of 2½  years even after intensive induction and consolidation is still standard for adult ALL; all attempts to omit maintenance led to inferior outcome. MTX preferably given intravenously (i.v.) and mercaptopurine (MP) given orally are the backbone of maintenance. Attempts for intensification by i.v. application of higher doses MP did not improve outcome in adults [20]. It may be important to aim for leukocyte counts below 3,000/μl during maintenance [21], which is rarely done in adults. Intensification cycles with vincristine and steroids did not provide additional benefit at least in pediatric trials using intensive reinduction [22]. Furthermore in adults prolonged steroid therapy may lead to an increase of late effects such as osteonecrosis. Randomized trials also failed to demonstrate an advantage of intensified maintenance with HD cycles although the compliance in these trials is unclear.

Adults often show poor compliance to intensive maintenance due to toxicities and moreover social reasons. Even for conventional maintenance compliance may be a problem. Furthermore it is open whether and to what extent maintenance therapy is necessary in subgroups. In mature B-ALL maintenance is not required, in T-ALL with relapses up to 2½  years it may be less important than in B-precursor ALL with relapses up to 5 years. In Ph+ ALL maintenance with kinase inhibitors appears to be of utmost importance after chemotherapy as well as after stem cell transplantation. It is probably reasonable to evaluate MRD during maintenance in order to detect upcoming relapses early in Ph+ as in Ph-negative ALL.