Changes in the characteristics of the bone marrow during therapy for acute non-lymphocytic leukemia: relationship to response to remission induction therapy

The cancer and leukemia group B pathology committee at 50

The Pathology Committee of the Cancer and Leukemia Group B (CALGB) is broadly and deeply integrated into the multidisciplinary clinical and scientific operations of the group. It has five major functions in CALGB. First, it insures the highest possible quality of pathologic data in tissue-based correlative science studies through comprehensive quality control of all tissues collected, banked, and distributed to investigators and of all morphology-based studies done within the CALGB. Within this context, the Pathology Committee has the goal of eliminating, to the greatest degree possible, variation in methodology, interpretation, and reporting of pathologic data that would compromise reproducibility of correlative science results and to assure accuracy, uniformity, and completeness of the pathologic data. Second, the committee provides expert pathologic consultation in the development of clinical trials and correlative science studies that involve pathologic issues and/or materials. Third, it provides high-quality tissue banking and centralized morphology-based technical support services (e.g., histologic sections for immunohistochemistry, tissue microarrays, etc.) for all CALGB investigators. Fourth, it initiates and executes high-quality pathologic research using CALGB and intergroup resources. Lastly, it provides group-wide education on pathology-related issues relevant to trial design, scientific study design, and specimen banking.

The relationship of the in vivo cell cycle characteristics and treatment outcome in acute myelogenous leukemia to the expression of the FMS and MYC proto-oncogenes

Fms expression was measured by Northern blot analysis in the pretherapy leukemia cells of 30 patients with acute myelogenous leukemia (AML) who either entered CR or who were shown to have drug resistant disease. High levels of fms expression correlated with a CR outcome and were strongly associated with the fall in the number of leukemia cells during the first six days of remission induction therapy. In contrast, similar studies of myc expression failed to demonstrate any relationship to treatment outcome. Considering those genes whose expression have been measured to date, the level of expression of fms is the one which is most highly correlated with treatment outcome in AML. No significant relationship between the expression levels of these two genes and the cell cycle characteristics of leukemia cells in vivo were detected.

Mitoxantrone and 5-azacytidine for refractory/relapsed ANLL or CML in blast crisis: a leukemia intergroup study

In an effort to determine if cell cycle active agents are augmented when given after non-cell cycle active agents, 104 patients with either multiply relapsed or refractory acute nonlymphocytic leukemia or blast crisis of chronic myelogenous leukemia were treated with mitoxantrone. Patients whose bone marrow did not show significant cytoreduction received 5-azacytidine. Twenty-seven of the 93 evaluable patients (23%) with ANLL achieved a complete remission. A total of 28% of patients receiving mitoxantrone alone achieved remission compared to 15% for those receiving mitoxantrone and 5-azacytidine. Relapsed patients had a higher CR rate (36%) than refractory patients (15%). Nausea, vomiting, and stomatitis were common but rarely severe. The median duration of remission was 3.7 months and patients with abnormal karyotypes had longer remission durations than those with normal karyotypes. In this patient population, there was no evidence that 5-azacytidine given after mitoxantrone increased the complete remission rate.

The selective use of AMSA following high-dose cytarabine in patients with acute myeloid leukaemia in relapse: a Leukemia Intergroup study

This clinical trial was designed to evaluate the role of high-dose cytarabine (ara-C) in the treatment of adults with acute myeloid leukaemia (AML) in first relapse. We also tested the hypothesis that the selective use of AMSA (100 mg/m2/d on days 7, 8 and 9) would increase the complete remission (CR) rate when leukaemia cells remained in the bone marrow immediately following 6 d of Ara-C (2-3 g/m2/12 h) alone. Of 155 patients evaluable for response, 115 (74%) experienced marked cytoreduction by day 6 and received no further induction chemotherapy; 53 (45%) of these patients achieved CR after one course and 45 (38%) had resistant disease. The 36 patients (23%) with inadequate cytoreduction after the 6 d of ara-C alone were randomly assigned either to no further chemotherapy (21 patients) or to 3 d of AMSA (15 patients). The CR rates after one course were 14% and 53%, respectively (P = 0.01), and the fractions with resistant disease were 76% and 40%, respectively. The fractional reduction of leukaemia cells in the day 6 bone marrow aspirate specimen (P < 0.0001) and the reduction in the leukaemia cell mass measured in the day 6 marrow biopsy (P = 0.001) were the strongest predictors for achieving CR versus having residual disease in univariate analyses. The median duration of remission was 5 months, but seven patients (10%) remain in CR after 30-92 + months. Among the 140 patients who received only the 6 d of ara-C, the pretreatment albumin (P = 0.002) and lactate dehydrogenase (P = 0.01) levels were the strongest predictors of response in univariate analyses, but only the albumin remained significant (P = 0.01) in a stepwise logistic regression analysis. Those patients with albumin > 4.0 mg/dl and LDH < 125% of normal had a 71% CR rate, and only 16% had resistant disease. Thus, pretreatment characteristics and rapid cytoreductin in the day 6 bone marrow sample identified a favourable subset of patients with AML in first relapse, some of whom responded quite well to 6 d of ara-C alone and have had long disease-free remissions.

c-myc and c-myb expression in acute myelogenous leukemia

Monoclonal antibodies and flow cytometry were used to detect the expression of c-myc and c-myb in the bone marrow (BM) and peripheral blood (PB) cells of patients with acute myelogenous leukemia (AML). The expression of neither gene was correlated with the percent blast cells in the BM or PB nor was there a correlation between c-myc and c-myb expression. A wide range of expression of each gene was found within each FAB type of AML. Patients who had a high proportion of leukemia cells expressing c-myb were less likely to respond to remission induction therapy than patients in whom a low proportion of cells expressed c-myb. This association appears to reflect an inverse relationship between the proportion of cells expressing c-myb and the sensitivity of leukemia cells to the killing effects of chemotherapy in vivo. Treatment outcome was unrelated to c-myc expression.

Predicting remission outcome in acute non-lymphocytic leukemia: general principles and their application to residual marrow leukemia

The objective of this paper is to demonstrate the importance of a rigorous and comprehensive evaluation of predictive tests in acute leukemia, especially when these may influence therapeutic decisions. To illustrate these issues, we have chosen an emerging test, early residual bone marrow leukemia, as the example and we have presented actual data from Leukemia Intergroup Studies of adults with first relapse acute non-lymphocytic leukemia induced with high-dose cytosine arabinoside. We show how the choice of a suitable cut-off value to discriminate between patients predicted to have different remission rates is influenced by several variables including the reasons for remission failure, the estimated efficacy and toxicity of the intervention to be employed, and considerations of resource utilization. We suggest that before applying a new predictive test in practice, clinicians should carefully evaluate its performance, and the consequences of its use in their own clinical settings.

Some reasons for the lack of progress in the treatment of acute myelogenous leukemia: a review of three consecutive trials of the treatment of poor prognosis patients

The failure of three consecutive treatment protocols to significantly increase the complete remission rate for poor prognosis newly diagnosed patients with acute myelocytic leukemia led to a detailed investigation of the causes of treatment failure. In the majority of cases treatment failure was attributable to "clinical resistance" to therapy. Upon close examination two types of "clinical resistance" were discernible: the failure of chemotherapy to produce adequate cytotoxic effects ("classical" drug resistance), and treatment failure attributed to the rapid regrowth of leukemia cells subsequent to the substantial killing of leukemia cells by cytotoxic therapy ("biological" resistance). Each form of resistance accounted for one-half of the treatment failures.

Studies of the proliferation and differentiation of immature myeloid cells in vitro: 4: Preculture proto-oncogene expression and the behaviour of myeloid leukemia cells in vitro

Studies were conducted to determine the relationship between the pretherapy characteristics of leukemia cells and their behaviour during culture in vitro. Leukemia cells which proliferated well in vitro also proliferated well in vivo. Cells which manifested myeloid or monocytic differentiation in vivo tended to manifest differentiation along these lines in vitro. Cells which manifested high levels of expression of c-fms, c-fes, or triose phosphate isomerase prior to culture were likely to differentiate in vitro, with high levels of c-fes expression being related to myeloid maturation. These observations suggest that differentiation at the molecular level prior to culture is a requisite for leukemia cell differentiation in vitro. The same may be true for differentiation in vivo under the influence of exogenously administered agents such as cytotoxic chemotherapy or recombinant growth factors.

Use of the day 6 bone marrow to alter remission induction therapy in patients with acute myeloid leukaemia: a leukemia intergroup study

Patients with acute myeloid leukaemia who fail to show substantial bone marrow cytoreduction by day 6 of induction therapy enter complete remission (CR) less frequently than patients with good bone marrow leukaemic cytoreduction. The objective of the current study was to determine whether an increase in the intensity of therapy on days 8, 9 and 10 ('augmentation' of remission induction therapy) for patients with poor bone marrow cytoreduction detected in the day 6 bone marrow could improve the complete remission rate without increasing the number of toxic deaths. Patients from six centres were entered and treated with standard dose ara-C for 7 or 10 d and an anthracycline for the first 3 d. Patients aged less than 60 years and with greater than 30% bone marrow biopsy cellularity or greater than 10% abnormal cells on the aspirate obtained 6 d after the start of therapy were augmented with cytosine arabinoside 3 g/m2 every 12 h on days 8, 9 and 10. Therapy was augmented in 116 of the 252 patients less than 60 years. There was a highly statistically significant difference between augmented and nonaugmented patients (P less than 0.001) for the per cent biopsy cellularity and per cent abnormal cells in the day 6 marrow. The CR rate for augmented patients was 69% and for nonaugmented patients 60% suggesting that augmentation therapy abrogated the prognostic significance of more extensive residual leukaemia in the day 6 bone marrow. The results suggest that augmentation of remission induction for patients with poor bone marrow cytoreduction detected 6 d after initiation of therapy, may salvage patients who are destined to fail remission induction because of resistant disease without producing excessive toxicity.

The treatment of acute non-lymphocytic leukemia

The treatment of acute nonlymphocytic leukemia involves a two stage approach. During the first stage, remission induction, cytotoxic drugs are administered to return hematopoiesis to normal. During the second stage, therapy is administered in an attempt to prolong the duration of remission. The clinical approaches and the problems incurred during these stages are not identical. At the time of diagnosis a decision must be made regarding whether or not the patient is likely to benefit from chemotherapy. If the answer is in the affirmative, then a decision must be made regarding the appropriate chemotherapeutic regimen. The optimal approach for the treatment of patients appears to vary depending on the age of the patient and whether or not there is a history of toxic exposure in the past. Overall remission rates vary from 40% to 85% depending upon the age of the patient and the patient's past history. Patients whose leukemia is induced into complete remission benefit from therapy administered after complete remission is attained. The optimal therapy, however, has not as yet been clearly defined. Conventional maintenance therapy appears to provide little benefit. On the other hand, the more intensive therapies are associated with substantial risk to the patient. The role of these modalities in the treatment of older patients is currently under investigation.