David Hakimian

Granulocytic sarcoma is associated with the 8;21 translocation in acute myeloid leukemia.

PURPOSE Since the only three cases of granulocytic sarcoma among patients with acute myeloid leukemia (AML) seen at our institution during the last 12 years were each associated with the 8;21 translocation [t(8;21)], we sought to determine if this association is specific and more frequent than previously recognized. PATIENTS AND METHODS We report three patients with AML and t(8;21) who developed granulocytic sarcomas, and review the world literature. RESULTS Between 1980 and 1992, 53 cases of AML French-American-British (FAB) M2 were identified at our institution. Eight (15%) patients had t(8;21). Three of these eight patients (38%) developed granulocytic sarcoma. All three of our patients received conventional intensive antileukemic chemotherapy yet had short relapse-free survival durations. Several series of patients with t(8;21) report that granulocytic sarcomas occur in approximately 18% of this population, which is four times the expected incidence in AML. Thirty-seven cases have been previously reported. Although karyotype analyses were not reported in many cases of granulocytic sarcoma in the literature, the vast majority of abnormal karyotypes in patients with AML involved t(8;21). Recent work with a cell line derived from a patient with t(8;21) indicates that such cells are unusually adherent to culture bottles and are aggregable CONCLUSION Our data suggest that this association is more common than generally recognized and may be specific. Patients with t(8;21) should be observed closely for signs and symptoms of granulocytic sarcoma. These patients may have a less favorable prognosis than other patients with t(8;21). Cooperative oncology groups should retrospectively identify patients with AML and t(8;21) who had a poor outcome to determine if they had a disproportionate incidence of granulocytic sarcoma. If so, aggressive therapy such as bone marrow transplantation may be warranted early in the therapeutic strategy.

2-Chlorodeoxyadenosine is an active salvage therapy in advanced indolent non-Hodgkin's lymphoma.

PURPOSE To determine the response rate to 2-chlorodeoxyadenosine (2-CdA; cladribine) in patients with advanced indolent non-Hodgkins lymphoma (NHL) who fail to respond to or progress after a response to standard chemotherapy drugs. PATIENTS AND METHODS Twenty-one patients were treated with at least one cycle of 2-CdA 0.1 mg/kg/d by continuous infusion for 5 or 7 days. RESULTS The overall response rate (complete response [CR] and partial response [PR]) was nine of 21 patients (43%; 95% confidence interval, 22% to 64%). Unmaintained durable responses (longest follow-up, 29+ months) have been observed. The treatment was well tolerated by all patients. The major toxicity was related to myelosuppression (predominantly neutropenia) and immunosuppression with infection. CONCLUSION The purine analog 2-CdA is an active salvage therapy in pretreated patients with indolent NHL, and deserves further assessment in untreated patients and in combination with other chemotherapy agents.

New Insights into the Pathogenesis of Coagulation Dysfunction in Acute - Promyelocytic Leukemia

Patients with acute promyelocytic leukemia (APL) are at high risk for the development of life-threatening thrombotic and hemorrhagic complications, particularly during induction chemotherapy. This propensity has been attributed to the release of tissue factor (TF)-like procoagulants from the leukemic cells leading to disseminated intravascular coagulation (DIC). However, recent data suggest that the pathogenesis of the coagulopathy is more complicated and may involve activation of the generalized proteolytic cascade resulting in either clotting and/or excessive fibrinolysis. Furthermore, controversy exists regarding the mechanism(s) responsible for the activation of either clotting or fibrinolysis. The malignant promyelocyte may act directly to activate coagulation and/or fibrinolysis. Alternatively, reactive inflammatory cells, which express procoagulant and/or profibrinolytic activities may play an essential role. A third possibility may involve endothelial cell expression of mediators with procoagulant/profibrinolytic properties. Putative profibrinolytic mechanisms include the release of urokinase-type and tissue-type plasminogen activators, decreases in plasminogen activator inhibitor-1 and 2, and decreases in alpha-2 plasmin inhibitor. Putative procoagulant mechanisms include the release of tissue factor, Cancer Procoagulant, or cytokines such as interleukin-1, tumor necrosis factor and vascular permeability factor. Putative anticoagulant mediators include annexins, a group of proteins in human tissue which bind phospholipids and have anticoagulant activity, which have been reported in patients with APL. The current treatment of APL is rapidly evolving because of the efficacy of all-trans retinoic acid (ATRA). All-trans retinoic acid promotes terminal differentiation of leukemic promyelocytes leading to complete remission in the majority of patients with APL with rapid resolution of the coagulopathy. Although the mechanism by which this occurs has not been established, preliminary data suggest that ATRA blocks the downregulation of the thrombomodulin gene and the up-regulation of the tissue factor gene induced by tumor necrosis factor. Since APL is a relatively uncommon disorder, the collaboration of cooperative oncology groups will be important to study patients receiving ATRA or conventional chemotherapy to further elucidate the mechanism(s) of the coagulopathy.

Cladribine in the treatment of relapsed or refractory chronic lymphocytic leukemia

PURPOSE Cladribine (2-CdA), a purine analog resistant to adenosine deaminase, has significant activity in a variety of lymphoproliferative diseases. This study was designed to determine the efficacy of 2-CdA in patients with relapsed or refractory chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS Twenty-six patients aged 40 to 88 years (median, 64) who either had relapsed after an initial response or were refractory to conventional chemotherapy with at least an alkylating agent were treated with 2-CdA 0.1 mg/kg/d by continuous intravenous infusion for either 5 or 7 days every 28 days for a maximum of six cycles. RESULTS No complete remissions (CRs) occurred. Eight of 26 patients (31%) achieved a partial remission (PR). The actuarial median time to progression (TTF) in responding patients is 16 months (range, 6 to 22). The actuarial median survival duration of the responding patients is 12 months (range, 8 to 28). Eight of 26 patients (31%) sustained early toxicity. Seven of these eight patients died before the first reevaluation of infection (n = 3), pericardial tamponade (n = 1), Stevens-Johnson syndrome (n = 1), and stroke (n = 2). No nausea, emesis, alopecia, or renal, hepatic, or cardiac toxicity was observed. CONCLUSION 2-CdA has activity in patients with relapsed or refractory CLL. However, patients who have received multiple prior regimens that included fludarabine are less likely to respond, and there can be significant morbidity. Treatment of patients with less prior therapy earlier in the natural history of the disease may lead to improved and more durable responses.

Hypocholesterolemia in hairy cell leukemia: A marker for proliferative activity

Hypocholesterolemia is a well‐documented phenomenon associated with a variety of hematological malignancies and nonmalignant disorders associated with splenomegaly. To determine the incidence of hypocholesterolemia in patients with hairy cell leukemia (HCL), we measured the serum cholesterol levels before and after a single cycle of 2‐chlorodeoxyadenosine (2‐CdA) in 46 patients. The mean pre‐treatment serum cholesterol level was 152.8 mg/dl (range, 60 to 293 mg/dl). The mean post‐treatment serum cholesterol level was 190.0 mg/dl. This was significantly higher than the pre‐treatment values (P < 0.0001). Twelve patients who had previously undergone splenectomy showed a similar response to treatment, with a pre‐treatment value of 180.0 mg/dl and a post‐treatment value of 219.8 mg/dl (P < 0.0001). However, there was a significant difference in the pre‐treatment serum cholesterol levels in the nonsplenectomized patients (143.0 mg/dl) compared to the splenectomized patients (180.0 mg/dl) (P < 0.03). The pre‐treatment serum cholesterol did not correlate with the pre‐treatment splenic index (correlation coefficient = −0.39, P < 0.065). Similarly, there was no correlation between the change in splenic index and the change in serum cholesterol level post‐treatment. These findings suggest that hypocholesterolemia in HCL is related to tumor burden and not to splenomegaly alone. Since cholesterol is critical to hairy cell metabolism and structure, treatment strategies interfering with cholesterol synthesis may be productive. Am. J. Hematol. 55:129–133 1997.

Technetium-99m sulfur colloid scanning and correlative magnetic resonance imaging in patients with hairy cell leukemia and hypocellular bone marrow biopsies after 2-chlorodeoxyadenosine.

It has been observed that some patients in complete remission (CR) after 2-chlorodeoxyadenosine (2-CdA) for hairy cell leukemia (HCL) have hypocellular bone marrow biopsies despite normal peripheral blood cell counts. This discrepancy between bone marrow cellularity and peripheral blood cell counts suggests the possibility of abnormal sites of hematopoiesis. To determine sites of hematopoiesis, 11 radionuclide scans using technetium-99m (99mTc) sulfur colloid were performed in eight patients. Although no single, pattern was observed on the 99mTc sulfur colloid scans, two of the eight patients, both with virtually aplastic marrows, had multiple areas of increased uptake in the distal appendicular skeleton, suggesting abnormal sites of hematopoiesis. The same two patients had magnetic resonance imaging (MRI), which confirmed the abnormal sites of hematopoiesis.