Acute promyelocytic leukemia after treatment for non-Hodgkin's lymphoma with drugs targeting topoisomerase II

Comparison of gene regulatory networks to identify pathogenic genes for lymphoma

Lymphoma is the most complicated cancer that can be divided into several tens of subtypes. It may occur in any part of body that has lymphocytes, and is closely correlated with diverse environmental factors such as the ionizing radiation, chemocarcinogenesis, and virus infection. All the environmental factors affect the lymphoma through genes. Identifying pathogenic genes for lymphoma is consequently an essential task to understand its complexity in a unified framework. In this paper, we propose a new method to expose high-confident edges in gene regulatory networks (GRNs) for a total of 32 organs, called Filtered GRNs (f-GRNs), comparison of which gives us a proper reference for the Lymphoma, i.e. the B-lymphocytes cells, whose f-GRN is closest with that for the Lymphoma. By using the Gene Ontology and Biological Process analysis we display the differences of the two networks' hubs in biological functions. Matching with the Genecards shows that most of the hubs take part in the genetic information transmission and expression, except a specific gene of Retinoic Acid Receptor Alpha (RARA) that encodes the retinoic acid receptor. In the lymphoma, the genes in the RARA ego-network are involved in two cancer pathways, and the RARA is present only in these cancer pathways. For the lymphoid B cells, however, the genes in the RARA ego-network do not participate in cancer-related pathways.

Acute promyelocytic leukemia following chemotherapy for EBV-associated hemophagocytic lymphohistiocytosis

We report a case of chemotherapy-related acute promyelocytic leukemia (APL) following therapy with VP-16/etoposide for EBV-associated hemophagocytic lymphohistiocytosis (HLH). A 17-month-old male presented with fever and lymphadenopathy. Bone marrow and liver biopsies showed hemophagocytosis. He responded well to chemotherapy including dexamethasone, VP-16/etoposide, and cyclosporine. One and a half year later, he developed fever and pancytopenia. Clinical work-up revealed APL with t(15;17)(q22;q12);PML-RARα translocation. He underwent chemotherapy for APL and is in remission 8 years after diagnosis. Alternative non-leukemogenic agents to effectively treat HLH would be desirable.

Is age an independent risk factor for chemically induced acute myelogenous leukemia in children?

Secondary or therapy-related acute myelogenous leukemia (t-AML) is a rare but unfortunate consequence of treatment with certain classes of cytotoxic chemotherapeutic agents or chronic exposure to high concentrations of benzene. Drugs known to produce AML following chemotherapy of primary malignancy are usually alkylating agents or topoisomerase II inhibitors. Both children and adults develop AML following treatment with these classes of antineoplastic drugs. In this review, the effect of age at treatment on a child's susceptibility to developing therapy related AML was investigated. The clinical literature describing pediatric cancer patients treated with cytotoxic chemotherapeutic agents was used to characterize risk factors associated with chemical leukemogenesis in children. As demonstrated in the published literature, the risk of developing AML following chemotherapy is not reliably correlated with the age of the pediatric patient. There is no consistent evidence that indicates that younger children will be at increased risk; in fact, some studies suggest that younger children might actually display a decreased susceptibility. The age dependency of treatment-related malignancies (all types) in children appears to vary considerably with the type of secondary neoplasm in question. For example, secondary solid tumors such as breast, central nervous system (CNS), bone, and thyroid cancer are highly dependent on the age of the patient at time of diagnosis and treatment; in contrast, an age dependency for t-AML risk was not observed in these same patient populations. Predictably, the induction of t-AML in children follows a rational dose-response relationship, with increasing doses of chemotherapy resulting in greater risk. Recent U.S. Environmental Protection Agency (EPA) cancer risk assessment guidance recommends a default assumption that children are inherently up to 10-fold more sensitive than adults to carcinogen exposures. Available scientific and medical literature does not support the hypothesis that children necessarily possess an increased risk of developing AML following leukemogenic chemical exposure.

Formaldehyde as a potential human leukemogen: an assessment of biological plausibility

The International Agency for Research on Cancer (IARC, 2004) recently reevaluated the epidemiological data on formaldehyde and concluded that there was "strong but not sufficient evidence for a causal association between leukaemia and occupational exposure to formaldehyde." This conclusion was tempered since a mechanism for leukemia induction could not be identified. Chemically induced leukemia is a well-studied phenomenon with benzene and a number of cancer chemotherapeutic drugs recognized as capable of causing this effect. Abundant in vitro and in vivo data in animals and humans demonstrate that exposure to sufficient doses of these recognized leukemogens can initiate a cascade of events leading to hematopoietic toxicity and the subsequent development of leukemia. This review addresses the biological plausibility that formaldehyde might be capable of causing any type of leukemia by providing a broad overview of the scientific data that must be considered in order to support or refute a conclusion that a particular substance might be leukemogenic. Data on benzene and selected chemotherapeutic cancer drugs are used as examples and are briefly summarized to demonstrate the similar biological events thought to result in leukemogenesis. These data are compared and contrasted with the available data on formaldehyde in order to judge whether they fulfill the criteria of biological plausibility that formaldehyde would be capable of inducing leukemia as suggested by the epidemiological data. Based on the epidemiological data, it is reasonable to expect that if formaldehyde was capable of inducing leukemia, in vivo and in vitro data would offer supporting evidence for biological plausibility. In particular, there is (1) no evidence to suggest that formaldehyde reaches any target organ beyond the site of administration including the bone marrow, (2) no indication that formaldehyde is toxic to the bone marrow/hematopoietic system in in vivo or in vitro studies, and (3) no credible evidence that formaldehyde induces leukemia in experimental animals. As discussed in this review, based on the key biological events that occur in the process of chemically induced leukemia, there is inadequate biological evidence currently available to corroborate existing weak epidemiological associations. This provides an insufficient database to conclude that there is a causal relationship for formaldehyde and leukemia risk.

Do children have increased susceptibility for developing secondary acute myelogenous leukemia?

This study was undertaken to evaluate the effects of age on a child's susceptibility to developing leukemia following exposure to known leukemogenic agents. The clinical literature describing the risk of developing acute myelogenous leukemia (AML) following treatment with alkylating agents or topoisomerase reactive drugs (known leukemogens) was used as a basis for this investigation. Based on this preliminary assessment, the age of the child does not appear to be an independent variable for risk following treatment with either class of drug. Although the number of studies and cases was very small, the available scientific and medical literature does not support the hypothesis that children will necessarily have an altered susceptibility or increased risk of developing chemotherapy-induced AML.

Therapy-related acute promyelocytic leukemia

PURPOSE

To analyze patient cases of therapy-related acute promyelocytic leukemia (tAPL), occurring after chemotherapy (CT), radiotherapy (RT) or both for a prior disorder, diagnosed during the last 20 years in three European countries.

PATIENTS AND METHODS

The primary disorder and its treatment, interval from primary disorder to tAPL, characteristics of tAPL, and its outcome were analyzed in 106 patients.

RESULTS

Eighty of the 106 cases of tAPL were diagnosed during the last 10 years, indicating an increasing incidence of tAPL. Primary disorders were predominantly breast carcinoma (60 patients), non-Hodgkin's lymphoma (15 patients), and other solid tumors (25 patients). Thirty patients had received CT alone, 27 patients had received RT alone, and 49 patients had received both. CT included at least one alkylating agent in 68 patients and at least one topoisomerase II inhibitor in 61 patients, including anthracyclines (30 patients), mitoxantrone (28 patients), and epipodophyllotoxins (19 patients). Median interval from primary disorder to tAPL diagnosis was 25 months (range, 4 to 276 months). Characteristics of tAPL were generally similar to those of de novo APL. With treatment using anthracycline-cytarabine-based CT or all-trans-retinoic acid combined with CT, actuarial survival was 59% at 8 years.

CONCLUSION

tAPL is not exceptional, and develops usually less than 3 years after a primary neoplasm (especially breast carcinoma) treated in particular with topoisomerase II-targeted drugs (anthracyclines or mitoxantrone and less often etoposide). Characteristics and outcome of tAPL seem similar to those of de novo APL.

Long-term Results of a Phase I/II Study of High-Dose Thoracic Radiotherapy With Concomitant Cisplatin and Etoposide in Limited Stage Small-Cell Lung Cancer

This report presents the results from a Mayo Clinic initiated phase I/II study exploring a potentially more aggressive local and systemic approach for treatment of limited-stage small-cell lung cancer (LSSCLC). Five patients with LSSCLC received three cycles of induction cyclophosphamide, etoposide, and infusion cisplatin chemotherapy. This was followed by accelerated hyperfractionated thoracic radiotherapy (AHFTRT) consisting of 30 Gy given as 1.5-Gy fractions twice daily with a 2-week break and then the AHFTRT was repeated. The AHFTRT was given concomitantly with daily oral etoposide and daily intravenous cisplatin. Prophylactic cranial radiation was delivered with the AHFTRT. After completion of the AHFTRT, patients received 4 cycles of oral etoposide maintenance chemotherapy. Follow-up of patients was continued until death or a minimum of 42 months. Three patients had severe toxic responses. No patients completed the entire protocol because of toxicity or progression during treatment. Three patients completed the majority of the protocol except for the four cycles of maintenance etoposide. Four of five patients achieved a complete response. There were two recurrences within the irradiated field, and distant metastases developed in four patients. Acute nonlymphocytic leukemia developed in one patient, who died 2 months later. No patient completed the entire protocol, because of toxicity or progression; therefore, this protocol cannot be recommended for the treatment of LSSCLC.

Pregnancy after treatment of secondary acute promyelocytic leukemia following Hodgkin's disease: a case report

The authors report a case of therapy-related acute promyelocytic leukemia (t-APL), with typical cytogenetic translocation t(15;17), which appeared following chemotherapy (ABVD), and radiotherapy for Hodgkin's disease (IIB). After treatment with all-trans retinoic acid (Vesanoid(R) 45 mg/m2 daily) complete remission of t-APL was achieved. Then only one course of chemotherapy '3+7' (doxorubicin 45 mg/m2 1-3 d, cytosar 200 mg/m2 1-7d) was applied and the patient interrupted further treatment in July 1994. Four years later she had a normal pregnancy and delivered a healthy female infant in December 1998.