Favorable cytogenetic abnormalities in secondary leukemia

Acute Myelocytic Leukemia and Chronic Myelomonocytic Leukemia Simultaneously with Resectable Breast Cancer: A Report of two Cases

This report describes 2 patients who developed acute myelocytic leukemie (AML) type M2 and chronic myelomonocytic leukemia (CMML) of the FAB classification, respectively 2 months and 2 weeks after diagnosis of operable breast cancer. The patient with AML showed pancytopenia 2 months before the diagnosis of AML, had a normal karyotype, and showed a good response to chemotherapy. The patient with CMML had a normal karyotype, and she was treated with hydroxyurea and supportive therapy. The 2 patients had no previous exposure to irradiation or cytotoxic therapy. These cases show that breast cancer and either leukemia or myelodysplastic syndrome may be associated even without previous irradiation or combination chemotherapy.

Acute Monoblastic Leukemia with t(9;11) in a Patient Receiving Chemotherapy for Ovarian Cancer: Secondary Leukemia or Fortuitous Association of Two Neoplasias?

We describe the clinical course of a 61 years old patient who developed fulminant acute monoblastic leukemia (MSA, FAB) while still on systemic chemotherapy for an advanced adenocarcinoma of the ovary. The leukemia developed following chemotherapy with Cyclophosphamide and Cisplatin (9 cycles), and then Cyclophosphamide and Carboplatin (6 cycles) resulting in a partial remission of the ovarian tumor. Survival from the onset of acute leukemia was extremely short and the cause of death was intracerebral bleeding. Cytogenetic analysis of the leukemic cells revealed a 9:11 translocation, a pattern usually occurring in de novo leukemias. The literature on the association of solid tumors, particularly ovarian cancer, with acute leukemia is reviewed; while systemic chemotherapy for ovarian cancer definitely increases the risk of secondary leukemia, especially if alkylating agents are administered, the occurrence of leukemia during the administration of chemotherapy for the solid tumor is distinctly unusual. Our patient seems to be an additional example of a recently described therapy-related variant of acute leukemia developing shortly after the onset of chemotherapy and characterized by a rapidly downhill clinical course, a monocytic lineage and a cytogenetic rearrangement t(9;11)(p22;q23). While the number of these newly described cases is still small, this additional example should increase the awareness of this potential association in Cisplatin-treated patients.

Therapy-related myeloid neoplasms

Session 5 of 2007 Workshop of the Society for Hematopathology/European Association for Haematopathology focused on therapy-related myeloid neoplasms. This report discusses the diversity and relevance of clinical, pathologic, and genetic features and provides an update on the pathogenesis of these disorders. We highlight common diagnostic issues such as the differentiation between therapy-related myelodysplastic syndrome and therapy-related acute erythroid leukemia. As similar therapeutic interventions are frequently considered for patients with either of these diagnoses, in the current World Health Organization classification, regardless of morphologic presentation, therapy-related myeloid neoplasms are considered together as a unique clinicopathologic syndrome of therapy-related myelodysplastic syndrome/acute myeloid leukemia. Nevertheless, recognition of the diverse morphologic features is crucial as bone marrow morphologic examination remains the first and important step of patient evaluation. We also present examples of therapy-related acute myeloid leukemias with recurrent cytogenetic abnormalities. In these cases, the precise classification is clinically important because it is associated with distinct clinical outcome.

Topoisomerase II and the etiology of chromosomal translocations

Acute leukemias with balanced chromosomal translocations, protean morphologic and immunophenotypic presentations but generally shorter latency and absence of myelodysplasia are recognized as a complication of anti-cancer drugs that behave as topoisomerase II poisons. Translocations affecting the breakpoint cluster region of the MLL gene at chromosome band 11q23 are the most common molecular genetic aberrations in leukemias associated with the topoisomerase II poisons. These agents perturb the cleavage-religation equilibrium of topoisomerase II and increase cleavage complexes. One model suggests that this damages the DNA directly and leads to chromosomal breakage, which may result in untoward DNA recombination in the form of translocations. This review will summarize the evidence for topoisomerase II involvement in the genesis of translocations and extension of the model to acute leukemia in infants characterized by similar MLL translocations.

Therapy-related myelodysplastic syndrome with trisomy 1q due to der(1;7) and megakaryoblastic proliferation developing during complete remission of therapy-related acute myeloid leukemia with t(8;21)

Therapy-related acute myeloid leukemia (t-AML) with t(8;21) and therapy-related myelodysplastic syndrome (t-MDS) with trisomy 1q due to der(1;7) developed in the same patient with T-cell lymphoma at intervals of six years. After the development of t-MDS with trisomy 1q, during complete remission of t-AML, the number of megakaryoblasts increased to maximally 74% of leukocytes in the blood. This is a very rare case of two separate therapy-related myeloid malignancies (early t-AML and late t-MDS) and is also a notable case of t-MDS with trisomy 1q due to der(1;7) accompanied by megakaryoblastic proliferation.

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.

Unique balanced chromosome abnormalities in treatment-related myelodysplastic syndromes and acute myeloid leukemia: report from an international workshop

A total of 123 balanced rearrangements, including 26 occurring as a sole anomaly, not known to be recurrent in myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) prior to the Workshop, were ascertained retrospectively from 104 patients with treatment-related MDS/AML (t-MDS/t-AML). Thirteen of the aberrations were reported previously in single cases and hence may be classified as recurrent as a result of the Workshop. Patients with Unique aberrations had complex karyotypes more often (P < 0.001 for all pairwise comparisons) than did other Workshop subgroups, with 72% having 3 or more aberrations. Among 85 cases with secondary chromosomal abnormalities, -5, -7, del(5q), and del(7q) were observed in 76%, which is significantly higher (P < or = 0.007 for all pairwise comparisons) than the frequencies found in the Workshop subgroups of patients with previously known recurring aberrations. The chromosome bands most often involved in balanced aberrations were 1p36 and 3q26-27. Treatment exposure was significantly different (less topoisomerase II inhibitor exposure, more radiotherapy-only exposure) than for patients with 11q23 (P < 0.001 and P = 0.002, respectively) and 21q22 (P = 0.007 and P = 0.002, respectively) abnormalities. The median time from the first toxic exposure to secondary disease, 59 months, was significantly longer (P < or = 0.016 for all significant pairwise comparisons) than the median latency of all other patients except those in the Rare subgroup, and the median survival time, 7 months, was significantly shorter than for patients in the 21q22, inv(16), and t(15;17) subgroups (P < or = 0.002 for all pairwise comparisons), but similar to patients in the 11q23 and Rare subgroups. In contrast to known recurring abnormalities, significantly more patients (61%, all P < 0.001) presented with t-MDS, with over one-third of these patients progressing to t-AML. Thus, this group of patients appears to be more similar to the typical t-MDS/t-AML patients, with complex karyotypes as well as chromosome 5 and 7 abnormalities, than to those with recurrent balanced rearrangements.

Biology and therapy of secondary leukaemias

Secondary leukaemias are common, accounting for more than 40% of all patients with acute myeloid leukaemia (AML) or myelodysplastic syndrome (MDS). A clinical history of exposure to haematotoxins or radiation is helpful; however, many older patients are diagnosed with leukaemia with no antecedent history of exposure. These patients' disease show a remarkably similar phenotype to classic therapy-related leukaemia. The specific cytogenetic abnormalities common to MDS, alkylating-agent-related AML and poor-prognosis AML (3q-, -5, 5q-, -7, 7q-, +8, +9, 11q-, 12p-, -18, -19,20q-, +21, t(1;7), t(2;11)), probably reflect a common pathogenesis distinct from that of other de novo AMLs, although the pathogenetic pathway has yet to be elucidated. Possibly, tumour suppressor genes are implicated and genomic instability may be a cause of multiple unbalanced chromosomal translocations or deletions. Typically, these patients are either elderly or have a history of exposure to alkylating agents or environmental exposure 5-7 years prior to diagnosis. Another distinct entity affects the mixed lineage leukaemia (MLL) gene located on 11q23. These account for about 3% of patients with therapy-related leukaemia and have a short latency period from exposure, usually to an inhibitor of topoisomerase II. Other therapy-related patients with t(8:21), inv16 or t(15;17) translocations should be treated as any other de novo AML with similar cytogenetics. In summary, the major prognostic factor is related to the pathogenetic mechanisms of the leukaemia. Cytogenetics and molecular features are a better predictor of outcome than patient history. Patients should receive standard induction therapy. However, the long-term outcome is relatively poor; the best results being obtained among patients undergoing allogeneic transplantation.

The cytogenetics of myelodysplastic syndromes

The myelodysplastic syndromes are a collection of five clinico-pathological entities with a wide spectrum of clinical behaviours and survival outcomes. Cytogenetic analysis has been instrumental in refining the prognosis, predicting the likelihood of progression to acute myeloid leukaemia and median survival, and in establishing clonality of these diseases. This review highlights the most frequent abnormalities and summarizes their clinical and genetic features.

Leukemias related to treatment with DNA topoisomerase II inhibitors

The epipodophyllotoxins etoposide and teniposide and other DNA topoisomerase II inhibitors including anthracyclines and dactinomycin are highly efficacious anticancer drugs. All are associated with a distinct form of leukemia characterized by chromosomal translocations as a treatment complication. Most of the translocations disrupt a breakpoint cluster region (bcr) of the MLL gene at chromosome band 11q23. Other characteristic translocations also may occur. The normal function of the nuclear enzyme DNA topoisomerase II is to catalyze changes in DNA topology between relaxed and supercoiled states by transiently cleaving and re-ligating both strands of the double helix. Anticancer drugs that are DNA topoisomerase II inhibitors are cytotoxic because they form complexes with DNA and DNA topoisomerase II. The complexes decrease the re-ligation rate, disrupt the cleavage-re-ligation equilibrium, and have a net effect of increasing cleavage. The increased cleavage damages the DNA and leads to chromosomal breakage. Cells with irreparable DNA damage die by apoptosis. The association of DNA topoisomerase II inhibitors with leukemia suggests that the drug-induced, DNA topoisomerase II-mediated chromosomal breakage may be relevant to translocations in addition to this anti-neoplastic, cytotoxic action. Epidemiological studies, genomic translocation breakpoint cloning and in vitro DNA topoisomerase II cleavage assays together lead to a model for treatment-related leukemia in which DNA topoisomerase II causes chromosomal breakage and translocations form when the breakage is repaired.

Early secondary acute myelogenous leukemia in breast cancer patients after treatment with mitoxantrone, cyclophosphamide, fluorouracil and radiation therapy

BACKGROUND

The topoisomerase II-targeted drugs, epipodophyllotoxins and anthracyclines, have been shown to induce therapy-related AML (t-AML) characterized by a short latency period after chemotherapy, the absence of prior myelodysplastic syndrome and stereotyped chromosome aberrations. Few reports have been published on patients treated with the anthracenedione mitoxantrone which also targets topoisomerase II. We observed 10 cases of such t-AML over a 7-year-period in breast cancer patients treated with mitoxantrone combined with fluorouracil, cyclophosphamide and regional radiotherapy, and in three cases with vindesine.

PATIENTS AND METHODS

We retrospectively analyzed patients referred to our hospital for AML with a past history of polychemotherapy for breast cancer, including mitoxantrone, either as adjuvant (8 patients)/neoadjuvant (1 patient) therapy or for metastatic disease (1 patient). We studied the probability of developing t-AML in a prospective series of 350 patients treated with an adjuvant FNC regimen (mitoxantrone, fluorouracil, cyclophosphamide) and radiation therapy.

RESULTS

The median age was 45 years (range 35-67). t-AML developed 13-36 months (median 16) after beginning chemotherapy for breast cancer, and 4-28 months (median 10.5) after ending treatment. As described in t-AML following treatment with epipodophyllotoxins or anthracyclines, we found a majority of FAB M4, M5 and M3 phenotypes (7 of 10), and characteristic karyotype abnormalities that also can be found in de novo AML: breakpoint on chromosome 11q23 (3 patients), inv(16)(p13q22) (2 patients), t(15;17)(q22;q11) (1 patient), t(8;21)(q22;q22) (1 patient) and del(20q)(q11) (1 patient). The prognosis was poor. All patients died of AML shortly after diagnosis. Since two patients had been enrolled in a prospective trial for the treatment of breast cancer which included 350 patients, the probability of developing t-AML was calculated to be 0.7% from 25-40 months, using the Kaplan-Meier method (95%, confidence interval (95% CI): 0.1-4.5).

CONCLUSIONS

The combination of mitoxantrone with cyclophosphamide, fluorouracil, and radiation therapy can induce t-AML, as with other topoisomerase II-targeted drugs. Despite a low incidence, the prognosis appears to be poor.

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

We report a patient who developed acute promyelocytic leukemia (APL) concomitantly with a second relapse of non-Hodgkin's lymphoma (NHL), intermediate grade, WF type E. At diagnosis and at first NHL relapse, the patient had received the same chemotherapy regimen, which included drugs targeting DNA topoisomerase II, i.e., etoposide (total dose 5,760 mg) and idarubicin (total dose 180 mg). Thirty-eight months after initial treatment, the patient showed pancytopenia associated with lymphoma recurrence. Bone marrow examination revealed the presence of atypical promyelocytes with Auer rods; cytogenetics showed t(15;17), and molecular analysis detected promyelocytic leukemia-retinoic acid receptor alpha rearrangement. APL reached complete remission after all trans retinoic acid therapy, whereas NHL did not respond to further chemotherapy. In the literature, five other patients developed APL after treatment for lymphoma, from a total of 59 patients developing sAPL after treatment for any type of neoplasia.

Secondary leukemias induced by topoisomerase-targeted drugs

The major established cause of acute myeloid leukemia (AML) in the young is cancer chemotherapy. There are two forms of treatment-related AML (t-AML). Each form has a de novo counterpart. Alkylating agents cause t-AML characterized by antecedent myelodysplasia, a mean latency period of 5-7 years and complete or partial deletion of chromosome 5 or 7. The risk is related to cumulative alkylating agent dose. Germline NF-1 and p53 gene mutations and the GSTT1 null genotype may increase the risk. Epipodophyllotoxins and other DNA topoisomerase II inhibitors cause leukemias with translocations of the MLL gene at chromosome band 11q23 or, less often, t(8;21), t(3;21), inv(16), t(8;16), t(15;17) or t(9;22). The mean latency period is about 2 years. While most cases are of French-American-British (FAB) M4 or FAB M5 morphology, other FAB AML subtypes, myelodysplastic syndrome (MDS), acute lymphoblastic leukemia (ALL) and chronic myelogenous leukemia (CML) occur. Between 2 and 12% of patients who receive epipodophyllotoxin have developed t-AML. There is no relationship with higher cumulative epipodophyllotoxin dose and genetic predisposition has not been identified, but weekly or twice-weekly schedules and preceding l-asparaginase administration may potentiate the risk. The translocation breakpoints in MLL are heterogeneously distributed within a breakpoint cluster region (bcr) and the MLL gene translocations involve one of many partner genes. DNA topoisomerase II cleavage assays demonstrate a correspondence between DNA topoisomerase II cleavage sites and the translocation breakpoints. DNA topoisomerase II catalyzes transient double-stranded DNA cleavage and rejoining. Epipodophyllotoxins form a complex with the DNA and DNA topoisomerase II, decrease DNA rejoining and cause chromosomal breakage. Furthermore, epipodophyllotoxin metabolism generates reactive oxygen species and hydroxyl radicals that could create abasic sites, potent position-specific enhancers of DNA topoisomerase II cleavage. One proposed mechanism for the translocations entails chromosomal breakage by DNA topoisomerase II and recombination of DNA free ends from different chromosomes through DNA repair. With few exceptions, treatment-related leukemias respond less well to either chemotherapy or bone marrow transplantation than their de novo counterparts, necessitating more innovative treatments, a better mechanistic understanding of the pathogenesis, and strategies for prevention.

Therapy-related myeloid leukemia

One of the most serious possible consequences of cancer therapy is the development of a second cancer, especially leukemia. Several distinct subsets of therapy-related leukemia can be distinguished currently. These include classic therapy-related myeloid leukemia, leukemia that follows treatment with agents that inhibit topoisomerase II, acute lymphoblastic leukemia, and leukemias with 21q22 rearrangements or inv(16) or t(15;17). These types of leukemia are discussed in detail in this article.

Acute leukaemia following renal transplantation

Four renal transplant patients on immunosuppressive therapy who presented with acute myeloid leukaemia are described. In two cases, azathioprine may have played an important role as a cofactor in leukaemogenesis. In a third case, the alkylating agent cyclophosphamide may have contributed. All patients were treated for leukaemia with full doses of cytotoxic chemotherapy and, in each case, a functioning renal allograft was preserved throughout the treatment despite attenuation of immunosuppressive therapy. Three patients achieved complete remission. Of the three, one is surviving at 2 years and two expired during the pancytopenic phase of their treatment with no active leukaemia present, and with intact renal function. As increasing expertise in the field of organ transplantation allows patients to survive longer, such patients' exposure to immunosuppressive and potentially leukaemogenic drugs is prolonged. The risk of secondary neoplasia has been previously documented in this population. Two of the four cases reported here suffered from polycystic kidney disease as their underlying condition. While this report suggests that the leukaemias are related to renal transplantation, we cannot rule out an association with the underlying disease which led to the transplant. This report further suggests that the leukaemia that develops in such patients may respond to standard therapy, and that such treatment does not compromise the transplanted kidney.

Therapy-related acute myeloid leukemia with t(8;16)(p11;p13) following anthracycline-based therapy for nonmetastatic osteosarcoma

A case of therapy-related AML with t(8;16)(p11;p13) 14 months following the end of anthracycline-containing chemotherapy for a nonmetastatic osteosarcoma of the left tibia is presented. The patient was successfully treated with intensive remission-induction chemotherapy. Subsequently, he underwent an uncomplicated allogeneic bone marrow transplantation from his HLA-identical brother and is at present alive and disease-free 10 months after diagnosis of the secondary AML.

Prognostic factors in myelodysplastic syndromes: analysis of five scoring systems

PURPOSE

To evaluate the prognostic significance of five scoring systems applied with predictive trends to myelodysplastic syndromes (MDS).

PATIENTS AND METHODS

This study was comprised of 226 patients with MDS diagnosed in accordance with the FAB criteria and followed up in our department between January 1975 and April 1992. The following MDS subtypes were found: refractory anaemia (RA), 59 cases; refractory sideroblastic anaemia (RSA), 49 cases; refractory anaemia with excess of blasts (RAEB), 56 cases; RAEB in transformation (RAEB-T) 48 cases; and chronic myelomonocytic leukemia (CMML), 14 cases. The following scoring systems were applied: Mufti's 1985, Varela's 1985, Sanz's 1989, Rubio's 1991 and Aul's 1992. The statistical analysis was performed according to Kaplan-Meier actuarial systems and the log-rank test of survival.

RESULTS

(1) Three groups (A, B and C) can be defined by Mufti's system, with median survival of 54.0, 16.0 and 8.5 months, respectively. The majority of cases (138) were included in group B. Group A did not reach 25 per cent of actuarial survival probability, whereas groups B and C did at 31.1 and 12.2 months, respectively. With regard to the morphologic subtypes, RA and RSA were included in groups A and B, and RAEB, RAEB-T and CMML pertained mostly to group C. Sixty-six cases (33.6 per cent) developed into acute leukemia (AL) corresponding to those last groups. (2) The three groups defined by Varela's system (0-1, 2-5 and 6 or more) had median survival of 91.8, 24 and 13 months, respectively. As in the former system, group 0-1 did not reach 25 per cent actuarial probability, this appearing at 60 and 20 months, respectively, in groups 2-5 and > 6. The distribution of the cytological varieties, RA and RSA among the groups is heterogenous although they were more common within the cases included in groups 0-1. All cases developing AL were included in the groups 2-5 and > 6. (3) The three groups of the system proposed by Sanz (0-1, 2-3 and 4-5) had median survival of, 55.3, 15 and 12.6 months respectively. As in the preceding cases, group 0-1 did not reach the 25 per cent actuarial probability, while this figure appeared at 28.2 months for group 2-3 and at 19.3 months for group 4-5. RA and RSA varieties were included chiefly in group 0-1, while RAEB and RAEB-T appear mostly in groups 2-3 and 4-5. The distribution of the cases and the evolution of AL was heterogeneous according to this system, although they predominate in groups 2-3 and 4-5. (4) Using the Aul's system, three groups A, B and C were defined. The median survival time was 14 months for group C and 24 months for group B. For group A, the median survival was not reached. RA and RSA were exclusive for group A, while RAEB and RAEB-T varieties were outstanding in group C. Regarding the evolution to leukemia the differences observed had no statistical relevance. (5) Three prognostic groups were defined by Rubio's system (namely 0-2.5, 3-5.5, > or = 6) with median survival of 53.3, 16.8 and 10.5 months, respectively. A striking difference was seen when studying the cumulated survival observed, in each of the three percentages considered, between the groups. The different cytological varieties were reasonably distributed with higher incidence of RA and RSA in group I and RAEB, RAEB-T and CMML in group III. This system offers statistical significance when comparing RA with RSA, RAEB with RAEB-T and, obviously RA+RSA with RAEB+RAEB-T+CMML. The evolution into AL also showed statistical significance with respect to the three groups.

International Commission for Protection Against Environmental Mutagens and Carcinogens. Mutagenicity and carcinogenicity of topoisomerase-interactive agents

Drugs that interact with DNA topoisomerases I and II hold great promise for the treatment of cancer, however, like many other anti-cancer agents, they are a double-edged sword and may themselves cause mutation and cancer. In vitro studies show that clinically effective agents, such as etoposide, doxorubicin and others, stabilize a ternary complex where topoisomerase II is covalently linked to DNA. This complex represents an intermediate in the topoisomerase-II catalyzed DNA supercoil relaxation reaction. Camptothecin and its analogues stabilize a similar ternary complex, in vitro, consisting of topoisomerase I covalently linked to DNA at single-strand breaks. Short-term tests of genotoxicity confirm that topoisomerase-interactive agents are mutagenic and suggest common mechanisms by which they induce mutation and selectively kill tumor cells. These agents induce sister-chromatid exchange, chromosomal aberrations and mutations in specific mammalian genes. Their propensity to induce small colonies in the L5178/TK+/(-)-3.7.2C assay implies that topoisomerase-interactive agents induce large DNA rearrangements and deletions. These may result from topoisomerase-subunit exchange at drug-stabilized ternary complexes or from attempts by the cell to bypass the replication block caused by stabilized ternary complexes. Studies in bacterial mutation assays suggest that topoisomerase-interactive agents may also induce mutations, albeit at a lower rate, through simple DNA intercalation or via generation of oxygen free radicals. Second malignancies observed in patients previously treated with topoisomerase II interactive agents suggest these may be an important clinical consequence of their capacity to induce mutation. In particular, a unique form of acute myelogenous leukemia is observed at strikingly high frequencies after treatment with relatively high doses of the epipodophyllotoxins etoposide and teniposide. This form of AML has been reported after the uses of other classes of topoisomerase-interactive agents as well. Cancer induction is therefore a toxic consequence predicted by short-term tests of genotoxicity and should be weighed against the potential therapeutic benefits of topoisomerase-interactive agents.

Translocation (3;21)(q26;q22) in therapy-related myelodysplasia following drugs targeting DNA-topoisomerase II combined with alkylating agents, and in myeloproliferative disorders undergoing spontaneous leukemic transformation

Translocation (3;21)(q26;q22) has been observed only rarely in de novo myelodysplasia (MDS) and de novo acute myeloid leukemia (AML), but, including the two new cases in the present study, the aberration has now been identified in at least 10 cases of t-MDS or t-AML. All these 10 patients had previously received alkylating agents, in nine patients combined with a drug targeting at DNA-topoisomerase II (doxorubicin in eight cases). Eight of the ten patients presented with t-MDS. A further 20 patients with various myeloproliferative disorders and an identical t(3;21) have been reported. In these cases, t(3;21) was not related to any specific type of previous therapy but was associated with transformation from chronic stage disease to overt AML.

Therapy-related acute promyelocytic leukaemia

We report three patients with acute promyelocytic leukaemia (APL) occurring after treatment for other malignant disorders. One patient had had razoxane (a drug affecting DNA topoisomerase II) for cancer of the colon, and the other two had had treatment for cancer of the breast. Two out of the three patients went into complete remission. We review the published literature on therapy-related acute promyelocytic leukaemia (t-APL) and suggest that it is a genuine clinical entity which may be caused by drugs affecting DNA topoisomerase II, and has a prognosis similar to de novo APL.

Acute promyelocytic leukemia with t(15;17) abnormality after chemotherapy containing etoposide for Langerhans cell histiocytosis

BACKGROUND

Epipodophyllotoxins, etoposide and teniposide, have been shown to be implicated in the development, of acute myelogenous leukemia in patients treated for solid tumors or acute lymphoblastic leukemia. Etoposide has been shown to be an effective agent against Langerhans cell histiocytosis (LCH) and has gained wider use recently for first-line and salvage chemotherapy in cases of systemic LCH.

METHODS

The authors report two patients with secondary acute promyelocytic leukemia (APL) with a t(15;17) abnormality after chemotherapy that included etoposide for the treatment of LCH.

RESULTS

Patient 1, a 6-year-old girl, had APL develop 11 months after cessation of therapy that included vinblastine, prednisolone, and etoposide (9600 mg/m2 in total dose) for LCH. Patient 2, a 3-year-old girl, had APL develop 9 months after cessation of therapy that included vincristine, methotrexate, prednisolone, cyclophosphamide (10,800 mg/m2), and etoposide (4800 mg/m2) for LCH.

CONCLUSIONS

The authors have experience with four patients treated with etoposide for LCH and suggest that there is a predisposition to secondary APL with t(15;17) for patients with LCH treated with etoposide. The authors warn against the imprudent use of etoposide as a first-line therapy for LCH.

Therapy-related acute myelogenous leukemia associated with 11q23 chromosomal abnormalities and topoisomerase II inhibitors: report of four additional cases and brief commentary

We report 4 additional cases of therapy-related acute myelogenous leukemia (t-AML) with the translocation t(9;11)(p22q23). Chemotherapy for the primary malignancy (breast carcinoma in 2, non-Hodgkin's lymphoma in 2) included agents with topoisomerase II inhibitory activity (doxorubicin in 2; doxorubicin and etoposide in 1; doxorubicin, etoposide and mitoxantrone in 1) as well as alkylators. In agreement with previous reports, the leukemia was monoblastic (FAB M5 subtype) in all 4 patients, with only 1 having prior myelodysplasia, and the latency period from primary therapy was relatively short (24-48 months). All patients received potentially curative treatment for the leukemia which included allogeneic bone marrow transplantation in 3; however, all died (3 of t-AML and 1 of lymphoma). Therapy-related AML associated with exposure to agents with topoisomerase II inhibitory activity (epipodophyllotoxins and anthracyclines) is a distinct entity, the genetic basis and optimal treatment of which remain to be determined.

Specific chromosomal translocations and therapy-related leukemia induced by bimolane therapy for psoriasis

This paper reports for the first time results of cytogenetic studies on 14 consecutive secondary acute non-lymphocytic leukemia (S-ANLL) induced by bimolane therapy. They included 10 males and 4 females with ages ranging from 17 to 54 years. They had all suffered from psoriasis and received bimolane treatment before the occurrence of their leukemia. The total dose of bimolane ranged from 40 to 400 g (mean dose 194 g). The interval between the initiation of bimolane therapy and the diagnosis of leukemia was 12-96 months (median 30 months). A preleukemic phase was only found in one case. No dysplastic features in the hemopoietic series were seen in any patient. Chromosome analysis of bone marrow cells using banding techniques revealed clonal karyotypic abnormalities in all cases: t(15;17) in 8 cases of M3, of which 75% had extra abnormalities, t(8;21) in 4 cases of M2, del(7q) only in one case of M4 and one case of M5. After antileukemic therapy, complete remission was obtained in 10 out of 12 cases with specific translocations and one out of 2 cases with 7q-anomaly, respectively. The former survived 4-58 months (median 12 months), while the latter 1 and 9 months, respectively. This study indicates that: (1) bimolane is a causative factor of leukemia in this series; (2) the leukemia in our series is therapy-related leukemia (TRL) rather than de novo ANLL; (3) there exists, in fact, a new subgroup of TRL characterized by specific rearrangements, whose clinical, hematological and prognostic features and pathogenetic mechanism may be different from classical TRL characterized by chromosome abnormalities involving absence or deletion of parts of chromosome 5 and/or 7.

Secondary acute lymphoblastic leukemia with t (4;11): report on two cases and review of the literature

We report two cases of secondary acute lymphoblastic leukemia (ALL) with t (4;11) (q21;q23) translocation occurring after chemotherapy and radiotherapy for a prior cancer. Seven previously published cases of secondary ALL with t (4;11) (q21;q23) are also reviewed. Most patients had received a combination of topoisomerase II inhibitors (anthracyclines, mitoxantrone, or the epipodophillotoxin derivatives VP16 or VM26) and cyclophosphamide, which have also been implicated in the pathogenesis of secondary acute myeloid leukemia (AML) with 11q23 rearrangements. These observations give further support to the existence of a subgroup of secondary acute leukemias with cytogenetic findings "specific" for de novo ALL and AML, especially those with translocations involving the 11q23 region.

The role of intensive chemotherapy in myelodysplastic syndromes

We review results of intensive chemotherapy (IC) obtained in myelodysplastic syndromes (MDS). Overall, the complete remission (CR) rates and median CR duration obtained with IC are low in MDS, especially when compared to results obtained in de novo AML treated with the same chemotherapy regimens; very few MDS patients achieve prolonged remissions. Failure to achieve CR, in MDS, results both from a high incidence of resistant disease and toxic deaths, the latter being due to longer periods of aplasia than in de novo AML. However some subgroups of MDS seem to obtain higher CR rates and more prolonged remissions. These include patients younger than 45 to 50 years, those with a large excess of marrow blasts or Auer rods at diagnosis, and patients with a normal karyotype or at least without involvement of chromosomes 5 and/or 7. Results of IC clearly have to be improved in MDS. Higher CR rates may possibly be obtained by intensifying induction regimens, but this will probably require the addition of growth factors, in order to reduce the already very long periods of aplasia seen with IC in MDS. For consolidation therapy, new approaches, and especially autologous bone marrow transplantation, will have to be investigated.

Two different classes of therapy-related and de-novo acute myeloid leukemia?

Two different classes of therapy-related acute myeloid leukemia (t-AML) seem to emerge. One class follows therapy with alkylating agents, increases in frequency with age, often presents with myelodysplasia (MDS), responds poorly to chemotherapy, and shows monosomy 7(-7), monosomy 5(-5), or loss of various parts of the long arms of these chromosomes (5q- and 7q-). The other class is related to therapy with cytostatic drugs targeting at DNA-topoisomerase II, often presents with overt leukemia, responds more favorably to chemotherapy, and shows balanced chromosome aberrations, primarily translocations involving chromosome bands 11q23 and 21q22. These two classes of t-AML may have their counterparts in de-novo acute myeloid leukemia (de-novo AML).

Cytogenetics of secondary myelodysplasia (sMDS) and acute nonlymphocytic leukemia (sANLL)

76 cases of secondary myelodysplasia (sMDS) and acute non-lymphocytic leukemia (sANLL) were cytogenetically analyzed. Among the 36 sMDS patients, 13 (36%) had only normal karyotypes whereas 23 (64%) displayed clonal chromosomal abnormalities. The most common aberrations were -7, 5q-, -5, and +8. In 10 patients (43% of the cytogenetically aberrant cases), clones with only one anomaly, mostly 5q- or -7, were found. Of the 40 sANLL patients, normal karyotypes were detected in 10 (25%). Among the 30 (75%) abnormal cases, the most frequent aberrations were -7, -5, +8, 7q-, -17, and +21. 12 patients (40%) had clones with single abnormalities, most often -7. In 4 sANLL patients cytogenetically unrelated clones were detected. A survey of all previously published secondary hematologic neoplasias reveals that the most frequent abnormalities in sMDS are -7 (41%), 5q- (28%), and -5 (11%), followed by der(21q), +8, 7q-, der(12p), t(1;7), -12, -17, der(17p), der(3p), der(6p), and -18. Clones with single aberrations have been found in 45% of the cases and cytogenetically unrelated clones have been described in 6%. The most common abnormalities in sANLL are -7 (38%), 5q- (17%), -5 (15%), +8 (13%), and -17 (11%), followed by der(3q), der(11q), der(12p), -21, 7q-, -18, der(3p), der(17p), +21, der(21q), der(6p), and -16. 38% of the sANLL patients have had clones with only one aberration and 3% have had unrelated clones. The frequencies of these nonrandom abnormalities in sMDS and sANLL are thus remarkably similar - the only exception appears to be 5q-, which is more common in sMDS. Also the mean number of abnormalities per case is similar - 5.3 in sMDS and 5.6 in sANLL. When the incidences of characteristic cytogenetic abnormalities were correlated with the type of previous therapy, -7 was found to be more frequent in sMDS and sANLL patients who had been exposed to chemotherapy whereas 5q- was associated with previous exposure to ionizing radiation in sMDS patients.

Myeloid neoplasia in children treated for solid tumours

Therapy-related myeloid neoplasia developed 14 to 189 months after diagnosis of the primary malignancy in 12 out of 3365 children treated for malignant solid tumours; 6 of the 12 were in their first complete remission. The 10-year cumulative incidence of myeloid neoplasia was 1.3% (95% Cl 0.5-3.6) for the 447 patients with Hodgkin's disease, 1.3% (0.4-4.3) for the 420 with non-Hodgkin lymphoma, and 1.2% (0.3-5.2) for the 440 with neuroblastoma. This complication appeared in 1 of 180 children with brain tumours and in none of the 1878 with other malignancies. Risk of therapy-related myeloid neoplasia in patients with Hodgkin's disease was associated with recurrence of the primary malignancy, a combination of radiotherapy and chemotherapy with alkylating agents, and age greater than or equal to 12 years at diagnosis of Hodgkin's disease. Of the 8 patients who underwent chromosomal analysis of neoplastic myeloid cells, 2 showed complete loss of chromosome 7 and 4 showed t(9;11) or t(8;21) with or without del(16)(q22). The 2 patients who had received an epipodophyllotoxin had an 11q23 abnormality. The risk of therapy-related myeloid neoplasia is low in children with malignant solid tumours.