Two independent clones in myelodysplastic syndrome following treatment of acute myeloid leukemia

We describe a 55-year-old Japanese woman with therapy-related myelodysplastic syndrome (t-MDS) with 2 independent clones, t(1;2)(p36;p21) and t(11;12)(pl5;ql3). She was diagnosed with acute myeloid leukemia (AML) with cytological features of the bone marrow and peripheral blood. Cytogenetic evaluation revealed a 46,XX karyotype. She received chemotherapy and achieved complete remission (CR). Despite maintenance chemotherapy, she suffered a relapse. Chromosomal analysis showed t(1;2)(p36;p21) in 2 of 20 metaphases. At second CR, this clone transiently disappeared. Nine months later, t(1;2) (p36;p21) was detected again in 3 of 20 metaphases while the patient remained in CR. Six months later, bone marrow examination disclosed trilineage dysplasia without an excess of blasts, suggesting MDS. t(1;2)(p36;p21) was observed in 16 of 20 metaphases. The clinical course and serial cytogenetic findings were diagnostic of t-MDS. The duration of t-MDS was 6 years. During this period, persistent t(1;2)(p36;p21) and transient t(11;12)(p15;q13) were found. When t-MDS evolved toAML, cytogenetic evaluation revealed 46,XX,t(1;2)(p36;p21),del(7)(q22),add(19)(p13).

Risk of etoposide-related acute myeloid leukemia in the treatment of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

We studied the impact of etoposide on the prognosis of 81 patients (77 of whom were children <15 years old) with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). The study group received a median cumulative dose of 1,500 mg/m2 etoposide (range, 0-14,550 mg/m2), with a median follow-up period of 44 months (range, 20-88 months) from the diagnosis. Only 1 patient, who received 3150 mg/m2 etoposide, developed therapy-related acute myeloid leukemia (t-AML), at 31 months after diagnosis. Excluding 9 patients who underwent hemopoietic stem cell transplantation during the course of treatment, the prognosis was poorer for those patients who received less than a 1,000 mg/m2 cumulative dose of etoposide. Our results indicate that the risk of etoposide-related t-AML is low. An appropriate dosage of etoposide for the treatment of EBV-HLH would be in the range of 1,000 to 3,000 mg/m2. However, even at these doses, care must be taken to prevent the rare risk of t-AML.

Plasmablastic lymphoma in a patient with chronic lymphocytic leukemia heavily pretreated with cladribine (2-CdA): an unusual variant of Richter's syndrome

Patients with chronic lymphocytic leukemia (CLL) may develop a large-cell transformation known as Richter's syndrome (RS). RS usually presents as diffuse large-cell lymphoma (DLCL) or its immunoblastic variant, and it can be recognized simultaneously with CLL or even 23 yr after its diagnosis. We describe an unusual case of CLL treated with cladribine (2-CdA) in whom DLCL of the plasmablastic type (PBL) developed 4 yr after CLL (Rai IV) diagnosis and 1.5 yr after the 10th course of 2-CdA treatment. Immmunologic, cytogenetic, and molecular studies performed at the time of CLL and PBL coappearance indicated that both tumors originated from different B-cell progenitors. Both malignancies were refractory to VAD (vincristine, doxorubicin, dexamethasone)-based chemotherapy, and only partial response was achieved with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) salvage treatment. However, the patient died 6 months after the occurrence of RS due to rapid progression of PBL. This is the first description of a CLL patient who developed an unusual plasmablastic variant of RS. Recently, the PBL entity has been identified among DLCL associated with the human immunodeficiency virus (HIV) infection. We suggest that in our CLL patient heavily pretreated with 2-CdA, PBL arose as a second clone due to the prolonged and severe state of the host's immunosuppression. Overall survival with current strategies is poor, and further insight into the natural history, biology, and treatment of PBL are needed.

Second malignancies after ewing tumor treatment in 690 patients from a cooperative German/Austrian/Dutch study

BACKGROUND

Ewing tumor treatment involves high cumulative doses of alkylating agents and topoisomerase inhibitors, drugs capable of inducing second cancers. We analyzed the second cancer risk in a large cohort of consistently treated patients.

PATIENTS AND METHODS

Six hundred ninety Ewing tumor patients were treated between 1992 and 1999 with local therapy and vincristine. doxorubicin, ifosfamide and/or cyclophosphamide, and antinomycin D, with or without etoposide as a randomized question. Second cancer incidences were estimated by competing risk analyses; standardized incidence ratios (SIR) in comparison to registry data were compiled.

RESULTS

After a median observation time of 56 months (32 months for survivors), 6 of 690 patients had developed second cancers: MDS/AML, two, ALL/NHL, two, squamous cell carcinoma, one, liposarcoma, one. SIR were increased 20-30 fold in comparison to the general population. The cumulative second cancer risk five years after diagnosis of the Ewing tumor was 0.0093 for the total group, zero for patients without etoposide, and 0.0118 with etoposide. Additional phase II high-dose therapy increased the risk to 0.0398 after five years.

CONCLUSIONS

The second cancder risk observed was in the range to be expected in cancer survivors. High-dose therapy, and less markedly, etoposide, may contribute to the overall second cancer risk.

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.

Therapy-related CD7+ acute myeloid leukemia with trisomy 8 following acute monocytic leukemia

We report a patient who developed CD7+ therapy-related acute myeloid leukemia (t-AML) with trisomy 8 after chemotherapy for AML.

Near-precise interchromosomal recombination and functional DNA topoisomerase II cleavage sites at MLL and AF-4 genomic breakpoints in treatment-related acute lymphoblastic leukemia with t(4;11) translocation

We analyzed the der(11) and der(4) genomic breakpoint junctions of a t(4;11) in the leukemia of a patient previously administered etoposide and dactinomycin by molecular and biochemical approaches to gain insights about the translocation mechanism and the relevant drug exposure. The genomic breakpoint junctions were amplified by PCR. Cleavage of DNA substrates containing the normal homologues of the MLL and AF-4 translocation breakpoints was examined in vitro upon incubation with human DNA topoisomerase IIalpha and etoposide, etoposide catechol, etoposide quinone, or dactinomycin. The der(11) and der(4) genomic breakpoint junctions both involved MLL intron 6 and AF-4 intron 3. Recombination was precise at the sequence level except for the overall gain of a single templated nucleotide. The translocation breakpoints in MLL and AF-4 were DNA topoisomerase II cleavage sites. Etoposide and its metabolites, but not dactinomycin, enhanced cleavage at these sites. Assuming that DNA topoisomerase II was the mediator of the breakage, processing of the staggered nicks induced by DNA topoisomerase II, including exonucleolytic deletion and template-directed polymerization, would have been required before ligation of the ends to generate the observed genomic breakpoint junctions. These data are inconsistent with a translocation mechanism involving interchromosomal recombination by simple exchange of DNA topoisomerase II subunits and DNA-strand transfer; however, consistent with reciprocal DNA topoisomerase II cleavage events in MLL and AF-4 in which both breaks became stable, the DNA ends were processed and underwent ligation. Etoposide and/or its metabolites, but not dactinomycin, likely were the relevant exposures in this patient.

Human LPP gene is fused to MLL in a secondary acute leukemia with a t(3;11) (q28;q23)

The mixed lineage leukemia, MLL, gene is frequently rearranged in patients with secondary leukemia following treatment with DNA topoisomerase II inhibitors. By FISH and Southern blot analyses we identified a rearrangement in the MLL gene due to a novel t(3;11)(q28;q23) chromosomal translocation in a patient who developed AML-M5 3 years after treatment for a follicular lymphoma. Through inverse PCR, the LPP (lipoma preferred partner) gene on 3q28 was identified as the MLL fusion partner. LPP contains substantial identity to the focal adhesion protein, zyxin, and is frequently fused to HMGIC in lipomas. The breakpoint occurred in intron 8 of MLL and LPP. Two in-frame MLL-LPP transcripts, which fuse MLL exon 8 to LPP exon 9, were detected by RT-PCR, although the smaller of these contained a deletion of 120 bp from the MLL sequence. The predicted MLL-LPP fusion protein includes the A/T hook motifs and methyltransferase domain of MLL joined to the two last LIM domains of LPP. A reciprocal LPP-MLL transcript, predicted to include the proline-rich and leucine zipper motifs, and the first LIM domain of LPP were also detected by RT-PCR. In summary, LPP is a newly identified MLL fusion partner in secondary leukemia resulting from topoisomerase inhibitors. The MLL-LPP and LPP-MLL predicted proteins contain many of the features present in other MLL rearrangements.

Richter's syndrome following cladribine therapy for chronic lymphocytic leukemia first manifested as pathologic fracture of the femur

Richter's syndrome (RS) refers to the development of aggressive non-Hodgkin's lymphoma (NHL) during the course of chronic lymphocytic leukaemia (CCL). It occurs in approximately 3% of patients with CLL. The isolated form of this complication in bone is extremely rare and, so far, has not been described in a patient treated with cladribine (2-CdA). We report a case of CLL treated successfully with 2-CdA, where isolated diffuse large B-cell lymphoma (LBCL) developed 2 years after the diagnosis of CLL Rai II and one year after the completion of 2-CdA treatment. RS was first manifested as a pathologic fracture of the left femur. The LBCL was clonally distinct from the original CLL cells. The patient was successfully treated with CHOP and radiotherapy and obtained complete response of the LBCL.

Magnetic resonance imaging of ethyl-nitrosourea-induced rat gliomas: a model for experimental therapeutics of low-grade gliomas

Human low-grade gliomas represent a population of brain tumors that remain a therapeutic challenge. Preclinical evaluation of agents, to test their preventive or therapeutic efficacy in these tumors, requires the use of animal models. Spontaneous gliomas develop in models of chemically induced carcinogenesis, such as in the transplacental N-ethyl-N-nitrosourea (ENU) rat model. However, without the ability to detect initial tumor formation, multiplicity or to measure growth rates, it is difficult to test compounds for their interventional or preventional capabilities. In this study Fisher-334 rats, treated transplacentally with ENU, underwent magnetic resonance imaging (MRI) examination in order to evaluate this approach for detection of tumor formation and growth. ENU-induced intracranial cerebral tumors were first observable in T2-weighted images beginning at 4 months of age and grew with a mean doubling time of 0.487 +/- 0.112 months. These tumors were found histologically to be predominately mixed gliomas. Two therapeutic interventions were evaluated using MRI, vitamin A (all-trans retinol palmitate, RP), as a chemopreventative agent and the anti-angiogenic drug SU-5416. RP was found to significantly delay the time to first tumor observation by one month (P = 0.05). No differences in rates of tumor formation or growth rates were observed between control and RP-treated groups. MRI studies of rats treated with SU-5416 resulted in reduction in tumor growth rates compared to matched controls. These results show that MRI can be used to provide novel information relating to the therapeutic efficacy of agents against the ENU-induced tumor model.

The nature of tamoxifen action in the control of female breast cancer

Tamoxifen, now in use in the breast cancer clinic worldwide, was a study subject of controversy showing an estrogenic property on one occasion and an anti-estrogenic property on another occasion. The outcomes of 4 case-control studies of tamoxifen use were disclosed through 4 publications in 1998. The contents of these reports were intriguing, not only to surgeons of breast cancer clinics, but also to researchers of oncological science in general. The results of 4 research groups, being compatible with each other, were summarized in succession as follows: a) long-term use of tamoxifen reduced the occurrence of estrogen receptor (ER)-positive tumors by 69%, but no difference in the occurrence of ER(-) tumors was seen; b) the incidence of endometrial cancer was increased in the tamoxifen group; c) in women who did not have breast cancer and who had had a hysterectomy, there was no difference of breast cancer occurrence between the placebo- and tamoxifen-arms. Nevertheless, there was a statistically significant reduction of breast cancer among women receiving tamoxifen who also used hormone-replacement therapy during the trial; d) there was also no case-control difference of breast cancer occurrence between tamoxifen- and placebo-groups, when tested in a healthy population with a strong family history; e) the beneficial effect of long term use of tamoxifen in patients with early breast cancer, as assessed in terms of recurrence reduction, survival improvement and suppression of a contralateral tumor growth, was restricted to ER(+) patients; f) there was a positive correlation between the duration of tamoxifen use and the occurrence of endometrial cancer. All these observations provide strong support to the concept of the steroid criminal theory of human carcinogenesis in general. On the basis of both tamoxifen data and other information surrounding the hormonal aspect of human carcinogenesis of multiple tumors including breast cancer, we propose that the steroid generating system, as linked to the ever changing environment, plays a cardinal role as the transmitter of steroidal signals that can be taken as a "go" sign by the local oncogene-tumor suppressor gene complex of one target tissue and as a "stop" sign by that of another target tissue. The fitness of the tamoxifen data to the steroid carcinogenesis concept was discussed in the light of experimental pathology of chemical carcinogens, including the mammocarcinogen 7,12-dimethyl-benz(a)anthracene.

[Risk and prognosis of corpus carcinomas after tamoxifen treatment of breast carcinoma]

BACKGROUND

Dysphagia after radiotherapy of thoracic tumors may be caused by recurrences or by radiation damage to the esophagus.

CASE REPORT

A 75-year-old patient presented with a complete obstruction of the esophagus 5 months after CHARTWEL radiotherapy for a non-small cell lung cancer. During the last week of radiotherapy mild dysphagia (Grade 1 EORTC/RTOG, Grade 2 MRC-CHART-Score) occurred that persisted over the following months. X-ray and endoscopic investigations revealed an easily removable food bolus without evidence of esophageal stricture or ulceration.

CONCLUSION

The case report describes a mild but prolonged early radiation reaction of the esophagus. In comparison with conventional fractionation the incidence of dysphagia is higher after accelerated fractionation schedules. The pathophysiologic mechanisms underlying persistent dysphagia are currently unknown. Beside of recurrences, radiation effects to the esophagus should be considered if dysphagia after irradiation of thoracic tumors occurs, because, as in this case, therapy may rapidly improve the symptoms.

Secondary acute myelogenous leukemia and myelodysplasia without abnormalities of chromosome 11q23 following treatment of acute leukemia with topoisomerase II-based chemotherapy

Therapy-related MDS and AML are complications of intensive chemotherapy regimens. Traditionally, patients exposed to topoisomerase II inhibitors are reported to develop secondary AML with abnormalities of chromosome 11q23. We evaluated the long-term hematologic toxicity of topoisomerase II-intensive high-dose mitoxantrone-based chemotherapy in 163 newly diagnosed acute leukemia patients treated over an 8 year period. Nine (5.5%) patients developed new cytogenetic abnormalities. Four patients developed MDS with progression to AML, three patients developed new abnormalities at the time of relapse, and three patients (including one of the former patients) had changes that were not associated with hematologic disease. The abnormalities most frequently involved chromosomes 7q, 20q, 1q, and 13q. Despite the use of topoisomerase II-intensive treatment, no patient developed an abnormality involving chromosome 11q23. Spontaneous resolution of some changes and prolonged persistence of others in the absence of hematologic disease indicates that some cytogenetic changes are not sufficient to promote leukemogenesis.

Detection of chromosome abnormalities pre-high-dose treatment in patients developing therapy-related myelodysplasia and secondary acute myelogenous leukemia after treatment for non-Hodgkin's lymphoma

PURPOSE

To assess whether pre-high-dose therapy (HDT)-related factors play a critical role in the development of therapy-related myelodysplasia (tMDS) or secondary acute myelogenous leukemia (sAML).

PATIENTS AND METHODS

Twenty-nine of 230 patients with a primary diagnosis of non-Hodgkin's lymphoma (NHL) developed tMDS/sAML after HDT comprising cyclophosphamide and total-body irradiation (TBI) supported by autologous hematopoietic progenitor cells. G-banding and fluorescence in-situ hybridization (FISH) were used to detect clonal cytogenetic abnormalities.

RESULTS

The majority of patients showed complex karyotypes at diagnosis of tMDS/sAML containing, in particular, complete or partial loss of chromosomes 5 and/or 7. Using single locus-specific FISH probes, significant levels of clonally abnormal cells were found before HDT in 20 of 20 tMDS/sAML patients screened, compared with three of 24 patients screened who currently have not developed tMDS/sAML, at a median follow-up of 5.9 years after HDT.

CONCLUSION

Prior cytotoxic therapy may play an important etiologic role and may predispose to the development of tMDS/sAML. Using a triple FISH assay designed to detect loss of chromosomal material from 5q31, 7q22, or 13q14, significant levels of abnormal cells can be detected before HDT and may predict which patients are at increased risk of developing secondary disease. Further prospective evaluation of this FISH assay is warranted to determine its predictive power in this setting.

Parotid mucoepidermoid carcinoma following chemotherapy for childhood acute lymphoblastic leukemia

Primary parotid gland tumors are rare during childhood; however, these tumors are more common as second malignant neoplasms following radiation therapy. The authors report a case of secondary parotid mucoepidermoid carcinoma after chemotherapy for childhood acute lymphoblastic leukemia.