Modeling of response to endocrine therapy in a panel of human luminal breast cancer xenografts.

Resistance to endocrine therapy is a major complication of luminal breast cancer and studies of the biological features of hormonal resistance are limited by the lack of adequate preclinical models. The aim of this study is to establish and characterize a panel of primary human luminal breast carcinoma xenografts, and to evaluate their response to endocrine therapies. Four hundred and twenty-three tumor fragments obtained directly from patients have been grafted in the interscapular fatpad of Swiss nude mice. After stable engraftment with estradiol supplementation, xenografted tumors have been validated by conventional pathology and immunohistochemistry examination, and additional molecular studies. In vivo tumor growth and response to different endocrine treatments were evaluated. We have engrafted 423 tumors including 314 ER+ tumors, and 8 new luminal breast cancer xenografts have been obtained (2.5%). Tumor take was much lower for luminal tumors than for non-luminal tumors (2.5 vs. 24.7%, P < 0.0001), and was associated with two independent criteria, i.e., ER status (P < 0.0001) and a high grade tumor (P = 0.05). Histological and immunohistochemical analyses performed on patient's tumors and xenografts showed striking similarities in the tumor morphology as well as in the expression level of ER, PR, and HER2. Response to hormone therapy, evaluated in 6 luminal models, showed different sensitivities, thus exhibiting heterogeneity similar to what is observed in the clinic. We have established a panel of primary human luminal breast cancer xenografts, recapitulating the biological and clinical behaviors of patient tumors, and therefore suitable for further preclinical experiments.

Sequential reduction of mitochondrial transmembrane potential and generation of reactive oxygen species in early programmed cell death.

Programmed cell death (PCD) is a physiological process commonly defined by alterations in nuclear morphology (apoptosis) and/or characteristic stepwise degradation of chromosomal DNA occurring before cytolysis. However, determined characteristics of PCD such as loss in mitochondrial reductase activity or cytolysis can be induced in enucleated cells, indicating cytoplasmic PCD control. Here we report a sequential disregulation of mitochondrial function that precedes cell shrinkage and nuclear fragmentation. A first cyclosporin A-inhibitable step of ongoing PCD is characterized by a reduction of mitochondrial transmembrane potential, as determined by specific fluorochromes (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine++ + iodide; 3,3'dihexyloxacarbocyanine iodide). Cytofluorometrically purified cells with reduced mitochondrial transmembrane potential are initially incapable of oxidizing hydroethidine (HE) into ethidium. Upon short-term in vitro culture, such cells acquire the capacity of HE oxidation, thus revealing a second step of PCD marked by mitochondrial generation of reactive oxygen species (ROS). This step can be selectively inhibited by rotenone and ruthenium red yet is not affected by cyclosporin A. Finally, cells reduce their volume, a step that is delayed by radical scavengers, indicating the implication of ROS in the apoptotic process. This sequence of alterations accompanying early PCD is found in very different models of apoptosis induction: glucocorticoid-induced death of lymphocytes, activation-induced PCD of T cell hybridomas, and tumor necrosis factor-induced death of U937 cells. Transfection with the antiapoptotic protooncogene Bcl-2 simultaneously inhibits mitochondrial alterations and apoptotic cell death triggered by steroids or ceramide. In vivo injection of fluorochromes such as 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide; 3,3'dihexyloxacarbocyanine iodide; or HE allows for the detection of cells that are programmed for death but still lack nuclear DNA fragmentation. In particular, assessment of mitochondrial ROS generation provides an accurate picture of PCD-mediated lymphocyte depletion. In conclusion, alterations of mitochondrial function constitute an important feature of early PCD.

Establishment and characterisation of a new breast cancer xenograft obtained from a woman carrying a germline BRCA2 mutation.

BACKGROUND: The BRCA2 gene is responsible for a high number of hereditary breast and ovarian cancers, and studies of the BRCA2 biological functions are limited by the lack of models that resemble the patient's tumour features. The aim of this study was to establish and characterise a new human breast carcinoma xenograft obtained from a woman carrying a germline BRCA2 mutation. METHODS: A transplantable xenograft was obtained by grafting a breast cancer sample into nude mice. The biological and genetic profiles of the xenograft were compared with that of the patient's tumour using histology, immunohistochemistry (IHC), BRCA2 sequencing, comparative genomic hybridisation (CGH), and qRT-PCR. Tumour response to standard chemotherapies was evaluated. RESULTS: Histological profile identified the tumour as a basal-like triple-negative breast cancer. Targeted BRCA2 DNA sequencing of the xenograft showed the presence of the mutation previously identified in the carrier. Comparative genomic hybridisation array profiles of the primary tumour and the xenograft revealed a high number of similar genetic alterations. The therapeutic assessment of the xenograft showed sensitivity to anthracyclin-based chemotherapy and resistance to docetaxel. The xenograft was also highly sensitive to radiotherapy and cisplatin-based treatments. CONCLUSIONS: This study describes a new human breast cancer xenograft obtained from a BRCA2-mutated patient. This xenograft provides a new model for the pre-clinical drug development and for the exploration of the drug response biological basis.

CD44 targeting reduces tumour growth and prevents post-chemotherapy relapse of human breast cancers xenografts.

CD44 is a marker of tumour-initiating cells and is upregulated in invasive breast carcinoma; however, its role in the cancer progression is unknown. Here, we show that antibody-mediated CD44-targeting in human breast cancer xenografts (HBCx) significantly reduces tumour growth and that this effect is associated to induction of growth-inhibiting factors. Moreover, treatment with this antibody prevents tumour relapse after chemotherapy-induced remission in a basal-like HBCx.

Mitochondrion as a novel target of anticancer chemotherapy.

Mitochondrial membrane permeabilization is a critical event in the process leading to physiologic or chemotherapy-induced apoptosis (programmed cell death). This permeabilization event is, at least in part, under the control of the permeability transition pore complex (PTPC). Oncoproteins from the Bcl-2 family and tumor suppressor proteins from the Bax family interact with PTPC to inhibit or facilitate membrane permeabilization, respectively. Conventional chemotherapeutic agents elicit mitochondrial permeabilization in an indirect fashion by induction of endogenous effectors that are involved in the physiologic control of apoptosis. However, an increasing number of experimental anticancer drugs, including lonidamine, arsenite, betulinic acid, CD437, and several amphipathic cationic alpha-helical peptides, act directly on mitochondrial membranes and/or on the PTPC. Such agents may induce apoptosis in circumstances in which conventional drugs fail to act because endogenous apoptosis induction pathways, such as those involving p53, death receptors, or apical caspase activation, are disrupted. However, stabilization of the mitochondrial membrane by antiapoptotic Bcl-2-like proteins reduces the cytotoxic potential of most of these drugs. Targeting of specific PTPC components may overcome this Bcl-2-mediated apoptosis inhibition. One strategy involves cross-linking of critical redox-sensitive thiol groups within the PTPC; another involves the use of ligands to the mitochondrial benzodiazepine receptor. Thus, the design of mitochondrion-targeted cytotoxic drugs may constitute a novel strategy for overcoming apoptosis resistance.

Bcl-2 and Bcl-XL antagonize the mitochondrial dysfunction preceding nuclear apoptosis induced by chemotherapeutic agents.

A number of apoptosis-inducing agents used in cancer therapy (etoposide, doxorubicin, 1-beta-D-arabinofuranosylcytosine), as well as the proapoptotic second messenger ceramide, induce a disruption of the mitochondrial transmembrane potential (delta psi m) that precedes nuclear DNA fragmentation. This effect has been observed in tumor cell lines of T-lymphoid, B-lymphoid, and myelomonocytic origin in vitro. Circulating tumor cells from patients receiving chemotherapy in vivo also demonstrate a delta psi m disruption after in vitro culture that precedes nuclear apoptosis. Transfection-enforced hyperexpression of the proto-oncogenes bcl-2 and bcl-XL protects against chemotherapy-induced apoptosis, at both the level of the mitochondrial dysfunction preceding nuclear apoptosis and the level of late nuclear apoptotic events. Bcl-2-mediated inhibition of ceramide-induced delta psi m disruption is observed in normal as well as anucleate cells, indicating that bcl-2 acts on an extranuclear pathway of apoptosis. In contrast to Bcl-2 and Bcl-XL, hyperexpression of the protease inhibitor cytokine response modifier A fails to protect tumor cells against chemotherapy-induced delta psi m disruption and apoptosis, although cytokine response modifier A does prevent the delta psi m collapse and posterior nuclear apoptosis triggered by cross-linking of Fas/Apo-1/CD95. In conclusion, delta psi m disruption seems to be an obligatory step of early (pre-nuclear) apoptosis, and delta psi m is stabilized by two members of the bcl-2 gene family conferring resistance to chemotherapy.

Apoptosis-associated derangement of mitochondrial function in cells lacking mitochondrial DNA.

U937 cells lacking mitochondrial DNA (rho [symbol: see text] cells) are auxotrophic for uridine and pyruvate, hypersensitive to hypoglycemic conditions, and resistant to antimycin A-induced apoptosis. In spite of their obvious metabolic defects, rho [symbol: see text] cells possess a normal mitochondrial transmembrane potential, as well as near-normal capacity to generate superoxide anion after menadione treatment. Similarly to rho + controls, rho [symbol: see text] cells undergo apoptosis in response to tumor necrosis factor-alpha plus cycloheximide. Detailed comparison of the apoptotic process in rho + and rho [symbol: see text] cells reveals essentially the same sequence of events. In response to tumor necrosis factor/cycloheximide, cells first lose their mitochondrial transmembrane potential (delta psi m) and then manifest late apoptotic alterations, such as generation of reactive oxygen species and DNA fragmentation. Experiments involving isolated mitochondria from rho + and rho [symbol: see text] cells confirm that rho [symbol: see text] mitochondria can be induced to undergo permeability transition, a process thought to account for the pre-apoptotic delta psi m disruption in cells. Like rho + mitochondria, rho [symbol: see text] mitochondria contain a pre-formed soluble factor that is capable of inducing chromatin condensation in isolated nuclei in vitro. This factor is released from mitochondria upon induction of permeability transition by calcium or the specific ligand of the adenine nucleotide translocator atractyloside. In conclusion, it appears that all structures involved in the maintenance and pre-apoptotic disruption of the delta psi m, as well as a mitochondrial apoptotic factor(s), are present in rho [symbol: see text] cells and thus are controlled by the nuclear rather than by the mitochondrial genome. These findings underline the contribution of mitochondria to the apoptotic process.

Phase II trial of fludarabine monophosphate in patients with mantle-cell lymphomas.

PURPOSE: The aim of this phase II trial was to assess the efficacy of fludarabine monophosphate in untreated and pretreated mantle-cell lymphomas (MCL). PATIENTS AND METHODS: Fifteen patients with MCL were included in the study. In two cases, fludarabine was the first-line therapy, the second in four cases, the third in five cases, and the fourth in four cases. The diagnosis of MCL was based on the criteria of the European Lymphoma Task Force (ELTF), with morphologic, immunologic, and cytogenetic data. Patients were treated with intravenous fludarabine 25 mg/m2/d for 5 days every 4 weeks. RESULTS: Toxicity of fludarabine was mild: World Health Organization (WHO) grade 3 and 4 granulocytopenia occurred in 15 of 56 assessable cycles (cy) (27%), there was no grade 3 or 4 thrombocytopenia, one grade 3 bacterial lung infection, and no treatment-related death. There were five partial responses (33%) but no complete response. The duration of these responses was short and ranged from 4 to 8 months. CONCLUSION: These results suggest that fludarabine can be moderately effective in the treatment of MCL. Fludarabine appears to be far less effective than in chronic lymphocytic leukemia (CLL) and follicular non-Hodgkin's lymphoma (NHL). Therefore, fludarabine should be evaluated in association with other chemotherapeutic agents in MCL.

Low-grade stage III-IV follicular lymphoma: multivariate analysis of prognostic factors in 484 patients--a study of the groupe d'Etude des lymphomes de l'Adulte.

PURPOSE: To identify the prognostic factors that influence overall survival (OS) in patients with stage III-IV follicular lymphomas and evaluate the clinical usefulness and the prognostic value of the International Prognostic Index (IPI). PATIENTS AND METHODS: Four hundred eighty-four patients with Ann Arbor stage III-IV follicular lymphomas treated in two phase III trials from 1986 to 1995 were screened for this study. All histologic slides were reviewed by two hematopathologists. The influence of the initial parameters on survival was defined by univariate (log-rank test) and multivariate (Cox model) analyses. RESULTS: The poor prognostic factors for OS (age > 60 years, "B" symptom(s), > or = two extranodal sites, stage IV disease, tumor bulk > 7 cm, at least three nodal sites > 3 cm, liver involvement, serous effusion-compression or orbital/epidural involvement, and erythrocyte sedimentation rate > 30 mm/h) that were significant in univariate analysis were subjected to multivariate analysis. Three factors remained significant: B symptom(s) (risk ratio = 1.80), age greater than 60 years (risk ratio = 1.60), and at least three nodal sites greater than 3 cm (risk ratio = 1.71). When the IPI was applied to these patients, the score was 1, 2, 3, and 4-5 in 49%, 39%, 11%, and 2%, respectively, and it was significant for progression-free survival (P =.002) and OS (P =.0001). CONCLUSION: Three prognostic factors for poor OS were identified: B symptoms, age greater than 60 years, and at least three nodal sites greater than 3 cm. The IPI was prognostic for OS, but in this population, a very low number of patients belonged to the high-risk groups.

Mitochondria in chemotherapy-induced apoptosis: a prospective novel target of cancer therapy (review).

Resistance to apoptosis is a frequent characteristic of cancer cells and participates both in the initial phase of carcinogenesis and in the development of chemotherapy resistance. Recently, it has become clear that a disruption in mitochondrial membrane function is a decisive event of the apoptotic process leading to the disposal of chemotherapy-treated cells. Opening of the mitochondrial megachannel (also called permeability transition pore) is at least in part responsible for the disruption of mitochondrial membrane integrity in apoptosis. The megachannel is regulated by numerous endogenous effectors including members of the Bcl-2/Bax family, the redox status of the cell, cytosolic Ca2+ levels, ceramide, and amphipathic peptides. Chemotherapeutic agents may induce opening of the megachannel by modulating some of these endogenous effectors. The disruption of mitochondrial membrane integrity involves a loss of metabolic functions and the liberation of intermembrane proteins into the cytosol. Such proteins, which normally are well secluded in mitochondria, include cytochrome c and AIF (apoptosis inducing factor), which both activate caspases and endonucleases upon release into the cytosol. Strategies for the development of chemotherapeutic agents acting on mitochondria are discussed.

Efficacy of autologous stem cell transplantation in mantle cell lymphoma: a 3-year follow-up study.

This study was designed to evaluate the efficacy of therapeutic intensification with autologous stem cell transplantation (ASCT) for mantle cell lymphomas (MCL) in terms of response rate, duration of response, and event-free and overall survivals. Twenty-four patients with confirmed MCL responding to chemotherapy received a high-dose chemo-radiotherapy regimen followed by ASCT. Transplantation was performed during first-line therapy in nine cases, second-line in 13 cases and third-line in two cases. The source of hematopoietic stem cells was peripheral blood for 19 cases. At the time of ASCT, eight patients were in complete remission (33%). Seventeen of the 24 cases received an intensified regimen with TBI and seven received the BEAM or the BEAC regimen. After transplantation, 19 patients were in CR (79%). Nine of these were alive in continued CR at a median follow-up of 34 months, while seven relapsed at a median of 18 months. One patient died from Pneumocystis carinii interstitial pneumonitis and five patients developed secondary malignancies. With a median follow-up after transplantation of 34 months, the 3-year event-free survival was 55% and the 3-year overall survival was 68%. These results indicate that therapeutic intensification with ASCT might be an effective treatment for mantle cell lymphomas. Bone Marrow Transplantation (2000) 25, 251-256.

VIP (etoposide, ifosfamide and cisplatinum) as a salvage intensification program in relapsed or refractory Hodgkin's disease.

Forty-two patients with refractory (15 patients) or relapsed (27 patients) Hodgkin's disease (HD) were included in a prospective single center study evaluating the efficacy of a regimen VIP combining etoposide 75 mg/m2/day days 1-5, ifosfamide 1.2 g/m2/day days 1-5 and cisplatinum 20 mg/m2/day days 1-5, one course every 4 weeks as salvage therapy in patients with refractory or relapsed Hodgkin's disease, potentially eligible for high-dose chemotherapy with reinjection of hematopoietic stem cells (HSC). If patients were considered chemosensitive after two courses of VIP, high-dose chemotherapy followed by the reinjection of HSC was planned. After two courses of VIP, 67% achieved an objective response including 38% complete responses. Overall, 28 patients went on to high-dose therapy with reinjection of HSC, and 46% of grafted patients are in a sustained complete remission. When the overall patient population is considered, 33% are in complete remission (CR) with a median follow-up of 37 months. A CR of less than 12 months and refractory disease were associated with a poor survival. These results showed that the VIP regimen is effective in relapsed or refractory HD and allows high-dose therapy to be given in the case of most responding patients. However, results in patients with refractory disease or a first complete remission of less than 12 months need to be further improved.

Ex vivo expansion of megakaryocyte precursor cells in autologous stem cell transplantation for relapsed malignant lymphoma.

To evaluate the impact of ex vivo expanded megakaryocyte (MK) progenitors on high-dose chemotherapy-induced thrombocytopenia, we conducted a phase II study in 10 patients with relapsed lymphoma. Two fractions of peripheral blood progenitor cells (PBPC) were cryopreserved, one with enough cells for at least 2 x 10(6) CD34+ cells/kg and a second obtained after CD34+ selection. Ten days before autologous stem cell transplantation, the CD34+ fraction was cultured with MGDF+SCF for 10 days. After BEAM (BCNU, cyclophosphamide, cytarabine, and melphalan) chemotherapy, patients were reinfused with standard PBPC and ex vivo expanded cells. No toxicity was observed after reinfusion. The mean fold expansion was 9.27 for nucleated cells, 2 for CD34+ cells, 676 for CD41+ cells, and 627 for CD61+ cells. The median date of platelet transfusion independence was day 8 (range: 7-12). All patients received at least one platelet transfusion. In conclusion, ex vivo expansion of MK progenitors was feasible and safe, but this procedure did not prevent BEAM-induced thrombocytopenia. Future studies will determine if expansion of higher numbers of CD34+ cells towards the MK-differentiation pathway will translate into a functional effect in terms of shortening of BEAM-induced thrombocytopenia.

Is mantle cell lymphoma a sex-related disease?

Mantle cell lymphomas are characterized by a male predominance with a range between 55 and 65 years (sex ratio M/F of 6.5). When the sex ratio of patients having mantle cell lymphoma was compared to that of each of the subtypes of non-Hodgkin's lymphomas, it was significantly higher in all cases except Burkitt's and lymphoblastic T-cell lymphomas. These observations suggest a possible relation between the chromosome X and mantle cell lymphomas which has to be explored.

Mantle cell lymphomas: characteristics, natural history and prognostic factors of 45 cases.

We reviewed 77 cases considered as lymphocytic lymphomas of intermediate differentiation or diffuse centrocytic lymphomas. Forty-five cases were diagnosed as mantle cell lymphoma (MCL). The architectural pattern was diffuse in 95%, 8 cases presented large blastoid cells and CD5 positivity was observed in 28/34 cases. Of 20 cases studied, 8 presented a t(11;14)(q13;q32). Patient characteristics were: median age 59 years, B symptoms in 38%, 87% stages III-IV, bone marrow involvement in 67% with peripheral leukemic cells in 24%. Forty-four patients were treated with chemotherapy and 7 received radiotherapy. The complete response (CR) rate was 58%. Of the 26 CR, 19 relapsed at a median of 15 months. Disease-free survival was 42% and overall survival was 73% at 3 years. In a univariate analysis, overall survival was related to liver and bone marrow involvement, the presence of peripheral lymphomatous cells and achieving a complete response.

[Semen preservation and gonadal toxicity in the treatment of non Hodgkin lymphoma. Experience at the Gustave-Roussy Institute from 1980 to 1993]. / Autoconservation de sperme et toxicité gonadique après traitement pour lymphome non hodgkinien. Expérience de l'institut Gustave-Roussy de 1980 à 1993.

More than 50% of patients with non Hodgkin's lymphomas (NHL) are long-term survivors. We have retrospectively analysed the indication of semen cryopreservation and late gonadal toxicity for 213 males patients consecutively treated at the Gustave Roussy institute from 1980 to 1993 for NHL. The mean age was 30 years (15-42) and all patients received chemotherapy with or without radiotherapy. Initial spermograms and cryopreservation of semen were obtained in only 24 patients (half of them between 1991 and 1993). Spermogram characteristics were as follows: 11 normal; 13 abnormal with oligospermia (n = 7), asthenospermia (n = 7), and teratospermia (n = 8). No relation was found between the pretherapeutic status and the semen sample quality. Cryopreservation was possible in only 22 cases, and among the 16 surviving patients, two have undergone insemination and the remaining 14 are maintaining their cryopreserved semen samples. Long-term gonadal toxicity was assessed on spermograms of nine patients: three of whom had evidence of return to pretherapeutic status. FSH levels were assayed for 48 patients: at a threshold of 8 g/m2 of cyclophosphamide, 86% of patients had elevated values (P < 10(-6). Cumulated doxorubicin doses were not correlated with FSH elevation. Five patients have had children after treatment. In conclusion, chemotherapy for NHL seems to induce an intermediate level of gonadal toxicity which is between that of MOPP and ABVD. Complete information about gonadal toxicity of chemotherapy is warranted for young male patients who are to receive chemotherapy and semen cryopreservation should be suggested to this population.

Choroidal and adnexal extranodal marginal zone B-cell lymphoma: presentation, imaging findings, and therapeutic management in a series of nine cases.

PURPOSE: To describe the clinical and imaging presentation, pitfalls in the diagnosis of choroidal extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT), as well as the therapeutic management and prognosis. METHODS: A retrospective case review of nine choroidal MALT lymphomas was performed. Initial clinical presentation and imaging findings of these histologically confirmed cases of lymphoma were analyzed. Treatment methods, time to diagnosis, systemic work-up, and treatment prognosis were assessed. RESULTS: Initial presentation was essentially blurred vision. The features described on examination were: anterior and posterior scleritis, iridocyclitis, choroidal infiltration, and exudative retinal detachment. Fluorescein and indocyanine green angiography as well as ultrasonography and optic coherence tomography provided arguments in favor of the diagnosis. Biopsy sites included conjunctiva, Tenon's capsule, deep scleral tissue, episclera, lacrimal gland, and choroid. Treatment mostly consisted of a combination of chemotherapy and radiotherapy. The mean time to diagnosis was 12 months. CONCLUSIONS: Owing to the insidious onset of these tumors and their ability to simulate other conditions, the diagnosis is commonly delayed. The prognosis is generally good and treatment is effective in the case of localized lymphoma.

[Breast conserving surgery in locoregional treatment of breast carcinoma after Hodgkin lymphoma]. / Traitement conservateur dans la prise en charge locorégionale du cancer du sein après lymphome de Hodgkin.

PURPOSE: To report characteristics and outcome of breast cancer after irradiation for Hodgkin lymphoma with special focus on breast conservation surgery. PATIENTS AND METHODS: Medical records of 72 women who developed either ductal carcinoma in situ or stage I-III invasive carcinoma of the breast after Hodgkin lymphoma between 1978 and 2009 were retrospectively reviewed. RESULTS: Median age at Hodgkin lymphoma diagnosis was 23 years old. Median total dose received by the mediastinum was 40 Gy, mostly by a mantle field technique. Breast cancer occurred after a median time interval of 21 years. Ductal invasive carcinoma and ductal carcinoma in situ represented respectively 71% and 19% of the cases. Locoregional treatment for breast cancer consisted of mastectomy with or without radiotherapy in 39 patients and of lumpectomy with or without adjuvant radiotherapy in 32 patients. The isocentric lateral decubitus radiation technique was used in 17 patients after breast conserving surgery (57%). With a median follow-up of 7 years, 5-year overall survival rate and locoregional control rate were respectively 74.5% and 82% for invasive carcinoma and 100% and 92% for in situ carcinoma. Thirteen patients died of progressive breast cancer and contralateral breast cancer was diagnosed in ten patients (14%). CONCLUSIONS: Breast conserving treatment can be an option for breast cancers that occur after Hodgkin lymphoma despite prior thoracic irradiation. It should consist of lumpectomy and adjuvant breast radiotherapy with use of adequate techniques, such as the lateral decubitus isocentric position.

[High risk of cardiac dysfunction after treatment of secondary acute myeloid leukemia following chemotherapy and radiotherapy for breast cancer]. / Risque élevé de dysfonction cardiaque des leucémies aiguës myéloïdes secondaires à un cancer du sein.

Secondary acute myeloid leukaemia (AML) occurring after breast cancer is a rare long-term complication of the chemo- and/or radiation therapy required to treat breast cancer. The usually recognized curative option of these secondary AML includes courses of anthracycline-based chemotherapy followed by haematopoietic stem cell transplantation (HSCT). Cardiac dysfunction during AML treatment of these patients previously treated with anthracyclines for breast cancer has not been reported to date. We evaluated the evolution of cardiac function in seven patients treated with anthracyclines and/or autologous or allogeneic bone marrow transplantation for secondary AML occurring after breast cancer. All of the patients who received a cumulative anthracycline dose above the cardiac toxicity threshold developed cardiac symptoms during AML chemotherapy courses. Moreover, four of the five transplanted patients developed severe heart failure among which two were fatal. Thus, the risk of severe cardiac dysfunction after treatment of secondary AML following breast cancer must be taken in account as part of the therapeutic strategy of those patients. As discussed here, an accurate evaluation of risk factors, the use of sensitive detection tests and of cardioprotective drugs as well as that of non-cardiotoxic chemotherapy might decrease the occurrence and severity of this life-threatening complication.