Risk of secondary leukemia after treatment with etoposide (VP-16) for Langerhans' cell histiocytosis in Italian and Austrian-German populations

Long-term outcomes among adults with Langerhans cell histiocytosis

Advances in the treatment of Langerhans cell histiocytosis (LCH) have resulted in a growing survivor population. There is a lack of data on long-term outcomes among adults with LCH. We conducted a retrospective record review of 219 adults (aged ≥18 years) with LCH. Most common presentation was multisystem (34.2%), followed by single-system pulmonary (32%), unifocal (28.3%), and single-system multifocal (5.5%) LCH. Risk organ involvement (the liver, spleen, or bone marrow) was seen in 8.7% of cases, and 40 of 88 (45.5%) tested cases were BRAFV600E. At a median follow-up of 74 months, 5-year progression-free survival (PFS) was 58.3% and estimated median PFS was 83 months. Median overall survival (OS) was not reached; 5- and 10-year OS rates were 88.7% and 74.5%, respectively. Risk organ involvement was associated with worse PFS (hazard ratio [HR], 4.5) and OS (HR, 10.8). BRAFV600E was not associated with risk organ involvement or survival. When compared with matched unaffected US population, individuals with LCH had a significantly higher risk of overall mortality (standardized mortality ratio [SMR], 2.66), specifically among those aged <55 years at diagnosis (SMR, 5.94) and those with multisystem disease (SMR, 4.12). Second cancers occurred in 16.4% cases, including diverse hematologic and solid organ malignancies. LCH-associated deaths constituted 36.1% of deaths and occurred within 5 years of diagnosis. After 5 years, non-LCH causes of death, including second cancers, chronic obstructive pulmonary disease, and cardiovascular diseases, predominated. Our study highlights, to our knowledge, for the first time, that adults with LCH experience early and late mortality from non-LCH causes and the need for development of targeted survivorship programs to improve outcomes.

Pyrazole-Enriched Cationic Nanoparticles Induced Early- and Late-Stage Apoptosis in Neuroblastoma Cells at Sub-Micromolar Concentrations

Neuroblastoma (NB) is a severe form of tumor occurring mainly in young children and originating from nerve cells found in the abdomen or next to the spine. NB needs more effective and safer treatments, as the chance of survival against the aggressive form of this disease are very small. Moreover, when current treatments are successful, they are often responsible for unpleasant health problems which compromise the future and life of surviving children. As reported, cationic macromolecules have previously been found to be active against bacteria as membrane disruptors by interacting with the negative constituents of the surface of cancer cells, analogously inducing depolarization and permeabilization, provoking lethal damage to the cytoplasmic membrane, and cause loss of cytoplasmic content and consequently, cell death. Here, aiming to develop new curative options for counteracting NB cells, pyrazole-loaded cationic nanoparticles (NPs) (BBB4-G4K and CB1H-P7 NPs), recently reported as antibacterial agents, were assayed against IMR 32 and SHSY 5Y NB cell lines. Particularly, while BBB4-G4K NPs demonstrated low cytotoxicity against both NB cell lines, CB1H-P7 NPs were remarkably cytotoxic against both IMR 32 and SHSY 5Y cells (IC50 = 0.43–0.54 µM), causing both early-stage (66–85%) and late-stage apoptosis (52–65%). Interestingly, in the nano-formulation of CB1H using P7 NPs, the anticancer effects of CB1H and P7 were increased by 54–57 and 2.5–4-times, respectively against IMR 32 cells, and by 53–61 and 1.3–2 times against SHSY 5Y cells. Additionally, based on the IC50 values, CB1H-P7 was also 1-12-fold more potent than fenretinide, an experimental retinoid derivative in a phase III clinical trial, with remarkable antineoplastic and chemopreventive properties. Collectively, due to these results and their good selectivity for cancer cells (selectivity indices = 2.8–3.3), CB1H-P7 NPs represent an excellent template material for developing new treatment options against NB.

Spectrum of second primary malignancies and cause-specific mortality in pediatric and adult langerhans cell histiocytosis

With the advent of targeted therapeutics in Langerhans cell histiocytosis (LCH), there is a growing survivor population that might be at risk for late mortality from non-LCH causes, including second primary malignancies (SPMs). We undertook a large study using the Surveillance, Epidemiology, and End Results (SEER) database to evaluate the patterns of SPMs and cause-specific mortality among individuals with LCH (2000-2016) from the US. We found an increased risk of SPMs in the cohort (standardized incidence ratio [SIR] 2.07). The pediatric group was at a high risk of developing Hodgkin lymphoma (SIR 60.93) and non-Hodgkin lymphoma (SIR 60.88). People with adult-onset LCH were found to have a high risk of developing miscellaneous malignant cancers (SIR 11.43), which primarily included myelodysplastic syndrome. Adults were also at a high risk of developing carcinoma in-situ of vulva at 2-11 months [SIR 62.72] and B-ALL at 60-119 months [SIR 66.29] after LCH diagnosis. Additionally, 5% and 1% of the patients developed prior or concomitant malignancies with LCH, respectively. The 5 yr overall survival (OS) was 96.6% for pediatric and 88.5% for adult LCH cohorts. Most common cause of death was infections in pediatric and SPMs in adult LCH. Our study highlights that despite advances in treatments, people with LCH have an increased mortality risk from non-LCH causes when compared with the general population, including a high risk of SPMs.

Langerhans cell histiocytosis and associated malignancies: A retrospective analysis of 270 patients

PURPOSE

The frequency of Langerhans cell histiocytosis (LCH) and associated malignancies (AM) is greater than statistically expected. Here, we analyze LCH-AM co-occurrence in both children and adults.

METHODS

Between 1991 and 2015, data were collected by regular questionnaires to members of the Histiocyte Society and searches in PubMed and Abstract Books. Patients were grouped by age at LCH diagnosis (≤ and >18 years), and types and timing of AM occurrence were plotted with respect to the LCH diagnosis. For the statistical analysis, only the first AM were considered.

RESULTS

A total of 285 LCH-AM in 270 patients were identified, 116 (43%) ≤ 18 years, and 154 (57%) >18 years. In childhood LCH-AM pairs, leukemias and myeloproliferative disorders (n = 58; 50.0%) prevailed over solid tumors (n = 43; 37.1%) and lymphoma (n = 15; 12.9%). In adults, solid tumors were reported in 61 patients (39.6%), lymphoma, and leukemias and myeloproliferative disorders in 56 (36.4%) and 37 (24.0%) patients, respectively. In most children, AM followed LCH (n = 69, 59.5%), whereas in adults, LCH and AM occurred concurrently in 69 patients (44.8%). In children, T-lineage acute lymphoblastic leukemia (ALL) and promyelocytic acute myeloid leukemia (AML) and retinoblastoma were over-represented and thyroid carcinoma in adults.

CONCLUSIONS

The largest collection of data on LCH-AM to date clearly indicates inherent relationships between specific types of AM and LCH, which may be due to therapy effects, clonal evolution, and germ-line predisposition, respectively. Prospective thorough genetic analysis is warranted and will hopefully shed light on the association of LCH and second neoplasms.

Etoposide, an anticancer drug involved in therapy-related secondary leukemia: Enzymes at play

Etoposide is a semi-synthetic glycoside derivative of podophyllotoxin, also known as VP-16. It is a widely used anticancer medicine in clinics. Unfortunately, high doses or long-term etoposide treatment can induce therapy-related leukemia. The mechanism by which etoposide induces secondary hematopoietic malignancies is still unclear. In this article, we review the potential mechanisms of etoposide induced therapy-related leukemia. Etoposide related leukemogenesis is known to depend on reactive oxidative metabolites of etoposide, notably etoposide quinone, which interacts with cellular proteins such as topoisomerases II (TOP2), CREB-binding protein (CREBBP), and T-Cell Protein Tyrosine Phosphatase (TCPTP). CYP3A4 and CYP3A5 metabolize etoposide to etoposide catechol, which readily oxidizes to etoposide quinone. As a poison of TOP2 enzymes, etoposide and its metabolites induce DNA double-stranded breaks (DSB), and the accumulation of DSB triggers cell apoptosis. If the cell survives, the DSB gives rise to the likelihood of faulty DNA repair events. The gene translocation could occur in mixed-lineage leukemia (MLL) gene, which is well-known in leukemogenesis. Recently, studies have revealed that etoposide metabolites, especially etoposide quinone, can covalently bind to cysteines residues of CREBBP and TCPTP enzymes, . This leads to enzyme inhibition and further affects histone acetylation and phosphorylation of the JAK-STAT pathway, thus putatively altering the proliferation and differentiation of hematopoietic stem cells (HSC). In brief, current studies suggest that etoposide and its metabolites contribute to etoposide therapy-related leukemia through TOP2 mediated DSB and impairs specific enzyme activity, such as CREBBP and TCPTP.

Dendrimer Nanodevices and Gallic Acid as Novel Strategies to Fight Chemoresistance in Neuroblastoma Cells

Human neuroblastoma (NB), a pediatric tumor inclined to relapse, after an initial response to therapy, usually develops resistance. Since several chemotherapeutics exert anticancer effect by increasing reactive oxygen species (ROS), NB cells overproduce antioxidant compounds becoming drugs-resistant. A strategy to sensitize NB cells to chemotherapy involves reducing their antioxidant defenses and inducing ROS overproduction. Concerning this, although affected by several issues that limit their clinical application, antioxidant/pro-oxidant polyphenols, such as gallic acid (GA), showed pro-oxidant anti-cancer effects and low toxicity for healthy cells, in several kind of tumors, not including NB. Herein, for the first time, free GA, two GA-dendrimers, and the dendrimer adopted as GA reservoir were tested on both sensitive and chemoresistant NB cells. The dendrimer device, administered at the dose previously found active versus sensitive NB cells, induced ROS-mediated death also in chemoresistant cells. Free GA proved a dose-dependent ROS-mediated cytotoxicity on both cell populations. Intriguingly, when administered in dendrimer formulations at a dose not cytotoxic for NB cells, GA nullified any pro-oxidant activity of dendrimer. Unfortunately, due to GA, nanoformulations were inactive on NB cells, but GA resized in nanoparticles showed considerable ability in counteracting, at low dose, ROS production and oxidative stress, herein induced by the dendrimer.

Treatment of Langerhans cell histiocytosis with a modified risk-adapted protocol-experience from a tertiary cancer institute in India

BACKGROUND

Involvement of risk-organs (RO+) in Langerhans cell histiocytosis (LCH) and inadequate early response identifies patients at high risk for relapse and mortality requiring intensive salvage therapy including stem cell transplant, adding cost and toxicity. To mitigate this, we used a standard induction, augmented with metronomic etoposide, and prolonged maintenance-similarly augmented for RO+, and retrospectively analyzed its impact.

PROCEDURE

LCH patients from 2009 through 2014 were included. Patients received standard vinblastine and prednisolone therapy weekly till week 25 for RO+. Single site (SS) and multisystem (MS) without risk organ involvement (RO-) received 3-weekly pulses from week 13 till week 25. Maintenance was 3-weekly vinblastine and 5-day prednisolone pulses, daily 6-mercaptopurine (60 mg/m² ) and weekly methotrexate (15 mg/m² ) for 18 and 9 months for RO+ and MSRO-, respectively. RO+ also received oral etoposide (50 mg/m² ) for 21 of every 28-day cycle for the first year.

RESULTS

Fifty consecutive patients were analyzed. Median age was 36 months (4-189 months). SS, MSRO-, and RO+ were 29 (58%), 12 (24%), and nine (18%), respectively. Four were lost to follow-up and excluded from further evaluation. On response evaluation at week 6, 24 (52%) had no active disease (NAD), 17 (37%) had AD-better (where AD is active disease), and one (2%) had AD-worse. In RO+, eight (66.6%) had AD-better and three (25%) had NAD. Forty-five patients had NAD by week 12. Three patients relapsed. With median follow-up of 39 months (8-84), 5-year event free survival was 85.6% (RO- and SS), and 100% for RO+. One patient's death in remission from unrelated causes resulted in overall survival of 97%.

CONCLUSIONS

RO+LCH receiving oral etoposide augmented induction and maintenance had early and durable responses. Prolonging maintenance lowered reactivation rates in RO+ and RO-LCH, resulting in excellent survival.

Refractory LCH With Secondary Intracranial PNET: A Case Report and Review of Literature

The occurrence of second malignant neoplasms in patients with Langerhans cell histiocytosis is infrequent but has been reported. Here we report the case of a child with refractory Langerhans cell histiocytosis who was treated with cladribine and later developed a secondary intracranial primitive neuroectodermal tumor. The possible association of cladribine with second neoplasm is further discussed.

Glutathione-mediated antioxidant response and aerobic metabolism: two crucial factors involved in determining the multi-drug resistance of high-risk neuroblastoma

Neuroblastoma, a paediatric malignant tumor, is initially sensitive to etoposide, a drug to which many patients develop chemoresistance. In order to investigate the molecular mechanisms responsible for etoposide chemoresistance, HTLA-230, a human MYCN-amplified neuroblastoma cell line, was chronically treated with etoposide at a concentration that in vitro mimics the clinically-used dose. The selected cells (HTLA-Chr) acquire multi-drug resistance (MDR), becoming less sensitive than parental cells to high doses of etoposide or doxorubicin. MDR is due to several mechanisms that together contribute to maintaining non-toxic levels of H₂O₂. In fact, HTLA-Chr cells, while having an efficient aerobic metabolism, are also characterized by an up-regulation of catalase activity and higher levels of reduced glutathione (GSH), a thiol antioxidant compound. The combination of such mechanisms contributes to prevent membrane lipoperoxidation and cell death. Treatment of HTLA-Chr cells with L-Buthionine-sulfoximine, an inhibitor of GSH biosynthesis, markedly reduces their tumorigenic potential that is instead enhanced by the exposure to N-Acetylcysteine, able to promote GSH synthesis.

Collectively, these results demonstrate that GSH and GSH-related responses play a crucial role in the acquisition of MDR and suggest that GSH level monitoring is an efficient strategy to early identify the onset of drug resistance and to control the patient's response to therapy.

Pulmonary Langerhans cell histiocytosis, acute myeloid leukemia, and myelofibrosis in a large family and review of the literature

BACKGROUND

There is mounting evidence that Langerhans cell histiocytosis (LCH) and acute myeloid leukemia (AML) are hematopoietic neoplasms that arise from the same myeloid precursor cell. In addition, studies suggest a relationship between LCH and primary idiopathic myelofibrosis (MF). Furthermore familial LCH, AML, and MF have each been reported.

METHODS

We examined more than 750 pedigrees of familial hematologic malignancies for evidence of familial LCH, AML, and/or MF and identified one family with all three neoplasms, which is presented here.

FINDINGS

In four generations of this large family there are five cases of AML in three generations, two cases of LCH in two generations and three cases of MF in two generations. Anticipation of -18 and -6 years was present in the patients with MF, and -8 years in the patients with LCH. Anticipation was also identified between one AML patient pair in generations III and IV (-18 years) and three patients with AML in generations II, III, and IV (-5 years and -10 years).

INTERPRETATION

This is the first report of familial LCH, AML, and MF in one family. The pedigree suggests a common basis for these entities, which is further suggested by the presence of anticipation in the pedigree.

Global characteristics of childhood acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) comprises approximately 5-10% of childhood acute myeloid leukemia (AML) cases in the US. While variation in this percentage among other populations was noted previously, global patterns of childhood APL have not been thoroughly characterized. In this comprehensive review of childhood APL, we examined its geographic pattern and the potential contribution of environmental factors to observed variation. In 142 studies (spanning >60 countries) identified, variation was apparent-de novo APL represented from 2% (Switzerland) to >50% (Nicaragua) of childhood AML in different geographic regions. Because a limited number of previous studies addressed specific environmental exposures that potentially underlie childhood APL development, we gathered 28 childhood cases of therapy-related APL, which exemplified associations between prior exposures to chemotherapeutic drugs/radiation and APL diagnosis. Future population-based studies examining childhood APL patterns and the potential association with specific environmental exposures and other risk factors are needed.

Lymphohematopoietic cancers induced by chemicals and other agents and their implications for risk evaluation: An overview

Lymphohematopoietic neoplasia are one of the most common types of cancer induced by therapeutic and environmental agents. Of the more than 100 human carcinogens identified by the International Agency for Research on Cancer, approximately 25% induce leukemias or lymphomas. The objective of this review is to provide an introduction into the origins and mechanisms underlying lymphohematopoietic cancers induced by xenobiotics in humans with an emphasis on acute myeloid leukemia, and discuss the implications of this information for risk assessment. Among the agents causing lymphohematopoietic cancers, a number of patterns were observed. Most physical and chemical leukemia-inducing agents such as the therapeutic alkylating agents, topoisomerase II inhibitors, and ionizing radiation induce mainly acute myeloid leukemia through DNA-damaging mechanisms that result in either gene or chromosomal mutations. In contrast, biological agents and a few immunosuppressive chemicals induce primarily lymphoid neoplasms through mechanisms that involve alterations in immune response. Among the environmental agents examined, benzene was clearly associated with acute myeloid leukemia in humans, with increasing but still limited evidence for an association with lymphoid neoplasms. Ethylene oxide and 1,3-butadiene were linked primarily to lymphoid cancers. Although the association between formaldehyde and leukemia remains controversial, several recent evaluations have indicated a potential link between formaldehyde and acute myeloid leukemia. The four environmental agents examined in detail were all genotoxic, inducing gene mutations, chromosomal alterations, and/or micronuclei in vivo. Although it is clear that rapid progress has been made in recent years in our understanding of leukemogenesis, many questions remain for future research regarding chemically induced leukemias and lymphomas, including the mechanisms by which the environmental agents reviewed here induce these diseases and the risks associated with exposures to such agents.

Acute Myeloid Leukemia With t(9;11) (p22;q23) and Synchronous Langerhans Cell Histiocytosis

We present here the first report of an adult patient with simultaneous LCH and AML with t(9;11).5

Therapy prolongation improves outcome in multisystem Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH)-III tested risk-adjusted, intensified, longer treatment of multisystem LCH (MS-LCH), for which optimal therapy has been elusive. Stratified by risk organ involvement (high [RO+] or low [RO-] risk groups), > 400 patients were randomized. RO+ patients received 1 to 2 six-week courses of vinblastine+prednisone (Arm A) or vinblastine + prednisone + methotrexate (Arm B). Response triggered milder continuation therapy with the same combinations, plus 6-mercaptopurine, for 12 months total treatment. 6/12-week response rates (mean, 71%) and 5-year survival (84%) and reactivation rates (27%) were similar in both arms. Notably, historical comparisons revealed survival superior to that of identically stratified RO+ patients treated for 6 months in predecessor trials LCH-I (62%) or LCH-II (69%, P < .001), and lower 5-year reactivation rates than in LCH-I (55%) or LCH-II (44%, P < .001). RO- patients received vinblastine+prednisone throughout. Response by 6 weeks triggered randomization to 6 or 12 months total treatment. Significantly lower 5-year reactivation rates characterized the 12-month Arm D (37%) compared with 6-month Arm C (54%, P = .03) or to 6-month schedules in LCH-I (52%) and LCH-II (48%, P < .001). Thus, prolonging treatment decreased RO- patient reactivations in LCH-III, and although methotrexate added no benefit, RO+ patient survival and reactivation rates have substantially improved in the 3 sequential trials. (Trial No. NCT00276757 www.ClinicalTrials.gov).

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.

Multisystem Langerhans cell histiocytosis in children: current treatment and future directions

Langerhans cell histiocytosis (LCH) is a rare (about 3-5 cases per million children aged 0-14 years), non-malignant disease characterized by proliferation and accumulation of clonal dendritic cells, extreme clinical heterogeneity, and an unpredictable course. Three large-scale, international, prospective therapeutic studies (LCH-I to III) for multisystem LCH (MS-LCH) have been conducted by the Histiocyte Society since 1991. The cumulative lessons from these studies are summarized in this review. Patients with MS-LCH represent a heterogeneous group with respect to disease severity and outcome, therefore treatment stratification and risk-tailored treatment are mandatory. The risk for mortality can be predicted based on involvement of 'risk organs' (e.g. hematopoietic system, liver, and/or spleen) at diagnosis and on response to initial therapy (assessed after 6-12 weeks of treatment). Thus, patients without involvement of risk organs (low-risk group) are not at risk for mortality but need systemic therapy in order to control the disease activity and avoid reactivations and permanent consequences. Patients with risk organ involvement (risk group) are at risk for mortality, and lack of therapy response defines a subgroup with a particularly dismal prognosis (high-risk group). Those patients in the risk group who respond to therapy and survive are at risk for reactivations and permanent consequences. The LCH-I study compared the efficacy of vinblastine and etoposide, and concluded that they are equivalent single-agent treatments for children with MS-LCH. However, the results of this trial were inferior with respect to response rate at week 6, disease reactivation rate, and sequelae, when compared with historical trials using more intensive regimens. The combination of prednisolone and vinblastine was established as a standard first-line treatment through the LCH-II and LCH-III studies. The regimen consists of one to two 6-week courses (continuous oral corticosteroids 40 mg/m2/day for 4 weeks, tapered over 2 weeks plus weekly vinblastine intravenous push) of initial therapy, followed by a continuation phase (three weekly pulses of oral prednisolone 40 mg/m2/day for 5 days plus a vinblastine injection). The addition of a third drug to the standard combination (etoposide in LCH-II and methotrexate in LCH-III) failed to significantly improve survival in the risk group. The remaining mortality in the risk group is about 20%, and up to 40% in the high-risk group. Concerning low-risk MS-LCH, comparison of results of the LCH-II study with historical data suggested that the remaining reactivation rate of about 50% (and possibly permanent consequences) could be reduced by prolongation of the total treatment duration. To study this hypothesis, in the low-risk group of the LCH-III study standard maintenance therapy was randomly given for a total treatment duration of 6 and 12 months. Unpublished preliminary data from this recently closed trial suggested that prolongation of the treatment duration may significantly improve reactivation-free survival. In summary, several studies have shown that systemic therapy is indicated for all patients with MS-LCH. A standard two-drug regimen consisting of an initial 'intensive' phase for 6-12 weeks, followed by a less intensive 'maintenance phase' for a total treatment duration of at least 12 months is recommended for patients treated outside of clinical trials. Non-responders, particularly those with progressive disease in risk organs, are eligible for experimental salvage approaches. Remaining questions will be addressed in the upcoming LCH-IV trial, which is in the process of intensive preparation.

Chromatin remodelling at the topoisomerase II-beta promoter is associated with enhanced sensitivity to etoposide in human neuroblastoma cell lines

Etoposide, an inhibitor of topoisomerase II, promotes DNA damage and apoptosis of cancer cells and is a component of standard therapy for neuroblastoma. Resistance to etoposide has been observed in neural tumour cells expressing lower levels of topoisomerase II. In the present study, we have examined the contribution of epigenetic modulation of gene expression in the potentiation of etoposide-mediated cytotoxicity in neuroblastoma cells. Specifically, we studied the effects of histone deacetylase inhibition with valproic acid on topoisomerase II gene expression and apoptosis in response to etoposide. Using human neuroblastoma cell lines SK-N-AS and SK-N-SH, we show that although the combination of valproic acid and etoposide promoted a reduction in growth compared to either drug alone in both cells, the effect was substantially enhanced in SK-N-AS compared to SK-N-SH cells. An increase in histone H3 acetylation and p21 expression was observed in both cell lines, however, upregulation of topoisomerase II-beta gene expression and an increase in PARP cleavage was observed in SK-N-AS cells only. Furthermore, chromatin immunoprecipitation assays revealed an increase in acetylation of histone H3 at the cognate topoisomerase II-beta gene after treatment with valproic acid in SK-N-AS cells. These results suggest a potential epigenetic mechanism of regulation of the topoisomerase II-beta gene and a possible role for its increased expression in the sensitivity of SK-N-AS neuroblastoma cells to etoposide.

Outcomes of a two-drug chemotherapy regimen for intraocular retinoblastoma

BACKGROUND

Retinoblastoma is the most common intraocular tumor of childhood. Vision salvage rates in advanced cases are less than ideal, and the optimal treatment for intraocular retinoblastoma has not been established. We report the results of an institutional retinoblastoma treatment trial to determine the vision salvage rates and toxicity of a regimen combining carboplatin and etoposide with focal retinal therapy.

PROCEDURE

Twenty-nine patients diagnosed with retinoblastoma in 48 eyes were treated between 1992 and 2004 with at least six cycles of carboplatin and etoposide combined with focal retinal therapy.

RESULTS

The response rate of eyes after six cycles of chemotherapy was 85.4%. Twenty-two eyes were enucleated, but only seven eyes received EBRT. The vision salvage rate without EBRT was 82.6% for eyes with Reese-Ellsworth (R-E) groups I-IV tumors and 20% for eyes with R-E group V tumors. The vision salvage rate without EBRT for eyes with Murphree groups A and B tumors was 77.3% but was only 26.9% for eyes with groups C and D tumors. Acute side effects were minimal.

CONCLUSIONS

The combination of carboplatin and etoposide with focal therapy is a well-tolerated regimen that has acceptable vision salvage rates for R-E groups I-IV and Murphree groups A and B retinoblastoma. This combination avoids the use of EBRT and the toxicity of additional chemotherapy agents. However, patients with R-E group V and Murphree groups C and D retinoblastoma have poorer outcomes and require more intensive therapy.

Improved outcome in multisystem Langerhans cell histiocytosis is associated with therapy intensification

Multisystem Langerhans cell histiocytosis (MS-LCH) is associated with high mortality when patients have risk organ involvement (RO(+)) or are younger than 2 years. In an international randomized trial, LCH-II, we intensified their treatment: arm A consisted of 6 weeks of daily prednisone and weekly vinblastine followed by 18 weeks of daily 6-mercaptopurine with vinblastine/prednisone pulses; etoposide was added in arm B. Considering all 193 randomized risk patients, there were similar outcomes: rapid (6 weeks) response (arm A vs arm B: 63%/71%), 5-year survival probability (74%/79%), disease reactivation frequency (46%/46%), and permanent consequences (43%/37%). However, (1) patients younger than 2 years without RO involvement (RO(-)) had 100% survival and uniformly high (> 80%) rapid response, (2) RO(+) patients not responding within 6 weeks had highest mortality, and (3) importantly, the more intensive arm B reduced mortality in RO(+) patients (relative hazard rate, accounting for differences in risk organ involvement, of 0.54; 95% CI = 0.29-1.00). Finally, comparison of RO(+) patients in LCH-I and LCH-II confirmed that increasing treatment intensity increased rapid responses (from 43% in arm A LCH-I to 68% in arm B LCH-II; P = .027) and reduced mortality (from 44% in arm A LCH-I to 27% in arm B LCH-II; P = .042). We conclude that intensified treatment significantly increases rapid response and reduces mortality in risk MS-LCH. This trial was registered at http://www.controlled-trials.com as no. ISRCTN57679341.

Treatment-related myelodysplastic syndrome/acute myeloid leukemia in survivors of childhood cancer--an update

Treatment-related myelodysplastic syndrome/acute myeloid leukemia (t-MDS/t-AML) is a devastating complication of treatment for childhood cancer. However, the major cause of premature death of children treated for cancer remains their primary cancer. The understanding of the presentation, incidence, predisposing risk factors and pathobiology of t-MDS/t-AML is increasing. This increased understanding has not yet been translated into improved outcomes of therapy for t-MDS/t-AML. However, newer approaches are under study.

Secondary acute promyelocytic leukemia following chemotherapy for non-Hodgkin's lymphoma in a child

Of the several kinds of therapy-related leukemia, therapy-related acute promyelocytic leukemia (t-APL) is most closely associated with topoisomerase II inhibitor administration for treatment of malignancies in adults. Although rare in children, the majority of therapy-related malignancies have been etoposide-related APL associated with Langerhans cell histiocytosis. The authors describe the development of t-APL after chemotherapy administered for non-Hodgkin's lymphoma (NHL) in an 8-year-old girl. One month after cessation of the 3-year chemotherapy regimen of doxorubicin and other agents but not etoposide or radiotherapy, the patient was diagnosed with t-APL with positive PML-RARA molecular abnormality. The patient attained a complete remission following treatment with all-trans retinoic acid-containing chemotherapy. Thereafter, she successfully received hematopoietic stem cell transplantation from an HLA-matched sibling donor. Development of t-APL associated with NHL in children appears to be rare.

Permanent consequences in Langerhans cell histiocytosis patients: a pilot study from the Histiocyte Society-Late Effects Study Group

BACKGROUND

Permanent consequences (PC) are often described among subjects with Langerhans cell histiocytosis (LCH) but data on the real incidence are scarce. Within the Histiocyte Society (HS), and in order to design a definitive late effects study, a retrospective survey was organized to describe the prevalence of PC among long-term survivors of LCH.

METHODS

Nine institutions contributed with their LCH patients having a minimum follow-up of 3 years. Information was collected on their disease-history, and on type and date of onset of any PC. Because of the retrospective type of this study, it was accepted that each institution might have used different criteria to assess PC.

RESULTS

One hundred eighty-two subjects were registered and in 95 (52%) at least 1 PC was reported. For some specific PC (e.g., anterior pituitary dysfunction) information was too scarce to provide reliable data. PC were more frequent among subjects with multisystem (MS) disease (71%), compared to those with single system (SS) disease (24%); P < 0.0001. The most frequently reported PC were diabetes insipidus (DI) (24%) orthopedic abnormalities (20%), hearing loss (13%), and neurological consequences (11.0%). Analysis of cumulative risk showed that some types of PC may become manifest more than 10 years from diagnosis.

CONCLUSIONS

This survey on selected cases of LCH survivors has confirmed that late sequels are frequent, and that they are even more common among those with MS LCH. Our findings highlight the need for long-term and patient-oriented follow-up in children with LCH.

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.

Granulocyte colony-stimulating factor and the risk of secondary myeloid malignancy after etoposide treatment

Event-free survival for children with acute lymphoblastic leukemia (ALL) now exceeds 80% in the most effective trials. Failures are due to relapse, toxicity, and second cancers such as therapy-related myeloid leukemia or myelodysplasia (t-ML). Topoisomerase II inhibitors and alkylators can induce t-ML; additional risk factors for t-ML remain poorly defined. The occurrence of t-ML among children who had received granulocyte colony-stimulating factor (G-CSF) following ALL remission induction therapy prompted us to examine this and other putative risk factors for t-ML in 412 children treated on 2 consecutive ALL protocols from 1991 to 1998. All children received etoposide and anthracyclines, 99 of whom received G-CSF; 284 also received cyclophosphamide, 58 of whom also received cranial irradiation. There were 20 children who developed t-ML at a median of 2.3 years (range, 1.0-6.0 years), including 16 cases of acute myeloid leukemia, 3 myelodysplasia, and 1 chronic myeloid leukemia. Stratifying by protocol, the cumulative incidence functions differed (P =.017) according to the use of G-CSF and irradiation: 6-year cumulative incidence (standard error) of t-ML of 12.3% (5.3%) among the 44 children who received irradiation without G-CSF, 11.0% (3.5%) among the 85 children who received G-CSF but no irradiation, 7.1% (7.2%) among the 14 children who received irradiation plus G-CSF, and 2.7% (1.3%) among the 269 children who received neither irradiation nor G-CSF. Even when children receiving irradiation were excluded, the incidence was still higher in those receiving G-CSF (P =.019). In the setting of intensive antileukemic therapy, short-term use of G-CSF may increase the risk of t-ML.

Minimising the long-term adverse effects of childhood leukaemia therapy

Malignancies in childhood occur with an incidence of 13-14 per 100,000 children under the age of 15 years. Acute lymphoblastic leukaemia with an incidence of 29% is the most common paediatric malignancy, whereas acute myeloid leukaemias account for about 5%. The treatment of acute leukaemias consists of sequential therapy cycles (induction, consolidation, intensification, maintenance therapy) with different cytostatic drugs over a time period of up to 1.5-3 years. Over the last 25 years of clinical trials, a significant rise in the rate of complete remissions as well as an increase in long-term survival has been achieved. Therefore, growing attention is now focused on the long-term effects of antileukaemic treatment. Several cytostatic drugs administered in the treatment of acute leukaemia in childhood are known to cause long-term adverse effects. Anthracyclines may induce chronic cardiotoxicity, alkylating agents are likely to cause gonadal damage and secondary malignancies and the use of glucocorticoids may cause osteonecrosis. Most of the long-term adverse effects have not been analysed systematically. Approaches to minimising long-term adverse effects without jeopardising outcome have included: the design of new drugs such as a liposomal formulation of anthracyclines, the development of anthracycline-derivates with lower toxicity, the development of cardioprotective agents or, more recently, the use of targeted therapy;alternative administration schedules like continuous infusion or timed sequential therapy; and risk group stratification by the monitoring of minimal residual disease. Several attempts have been made to minimise the cardiotoxicity of anthracyclines: decreasing concentrations delivered to the myocardium by either prolonging infusion time or using liposomal formulated anthracyclines or less cardiotoxic analogues, or the additional administration of cardioprotective agents. The advantage of these approaches is still controversial, but there are ongoing clinical trials to evaluate the long-term effects. The use of new diagnostic methods, such as diagnosis of minimal residual disease, which allow reduction or optimisation of dose, offer potential advantages compared with conventional treatment in terms of reducing the risk of severe long-term adverse effects. Most options for minimising long-term adverse effects have resulted from theoretical models and in vitro studies, but only some of the modalities such as the use of dexrazoxane, the continuous infusion of anthracyclines or timed sequential therapy, have been evaluated in prospective, randomised studies in patients. Future approaches to predict severe toxicity may be based upon pharmacogenetics and gene profiling.

Langerhans cell histiocytosis following childhood acute lymphoblastic leukemia

Langerhans cell histiocytosis (LCH) is a clonal proliferation of Langerhans cells of unknown etiology that results in a range of clinical manifestations. LCH has been known to be associated with a variety of malignant diseases. A 7-year-old boy was treated for standard-risk acute lymphoblastic leukemia (ALL) at age 2 years, on a Children's Cancer Group chemotherapy protocol for 3 years and developed LCH 2 years after completion of chemotherapy. The case and a review of literature on the association of LCH and ALL are presented.

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.

[Results of treatment with 2-chlorodeoxyadenosine in refractory or relapsed Langerhans cell histiocytosis. Study of 9 patients]

BACKGROUND

To analyse the results of the treatment with 2-chlorodeoxyadenosine (2CdA) in 9 patients with refractory or relapsed Langerhans cell histiocytosis (LCH) tracted in 8 Spanish hospitals between 1993 and 1999.

PATIENTS AND METHOD

In the 9 patients the following data were recorded: age, sex, organ involvement by LCH, first treatment and response, dose, number of cycles and schedule of administration 2CdA, response to 2CdA treatment, toxicity, disease-free survival (DFS) and overall survival (OS).

RESULTS

Median age was 25 years (range, 6-63). All patients had multiorganic involvement by LCH, with severe organ dysfunction in 4. 2CdA was administered as second line treatment in 7 cases and as third line in 2. The 2CdA dose was 0.1 mg/kg per day during 5 days in the majority of patients, and interval between cycles was 4 weeks. In 2 cases a complete remission (CR) was achieved and 4 cases attained a partial remission (PR) (overall response rate 66%). The main toxicity was hematologic, with neutropenia grade > 2 in 5 cases and thrombocytopenia > 2 in 5. Four patients had infections, with fatal evolution in one of them. After a median follow-up of 8 months (range 2-17), 2 patients remained in CR (12 months both), 4 in PR (range 2-12 months) and one had active disease (17 months). The other two died due to progressive disease and Aspergillus spp. sepsis, respectively. The actuarial probabilities of DFS and OS were 58% (95% CI, 38-78%) and 71% (95% CI, 54-88%), respectively.

CONCLUSIONS

2CdA is an active drug for patients with refractory or relapsed LCH, and its main toxicity is myelosuppression. The usefulness of 2CdA, isolated or in combination with other drugs, in patients with refractory or relapsed LCH must be assessed in controlled studies.

Langerhans cell histiocytosis after therapy for a malignant germ cell tumor of the central nervous system

Langerhans cell histiocytosis (LCH) is a clonal neoplastic disorder that results in a spectrum of clinical manifestations. Known to be associated with a variety of malignant diseases, LCH may precede, coincide with, or develop after the diagnosis of cancer. A child with a malignant germ cell tumor of the brain who subsequently experienced LCH is reported. The 8-year-old boy was treated for an immature teratoma of the posterior fossa with gross total resection and craniospinal irradiation preceding bleomycin, etoposide, and vinblastine chemotherapy for four cycles. Seven months after completion of therapy, he experienced multifocal bone disease with LCH.

Predictors of therapy-related leukemia and myelodysplasia following autologous transplantation for lymphoma: an assessment of risk factors

We analyzed data on 612 patients who had undergone high-dose chemoradiotherapy (HDT) with autologous stem cell rescue for Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) at the City of Hope National Medical Center, to evaluate the incidence of therapy-related myelodysplasia (t-MDS) or therapy-related acute myeloid leukemia (t-AML) and associated risk factors. A retrospective cohort and a nested case-control study design were used to evaluate the role of pretransplant therapeutic exposures and transplant conditioning regimens. Twenty-two patients developed morphologic evidence of t-MDS/t-AML. The estimated cumulative probability of developing morphologic t-MDS/t-AML was 8.6% ± 2.1% at 6 years. Multivariate analysis of the entire cohort revealed stem cell priming with VP-16 (RR = 7.7, P = 0.002) to be independently associated with an increased risk of t-MDS/t-AML. The influence of pretransplant therapy on subsequent t-MDS/t-AML risk was determined by a case-control study. Multivariate analysis revealed an association between pretransplant radiation and the risk of t-MDS/t-AML, but failed to reveal any association with pretransplant chemotherapy or conditioning regimens. However, patients who had been primed with VP-16 for stem cell mobilization were at a 12.3-fold increased risk of developing t-AML with 11q23/21q22 abnormalities (P = 0.006). Patients undergoing HDT with stem cell rescue are at an increased risk of t-MDS/t-AML, especially those receiving priming with VP-16 for peripheral stem cell collection.

Occurrence of acute nonlymphoblastic leukemia in two girls after treatment of recurrent, disseminated Langerhans cell histiocytosis

The occurrence of Langerhans cell histiocytosis (LCH) and acute leukemia in one individual has rarely been observed. Despite few exceptions, two distinct patterns of association appear evident: acute lymphoblastic leukemia preceding LCH and LCH preceding acute nonlymphoblastic leukemia (ANLL). The latency of ANLL after the diagnosis of LCH is suggestive of a therapy-related process. This report describes two new cases in whom ANLL was diagnosed 7 years 8 months and 5 years 8 months after the start of initial treatment of disseminated recurrent LCH. Morphology showed blasts from FAB-type M4/M5 in the first patient, who died due to progression of leukemia. The second patient showed myelodysplastic syndrome (refractory anemia with excess of blasts in transformation; RAEB-t) and is now in remission from leukemia 3 years 11 months after allogeneic bone marrow transplantation. The review of a total of 26 patients with ANLL after LCH suggests that the disease has a poor prognosis and allogeneic BMT seems to be the treatment of choice.

The relation of Langerhans cell histiocytosis to acute leukemia, lymphomas, and other solid tumors. The LCH-Malignancy Study Group of the Histiocyte Society

The frequency of Langerhans cell histiocytosis (LCH) and a malignant neoplasm occurring in the same individual appears to be greater than previously recognized. To define the occurrence and the pattern of these events, a Study Group of the Histiocyte Society initiated a registry of patients in whom this association occurred synchronously or asynchronously. Evaluation of 54 patients detected two patterns of associations between LCH and other disorders. First, it is possible that therapy of LCH promotes a secondary malignancy. Second, it is possible that a genetic predisposition, with or without the immunosuppression associated therapy for the malignancy, plays a role in the development and expression of disseminated LCH. Data collected by the LCH-Malignancy Study Group may provide insights into the etiology and pathophysiology of LCH.