Development and Phenotype of Heart Failure in Long-Term Survivors of Childhood Cancer: The CVSS Study

Background The CVSS (Cardiac and Vascular Late Sequelae in Long-Term Survivors of Childhood Cancer) study aimed to investigate the prevalence of different stages of heart failure (HF) in childhood cancer survivors (CCSs) compared with the general population. Methods and Results A total of 1002 CCSs (age range, 23-48 years) diagnosed with neoplasia before an age of 15 years underwent a comprehensive cardiovascular screening. An age- and sex-matched sample from the population-based GHS (Gutenberg Health Study) served as a comparison group. Although prevalence of HF was significantly higher in CCSs, prevalence of different HF stages varied strongly by specific tumor history. Compared with the population, the prevalence ratio was 2.6 (95% CI, 2.4-2.8) for HF stage A and 4.6 (95% CI, 4.1-5.1) for the composite of HF stage B to D in an age- and sex-adjusted Poisson regression model. Multivariable linear regression, adjusting for tumor entities, age, sex, and cardiovascular risk factors, revealed a lower left ventricular ejection fraction in patients with history of bone tumors (β, -4.30 [95% CI, -5.70 to -2.80]), soft tissue sarcoma (β, -1.60 [95% CI, -2.90 to -0.30]), and renal tumors (β, -1.60 [95% CI, -2.80 to -0.29]) compared with the population. The same model for the diastolic marker, ratio of the peak early diastolic filling velocity/lateral mitral annular early diastolic velocity, showed an association only with cardiovascular risk factors but not with tumor entities. Conclusions The prevalence of HF stage A to D was significantly higher among long-term CCSs compared with the population and varied strongly by tumor entity. Systolic dysfunction was primarily associated with tumor entities, whereas diastolic dysfunction was associated with a higher burden of cardiovascular risk factors in CCSs.

Glucosylceramide Synthase Inhibitors Induce Ceramide Accumulation and Sensitize H3K27 Mutant Diffuse Midline Glioma to Irradiation

H3K27M mutant (mut) diffuse midline glioma (DMG) is a lethal cancer with no effective cure. The glycosphingolipids (GSL) metabolism is altered in these tumors and could be exploited to develop new therapies. We tested the effect of the glucosylceramide synthase inhibitors (GSI) miglustat and eliglustat on cell proliferation, alone or in combination with temozolomide or ionizing radiation. Miglustat was included in the therapy protocol of two pediatric patients. The effect of H3.3K27 trimethylation on GSL composition was analyzed in ependymoma. GSI reduced the expression of the ganglioside GD2 in a concentration and time-dependent manner and increased the expression of ceramide, ceramide 1-phosphate, sphingosine, and sphingomyelin but not of sphingosine 1-phosphate. Miglustat significantly increased the efficacy of irradiation. Treatment with miglustat according to dose recommendations for patients with Niemann-Pick disease was well tolerated with manageable toxicities. One patient showed a mixed response. In ependymoma, a high concentration of GD2 was found only in the presence of the loss of H3.3K27 trimethylation. In conclusion, treatment with miglustat and, in general, targeting GSL metabolism may offer a new therapeutic opportunity and can be administered in close proximity to radiation therapy. Alterations in H3K27 could be useful to identify patients with a deregulated GSL metabolism.

Analysis of RBP expression and binding sites identifies PTBP1 as a regulator of CD19 expression in B-ALL

Despite massive improvements in the treatment of B-ALL through CART-19 immunotherapy, a large number of patients suffer a relapse due to loss of the targeted epitope. Mutations in the CD19 locus and aberrant splicing events are known to account for the absence of surface antigen. However, early molecular determinants suggesting therapy resistance as well as the time point when first signs of epitope loss appear to be detectable are not enlightened so far. By deep sequencing of the CD19 locus, we identified a blast-specific 2-nucleotide deletion in intron 2 that exists in 35% of B-ALL samples at initial diagnosis. This deletion overlaps with the binding site of RNA binding proteins (RBPs) including PTBP1 and might thereby affect CD19 splicing. Moreover, we could identify a number of other RBPs that are predicted to bind to the CD19 locus being deregulated in leukemic blasts, including NONO. Their expression is highly heterogeneous across B-ALL molecular subtypes as shown by analyzing 706 B-ALL samples accessed via the St. Jude Cloud. Mechanistically, we show that downregulation of PTBP1, but not of NONO, in 697 cells reduces CD19 total protein by increasing intron 2 retention. Isoform analysis in patient samples revealed that blasts, at diagnosis, express increased amounts of CD19 intron 2 retention compared to normal B cells. Our data suggest that loss of RBP functionality by mutations altering their binding motifs or by deregulated expression might harbor the potential for the disease-associated accumulation of therapy-resistant CD19 isoforms.

GD2 Expression in Medulloblastoma and Neuroblastoma for Personalized Immunotherapy: A Matter of Subtype

Neuroblastoma (NBL) and medulloblastoma (MB) are aggressive pediatric cancers which can benefit from therapies targeting gangliosides. Therefore, we compared the ganglioside profile of 9 MB and 14 NBL samples by thin layer chromatography and mass spectrometry. NBL had the highest expression of GD2 (median 0.54 nmol GD2/mg protein), and also expressed complex gangliosides. GD2-low samples expressed GD1a and were more differentiated. MB mainly expressed GD2 (median 0.032 nmol GD2/mg protein) or GM3. Four sonic hedgehog-activated (SHH) as well as one group 4 and one group 3 MBs were GD2-positive. Two group 3 MB samples were GD2-negative but GM3-positive. N-glycolyl neuraminic acid-containing GM3 was neither detected in NBL nor MB by mass spectrometry. Furthermore, a GD2-phenotype predicting two-gene signature (ST8SIA1 and B4GALNT1) was applied to RNA-Seq datasets, including 86 MBs and validated by qRT-PCR. The signature values were decreased in group 3 and wingless-activated (WNT) compared to SHH and group 4 MBs. These results suggest that while NBL is GD2-positive, only some MB patients can benefit from a GD2-directed therapy. The expression of genes involved in the ganglioside synthesis may allow the identification of GD2-positive MBs. Finally, the ganglioside profile may reflect the differentiation status in NBL and could help to define MB subtypes.

Mortality risk among 5-year survivors of childhood cancer in Germany-Results from the CVSS study (Cardiac and Vascular late Sequelae in long-term Survivors of childhood cancer study)

The growing population of long-term childhood cancer survivors is at increased risk for severe, therapy-related late effects and premature mortality. The cardiac and vascular late sequelae in long-term survivors of childhood cancer (CVSS) study is a cohort of patients from Germany diagnosed with a neoplasia prior to 15 years of age in the time period 1980 to 1990. Late mortality was evaluated in a total of 4505 individuals who survived 5 years or more after the initial diagnosis (5-year survivors). Survivors with a second primary tumor were excluded. Standardized mortality ratios (SMRs) were calculated. By December 2014, 400 patients had died. Available cause of death information from 188 individuals was used to estimate cause-specific mortality for all deceased persons. Compared to the population of (former) West Germany, we observed an excess overall mortality risk (SMR = 9.53, 95% confidence interval [CI] = 8.62-10.51). After correcting for missing cause of death information, an increased cancer mortality (SMR = 43.50, 95% CI = 25.79-73.50) in the 5-year survivors was detected. Cardiac death was ascertained in 14 individuals, resulting in an SMR of 10.85 (95% CI = 2.80-32.02) after correcting for missing values. In conclusion, childhood cancer survivors diagnosed in Germany in 1980 to 1990 have a higher mortality risk overall and an elevated risk of dying from cancer and cardiac causes in particular. The results are consistent with those of international cohort studies. However, the reported results are based on few cases and individuals with secondary cancers were excluded.

Development of heart failure in long-term survivors of childhood cancer: results from the cvss study

Background

Long-term survivors of childhood cancer (CCS) are at increased risk for cardiovascular sequelae, including heart failure (HF) as the largest non-malignant contributor to excess death. Yet, little is known about the risk factors, mechanisms of cardiac dysfunction and prevalence of different stages of HF in these patients.

Purpose

To investigate the development and prevalence of HF phenotypes in CCS compared to the general population.

Methods

The CVSS study is a prospective single-center cohort study investigating cardiovascular sequelae of CCS. Patients were eligible for the study when they were diagnosed with a neoplasia according to the International Classification of Childhood Cancer (ICCC 3) at an age prior to 15 years between 1980 and 1990, survived more than five years after initial cancer diagnosis and received antineoplastic treatment. Between 2013 and 2016, study individuals underwent a comprehensive, standardized clinical investigation in the CVSS cohort study including echocardiographic examination. HF was categorized as stages A to D according to current HF guidelines of the American Heart Association (AHA). A population-based sample free of cancer (age- and sex matched) serves as control group.

Results

From 1,002 individuals, all CCS with history of chemo- or radiotherapy and no subsequent neoplasia (n=877) were included (mean age 34.2 (±5.5) years, 44.7% (N=392) female). Age at diagnosis was 6.28 years (±4.24) and the mean interval from the date of diagnosis of cancer to the date of completion of baseline examination 28.5±3.2 years. Based on echocardiographic examination, clinical data and biomarker assessment, 26.6% of CCS were diagnosed with HF stage A, 21.1% with HF stage B and 2.1% with symptomatic HF, i.e. HF stage C/D. Importantly, prevalence of different HF stages varied strongly by specific tumor history. Compared to the population, the prevalence ratio (PR) was 1.16 [95% confidence interval 1.02/1.31] for stage A HF and 1.91 [1.63/2.23] for the composite of stage B to D HF in an age- and sex-adjusted Poisson regression model. Multivariable linear regression with the systolic marker left ventricular ejection fraction as dependent variable and adjustment for tumor entities, age, sex, and cardiovascular risk factors (CVRF) revealed a lower EF in patients with history of bone tumors (β −6.0 [−8.1/−3.0]), soft tissue sarcoma (β −2.2 [−4.1/−0.35]), leukemia (β −0.84 [−1.8/0.08]) and renal tumors (β −1.8 [−4.0/0.27]) compared to the population. In contrast, the same model for the diastolic marker E/E', showed an association only with CVRF, but not with tumor entities.

Conclusion

The prevalence of stage B to D HF was significantly higher among long-term CCS in the 3rd to 5th age decade compared to the population and varied strongly by tumor entity. Systolic dysfunction was primarily associated with history of tumor entities, whereas diastolic dysfunction was associated with the higher burden of CVRF in CCS.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This study is funded by the Deutsche Forschungsgemeinschaft (DFG) (SP 1381/2-1&2, FA 1038/2-1&2, WI 3881/2-1&2)

Promotion of Arterial Stiffness by Childhood Cancer and Its Characteristics in Adult Long-Term Survivors

Background

Vascular alterations induced by antineoplastic treatment might be considered as a possible underlying mechanism of increased cardiovascular sequelae in childhood cancer survivors (CCSs). We aimed to evaluate arterial stiffness among long‐term CCSs and to compare the data against a population‐based sample.

Methods and Results

Arterial stiffness was assessed by digital photoplethysmography (stiffness index; m/s) among 1002 participants of the CVSS (Cardiac and Vascular Late Sequelae in Long‐Term Survivors of Childhood Cancer) study, diagnosed with neoplasia (1980–1990) before an age of 15 years. A population‐based sample from the GHS (Gutenberg Health Study) (n=5252) was investigated for comparison. All subjects underwent a comprehensive, standardized clinical examination in the same study center. CCSs had higher stiffness index (β=0.66 m/s; 95% CI, 0.51–0.80 m/s) in multivariable linear regression analysis after adjustment for cardiovascular risk factors compared with the population sample of comparable age range. Stiffer vessels were found among CCSs also in absence of arterial hypertension (β=0.66; 95% CI, 0.50–0.81) or history of chemotherapy/radiotherapy (β=0.56; 95% CI, 0.16–0.96) in fully adjusted models. Moreover, stiffness index differed by tumor entity, with highest values in bone and renal tumors. Almost 5.2‐fold higher prevalence of stiffness index values exceeding age‐specific, population‐based reference limits was observed among CCSs compared with GHS participants.

Conclusions

This is the first study demonstrating increased arterial stiffness among long‐term CCSs. The data suggest that vascular compliance might differ in survivors of childhood cancer from the established development concept for arterial stiffness in the population; cancer growth and antineoplastic treatment might be relevant determinants of the pathobiological features.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02181049.

Tumor Lipids of Pediatric Papillary Renal Cell Carcinoma Stimulate Unconventional T Cells

Papillary renal cell carcinoma (PRCC) is a rare entity in children with no established therapy protocols for advanced diseases. Immunotherapy is emerging as an important therapeutic tool for childhood cancer. Tumor cells can be recognized and killed by conventional and unconventional T cells. Unconventional T cells are able to recognize lipid antigens presented via CD1 molecules independently from major histocompatibility complex, which offers new alternatives for cancer immunotherapies. The nature of those lipids is largely unknown and α-galactosylceramide is currently used as a synthetic model antigen. In this work, we analyzed infiltrating lymphocytes of two pediatric PRCCs using flow cytometry, immunohistochemistry and qRT-PCR. Moreover, we analyzed the CD1d expression within both tumors. Tumor lipids of PRCC samples and three normal kidney samples were fractionated and the recognition of tumor own lipid fractions by unconventional T cells was analyzed in an in vitro assay. We identified infiltrating lymphocytes including γδ T cells and iNKT cells, as well as CD1d expression in both samples. One lipid fraction, containing ceramides and monoacylglycerides amongst others, was able to induce the proliferation of iNKT cells isolated from peripheral blood mononuclear cells (PBMCs) of healthy donors and of one matched PRCC patient. Furthermore, CD1d tetramer stainings revealed that a subset of iNKT cells is able to bind lipids being present in fraction 2 via CD1d. We conclude that PRCCs are infiltrated by conventional and unconventional T cells and express CD1d. Moreover, certain lipids, present in pediatric PRCC, are able to stimulate unconventional T cells. Manipulating these lipids and T cells may open new strategies for therapy of pediatric PRCCs.

Safety and Activity of the Combination of Ceritinib and Dasatinib in Osteosarcoma

Osteosarcoma (OS) is the second most common cause of cancer-related death in pediatric patients. The insulin-like growth factor (IGF) pathway plays a relevant role in the biology of OS but no IGF targeted therapies have been successful as monotherapy so far. Here, we tested the effect of three IGF specific inhibitors and tested ceritinib as an off-target inhibitor, alone or in combination with dasatinib, on the proliferation of seven primary OS cells. Picropodophyllin, particularly in combination with dasatinib and the combination ceritinib/dasatinib were effective in abrogating the proliferation. The ceritinib/dasatinib combination was applied to the primary cells of a 16-year-old girl with a long history of lung metastases, and was more effective than cabozantinib and olaparib. Therefore, the combination was used to treat the patient. The treatment was well tolerated, with toxicity limited to skin rush and diarrhea. A histopathological evaluation of the tumor after three months of therapy indicated regions of high necrosis and extensive infiltration of macrophages. The extension of the necrosis was proportional to the concentration of dasatinib and ceritinib in the area, as analysed by an ultra performance liquid chromatography–tandem mass spectrometer (UPLC-MS/MS). After the cessation of the therapy, radiological analysis indicated a massive growth of the patient’s liver metastases. In conclusion, these data indicate that the combination of ceritinib/dasatinib is safe and may be used to develop new therapy protocols.

Benefits of Exercise Training for Children and Adolescents Undergoing Cancer Treatment: Results From the Randomized Controlled MUCKI Trial

Objective: In cancer patients, the impairment in muscle function is a frequently observed phenomenon. However, comprehensive evaluation of the effect of exercise training on muscle function in childhood cancer patients (CCPs) is sparse and therefore investigated in the MUCKI trial. Study Design: In the randomized controlled MUCKI trial, CCPs during intensive cancer treatment and aged 4-18 years were recruited. Eligible patients were enrolled soon after diagnosis as long as they were physically and mentally able to participate in exercise testing and training. Patients of the exercise group (n = 16) participated in average 2.7 ± 1.2 times per week in a combined resistance and endurance training with moderate exercise intensity, for a time period of 8.0 ± 2.1 weeks, while patients of the control group (n = 17) received usual care. Leg strength was evaluated as the primary endpoint. Secondary endpoints were 6-min walk performance, arm strength, body composition, fatigue, and health-related quality of life. Results: Comparisons of pre- and post-intervention results were evaluated by baseline and stratification criteria adjusted analysis and showed positive effects for the exercise group regarding leg strength [F _{(1, 20)} = 5.733; p = 0.027^*; η p 2 = 0.223], walking performance [F _{(1, 25)} = 4.270; p = 0.049^*; η p 2 = 0.146], fatigue [F _{(1, 13)} = 8.353; p = 0.013^*; η p 2 = 0.391], self-esteem [F _{(1, 6)} = 6.823; p = 0.040^*; η p 2 = 0.532], and self-reported strength and endurance capacity [F _{(1, 6)} = 6.273; p = 0.046^*; η p 2 = 0.511]. No significant differences were found for the other parameters. Conclusion: Within one of the first randomized controlled trials, the present study provides evidence for a positive effect of combined training in CCPs during intensive cancer treatment. Further research is needed to confirm these results and to evaluate their clinical impact. Clinical Trial Registration Number: NCT02612025.

Radiation-induced vascular changes in the intracranial irradiation field in medulloblastoma survivors: An MRI study

BACKGROUND AND PURPOSE

While survival times after treatment of medulloblastoma are increasing, little is known about radiochemotherapy (RCT)-induced cerebrovascular changes. High resolution vessel wall imaging (VWI) sequences are an emerging tool for the evaluation of cerebrovascular diseases. We performed VWI in medulloblastoma long-term survivors to screen for late sequelae of RCT.

MATERIAL AND METHODS

Twenty-two pediatric medulloblastoma survivors (mean age 25.8 years (10-53 years); 16.3 years (mean) post primary RCT (range 1-45 years)) underwent 2D VWI-MRI. Vessel wall thickening, contrast enhancement and luminal narrowing were analyzed. The findings were correlated with the patients' radiation protocols.

RESULTS

Vessel wall changes were observed the intracranial internal carotid artery (ICA) and the vertebrobasilar circulation (VBC) in 14 of 22 patients (63.6%). In multivariate analysis, time after RCT (OR = 1.38, p < 0.05) was strongest independent predictor for development of vessel wall alterations. The dose of radiation was not a relevant predictor.

CONCLUSIONS

With longer follow-up time intracranial vessel wall changes are observed more frequently in medulloblastoma survivors. Thus VWI is a useful tool to monitor vessel wall alterations of cranially irradiated patients, creating the prerequisite for further treatment of late sequelae.

Prevalence of mental distress among adult survivors of childhood cancer in Germany-Compared to the general population

BACKGROUND

Increasing survival rates after childhood cancer have raised the issue of long-term mental health consequences in adulthood. This study determines mental health distress among long-term survivors of pediatric cancer and compares it to control groups.

METHODS

Childhood cancer survivors (CCS; N = 951, aged 24-49 years) were compared to three age-matched control groups from the general population collected at three time points. The study compared the prevalence of clinically relevant symptoms of a wide range of common mental disorders (depression, somatic distress, suicidal ideation, generalized anxiety, panic, social anxiety, and sleep disturbances) using identical, validated questionnaires. CCS were identified by the German Childhood Cancer Registry. Controls were approached by a demographic consultation company (USUMA) which assured that the three samples were nationally representative.

RESULTS

Childhood cancer survivors reported higher education than controls and were less often married. All forms of common mental distress were increased among survivors. Twenty-four percent of male (N = 526) and 41% of female survivors (N = 425) reported some form of clinically relevant mental health symptoms. Somatic distress as the leading complaint was highly frequent among CCS (OR: 10.98, CI 95%: 7.24-16.64). Complaints by generalized anxiety (OR: 5.04, CI 95%: 2.61-9.70), panic (OR: 3.28, CI 95%: 1.60-6.70), depression (OR: 3.36, CI 95%: 2.22-5.09), and suicidality (OR = 2.22; CI 95%: 1.38-3.57) were also strongly increased. Female sex, low education, low income, and unemployment were associated with increased distress.

CONCLUSIONS

Findings indicate a need to integrate psycho-oncological screening and care into long-term aftercare. Somatic distress, as cause and indicator of psychological distress, should receive stronger attention, especially tiredness, low energy, and pain.

Susceptibility-weighted magnetic resonance imaging of cerebrovascular sequelae after radiotherapy for pediatric brain tumors

BACKGROUND AND PURPOSE

Due to sensitive neuroimaging techniques, cerebrovascular complications such as cerebral microbleeds (CMB) and cerebral cavernous malformations (CCM) are increasingly recognized as considerable late effects after treatment for pediatric brain tumor. The aim of this study was to analyze CMB in a cohort of patients after cranial irradiation therapy for medulloblastoma or other pediatric brain tumors using susceptibility-weighted magnetic resonance imaging (SWI).

MATERIALS AND METHODS

Forty former pediatric brain tumor patients were enrolled in this prospective cross-sectional study and examined by cranial MRI including SWI sequences. Cerebral microbleeds, clinical symptoms and disability were evaluated.

RESULTS

Thirty-six (90%) of the examined individuals (mean follow-up age 22.2 y; mean follow-up time 13.5 y) were affected by CMB. Longer follow-up time and higher craniospinal irradiation doses correlated with higher total lesion count (p < 0.01). Thirteen patients (32.5%) presented with clinical symptoms. Individuals with CMB were more severely disabled than patients without CMB (p < 0.05).

CONCLUSIONS

Cerebrovascular sequelae occur frequently after treatment for pediatric brain tumor. In this study, a remarkable part of pediatric brain tumor patients presents with CMB. As a sign of vascular damage, they can cause clinical symptoms and may correspond to neurocognitive decline. Further studies are needed to standardize MRI protocols and to improve quality of long-term follow-up.

Novel loss of function mutation in KRIT1/CCM1 is associated with distinctly progressive cerebral and spinal cavernous malformations after radiochemotherapy for intracranial malignant germ cell tumor

PURPOSE

Cerebrospinal cavernous malformations (CCMs) are vascular lesions characterized by dilated and leaky capillary caverns. CCMs can cause seizures, focal neurological deficits or acute intracranial hemorrhage; however, most patients are asymptomatic. CCMs occur either sporadically or as a familial autosomal-dominant disorder. We present a clinical and molecular study of a patient with distinctive cerebral and spinal cavernous malformations following radiochemotherapy for a malignant brain tumor.

METHODS

The patient had multiple magnet resonance imaging (MRI) examinations of his brain and spine following radiochemotherapy for a primary intracranial germ cell tumor (GCT), as part of his oncologic follow-up. The MRI sequences included susceptibility-weighted imaging (SWI). The coding exons and their flanking intronic regions of KRIT1/CCM1 gene were analyzed for mutations by polymerase chain reaction (PCR) and direct sequencing.

RESULTS

MRI revealed numerous cerebral and spinal microhemorrhages and pronounced cavernous malformations that progressed with subsequent follow-up imaging. Genetic analysis demonstrated a novel heterozygous KRIT1/CCM1 two base pair deletion (c.1535_1536delTG) in exon 14. This deletion leads to a frameshift with a premature stop codon at nucleotide position 1553 and a highly likely loss of function of the KRIT1 protein.

CONCLUSION

We describe a patient with a novel heterozygous germ line loss of function mutation in KRIT1, which is associated with rapid-onset and highly progressive CCMs after radiochemotherapy for a malignant brain tumor.

Next-generation sequencing reveals germline mutations in an infant with synchronous occurrence of nephro- and neuroblastoma

Although neuro- and nephroblastoma are common solid tumors in children, the simultaneous occurrence is very rare and is often associated with syndromes. Here, we present a unique case of synchronous occurrence of neuro- and nephroblastoma in an infant with no signs of congenital anomalies or a syndrome. We performed genetic testing for possible candidate genes as underlying mutation using the next-generation sequencing (NGS) approach to target 94 genes and 284 single-nucleotide polymorphisms (SNPs) involved in cancer. We uncovered a novel heterozygous germline missense mutation p.F58L (c.172T→C) in the anaplastic lymphoma kinase (ALK) gene and one novel heterozygous rearrangement Q418Hfs(*)11 (c.1254_1264delins TTACTTAGTACAAGAACTG) in the Fanconi anemia gene FANCD2 leading to a truncated protein. Besides, several SNPs associated with the occurrence of neuroblastoma and/or nephroblastoma or multiple primary tumors were identified. The next-generation sequencing approach might in the future be useful not only in understanding tumor etiology but also in recognizing new genetic markers and targets for future personalized therapy.

Massive pulmonary embolism in a young boy with T-cell leukaemia. Successful thrombolytic therapy by recombinant tissue plasminogen activator (rtPA)

Acute pulmonary embolism (PE) is a serious complication in association with malignant diseases. We describe the successful treatment of PE applying a systemic thrombolytic therapy in a 4-year-old boy with acute lymphoblastic leukaemia. The thrombolytic therapy with recombinant tissue plasminogen activator (rtPA) 0.1 mg/kg bodyweight per hour for six hours was continued for six days without important side effects. In particular no bleeding complications were observed. Computed tomography with contrast revealed a remarkable regression of the central PE. Without further delays the chemotherapy was resumed.