Craniospinal irradiation with concurrent temozolomide for primary metastatic pediatric high-grade or diffuse intrinsic pontine gliomas. A first report from the GPOH-HIT-HGG Study Group.

BACKGROUND: High-grade (HGG) and diffuse intrinsic pontine gliomas (DIPG) with primary metastatic spread are extremely rare and have a dismal prognosis. Analogous to simultaneous radiochemotherapy in non-metastatic HGG and DIPG, concurrent craniospinal irradiation (CSI) and metronomic temozolomide (metroTMZ) may represent a reasonable therapeutic approach. However, the antitumor efficacy and toxicity of this treatment still have to be investigated. PATIENTS AND METHODS: Between March 2007 and December 2012, six children with primary metastatic HGG (n = 4) or DIPG (n = 2) received CSI and concurrent metroTMZ based on individual treatment recommendations and, in some cases, within the HIT-HGG 2007 multicenter trial. Outcome and treatment-related toxicities were evaluated. RESULTS: All patients received irradiation to the entire craniospinal axis (35.2 Gy, n = 5; 36 Gy, n = 1:) and 5 received a local boost to macroscopic tumor deposits. Simultaneously, metroTMZ (75 mg/m(2)/day, n = 5; 60 mg/m(2)/day, n = 1) was administered. Additionally, 1 patient received nimotuzumab once per week. Within a median follow-up of 10.0 months (range 6.5-18.7 months), all patients experienced disease progression and 5 patients died. Median progression-free survival was 4.0 ± 0.8 months (range 2.4-10.7 months) and median overall survival was 7.6 ± 3.5 months (range 4.0-17.6 months). Acute myelosuppression most severely limited application of this aggressive treatment strategy. Severe hematotoxicities (≥ grade 3) occurred in all patients and metroTMZ had to be interrupted or discontinued in 4 out of 6 cases. CONCLUSION: Concurrent CSI and metroTMZ might represent a feasible treatment approach for primary metastatic HGG and DIPG. On the basis of our experience, severe but manageable acute hematotoxicity has to be expected. An international effort is warranted to reassess the efficacy and toxicity of this approach within a prospective study.

What's in a name? Intracranial peripheral primitive neuroectodermal tumors and CNS primitive neuroectodermal tumors are not the same.

BACKGROUND: Intracranial peripheral primitive neuroectodermal tumors (P-PNET) are extremely rare. They can be easily misdiagnosed as central nervous system primitive neuroectodermal tumors (CNS-PNET) or meningiomas. Little is known about the optimal treatment and prognosis of these tumors. PATIENTS AND METHODS: We evaluated the treatment and outcome of 17 patients with intracranial, nonmetastatic, genetically confirmed P-PNET. Three patients were treated at our institutions. Thirteen other cases providing sufficient treatment and follow-up information were extracted from the literature. RESULTS: The median age at diagnosis was 17 years. All patients underwent initial surgery. Complete resection was achieved in 9 of the 17 cases (53 %). Combined adjuvant treatment consisting of radiotherapy (focal, n = 10; craniospinal, n = 1) and chemotherapy was administered to 11 of the 17 patients (59 %). The median follow-up time was 1.4 years. In 8 of the 17 patients (47 %), the disease progressed; 4 of the 17 patients (24 %) died. The 2-year progression-free and overall survival rates were 64 % and 76 %, respectively. CONCLUSION: The differential diagnosis for intracranial, meningeal-based, small, round-cell tumors should include P-PNET. It is highly probable that complete resection has a positive impact on survival--as previously reported for extracranial P-PNET--but this cannot be shown by our data. Intensive adjuvant treatment consisting of radiotherapy and chemotherapy seems to be essential. A statistically grounded recommendation for the appropriate target volume and radiation dose is not yet possible. However, in most case reports of primary intracranial P-PNET published to date, patients were treated with focal irradiation. The optimal chemotherapy regimen has yet to be established, with both the Ewing tumor and CNS-PNET protocols being promising candidates for effective treatment.

Craniospinal irradiation with concurrent temozolomide and nimotuzumab in a child with primary metastatic diffuse intrinsic pontine glioma. A compassionate use treatment.

Primary metastatic diffuse intrinsic pontine glioma (DIPG) is relatively rare and associated with a dismal prognosis. Combining craniospinal irradiation (CSI) with concurrent temozolomide and nimotuzumab therapy may slightly improve tumor control and overall survival. However, little is known about the feasibility and toxicity of this treatment approach. Here, we describe the case of an 8-year-old girl with primary metastatic DIPG who received craniospinal radiotherapy, a local boost, and concurrent temozolomide and nimotuzumab treatment based on an individual therapy recommendation. Radiotherapy could be completed without any interruption. However, concurrent temozolomide had to be disrupted several times due to considerable acute myelotoxicity (grade III-IV).Maintenance immunochemotherapy could be started with a delay of 5 days and was performed according to treatment schedule. The disease could be stabilized for a few months. A routine MRI scan finally depicted disease progression 5.7 months after the start of irradiation. The patient died 1.9 months later.

Always expect the unexpected: lung abscess due to pseudomonas aeruginosa mimicking pulmonary aspergilloma in acute B-cell leukemia.

We report on a case of Pseudomonas aeruginosa sepsis and consecutive lung abscess in a 13-year-old patient with acute B-cell leukemia. At first, radiographic findings strongly suggested presence of pulmonary aspergilloma and only microbiological testing of the surgically enucleated mass revealed the correct underlying pathogen and confirmed final diagnosis.

Mismatch repair deficiency: a temozolomide resistance factor in medulloblastoma cell lines that is uncommon in primary medulloblastoma tumours.

BACKGROUND: Tumours are responsive to temozolomide (TMZ) if they are deficient in O(6)-methylguanine-DNA methyltransferase (MGMT), and mismatch repair (MMR) proficient. METHODS: The effect of TMZ on medulloblastoma (MB) cell killing was analysed with clonogenic survival assays. Expression of DNA repair genes and enzymes was investigated using microarrays, western blot, and immunohistochemistry. DNA sequencing and promoter methylation analysis were employed to investigate the cause of loss of the expression of MMR gene MLH1. RESULTS: Temozolomide exhibited potent cytotoxic activity in D425Med (MGMT deficient, MLH1 proficient; IC(50)=1.7 µM), moderate activity against D341Med (MGMT proficient, MLH1 deficient), and DAOY MB cells (MGMT proficient, MLH1 proficient). MGMT inhibitor O(6)-benzylguanine sensitised DAOY, but not D341Med cells to TMZ. Of 12 MB cell lines, D341Med, D283Med, and 1580WÜ cells exhibited MMR deficiency due to MLH1 promoter hypermethylation. DNA sequencing of these cells provided no evidence for somatic genetic alterations in MLH1. Expression analyses of MMR and MGMT in MB revealed that all patient specimens (n=74; expression array, n=61; immunostaining, n=13) are most likely MMR proficient, whereas some tumours had low MGMT expression levels (according to expression array) or were totally MGMT deficient (3 out of 13 according to immunohistochemistry). CONCLUSION: A subset of MB may respond to TMZ as some patient specimens are MGMT deficient, and tumours appear to be MMR proficient.

Delta(9)-tetrahydrocannabinol inhibits 17beta-estradiol-induced proliferation and fails to activate androgen and estrogen receptors in MCF7 human breast cancer cells.

BACKGROUND: Delta(9)-tetrahydrocannabinol (THC) exerts palliative effects in cancer patients, but produces adverse effects on the endocrine and reproductive systems. Experimental evidence concerning such effects is controversial. Whether THC exhibits estrogenic or androgenic activity in vitro was investigated. MATERIALS AND METHODS: Estrogenic effects of THC were analyzed in vitro by measuring the proliferation of estrogen-sensitive MCF7 cells. Androgenic activity was investigated by the A-Screen assay that measures androgen-dependent inhibition of proliferation of the androgen receptor (AR)-positive human mammary carcinoma cell line, MCF7-AR1. RESULTS: In contrast to 17beta-estradiol, included as positive control with an EC50 value (concentration required for 50% of maximal 17beta-estradiol-induced proliferation) of 1.00 x 10(-12) M, THC failed to induce cell proliferation in the MCF7 cell line at concentrations between 10(-13) and 10(-4) M. THC inhibited 17beta-estradiol-induced proliferation in wild-type MCF7 and MCF7-AR1 cells, with an IC50 value of 2.6 x 10(-5) M and 9 x 10(-6) M, respectively. CONCLUSION: THC failed to act as an estrogen, but antagonized 17beta-estradiol-induced proliferation. This effect was independent of the AR expression level.

Interferon-gamma mediated up-regulation of caspase-8 sensitizes medulloblastoma cells to radio- and chemotherapy.

Loss of caspase-8 expression - which has been demonstrated in a subset of Medulloblastoma (MB) - might block important apoptotic signalling pathways and therefore contribute to treatment resistance. In this study, IFN-gamma mediated up-regulation of caspase-8 in human MB cells was found to result in chemosensitization to cisplatin, doxorubicin and etoposide, and sensitisation to radiation. These effects were more prominent in D425 and D341 MB cells (low basal caspase-8 expression) when compared to DAOY MB cells (high basal caspase-8 expression). IFN-gamma mediated chemosensitization and radiosensitization effects were reduced by treatment with the caspase-8 specific inhibitor z-IETD-fmk. Treatment of IFN-gamma resulted in activation of STAT1 in DAOY MB cells and to a lesser extent in D425, but not in D341, indicating that IFN-gamma acts in MB cells through STAT1-dependent and -independent signalling pathways. Taken together, our results demonstrate that IFN-gamma mediated restoration of caspase-8 in MB cells might enhance apoptotic pathways relevant to the response to chemo- and radiotherapy.

Expression of BARHL1 in medulloblastoma is associated with prolonged survival in mice and humans.

Medulloblastoma is the most common malignant brain tumor in childhood, and development of targeted therapies is highly desired. Although the molecular mechanisms of malignant transformation are not fully understood, it is known that medulloblastomas may arise from cerebellar granule neuron precursors. The homeodomain transcription factor Barhl1 is known to regulate migration and survival of granule cell precursors, but its functional role in medulloblastoma is unknown. We show here that the expression of BARHL1 is significantly upregulated during human cerebellar development and in human medulloblastoma samples as compared with the normal adult cerebellum. We also detected high levels of Barhl1 expression in medulloblastomas of Math1-cre:SmoM2 mice, a mouse model for Sonic hedgehog-associated medulloblastomas that we developed previously. To investigate Barhl1 function in vivo during tumor development, we generated Barhl1(-/-)Math1-cre:SmoM2 mice. Interestingly, tumors that developed in these mice displayed increased mitotic activity and decreased neuronal differentiation. Moreover, survival of these mice was significantly decreased. Similarly, low expression of BARHL1 in human medulloblastoma cases was associated with a less favorable prognosis for patients. These results suggest that the expression of Barhl1 decelerates tumor growth both in human and in murine medulloblastomas and should be further investigated with respect to potential implications for individualized therapeutic strategies.

Which clinical and biological tumor markers proved predictive in the prospective multicenter trial HIT'91--implications for investigating childhood medulloblastoma.

BACKGROUND: Most recent studies analyzing candidate biological prognostic factors in childhood medulloblastoma (MB) are limited by small patient numbers due to dependence on fresh-frozen tumor material. By contrast, large archives of formalin-fixed, paraffin-embedded MB samples exist from homogeneously treated patients. PATIENTS AND METHODS: We have optimized RNA and DNA isolation from formalin-fixed paraffin-embedded MB samples. We then analyzed archived tumor samples from well-documented patients treated within the prospective randomized multicenter trial HIT'91 for DNA amplification of c-myc and N-myc, and mRNA expression of c-myc and trkC. RESULTS: TrkC and c-myc mRNA expression were identified as independent prognostic factors by multivariate analysis. Three risk groups were identified: 1) Favorable risk group: All 8 patients (2 metastatic) with elevated trkC and reduced c-myc mRNA expression (compared to levels of human cerebellum) remained relapse-free (7-year EFS 100%). 2) Poor risk group: 10 of 15 patients with metastatic disease and high c-myc and low trkC mRNA expression relapsed (7-year EFS 33%). 3) Intermediate risk group: The 7-year EFS of the remaining 78 patients was 65%. CONCLUSIONS: While the collection of fresh-frozen tumor samples is remaining a major challenge in large clinical trials, routinely processed paraffin-embedded tissue samples can be used to quantitate biological prognostic factors on the DNA and RNA level. Upon prospective validation of cut-off levels, this may lead to better risk-based stratification systems for children with medulloblastoma.