Investigational therapies for Ewing sarcoma: a search without a clear finding

Introduction: Ewing sarcoma family tumors (ESFT) are a group of aggressive diseases, characterized histologically by small, round, blue cells and genetically by translocation involving EWS and ETS partner genes. The current treatment of localized Ewing sarcoma (ES) requires a multi-disciplinary approach, including multidrug chemotherapy, administrated before and after local treatment, surgery and radiation therapy. Unfortunately, the cure rate of metastatic or refractory/recurrent disease is still very poor.

Areas covered: In this review, the authors summarize the new types of therapy and strategies aimed to improve the prognosis or cure ES. Herein, the authors discuss several preclinical and phase I-II studies with new-targeted therapies. The most studied therapies are insulin-like growth factor receptor (IGF1R) inhibitors but have limited efficacy. Other strategies include Mammalian Target of Rapamycin (mTOR) Inhibition, poly ADP ribose polymerase (PARP) inhibition, vascular endothelial growth factor (VEGF) inhibition, tyrosine kinase inhibitors and telomerase inhibitors, all with limited effectiveness.

Expert opinion: Future treatment strategies should combine one or more targeted therapies with conventional chemotherapy. Some combined modality treatments are under clinical study. However, treatment breakthroughs are still needed to improve the relatively poor prognosis of recurrent/metastatic ESFT.     

Oncogene-targeted antisense oligonucleotides for the treatment of Ewing sarcoma

The genetic hallmark of the Ewing sarcoma family of tumours (ESFT) is the presence of the t(11;22)(q24;q12) translocation, present in up to 85% of cases of ESFT, which creates the EWS/FLI1 fusion gene and results in the expression of a chimeric protein regulating many other genes. The inhibition of this protein by antisense strategies has shown its predominant role in the transformed phenotype of Ewing cells. In addition, the junction point at the mRNA level offers a target for short therapeutic nucleic acids that is present only in the cancer cells and not in the normal tissues of a patient. Several teams have, therefore, investigated the activity of antisense oligonucleotides and siRNAs targeted against the junction point in mRNA; thus, inhibiting EWS/FLI1 synthesis. Generally speaking, the molecules induce a cell growth inhibition in culture. Apoptosis has also been reported. One laboratory has reported the in vivo tumour inhibitory effect of phosphorothioate antisense oligonucleotide directed against the EWS part of EWS/FlI1 when injected intratumourally. Independently, a tumour inhibitory effect of oligonucleotides targeting the junction point has been demonstrated provided they are delivered by polymeric nanoparticles through the intratumoural route. Alongside this target, other genes participating to the maintenance of the transformed phenotype of Ewing cells have been downregulated by antisense strategies.     

Oncogene-targeted antisense oligonucleotides for the treatment of Ewing sarcoma

The genetic hallmark of the Ewing sarcoma family of tumours (ESFT) is the presence of the t(11;22)(q24;q12) translocation, present in up to 85% of cases of ESFT, which creates the EWS/FLI1 fusion gene and results in the expression of a chimeric protein regulating many other genes. The inhibition of this protein by antisense strategies has shown its predominant role in the transformed phenotype of Ewing cells. In addition, the junction point at the mRNA level offers a target for short therapeutic nucleic acids that is present only in the cancer cells and not in the normal tissues of a patient. Several teams have, therefore, investigated the activity of antisense oligonucleotides and siRNAs targeted against the junction point in mRNA; thus, inhibiting EWS/FLI1 synthesis. Generally speaking, the molecules induce a cell growth inhibition in culture. Apoptosis has also been reported. One laboratory has reported the in vivo tumour inhibitory effect of phosphorothioate antisense oligonucleotide directed against the EWS part of EWS/FlI1 when injected intratumourally. Independently, a tumour inhibitory effect of oligonucleotides targeting the junction point has been demonstrated provided they are delivered by polymeric nanoparticles through the intratumoural route. Alongside this target, other genes participating to the maintenance of the transformed phenotype of Ewing cells have been downregulated by antisense strategies.     

Soft tissue sarcoma in children: prognosis and management

Soft tissue sarcomas (STS) account for approximately 7% of malignant neoplasms in children. The heterogeneity of STS makes the diagnosis and therapy particularly difficult and should be reserved for specialized centers with expertise in treating cancer in children. Major progress in the accuracy of diagnosis and classification has been made by the identification of specific, recurring genetic alterations t(2;13)(q35;q14) and t(1;13)(p36;q14) in alveolar rhabdomyosarcomas (RMS), t(X;18)(p11;q11) for synovial sarcoma (SS) and t(11;22)(q24;q12) or t(21;22)(q22;q12) for Ewing's tumor family. As a result of large multicenter STS studies, such as the North-American Intergroup Rhabdomyosarcoma Study, the German Pediatric Soft Tissue Sarcoma Study Group (CWS), Italian Gruppo Cooperativo Italiano study and Sociètè Internationale d'Oncologie Pèdiatrique (SIOP) Malignant Mesenchymal Tumors study, the identification of more effective treatment strategies and improvement in prognosis have been made in the last 30 years. Prognostic variables were identified and, by exploring novel therapeutic strategies, criteria were established for the use of preoperative chemotherapy and radiotherapy, and primary and delayed second-look surgery. As a result of evaluation of different drugs active in STS, refinements in the utilization of chemotherapy have been made possible. Clinical trials have also been instrumental in defining the late effects of treatment. In STS the following drugs have proven to be useful: dactinomycin, vincristine, alkylating agents such as cyclophosphamide and ifosfamide, as well as anthracyclines such as doxorubicin (adriamycin) and epi-doxorubicin. Recommendations for radiation are dependent on the primary site and size of the tumour, histology, patient age and the extent of disease before and after surgical resection. In general, with conventional fractionation (1 x 1.8 to 2 Gy/day) radiotherapy doses between 40 and 50 Gy should be administered. The German CWS group explored the effectiveness of 32 Gy when accelerated and hyperfractionated, and given simultaneously to chemotherapy, and found it adequate for local tumor control in patients with selected favorable prognostic factors. When treated with a combination of chemotherapy and local therapy, STS showed an event-free survival between 50 and 80% [RMS 70%, extraskeletal Ewing sarcoma (EES) and peripheral neuroectodermal tumor (PNET) circa 50%, and SS 70 to 80%]. About one-fifth of patients with newly diagnosed RMS-like STS have metastatic disease. The 5-year survival rate among these patients is low (20 to 30%). Age (>10 years), bone, and/or bone marrow metastases are associated with a very poor prognosis (survival rate of about 5%). The value of high dose chemotherapy with hematopoietic stem cell rescue in patients with poor prognostic STS remains unclear and should be performed in controlled studies only.     

Cytotoxicity of treosulfan and busulfan on pediatric tumor cell lines

High-dose chemotherapy of solid tumors aims at eliminating residual or metastatic tumor cells, which remained after conventional treatment. Thus, anticancer drugs used for high-dose chemotherapy should display significant cytotoxicity against the respective tumors. As little data are available about the in-vitro toxicity of busulfan and treosulfan especially on pediatric tumor cell lines, we compared the cytotoxicity of treosulfan and busulfan on four Ewing tumor, four neuroblastoma, two osteosarcoma and two leukemia cell lines in vitro. Growth inhibition of tumor cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide test after 24, 48, 72 and 96 h. Treosulfan and busulfan reduced the growth of all tumor cell lines in a time-dependent and dose-dependent manner. In vitro treosulfan was consistently more cytotoxic than busulfan. Fifty percent growth inhibitions of 608-0.73 micromol/l were determined for treosulfan and of above 5,000-2.81 micromol/l for busulfan. Both drugs exhibited similar cytotoxicity profiles. Busulfan-sensitive/resistant cell lines were also sensitive/resistant to treosulfan. Overall, the leukemia cell lines were most sensitive to busulfan and treosulfan. The Ewing tumor cell lines were the second most sensitive followed by the neuroblastoma cell lines. The osteosarcoma cell lines were the most resistant cell lines. Although the in-vitro stability of both drugs makes direct comparison of their in-vitro toxicity difficult and does not allow any estimation of dosages needed clinically, the in-vitro results indicate substantial cytotoxicity of both drugs on leukemias, Ewing tumors and neuroblastomas. These data suggest further evaluation of treosulfan for high-dose chemotherapy of advanced Ewing tumors, neuroblastomas and high-risk leukemias.     

Sarcomas and pharmacogenetics

Sarcomas are a heterogeneous group of tumors, requiring different chemotherapeutic approaches. Recently, several regimens for metastatic tumors were evaluated with respect to the different responses to conventional chemotherapy of the various histologic subtypes of sarcomas. The impact of pharmacogenetics in the progress of chemotherapy appears to be crucial in defining the clinical response to many drugs, such as anthracycline or alkylating agents, that are widely used in treatment regimens for soft tissue sarcomas (STS) or sarcomas of the bone. Polymorphisms of metabolizing enzymes (e.g., cytochrome P450 and glutathione-S-transferase), transporter proteins (reduced folate carrier and P-glycoprotein) or target proteins (thymidylate synthase, methylenetetrahydrofolate reductase, dihydrofolate reductase, and c-KIT) may be responsible for an altered clinical outcome, in terms of both response and toxicity. The administration of new chemotherapeutic agents, such as imatinib for gastrointestinal tumors (GIST), requires the study of genetic polymorphisms possibly affecting the integrity of the target (c-KIT), which may provide valid information regarding possible developments of therapy. For STS and sarcoma of the bone, the genetic markers, which could be unambiguously predictive of the phenotypic profile of patients, are as yet undetermined.     

Optimal management strategies for rhabdomyosarcoma in children

Rhabdomyosarcoma is the most common sarcoma of childhood. Fortunately, the goal of cure is realistic for the majority of patients with localized tumors. However, management of these patients remains challenging. The fact that the tumor arises in a wide variety of primary sites, some of which are associated with specific patterns of local invasion, regional lymph node spread, and therapeutic response, requires physicians to be familiar with site-specific staging and treatment details. In addition, rhabdomyosarcoma requires multimodality therapy that can be associated with significant acute toxicities and long-term effects, particularly when administered to young children. These factors sometimes present a dilemma as to the best approach to optimize the chance of cure, minimize toxicity, and respect quality of life. The purpose of this review is to discuss 'optimal' management of this complicated tumor. Since the tumor is relatively rare, requires highly specialized care, and important management questions remain to be answered, optimal management of rhabdomyosarcoma includes enrollment in clinical trials whenever possible. Appropriate management begins with establishing the correct pathologic diagnosis, histologic subtype, primary site, extent of disease (International Society of Pediatric Oncology [SIOP]-TNM-Union Internationale Contre le Cancer stage or Intergroup Rhabdomyosarcoma Study Group [IRSG] stage), and extent of resection (IRSG group). Cooperative groups throughout North America and Europe have defined risk-adapted treatment based on these factors; this treatment requires a coordinated management plan that includes surgery, chemotherapy, and usually radiotherapy. The surgical approach for rhabdomyosarcoma is to excise the primary tumor whenever possible without causing major functional or cosmetic deficits. Wide excision is difficult in some primary sites and can be complicated by the fact that the tumor grows in a locally infiltrative manner so that complete resection is often neither possible nor medically indicated. Incompletely resected tumors are generally treated with radiotherapy. The cooperative groups reduce the dose of radiation based on the response of the tumor to chemotherapy and delayed primary resection to differing degrees. Response-adjusted radiation administration may reduce the long-term effects of radiotherapy, such as bone growth arrest, muscle atrophy, bladder dysfunction, and induction of second malignant neoplasms; however, it may also be associated with an increased risk of tumor recurrence. All patients with rhabdomyosarcoma require chemotherapy. A backbone of vincristine and dactinomycin with either cyclophosphamide (VAC) or ifosfamide (IVA) has been established. Risk-adapted treatment involves reducing or eliminating the alklyating agent for patients with the most favorable disease characteristics. Clinical trials are ongoing to improve outcomes for higher risk patients; newer agents, such as topotecan or irinotecan, in combination with VAC or use of agents in novel ways are being investigated. Acute and long-term toxicities associated with these chemotherapy regimens include myelosuppression, febrile neutropenia, hepatopathy, infertility, and second malignant neoplasms. A 5-year survival rate >70% has been achieved in recent trials for patients with localized rhabdomyosarcoma. However, the outcome for patients who present with metastatic disease remains poor. In the future, risk-adapted classification of rhabdomyosarcoma will likely be based on biologic features, such as the presence of chromosomal translocations or specific gene expression profiles. It is hoped that newer therapies directed at specific molecular genetic defects will benefit all patients with rhabdomyosarcoma.     

Only grading has independent impact on breast cancer survival after adjustment for pathological response to preoperative chemotherapy

Our objective was to determine pretreatment factors with an independent impact on survival after adjusting for response to preoperative chemotherapy and to describe parameters predictive for achieving a pathological complete remission (pCR) after preoperative chemotherapy containing an anthracycline. We performed univariate and multivariate analyses to describe the impact of the following pretreatment characteristics of 240 primary breast cancer patients who received preoperative chemotherapy containing an anthracycline at our institution on disease-free survival (DFS), distant disease-free survival (DDFS) and overall survival (OS): age, stage, clinical tumor size, clinical nodal status, grading, and expression of estrogen receptor, progesterone receptor, Her2/neu, Ki67, Bcl-2 and p53. Afterwards, the response to preoperative chemotherapy was added to the multivariate model in order to evaluate which pretreatment parameters retained their prognostic impact. In addition, univariate analysis was performed to describe pretreatment variables predictive for achieving a pCR. With a median follow-up of 6.4 years (range 0-10.4), only grading retained its independent impact on DFS, DDFS and OS [hazard ratio (HR) 1.5, 1.7 and 2.9, respectively; p<0.05] after adjusting for the strongest independent prognostic factors pathological T category at surgery (HR 1.6, 1.8 and 1.7, respectively; p<0.001) and pathological N category at surgery (HR 2.3, 2.4 and 2.1, respectively; p<0.001). Predictive factors for the achievement of pCR (p<0.05) were age under 35 years, lower stage or smaller clinical tumor size and higher expression of Bcl-2 at diagnosis. We conclude that only grading retained its independent prognostic impact on DFS, DDFS and OS after adjusting for pathological response of breast tumor and axillary lymph node metastases to preoperative chemotherapy. According to our data, it could be hypothesized that young patients with early tumor stage and small primary tumors might profit most from preoperative chemotherapy.     

Systemic treatment options for patients with refractory adult-type sarcoma beyond anthracyclines

For the subgroup of patients with inoperable gastrointestinal stromal tumors, progress has been made by the rapid development and approval of the targeted therapy imatinib mesylate. Small round cell sarcoma, such as Ewing/PNET, desmoplastic small round cell sarcoma and rhabdomyosarcoma, are chemotherapy-sensitive and potentially curable malignancies, which are treated with multimodality, dose-intensitive and neoadjuvant protocols regardless of size or overt metastatic disease. A limited number of effective agents available for the treatment of patients with metastatic adult soft-tissue sarcoma exists, which have failed anthracyline and ifosfamide-based chemotherapy. Most other high-grade (grading >I) so-called adult-type soft-tissue sarcomas such as fibro, lipo, pleomorphic and synovial sarcoma are treated with a anthracycline-based regimen with or without ifosfamide as front-line therapy. In this review, the therapeutic activities of drugs currently available as second-line treatment in patients with metastatic soft tissue sarcoma are summarized, providing an overview of contentious or emerging treatment issues. In relapsed 'adult-type' soft-tissue sarcomas trofosfamide, gemcitabine and ecteinascidin (ET-743) appear to be drugs associated with moderate activity and an acceptable toxicity profile. An interesting finding to be noted is that the different drugs have particular effects in distinct subtypes of soft-tissue sarcoma; however, it has to be taken into account that the number of patients included in those phase II trials are limited. The role of the newer agents (e.g. patupilone derivates, brostallicin) is currently not definable. The so-called selective therapy targeting vascular endothelial growth factor (receptor), epidermal growth factor receptor, c-kit, Raf kinase or platelet-derived growth factor receptor and bcl-2 antisensing, proteasome, protein kinase C/B, and mammalian target of rabamycin inhibition will continue to be tested in gastrointestinal stromal tumors patients refractory to imatinib mesylate as well as in selected sarcoma subtypes.     

The bone marrow microenvironment as a sanctuary for minimal residual disease in CML

Bcr-abl kinase inhibitors have provided proof of principal that targeted therapy holds great promise for the treatment of cancer. However, despite the success of these agents in treating chronic myelogenous leukemia (CML), the majority of patients continue to present with minimal residual disease contained within the bone marrow microenvironment. These clinical observations suggest that the bone marrow microenvironment may provide survival signals that contribute to the failure to eliminate minimal residual disease. The bone marrow microenvironment is comprised of multiple sub-domains which vary in cellular composition and gradients of soluble factors and matrix composition. Experimental evidence indicate that exposure of tumor cells to either bone marrow derived soluble factors or the extracellular matrix can confer a multi-drug resistance phenotype. Together, these data indicate that targeting such pathways may be a viable approach for increasing the efficacy of chemotherapy. Moreover, we propose that personalized medicine must go beyond understanding predictive models inherent to tumors but rather build predictive models that consider diversity in response due to interactions with the tumor microenvironment. Although review will focus on CML, understanding the contribution of the bone marrow microenvironment could contribute to rationale combination therapy in other types of leukemia, multiple myeloma and solid tumors which metastasize to the bone.     

Evaluation of ABT-751 against childhood cancer models in vivo

OBJECTIVE: ABT-751 is a novel antimitotic agent that binds tubulin at the colchicine binding site. ABT-751 is undergoing Phase I trials in children, but has not been evaluated against a range of pediatric tumor models in vivo. MATERIALS AND METHODS: ABT-751 was evaluated against 27 subcutaneously implanted xenograft models of childhood cancer including neuroblastoma [4], osteosarcoma [4], Ewing sarcoma [2] rhabdomyosarcoma [8], medulloblastoma [1] and eight kidney cancer lines (six Wilms tumors, two rhabdoid). ABT-751 was administered at 100 mg/kg P.O. on a schedule of 5 days on, 5 days off, 5 days on, repeating the cycle at 21 days. Tumor diameters were measured at 7 day intervals for a period of 12 weeks. Three measures of antitumor activity were used: (1) clinical response criteria [e.g., partial response (PR), complete response (CR), etc.]; (2) treated to control (T/C) tumor volume at day 21; and (3) a time to event measure based on the median event free survival (EFS) of treated and control lines. RESULTS: ABT-751 induced regression in 4 of 25 models (16%) including models of neuroblastoma that are refractory to vincristine and paclitaxel. Other regressions occurred in rhabdomyosarcoma and Wilms tumor models. ABT-751 significantly increased event free survival (EFS > 2.0) in eight models (33%) in addition to those with objective responses. CONCLUSIONS: ABT-751 demonstrated intermediate activity against this tumor panel. Neuroblastoma models appear somewhat more sensitive to this agent, with objective regressions also in rhabdomyosarcoma and Wilms tumor. ABT-751 was also active in several tumor lines intrinsically refractory to vincristine or paclitaxel.     

Phase II study of gemcitabine in children with solid tumors of mesenchymal and embryonic origin

The therapeutic benefit and side-effect profile of gemcitabine in adults with relapsed solid tumors is well known. So far, few data are available about its significance in pediatric relapsed solid tumors. To determine the efficacy and tolerability of gemcitabine in children, the drug was administered by intravenous short-term infusion over 30 min at a dose of 1200 mg/m2 weekly for 3 weeks as one cycle in children with relapsed solid tumor of embryonic or mesenchymal origin. From May 2003 to September 2004, 14 male and six female patients (2-23, median 15.8 years) were recruited for this prospective open-label phase II study (two-step Simon design). The patients suffered from rhabdomyosarcoma (n=8), Ewing's sarcoma (n=4), osteosarcoma (n=2), neuroblastoma (n=3), hepatoblastoma (n=2) and nephroblastoma (n=1). Median duration of therapy was 27.5 days (7-99), corresponding to 4.0 (2-11) infusions of gemcitabine. Two patients (neuroblastoma and Ewing) had stable disease documented for 69 and 70 days, whereas no objective responses were observed. In 34/94 administered infusions; doses had to be reduced or omitted for grade 3-4 hematotoxicity. Minimal activity was observed in this cohort of children with a wide spectrum of mesenchymal and embryonic tumors. Given the relatively low dose of gemcitabine administered, this study does not exclude the possibility of activity at higher doses. Secondly, the tolerability of gemcitabine in children was consistent with that expected in adults. For further studies in this population, we recommend the use of gemcitabine in combination with other agents.     

Novel bone cancer drugs: investigational agents and control paradigms for primary bone sarcomas (Ewing's sarcoma and osteosarcoma)

Background: New investigational agents and chemotherapy regimens including cyclophosphamide + topotecan, temozolomide + irinotecan, and anti-IGF-1R antibodies in Ewing's sarcoma (ES) and liposomal muramyltripeptide phosphatidylethanolamine (L-MTP-PE), aerosol therapy, and bone-specific agents in osteosarcoma (OS) may improve survival and/or quality of life on ‘continuation’ therapy. Objective: Review of investigational approaches and control paradigms for recurrent or metastatic primary bone tumors. Methods: Analyze temozolomide + irinotecan data and review in the context of other newer approaches including antiangiogenesis, anti-IGF-1R antibodies and bisphosphonates for ES. Review some current state-of-the-art approaches for OS including L-MTP-PE, anti-IGF-1R inhibition, aerosol therapies and bone specific agents. Results/conclusion: L-MTP-PE with chemotherapy in OS has been shown to improve survival; compassionate access is available for recurrence and/or metastases. Aerosol therapy (granulocyte–macrophage colony stimulating factor, cisplatin, gemcitabine) for lung metastases is a promising approach to reduce systemic toxicity. The bone-specific agents including denosumab (anti-receptor activator of NF-κB ligand antibody) and bisphosphonates may have benefit against giant cell tumor, ES and OS. Anti-IGF-1R antibody SCH717454 has preclinical activity in OS but best effectiveness will most likely be in combination with chemotherapy earlier in therapy. Both temozolomide + irinotecan and cyclophosphamide + topotecan combinations are very active in ES and are likely to be tested with anti-IGF-1R antibodies against ES.     

Evolution from empirical dynamic contrast-enhanced magnetic resonance imaging to pharmacokinetic MRI

For chemotherapy to be effective against cancers which grow as solid tumors, agents must reach all tumor cells in effective quantities. Although many clinical trials include studies of the pharmacokinetics of the agents in body fluids such as blood or cerebrospinal fluid (CSF), there is presently no widely applicable way to determine access of chemotherapeutic agents to all regions of a solid tumor in an individual patient. This review discusses a relatively new methodology in MR imaging - dynamic contrast-enhanced imaging for exploring tumor microcirculation and drug access by imaging the uptake, or leakage, of contrast agent into tumor interstitial (extracellular and extravascular) space. The aims and methods of dynamic contrast-enhanced MRI evaluations to measure contrast uptake are distinguished from dynamic contrast-enhanced MRI to measure blood volume or flow, by MR imaging of the first-pass effects of a contrast bolus. Measures of contrast uptake by dynamic MRI have demonstrated a convincing ability to aid in diagnosing the presence of viable tumor and to measure response for a range of human tumors. This body of clinical results will be summarized. While questions remain to be answered about how to extract non-invasive pharmacokinetic measures of drug access from these novel dynamic imaging methods, we are optimistic that these methods can provide important new clinical measures that reflect the range of biological variation within and between naturally-occurring solid tumors.     

Emerging treatments for soft tissue sarcoma of adults

Soft tissue sarcomas are a heterogeneous group of malignancies arising from mesenchymal tissues. Patients can present with a localised tumour (primary or local recurrence) at different sites (e.g., extremity, abdomen) or metastatic disease, which may require different treatment strategies. Is the surgical resection of a localised sarcoma enough or is it better to give an additional treatment like adjuvant and/or preoperative radiotherapy and/or chemotherapy? Which chemotherapy should be selected in the first or second line situation? Do new treatment options exist, such as targeted therapies? This review provides answers to some of these questions. To decide on consecutive treatment steps, it is important to know as many relevant factors as possible at first presentation. Therefore, the first part of this review discusses the specific characteristics and prognostic factors of importance for treatment planning. A short summary of current therapy strategies and existing standards is then given. The main body of the review summarises information on new and emerging clinical compounds for patients with soft tissue sarcoma of adults, including recent developments of targeted therapy.     

In-vitro toxicity of Ukrain against human Ewing tumor cell lines

Ukrain is advertised by the manufacturer as a drug for alternative cancer cures with high activity against progressive Ewing tumors. Using the MTT assay, we compared the cytotoxicity of Ukrain with the cytotoxicity of N,N',N'-triethylenethiophosphoramide (thioTEPA), Chelidonium majus L. alkaloids, doxorubicin, cyclophosphamide and etoposide against four human Ewing tumor cell lines. In addition, we studied the cytotoxicity of thioTEPA combined with C. majus L. alkaloids after 48, 72 and 96 h. All compounds reduced the growth of Ewing tumor cell lines in a dose-dependent manner. The concentrations that reduced cell growth by 50% ranged between 6.2 and 31.1 micromol/l for Ukrain, 1.9 and 26.1 micromol/l for C. majus L. extract, and 1.7 and 448 micromol/l for thioTEPA. The sensitivity profile of Ukrain was comparable to that of the C. majus L. alkaloids, and different from that of thioTEPA, cyclophosphamide, etoposide and doxorubicin. Overall, doxorubicin was the most cytotoxic drug followed by cyclophosphamide. Ukrain and the C. majus L. alkaloids were slightly more cytotoxic than etoposide, while thioTEPA showed the lowest cytotoxicity. Co-exposure of thioTEPA with C. majus L. alkaloids resulted in additive but not in synergistic cytotoxicity. The in-vitro results indicate that the cytotoxicity of Ukrain against Ewing tumors is comparable to that of etoposide. While the latter can be used on the basis of broad clinical experience and known risk-benefit ratio, Ukrain for the present might be considered as a candidate for subsequent drug development by xenograft studies followed by systematic clinical trials.     

Implications of genetic testing in the management of colorectal cancer

The prognosis of patients with colorectal cancer is impacted by various factors at the time of diagnosis, including location of the tumor, gender, age and overall performance status of the patient. Optimal postoperative management of patients who have undergone successful tumor resection involves the utilization of reliable determninants of prognosis to help select patients who would benefit from adjuvant treatment, while sparing others from drug-related adverse effects. Tailoring chemotherapy for patients with disseminated cancer, or for patients who receive adjuvant chemotherapy, is also critical. Interpatient differences in tumor response and drug toxicity are common during chemotherapy. Genomic variability of key metabolic enzyme complexes, drug targets, and drug transport molecules is an important contributing factor. The identification of genetic markers of response and prognosis will aid in the development of more individualized chemotherapuetic strategies for cancer patients. Potential prognostic indicators in colorectal cancer include oncogenes, tumor suppressor genes, genes involved in angiogenic and apoptotic pathways and cell proliferation, and those encoding targets of chemotherapy. Specifically, molecular markers such as deletion of 18q (DCC), p27 and microsatellite instability are promising as indicators of good or poor prognosis. Molecular determinants of efficacy and host toxicity of the most commonly used drugs in colorectal cancer, fluoracil, irinotecan and oxaliplatin, are being investigated. Alterations in gene expression, protein expression and polymorphic variants in genes encoding thymidylate synthase, dihydropyrimidine dehydrogenase, dUTP nucleotidehydrolase and thymidine phosphorylase (for fluoropyrimidine-based chemotherapy), uridine diphosphate glucosyltransferase (UGT) 1A1 and carboxylesterase (for irinotecan therapy), and excision repair cross-complementing genes (ERCC1 and ERCC2) and glutathione-S-transferase P1 (for oxalilplatin-based regimens) may be useful as markers for clinical drug response, survival and host toxicity.     

Orbital Rhabdomyosarcoma with a good life prognosis after surgical treatment in a 14-year-old patient

The orbital rhabdomyosarcoma is one of the most frequent malignant orbital tumours in children. At this age, the common histological types are the embryonal and alveolar type. The onset is mainly under the age of 16. Without a recent and correct treatment it can give metastasis in lung and bone. The hereby paper presents one clinical case of a teenager presented at the ophthalmological consultation for a small tumor located in the superomedial part of the orbit. Computed tomography (CT) and magnetic resonance imaging (MRI) supported the diagnosis revealing the location and extension of the tumor. During the surgery, we discovered two small tumors and the histological examination revealed an embryonal type of orbital rhabdomyosarcoma. After the surgery, the patient followed an oncological treatment consisting of chemotherapy and local radiotherapy. The prognosis for life was favorable, linked with the recent diagnosis and treatment, the histological type and the good response at the oncological treatment.