Molecular pathology in sarcomas

Abstract Bone and soft tissue sarcomas are an infrequent group of tumours. Their prevalence is 4 in 100 000 people/year, making the disease quite rare. Some of these tumours, such as synovial sarcoma, Ewing tumour and osteosarcoma, are more usual in adolescents or in young adults; there are, though, some neoplasias such as leiomyosarcoma or liposarcoma that are more frequent in patients over 55 years. There are more than a hundred different types of sarcomas from the histological point of view. This is the main limitation at the time of finding major clinic essays on patients with specific types of sarcomas. From the molecular point of view, these neoplasias are grouped into two main types: (a) sarcomas showing specific genetic alterations and relatively simple karyotypes, and translocations which originate gene fusions (e.g., EWS-FLI1 in Ewing tumour); or specific genetic mutations (e.g., c-kit in the gastrointestinal stromal tumour), and (b) sarcomas showing unspecific gene alterations and very complex karyotypes, and very numerous gains and losses. This review describes diverse types of molecular alterations as well, their utility in the clinical domain, as well as implications for the pathologist in translational research in sarcomas. *Supported by an unrestricted educational grant from Sanofi-Aventis.     

Recombinant human tumor necrosis factor: an efficient agent for cancer treatment

Recombinant human TNF (rhTNF) has a selective effect on endothelial cells in tumour angiogenic vessels. Its clinical use has been limited because of its property to induce vascular collapsus. TNF administration through isolated limb perfusion (ILP) for regionally advanced melanomas and soft tissue sarcomas of the limbs was shown to be safe and efficient. When combined to the alkylating agent melphalan, a single ILP produces a very high objective response rate. ILP with TNF and melphalan provided the proof of concept that a vasculotoxic strategy combined to chemotherapy may produce a strong anti-tumour effect. The registered indication of TNF-based ILP is a regional therapy for regionally spread tumours. In soft tissue sarcomas, it is a limb sparing neoadjuvant treatment and, in melanoma in-transit metastases, a curative treatment. Despite its demonstrated regional efficiency TNF-based ILP is unlikely to have any impact on survival. High TNF dosages induce endothelial cells apoptosis, leading to vascular destruction. However, lower TNF dosage produces a very strong effect that is to increase the drug penetration into the tumour, presumably by decreasing the intratumoural hypertension resulting in better tumour uptake. TNF-ILP allowed the identification of the role of alphaVbeta3 integrin deactivation as an important mechanism of antiangiogenesis. Several recent studies have shown that TNF targeting is possible, paving the way to a new opportunity to administer TNF systemically for improving cancer drug penetration. TNF was the first agent registered for the treatment of cancer that improves drug penetration in tumours and selectively destroys angiogenic vessels.     

Primary soft tissue tumours of the pelvis causing referred pain in the leg

Referred pain in the leg is occasionally due to a pelvic soft tissue tumour. Among 11 patients who presented this way, one had a lymphoma, one had a benign schwannoma, and nine had soft tissue sarcomas. Most patients had undergone a variety of procedures, including laminectomy, before the correct diagnosis was established. In five cases, an accurate diagnosis was obtained by needle biopsy. The lymphoma responded to chemotherapy, and the benign schwannoma was excised. Of the nine patients with soft tissue sarcoma, six underwent marginal/intracapsular excision, three receiving supplementary radiotherapy, and two were treated by nonsurgical means. Hindquarter amputation was technically impossible or inappropriate in these cases. All those with high-grade tumours have died or have metastases. Of four patients with low-grade tumours, three have exhibited only slow disease progression. Careful judgment and a precise histopathological diagnosis are required in planning treatment for patients with pelvic soft tissue tumours causing referred pain in the leg.     

Thérapeutiques ciblées dans les tumeurs de l’os et des tissus mous : vers une prise en charge individualisée

Sarcomas are rare types of tumours which present wide variations in their clinical and biological characteristics. In spite of successful locoregional treatment, metastasis will occur in close to 40% of patients. As a rule, doxorubicin is the first-line therapy for patients who have a metastatic soft tissue sarcoma, with very modest results. However, targeting the molecular anomalies which are characteristic of sarcomas could lead to improved patient survival, as has been demonstrated for gastrointestinal stroma tumours and dermatofibrosarcomas. Several clinical trials to evaluate new agents such as cell cycle inhibitors or anti-angiogenic drugs are currently under way. Molecules targeting the epigenetic anomalies of sarcomas are also a promising form of treatment. Finally, the use of nanotechnologies is creating new, original therapies currently under clinical evaluation, particularly in association with radiotherapy.     

Radiotherapeutic enhancement by razoxane

Razoxane blocks cell division in the G2/M phase of the cell generation cycle and appears to normalize tumour neovasculature development. These were the principal reasons for the examination and probably for the demonstration of the radiosensitizing activity of Rz. Specially intriguing has been the finding that radiation of primary tumour implants in animals treated with Rz has a powerful potentiating effect on the antimetastatic activity of the combination. This concept has not yet received any clinical examination. Clinical trials with radiotherapy and Rz have demonstrated the clearest beneficial effects in terms of response rates and maintained local control in soft tissue sarcomas and possibly in recurrent rectal and in bladder carcinomas. Interesting heightened activity has also been found in hepatic metastases from gastrointestinal tumours. Carcinomas of the cervix, bronchus and head and neck, however, have not shown any benefit from the combination compared with radiotherapy alone.     

Soft tissue sarcoma: the predominant primary malignancy in the retroperitoneum

Purpose. In the clinical work-up of a retroperitoneal mass, the diagnosis of soft tissue sarcoma is often not considered. Incidence rates of various malignant and benign retroperitoneal tumours were studied to determine the incidence of soft tissue sarcoma in comparison with other neoplasms in the retroperitoneal space.Method. Nation-wide data on retroperitoneal tumours, collected prospectively over a 5-year period (1 January 1989- 1 January 1994), were supplied by the Netherlands Cancer Registry and The Dutch Network and National Database for Pathology.Results. Seven hundred and six patients with a primary retroperitoneal neoplasm were identified; 566 patients had a malignant tumour (80%). A soft tissue sarcoma (STS) was the most frequently diagnosed malignant tumour (n = 192), The agestandardised incidence of retroperitoneal STS was 2.5 per million person-years. The male/female ratio for STS was 0.73. In females, STS comprised 41%of all malignant retroperitoneal tumours, carcinoma of unknown primary tumour site (CUP) comprised 31%, and malignant lymphomas (ML) comprised 22%, whereas in males these values were 28% (STS), 30% (CUP), and 32% (ML), respectively.Discussion. Soft tissue sarcomas, albeit rare, are relatively common primary tumours in the retroperitoneum, especially in women.     

Sensitivity of fresh isolates of soft tissue sarcoma, osteosarcoma and giant cell tumour cells to Apo2L/TRAIL and doxorubicin

Chemotherapy is an established treatment modality for bone sarcomas such as osteosarcoma (OS). However, the use of chemotherapy in high-grade soft tissue sarcomas remains controversial, with the most active chemotherapeutic agent, doxorubicin (DOX), reported to have a response rate of, at best only 34% and most studies reporting lower response rates. Apo2L/TRAIL is a member of the tumour necrosis factor (TNF) family of cytokines and induces death of tumour cells, but not normal cells. Its potent apoptotic activity is mediated through cell surface death domain-containing receptors, DR4/TRAIL-R1 and DR5/TRAIL-R2. We investigated the efficacy of Apo2L/TRAIL as a single agent, and in combination with clinically relevant chemotherapeutic drugs, in fresh isolates of primary malignant cells obtained from biopsy material. The data presented here demonstrate that, in a range of primary bone related tumours, as well as soft tissue sarcomas, chemotherapeutic agents were only moderately effective, in terms of induction of cell death. Apo2L/TRAIL alone had little or no effect on any bone-related tumour or sarcoma in culture. In contrast, the combination of Apo2L/TRAIL and chemotherapeutic drugs produced a significant increase in tumour cell death, with DOX and Apo2L/TRAIL proving to be the most effective combination. These data suggest the potential for Apo2L/TRAIL to increase the effectiveness of chemotherapeutic drugs in bone and soft tissue sarcomas, while perhaps concurrently allowing a reduction in the exposure to drugs such as DOX, and a consequent reduction in toxicity. The synergistic action between these two different classes of agents has yet to be tested in vivo but may prove clinically relevant in the treatment of this refractive class of malignancies.     

Treatment with neutrons: hadrontherapy part II: physical basis and clinical experience]

Neutrons have radiobiological characteristics, which differ from those of conventional radiotherapy beams (photons) and which offer a theoretical advantage over photons to fight radioresistance by the differential relative biological effect of them between normal and tumour tissues. Neutron therapy beneficed of great interest between 1975 and 1985. Many of phase III trials were conducted and indications have been definitively deducted of them. After briefly describing the properties of neutron beams, this review discusses the indication of neutron therapy on the basis of the clinical results. Salivary, prostate tumours and sarcomas are the main indications of neutron therapy. In concern to the prostate cancers, other alternative treatments reduce the neutron therapy field. For sarcomas, the lack of randomised trials limits the impact of the interest of neutrons. For other tumours, the ratio benefice/risk of neutron therapy is inferior to these obtained with photons and they could not be considered like classical indications.     

Structural alterations of the RB1 gene in human soft tissue tumours

Sixty-nine primary soft tissue tumours were examined for alterations of the RB1 gene which has previously been implicated in the genesis of retinoblastoma. In three tumours loss of both alleles of this gene (homozygous deletion) was detected. Two of these, both leiomyosarcomas, contained a chromosomal breakpoint within the RB1 gene, while in the third tumour, a radiation induced sarcoma, complete deletion was observed. Using a probe that detects a polymorphic locus within the RB1 gene we found loss of only one allele (heterozygous deletion) in 33% of soft tissue sarcomas examined, including two leiomyosarcomas, a malignant peripheral nerve sheath tumour, a rhabdomyosarcoma and a chondrosarcoma. When taken together our results suggest that alterations of the RB1 locus may play an important part in the pathogenesis of soft tissue tumours and particularly in leiomyosarcomas which accounted for four of the eight RB1 alterations observed in this study.     

Management of adult soft tissue sarcomas of the head and neck

Adult soft tissue sarcoma of the head and neck are rare and represent a heterogeneous group of tumours of different histological variants. Management of these neoplasms presents a great challenge. Malignant fibrous histiocytoma, fibrosarcoma, angiosarcoma and malignant peripheral nerve sheath tumour are the most frequently found sarcoma types in the head and neck. Although traditional morphological assessment is the foundation of clinical decision making, the role of immunohistochemistry and molecular biology are useful for diagnosis, prognosis and identification of possible targets for molecular therapy. The most frequently involved tumour sites are scalp/face, sinonasal tract/anterior skull base and parotid/neck. The management of soft tissue sarcomas in the head and neck is primarily surgical. Since it is difficult to obtain wide margins during surgical treatment in head and neck sarcomas, because of anatomic constraints, most patients undergo post-operative irradiation. Survival varies from 50 to 80%. Prognostic factors are tumour grade, margin status and tumour size. With further insight into the biology of soft tissue sarcoma, modern imaging techniques and new treatment options, we will most certainly be able to improve clinical outcome in patients with soft tissue sarcoma in the upcoming years.     

Concentration of vascular endothelial growth factor in the tumour tissue as a prognostic factor of soft tissue sarcomas

Previous studies have shown that the prognosis of patients who have tumours with high microvessel density (MVD) is worse than that of patients who have a lower density in a variety of cancers. In this study, we investigated the clinical relevance of neovascularity assessed by MVD and the concentration of vascular endothelial growth factor (VEGF) in the tumour tissue of patients with soft tissue sarcoma in comparison with major clinicohistologic parameters by univariate and multivariate analysis. In 115 patients with soft tissue sarcoma, MVD was measured by counting vessels stained with factor VIII antibody. The concentration of VEGF in the tumour tissue was determined by enzyme-linked immunosorbent assay. These parameters were then compared with disease outcome. The concentration of VEGF in the tumour tissue, but not MVD, was found to be correlated with disease outcome in patients with soft tissue, sarcoma. VEGF concentration in the tumour tissue showed a relationship with the clinical stage and histologic grade of the tumour. There was no significant difference in the levels of tissue VEGF concentration and MVD among soft tissue sarcomas classified according to histologic type. The level of tissue VEGF concentration in patients who had subsequent local recurrence and metastasis were significantly higher than the respective values in patients who did not have such disease outcome. No significant correlation existed between MVD and the concentration of VEGF in the tumour tissue. Univariate analysis showed that a high tissue VEGF concentration was associated with poor overall survival of the patient and a greater probability that local recurrence and metastasis had occurred. Multivariate analysis revealed that the tissue concentration of VEGF is an independent prognostic factor for the disease outcome of patients with soft tissue sarcoma. VEGF concentration in the tumour tissue, but not MVD, is an additional prognostic parameter for disease outcome in patients with soft tissue sarcoma, regardless of histologic type.     

The evaluation of trends in soft tissue sarcoma according to diagnostic criteria and consumption of phenoxy herbicides

The possible association between exposure to phenoxy herbicides and development of soft tissue sarcomas has been studied in both case-control and cohort studies. In these studies soft tissue sarcoma cases have been identified from either deaths with malignant neoplasms of the connective tissue (ICD-8 171) as the underlying cause of death, from incident cancer cases with the same topography code, or from incident cases of extraskeletal sarcomas, excluding lympho and reticulosarcomas. The current study shows that the choice of source material has a considerable influence on the registered occurrence of soft tissue sarcomas in a well defined population. In 1978 to 1982 an annual number of 33 deaths from ICD-8 171 was registered in Denmark, whereas the annual number of diagnosed extraskeletal sarcomas was 231. The distribution over histologic types differed between tumours coded to the connective tissue and extraskeletal sarcomas coded to specific organs. Furthermore, during the period 1943 to 1982 the mortality from ICD-8 171 increased slightly, whereas the incidence from all extraskeletal sarcomas decreased slightly, except for males since 1970. Time trends based on any of the three source materials should, however, be interpreted with caution.     

Treatment of advanced soft tissue sarcoma: conventional agents and promising new drugs

Effective treatment of advanced soft tissue sarcomas remains challenging, despite more than 30 years of clinical trials with conventional chemotherapy. Although some agents display modest efficacy against soft tissue sarcomas, modifications in the doses and combinations of therapies have not consistently led to significant improvements in response rates or concomitant increase in overall survival. Novel therapies designed to inhibit defined molecular alterations, as exemplified by the use of imatinib in gastrointestinal stromal tumors, have revolutionized the approach to the treatment of sarcomas. As more underlying genetic mechanisms are uncovered, new agents designed to target these lesions will lead to more specific, less toxic, and more effective therapies.     

Chondrosarcome myxoïde extrasquelettique du genou : analyse clinicopathologique et immunohistochimique à propos d’un cas

The extraskeletal myxoid chondrosarcoma (CME) is a rare malignant soft tissue tumour described as a distinct clinical, histological, immunohistochemical, genetical and evolutive entity. It represents only 2.5% of soft tissue sarcomas, and is considered by WHO as a low grade sarcoma. Its individualization is important because it has a long and indolent clinical course, and tumour-related death often occurs after a long survival period. The diagnostic key is morphological supported by immunohistochemistry and genetics t(9;22) that allow to differentiate it from other tumours with myxoid stroma and from chordoma. A new case of soft tissue myxoid chondrosarcoma (chordoid sarcoma) of the knee is reported.     

Soft tissue tumours of the retroperitoneum

Purpose. This review summarizes the more prevalent soft tissue tumours arising in the retroperitoneum and highlights some recent fundamental and diagnostic developments relevant to mesenchymal tumours.Discussion. The retroperitoneum is an underestimated site for benign and malignant neoplastic disease, and represents the second most common site of origin of primary malignant soft tissue tumours (sarcomas) after the deep tissues of the lower extremity. In contrast to the predominance of benign soft tissue lesions over malignant sarcomas elsewhere, retroperitoneal mesenchymal lesions are far more likely to be malignant. The differential diagnosis is primarily with the more common lymphoproliferative and parenchymatous epithelial lesions arising in this area, and with metastatic disease from known or unknown primary sites elsewhere.The most prevalent mesenchymal tumours at this site are of a lipomatous, myogenic or neural nature.Their generally late clinical presentation and poorly accessible location provides numerous clinical challenges; optimal radiological imaging and a properly performed biopsy are essential cogs in the management route. Histopathological diagnosis may be complicated, but has been aided by developments in the fields of immunohistochemistry and tumour (cyto)genetics. Despite significant advances in oncological management protocols, the prognosis remains generally less favourable than for similar tumours at more accessible sites.     

The value of FDG-PET in the detection, grading and response to therapy of soft tissue and bone sarcomas; a systematic review and meta-analysis

BACKGROUND: Sarcomas represent a significant diagnostic and therapeutic challenge that requires techniques to provide better assessment of the disease than provided by traditional means. FDG-PET depicts the increased metabolism in abnormal tissues, enabling visualisation and quantification in vivo. The objective of this review was to assess the diagnostic value of FDG-PET in the detection, grading and therapy response of soft tissue and bone sarcomas. METHODS: A systematic review and meta-analysis of clinical studies on FDG-PET and sarcomas was conducted. Databases of PubMed, Embase and Cochrane were searched for studies. Besides that, the references of identified studies were reviewed. Three reviewers independently assessed the methodological quality. Statistical pooling was possible for studies concerning detection and grading of studies with mixed sarcomas (soft tissue and bone) and studies with soft tissue sarcomas only. RESULTS: Twenty-nine studies met the inclusion criteria. There was disagreement between the reviewers in 21.5% of the questions from the criteria list. The methodological quality of most of the included studies was poor. Pooled sensitivity, specificity and accuracy of PET for the detection of sarcomas were 0.91, 0.85 and 0.88, respectively. The difference between the mean Standard Uptake Value (SUV) in malignant and benign tumours for the studies concerning mixed and soft tissue sarcomas was statistically significant, as well as the difference in FDG uptake between low and high grade mixed sarcomas. CONCLUSIONS: The meta-analysis in this study was limited by the fact that only a few studies had mutual comparable outcome parameters. Moreover, the methodological quality of the studies was generally poor. Nevertheless, our results indicate that FDG-PET can discriminate between sarcomas and benign tumours and low and high grade sarcomas based on the mean SUV. The diagnostic implications of these results have to be investigated, especially the discrimination between benign tumours and low grade sarcomas. Based on this meta-analysis, there is no indication to use FDG-PET in the standard treatment of sarcomas. In the future PET imaging in bone and soft tissue sarcomas should be directed to the clinical implication for the detection and grading of sarcomas and the treatment evaluation of locally advanced sarcomas.     

Biologie moléculaire des sarcomes des tissus mous

Soft tissue sarcoma includes tumours of various histological origins, with variable aggressiveness, and whose diagnosis, which determines treatment effectiveness, sometimes remains difficult to establish. Heterogeneous on the genetic level, these tumours can be classified according to our understanding of their molecular genetics: approximately 40% of sarcomas are characterized by a specific translocation or mutation. The remaining 60% have no specific modifications. In this group, approximately 20% are undifferentiated sarcomas with very simple genetics similar to differentiated lpiposarcomas, while leiomyosarcomas, pleomorphic rhabdomyosarcomas, pleomorphic liposarcomas, undifferentiated pleomorphic sarcomas, and, in particular, malignant fibrous histocytomas (MFH) are genetically very unstable, no specific rearrangement having been identified. Thanks to a number of technological advances, all of these genetic characteristics play a role in the molecular diagnosis of soft tissue sarcoma.     

Bacterial targeted tumour therapy-dawn of a new era

Original observation of patients' spontaneous recovery from advanced tumours after an infection or a "fever" inspired extensive research. As a result, Coley's toxin for the therapy of sarcomas and live Bacillus Calmette-Guerin (BCG) for bladder cancer were born. In addition, three genera of anaerobic bacteria have been shown to specifically and preferentially target solid tumours and cause significant tumour lyses. Initial research had focused on determining the best tumour colonizing bacteria, and assessing the therapeutic efficacy of different strategies either as a single or combination treatment modalities. However, although clinical trials were carried out as early as the 1960s, lack of complete tumour lyses with injection of Clostridial spores had limited their further use. Recent progress in the field has highlighted the rapid development of new tools for genetic manipulation of Clostridia which have otherwise been a hurdle for a long time, such as plasmid transformation using electroporation that bore the problems of inefficiency, instability and plasmid loss. A new Clostridium strain, C. novyi-NT made apathogenic by genetic modification, is under clinical trials. New genetic engineering tools, such as the group II intron has shown promise for genetic manipulation of bacteria and forecast the dawn of a new era for a tumour-targeted bacterial vector system for gene therapy of solid tumours. In this review we will discuss the potential of genetically manipulated bacteria that will usher in the new era of bacterial therapy for solid tumours, and highlight strategies and tools used to improve the bacterial oncolytic capability.     

Chimiothérapie des sarcomes des tissus mous métastatiques et localement avancés

Only two drugs, doxorubicin and ifosfamide, have demonstrated consistent response rates greater than 15% in phase-II trials with more than 30 patients. The new century has clearly begun a challenging period that brings into question the concept of the clinical trial for locally advanced and metastatic soft tissue sarcoma (STM). New active drugs are urgently needed for the treatment of sarcoma, and one of the main goals of clinical trials that assess the activity of new agents in well-known, advanced chemoresistant tumours is to identify, in a small cohort, potentially active drugs by comparing them to agents previously determined to be inactive. Due to the heterogeneity of both the tumours and the patients participating in phase-II trials, results are often inconclusive and controversial. Different histological subtypes behave like different diseases, with varying chemosensitivity (liposarcoma vs leiomyosarcoma). Overall survival and the full or partial response to chemotherapy, therefore, cannot be predicted by the same factors, using retrospective analysis; consequently, response rates should not be the only end points in assessing new agents and drug combinations for sarcoma. In terms of objective response (WHO response criteria), which, today, defines the activity of chemotherapy and biotherapy, the results produced by new drugs have been disappointing. None of the following agents have achieved an objective response rate greater than 15% in palliative care situations: taxanes, liposomal doxorubicin, gemcitabine, topotecan, and ET-743. However, under closer analysis, these studies revealed significant activity in a number of histologically distinct sarcoma subtypes: gemcitabine in uterine leiomyosarcomas, ET-743 in leiomyosarcoma and myxoid liposarcoma, and paclitaxel in angiosarcoma. These new drugs have opened up a new era of specific drugs for selected sarcomas and the emergence of a new drug treatment concept for the disease. Imatinib’s dramatic activity in advanced gastrointestinal stromal tumours (GIST) must change our strategic approach to managing patients with advanced sarcoma. The era of targeted therapy has began with the use of imatinib to treat GIST expressing a mutated tyrosine kinase receptor, and the discovery of other tumour targets, such as type-1 EGFR in synovialosarcoma, PDGFRB amplification in dermatofibrosarcoma protuberans and VEGFR amplification in many sarcomas targeted by antiangiogenic factors.     

Up-to-date monitoring of childhood cancer long-term survival in Europe: tumours of the sympathetic nervous system, retinoblastoma, renal and bone tumours, and soft tissue sarcomas.

BACKGROUND: Prognosis for most types of childhood tumours has improved during the last few decades. In this article we estimate up-to-date period survival for less common, but important childhood malignancies in Europe. METHODS: Using the database of the Automated Childhood Cancer Information System we calculated period estimates of 10-year survival for the 1995-1999 period for children aged 0-14 years diagnosed during 1985-1999 with tumours of the sympathetic nervous system (NS), retinoblastoma, renal tumours, bone tumours and soft tissue sarcomas in four European regions. RESULTS: Ten-year period survival for 1995-1999 was 66% in children with tumours of the sympathetic NS, 96% for retinoblastoma, 87% for renal tumours, 58% for bone tumours and 61% for soft tissue sarcomas. The higher period estimates, as compared with cohort and complete estimates indicate recent improvement in survival for tumours of the sympathetic NS and to a lesser extent for retinoblastoma and renal tumours. Region-specific period survival estimates were lowest for Eastern Europe for renal, bone and soft tissue tumours, but not for the other two tumour groups. CONCLUSION: There have been further improvements in the 1990s in long-term survival of children diagnosed with several malignancies, albeit to a different extent in different European regions.