Angelo Paolo Dei Tos

Pazopanib for metastatic soft-tissue sarcoma (PALETTE): a randomised, double-blind, placebo-controlled phase 3 trial.

BACKGROUND Pazopanib, a multitargeted tyrosine kinase inhibitor, has single-agent activity in patients with advanced non-adipocytic soft-tissue sarcoma. We investigated the effect of pazopanib on progression-free survival in patients with metastatic non-adipocytic soft-tissue sarcoma after failure of standard chemotherapy. METHODS This phase 3 study was done in 72 institutions, across 13 countries. Patients with angiogenesis inhibitor-naive, metastatic soft-tissue sarcoma, progressing despite previous standard chemotherapy, were randomly assigned by an interactive voice randomisation system in a 2:1 ratio in permuted blocks (with block sizes of six) to receive either pazopanib 800 mg once daily or placebo, with no subsequent cross-over. Patients, investigators who gave the treatment, those assessing outcomes, and those who did the analysis were masked to the allocation. The primary endpoint was progression-free survival. Efficacy analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00753688. FINDINGS 372 patients were registered and 369 were randomly assigned to receive pazopanib (n=246) or placebo (n=123). Median progression-free survival was 4·6 months (95% CI 3·7-4·8) for pazopanib compared with 1·6 months (0·9-1·8) for placebo (hazard ratio [HR] 0·31, 95% CI 0·24-0·40; p<0·0001). Overall survival was 12·5 months (10·6-14·8) with pazopanib versus 10·7 months (8·7-12·8) with placebo (HR 0·86, 0·67-1·11; p=0·25). The most common adverse events were fatigue (60 in the placebo group [49%] vs 155 in the pazopanib group [65%]), diarrhoea (20 [16%] vs 138 [58%]), nausea (34 [28%] vs 129 [54%]), weight loss (25 [20%] vs 115 [48%]), and hypertension (8 [7%] vs 99 [41%]). The median relative dose intensity was 100% for placebo and 96% for pazopanib. INTERPRETATION Pazopanib is a new treatment option for patients with metastatic non-adipocytic soft-tissue sarcoma after previous chemotherapy. FUNDING GlaxoSmithKline.

Calretinin: A novel immunocytochemical marker for mesothelioma

Immunohistochemistry is a powerful diagnostic adjunct in the differential diagnosis between malignant mesothelioma (especially of the epithelial type) and adenocarcinoma metastatic to the serous membranes. Most of the immunological probes commonly used, however, recognize antigens expressed by the epithelial malignancies and absent from mesothelial cells and mesotheliomas. Probes suitable for the positive identification of mesotheliomas are comparatively scarce and much less commonly used because of their reduced sensitivity and specificity, their unsuitability for staining routinely fixed and embedded tissues, or their lack of commercial availability. We now document that two different polyclonal antisera to calretinin consistently immunostain mesothelial cells and malignant mesotheliomas both in routinely fixed and embedded tissue sections and in cytological preparations of serous effusions. The diagnostic sensitivity of this novel immunocytochemical approach reached 100%, allowing immunostaining of all 44 mesotheliomas investigated, which included five biphasic and three sarcomatoid types. The specificity of calretinin immunoreactivity was checked against 294 adenocarcinomas of different origin (19 serosal metastases and 275 primary tumors potentially able to metastatize to serosal membranes) relevant for the discussion of the differential diagnosis with malignant mesothelioma: only 28 cases showed focal immunoreactivity for calretinin. We conclude that calretinin is a most useful marker for the positive identification of malignant mesotheliomas.

Risk of recurrence of gastrointestinal stromal tumour after surgery: an analysis of pooled population-based cohorts.

BACKGROUND The risk of recurrence of gastrointestinal stromal tumour (GIST) after surgery needs to be estimated when considering adjuvant systemic therapy. We assessed prognostic factors of patients with operable GIST, to compare widely used risk-stratification schemes and to develop a new method for risk estimation. METHODS Population-based cohorts of patients diagnosed with operable GIST, who were not given adjuvant therapy, were identified from the literature. Data from ten series and 2560 patients were pooled. Risk of tumour recurrence was stratified using the National Institute of Health (NIH) consensus criteria, the modified consensus criteria, and the Armed Forces Institute of Pathology (AFIP) criteria. Prognostic factors were examined using proportional hazards and non-linear models. The results were validated in an independent centre-based cohort consisting of 920 patients with GIST. FINDINGS Estimated 15-year recurrence-free survival (RFS) after surgery was 59·9% (95% CI 56·2-63·6); few recurrences occurred after the first 10 years of follow-up. Large tumour size, high mitosis count, non-gastric location, presence of rupture, and male sex were independent adverse prognostic factors. In receiver operating characteristics curve analysis of 10-year RFS, the NIH consensus criteria, modified consensus criteria, and AFIP criteria resulted in an area under the curve (AUC) of 0·79 (95% CI 0·76-0·81), 0·78 (0·75-0·80), and 0·82 (0·80-0·85), respectively. The modified consensus criteria identified a single high-risk group. Since tumour size and mitosis count had a non-linear association with the risk of GIST recurrence, novel prognostic contour maps were generated using non-linear modelling of tumour size and mitosis count, and taking into account tumour site and rupture. The non-linear model accurately predicted the risk of recurrence (AUC 0·88, 0·86-0·90). INTERPRETATION The risk-stratification schemes assessed identify patients who are likely to be cured by surgery alone. Although the modified NIH classification is the best criteria to identify a single high-risk group for consideration of adjuvant therapy, the prognostic contour maps resulting from non-linear modelling are appropriate for estimation of individualised outcomes. FUNDING Academy of Finland, Cancer Society of Finland, Sigrid Juselius Foundation and Helsinki University Research Funds.

Rare cancers are not so rare: the rare cancer burden in Europe

PURPOSE Epidemiologic information on rare cancers is scarce. The project Surveillance of Rare Cancers in Europe (RARECARE) provides estimates of the incidence, prevalence and survival of rare cancers in Europe based on a new and comprehensive list of these diseases. MATERIALS AND METHODS RARECARE analysed population-based cancer registry (CR) data on European patients diagnosed from 1988 to 2002, with vital status information available up to 31st December 2003 (latest date for which most CRs had verified data). The mean population covered was about 162,000,000. Cancer incidence and survival rates for 1995-2002 and prevalence at 1st January 2003 were estimated. RESULTS Based on the RARECARE definition (incidence <6/100,000/year), the estimated annual incidence rate of all rare cancers in Europe was about 108 per 100,000, corresponding to 541,000 new diagnoses annually or 22% of all cancer diagnoses. Five-year relative survival was on average worse for rare cancers (47%) than common cancers (65%). About 4,300,000 patients are living today in the European Union with a diagnosis of a rare cancer, 24% of the total cancer prevalence. CONCLUSION Our estimates of the rare cancer burden in Europe provide the first indication of the size of the public health problem due to these diseases and constitute a useful base for further research. Centres of excellence for rare cancers or groups of rare cancers could provide the necessary organisational structure and critical mass for carrying out clinical trials and developing alternative approaches to clinical experimentation for these cancers.

Coordinated expression and amplification of the MDM2, CDK4, and HMGI‐C genes in atypical lipomatous tumours

Atypical lipomatous tumours (ALTs) represent a distinctive subset of mesenchymal neoplasms featuring mature adipocytic differentiation. Most ALTs are characterized cytogenetically by the presence of supernumerary ring and/or long marker chromosomes derived from the chromosomal region 12q13–15. The 12q13–15 chromosome region contains several genes which may play an important role in human tumorigenesis. A series of ALTs was analysed by investigating the MDM2, CDK4, and HMGI‐C genes and their proteins. The study was extended to a series of ordinary lipomas, to determine whether the immunohistochemical investigation of these gene products might play any diagnostic role. Cytogenetic analysis revealed the presence of various cytogenetic aberrations involving the 12q13–15 region in 11/18 (61%) lipomas and of ring chromosomes in all ALTs. Overexpression of mdm2 protein was observed in 6/12 (50%) atypical lipomatous tumours. All lipomas were mdm2‐negative. cdk4 overexpression was present in 100% of ALTs. Weak cdk4 immunopositivity was detected in 2/18 (11%) ordinary lipomas in a minority of cells. HMGI‐C immunopositivity was observed in 10/12 (83%) ALTs. Positive immunoreactivity was also observed in 8/18 (44%) lipomas. Southern blot analysis revealed amplification of the CDK4 and MDM2 genes in 3/5 ALTs analysed. HMGI‐C was amplified in 3/5 cases and was deleted in one case. Mutation analysis of the CDK4 gene did not demonstrate any mutation. These data support the hypothesis that ordinary lipomas may form a molecular genetic and morphological continuum with ALT. At one end of the spectrum are lipomas characterized by 12q13–15 rearrangements and HMGI‐C activation and at the other end are ALTs with ring chromosomes, 12q13–15 amplification with overrepresentation of the HMGI‐C, CDK4 or MDM2 genes, and aberrant cdk4, mdm2, and HMGI‐C protein expression. These findings not only provide insights into the molecular pathogenesis of lipomatous tumours, but also indicate that the immunohistochemical analysis of mdm2 and cdk4 may help to increase diagnostic accuracy. Copyright

Myopericytoma of skin and soft tissues: clinicopathologic and immunohistochemical study of 54 cases.

Perivascular neoplasms comprise traditionally glomus tumor and hemangiopericytoma (HPC). Whereas glomus tumor represents a well-defined entity, the existence of HPC as a separate entity has been questioned because a number of neoplasms of different lines of differentiation are characterized by a HPC-like vascular growth pattern. Myopericytoma represents a recently delineated entity showing a HPC-like vascular pattern. A large series of myopericytoma of skin and soft tissues has been analyzed to further characterize the clinicopathologic spectrum of this entity. Fifty-four cases of myopericytoma of skin and soft tissues were retrieved and the histology reviewed. Immunohistochemical stainings using alpha-smooth muscle actin (ASMA), desmin, and h-caldesmon antibodies were performed, and clinical data and follow-up information were obtained from referring pathologists. Thirty-four patients were male and 18 were female (gender was unknown in 2 cases). Patient age ranged from 13 to 87 years (median, 52 years). The lower extremities were most commonly affected (26 cases) followed by the upper extremities (16 cases), the head and neck region (4 cases), and the trunk (2 cases); exact location was unknown in 5 cases. In 20 cases, the neoplasms were confined to the dermis, in 6 cases an extension into the subcutis was seen, and 24 as well as 4 cases arose in subcutaneous and deep soft tissue, respectively. Two cases were multicentric; and in 1 of these patients, multiple anatomic regions were involved. Histologically, in all cases, numerous thin-walled vessels and a concentric, perivascular arrangement of ovoid, plump spindled to round myoid tumor cells was seen. However, a broad morphologic spectrum ranging from hypocellular, fibroma-like (3 cases), myofibroma-like (2 cases), angioleiomyoma-like (12 cases), and HPC-like neoplasms (13 cases) to classic myopericytomas (14 cases) and immature, cellular lesions (2 cases) was noted. In addition, 2 neoplasms with focal glomoid features, 5 intravascular, and 1 malignant myopericytomas were found. Prominent cytologic atypia and increased proliferative activity (>3 mitoses/10 high power fields) was seen in 4 and 2 cases, respectively. Immunohistochemically, all cases tested stained positively for ASMA. In addition, 29 of 32 cases tested stained positively for h-caldesmon, whereas desmin was only focally positive in 3 of 33 cases. Follow-up information was available in 46 cases (range, 7-168 months; median, 48 months). Despite marginal or incomplete excision in 23 of 46 cases, only 2 neoplasms (1 malignant and 1 intravascular myopericytoma) recurred locally (within 1 and 4 years, respectively). Despite overlapping morphologic features to angioleiomyoma and myofibroma, myopericytoma represents a distinct perivascular, myoid neoplasm of skin and soft tissues, characterized by a broad morphologic spectrum of concentrically, perivascularly growing myoid tumor cells that stain positively for ASMA and often for h-caldesmon, whereas desmin is usually negative. Most cases of myopericytoma behave in a benign fashion, but local recurrences and rarely metastases may occur in atypical and malignant neoplasms.

bcl-2 EXPRESSION IN PLEURAL AND EXTRAPLEURAL SOLITARY FIBROUS TUMOURS

This study evaluated the immunoreactivity for bcl‐2, a molecule involved in the control of programmed cell death, in cases of pleural (14) and extrapleural (2) solitary fibrous tumour (SFT), malignant mesotheliomas of different histological types, and a variety of extrapleural CD34‐positive and CD34‐negative spindle‐cell tumours. In all SFTs, strong and diffuse immunostaining was demonstrated with anti‐bcl‐2 antibody, sharply contrasting with the complete lack of staining observed in all mesotheliomas. The specificity of immunodetection of bcl‐2 in SFT was confirmed by immunoblot analysis, showing a band consistent with the bcl‐2 protein. At extrapleural locations, strong bcl‐2 immunoreactivity was observed in Schwannoma (2/3 cases), synovial sarcoma (4/4 cases), and all cases of CD34‐positive gastrointestinal stromal tumour (GIST; 10/10 cases). Most sarcomas were bcl‐2‐negative. Lack of bcl‐2 expression was demonstrated in tumours which can pose problems in the differential diagnosis of SFT and can exhibit haemangiopericytoma‐like features, including haemangiopericytoma (3 cases), dermatofibrosarcoma protuberans (16 cases), and deep‐seated fibrous histiocytoma (3 cases). The constitutive expression of bcl‐2 in SFT widens the spectrum of available markers for these tumours, providing a useful adjunct to their differential diagnosis in difficult cases at pleural and extrapleural sites, and contributing to the understanding of their histogenesis and molecular pathogenesis.

Utility of the immunohistochemical detection of FLI-1 expression in round cell and vascular neoplasm using a monoclonal antibody

FLI-1 nuclear transcription factor has been proposed as a useful tool in the differential diagnosis of small round cell sarcomas. Recently, FLI-1 has been reported as the first nuclear marker of endothelial differentiation. However, its clinical use has been hampered by major interpretation problems, due to the presence of background staining as well as staining variation between different lots of the same antiserum. In this study, a novel monoclonal antibody raised against the carboxyl terminal of the FLI-1 protein (clone GI146-222, BD Pharmingen) was tested in a series of small round cell and vascular neoplasms. Furthermore, in order to assess FLI-1 specificity, we analyzed its expression in a series of common epithelial and nonepithelial malignancies. In total, 15 Ewings sarcomas, 10 rhabdomyosarcomas, 5 desmoplastic small round cell tumors, 10 synovial sarcomas, 10 high-grade pleomorphic sarcomas, 10 malignant melanomas, 5 Merkels carcinomas, 10 colonic adenocarcinomas, 10 breast carcinomas, 10 lung adenocarcinomas, 20 angiosarcomas, 5 epithelioid hemangioendotheliomas, 10 Kaposis sarcomas and 10 benign hemangiomas, were stained. A strong FLI-1 immunoreactivity was detected in all Ewings sarcomas and vascular neoplasms, highlighting the high sensitivity of FLI-1 monoclonal antibody. However, 2/5 Merkels carcinomas and 1/10 malignant melanomas showed a strong nuclear immunostaining, suggesting that FLI-1 may not be so helpful in the differential diagnosis of cutaneous Ewings sarcoma. In addition, a weak immunoreactivity was found in 3/5 Merkel cell carcinomas, 3/10 synovial sarcomas, 5/10 malignant melanomas, 6/10 lung adenocarcinomas and in 1/10 breast carcinomas. In contrast, all the rhabdomyosarcomas, desmoplastic small round cell tumors, high-grade pleomorphic sarcomas and colonic adenocarcinomas tested were negative. Importantly, in contrast with previous studies, no background staining was observed. Our results indicate that FLI-1 monoclonal antibody can be reliably applied to the differential diagnosis of small round cell neoplasms of soft tissue, and confirm its important role as nuclear marker of endothelial differentiation, mainly helpful in those cases in which technical artifacts are seen by using the traditional membranous and cytoplasmic endothelial markers.

EWSR1-CREB1 and EWSR1-ATF1 Fusion Genes in Angiomatoid Fibrous Histiocytoma

Purpose: Angiomatoid fibrous histiocytoma (AFH) is a low-grade mesenchymal neoplasm which usually occurs in children and adolescents. Either FUS-ATF1 or EWSR1-ATF1 have been detected in the few cases published, pointing to the interchangeable role of FUS and EWSR1 in this entity. EWSR1-ATF1 also represents the most frequent genetic alteration in clear cell sarcoma, suggesting the existence of a molecular homology between these two histotypes. We investigated the presence of EWSR1-CREB1, recently found in gastrointestinal clear cell sarcoma, and FUS-CREB1, as well as the already reported FUS-ATF1 and EWSR1-ATF1 in a series of AFH. Experimental Design: Fourteen cases were analyzed by fluorescence in situ hybridization (FISH) on paraffin-embedded tissue sections, using a commercial EWSR1 probe and custom-designed probes for FUS, ATF1, and CREB1. In two cases, four-color FISH was also done. Reverse transcription-PCR for the four hypothetical fusion genes was done in one case, for which frozen material was available. Results: Thirteen cases showed rearrangements of both EWSR1 and CREB1, whereas one case showed the rearrangement of both EWSR1 and ATF1. Four-color FISH confirmed the results in two selected cases. Reverse transcription-PCR showed EWSR1-CREB1 transcript in the case analyzed. Conclusion: We identified the presence of either EWSR1-CREB1 or EWSR1-ATF1 in all the cases, strengthening the concept of chromosomal promiscuity between AFH and clear cell sarcoma. Either the occurrence of a second unknown tumor-specific molecular event or, perhaps more likely, divergent differentiation programs of the putatively distinct precursor cells of AFH and clear cell sarcoma might be invoked in order to explain the two different phenotypes.

Soft tissue tumors associated with EWSR1 translocation

The Ewing sarcoma breakpoint region 1 (EWSR1; also known as EWS) represents one of the most commonly involved genes in sarcoma translocations. In fact, it is involved in a broad variety of mesenchymal lesions which includes Ewings sarcoma/peripheral neuroectodermal tumor, desmoplastic small round cell tumor, clear cell sarcoma, angiomatoid fibrous histiocytoma, extraskeletal myxoid chondrosarcoma, and a subset of myxoid liposarcoma. The fusion products between EWSR1 and partners usually results in fusion of the N-terminal transcription-activating domain of EWSR1 and the C-terminal DNA-binding domain of the fusion partner, eventually generating novel transcription factors. EWSR1 rearrangement can be visualized by the means of fluorescence in situ hybridization (FISH). As soft tissue sarcomas represent a diagnostically challenging group, FISH analysis is an extremely useful confirmatory diagnostic tool. However, as in most instances a split-apart approach is used, the results of molecular genetics must be evaluated in context with morphology.