Sarcoma Spheroids and Organoids-Promising Tools in the Era of Personalized Medicine.

Cancer treatment is rapidly evolving toward personalized medicine, which takes into account the individual molecular and genetic variability of tumors. Sophisticated new in vitro disease models, such as three-dimensional cell cultures, may provide a tool for genetic, epigenetic, biomedical, and pharmacological research, and help determine the most promising individual treatment. Sarcomas, malignant neoplasms originating from mesenchymal cells, may have a multitude of genomic aberrations that give rise to more than 70 different histopathological subtypes. Their low incidence and high level of histopathological heterogeneity have greatly limited progress in their treatment, and trials of clinical sarcoma are less frequent than trials of other carcinomas. The main advantage of 3D cultures from tumor cells or biopsy is that they provide patient-specific models of solid tumors, and they overcome some limitations of traditional 2D monolayer cultures by reflecting cell heterogeneity, native histologic architectures, and cell-extracellular matrix interactions. Recent advances promise that these models can help bridge the gap between preclinical and clinical research by providing a relevant in vitro model of human cancer useful for drug testing and studying metastatic and dormancy mechanisms. However, additional improvements of 3D models are expected in the future, specifically the inclusion of tumor vasculature and the immune system, to enhance their full ability to capture the biological features of native tumors in high-throughput screening. Here, we summarize recent advances and future perspectives of spheroid and organoid in vitro models of rare sarcomas that can be used to investigate individual molecular biology and predict clinical responses. We also highlight how spheroid and organoid culture models could facilitate the personalization of sarcoma treatment, provide specific clinical scenarios, and discuss the relative strengths and limitations of these models.

Platelet gel in cutaneous radiation dermatitis.

INTRODUCTION: Radiotherapy, alone or in combination with chemotherapy and/or surgery, is a fundamental and irreplaceable method of treating tumours. Nonetheless, although the technological advances made during recent years and the associated improvements in this type of treatment have reduced the incidence of complications, 5-15 % of patients still experience damage to the healthy tissues exposed to radiation. Cutaneous and mucosal lesions are severe collateral effects of radiotherapy that have an enormous impact on a patient's quality of life. Unfortunately, however, the efficacy of conventional treatments, while demonstrably useful in acute lesions, remains disputed in chronic cases. Nevertheless, numerous studies and clinical findings have demonstrated that topical, non-transfusional plasma-rich platelet gel is able to accelerate the regeneration and repair of tissues through the action of the various growth factors contained within the alpha granules of platelets. We therefore set out to evaluate the efficacy of autologous platelet gel, chosen for its limited cost and ease of preparation, in chronic cutaneous radiation dermatitis. METHODS: "Home-made" platelet gel was produced by treating platelets with autologous thrombin. The safety of the product was ensured by microbiological tests. The autologous platelet gel was applied topically once a week, for a mean duration of 35 days, to chronic third- and fourth-degree (European Pressure Ulcer Advisory Panel classification and Common Terminology Criteria for Adverse Events score) cutaneous radiation dermatitis in a group of ten patients previously treated for moderate-to-high grade (histology G2-G3) limb sarcoma by tumour excision and post-surgical radiotherapy (dose 50-64 Gy). The radiation dermatitis had appeared at different intervals after treatment and had all proved resistant to conventional treatments. RESULTS: The autologous platelet gel was found to be successful in seven out of the ten patients treated. The various phases of the healing process were observed in all cases. Platelet gel application was suspended in three patients: in one patient after one application due to tumour progression, in another patient after two applications due to development of distant metastases and in the third after six applications with only partial tissue response. At 5-year follow-up, six of the seven successfully treated patients remained free of both disease and lesion, while the remaining patient, the eldest, had passed away in the interim due to extraneous causes. CONCLUSION: Platelet gel treatment could therefore be used to bring about healing in chronic cutaneous radiation dermatitis, lending itself to better patient compliance and a favourable cost/benefit ratio, due to a reduction in the number of medications and hospital visits required.

YY1 overexpression is associated with poor prognosis and metastasis-free survival in patients suffering osteosarcoma.

BACKGROUND: The polycomb transcription factor Yin Yang 1 (YY1) overexpression can be causally implicated in experimental tumor growth and metastasization. To date, there is no clinical evidence of YY1 involvement in outcome of patients with osteosarcoma. Prognosis of osteosarcoma is still severe and only few patients survive beyond five years. We performed a prospective immunohistochemistry analysis to correlate YY1 immunostaining with metastatic development and survival in a selected homogeneous group of patients with osteosarcoma. METHODS: We studied 41 patients suffering from osteosarcoma (stage II-IVa). Multivariate analysis was performed using Cox proportional hazard regression to evaluate the correlation between YY1 expression and both metastasis development and mortality. RESULTS: YY1 protein is not usually present in normal bone; in contrast, a high number of patients (61%) showed a high score of YY1 positive cells (51-100%) and 39% had a low score (10-50% positive cells). No statistical difference was found in histology, anatomic sites, or response to chemotherapy between the two degrees of YY1 expression. Cox regression analysis demonstrated that the highest score of YY1 expression was predictive of both low metastasis-free survival (HR = 4.690, 95%CI = 1.079-20.396; p = 0.039) and poor overall survival (HR = 8.353, 95%CI = 1.863-37.451 p = 0.006) regardless of the effects of covariates such as age, gender, histology and chemonecrosis. CONCLUSION: Overexpression of YY1 in primary site of osteosarcoma is associated with the occurrence of metastasis and poor clinical outcome.

Involvement of the soluble urokinase receptor in chondrosarcoma cell mobilization.

High levels of urokinase receptor (uPAR) in tissue and serum of patients with chondrosarcoma correlate with poor prognosis. First, we analyzed the uPAR levels in tissues and plasma of five patients affected by chondrosarcoma. Interestingly, very high levels of uPAR and its soluble forms (SuPAR) were found on tumor cell surfaces and plasma, respectively, of two patients with lung metastases. Therefore, to investigate the role of SuPAR in chondrosaromas, we generated a primary cell culture from a chondrosarcoma tissue overexpressing uPAR on cell surfaces. We found that chondrosarcoma-like primary culture cells release a large amount of SuPAR in the medium. In vitro, SuPAR elicits chondrosarcoma cell migration likely through its uPAR(88-92) sequence, since the DII(88-183) or DIIDIIR(88-284) uPAR domains retain motogen effect whereas DI(1-87) or DIII(184-284) domains, both lacking the uPAR(88-92) sequence, are ineffective. Chondrosarcoma cells cross matrigel in response to SuPAR, and their invasion capability is abrogated by RERF peptide which inhibits uPAR(88-92) signalling. These findings assign a role to uPAR in mobilizing chondrosarcoma cells and suggest that RERF peptide may be regarded as a prototype to generate new therapeutics for the chondrosarcoma treatment.

Crosstalk between Macrophages and Myxoid Liposarcoma Cells Increases Spreading and Invasiveness of Tumor Cells.

Myxoid liposarcoma (MLPS) is the second most common subtype of liposarcoma and has tendency to metastasize to soft tissues. To date, the mechanisms of invasion and metastasis of MLPS remain unclear, and new therapeutic strategies that improve patients' outcomes are expected. In this study, we analyzed by immunohistochemistry the immune cellular components and microvessel density in tumor tissues from patients affected by MLPS. In order to evaluate the effects of primary human MLPS cells on macrophage polarization and, in turn, the ability of macrophages to influence invasiveness of MLPS cells, non-contact and 3D organotypic co-cultures were set up. High grade MLPS tissues were found heavily vascularized, exhibited a CD3, CD4, and CD8 positive T lymphocyte-poor phenotype and were massively infiltrated by CD163 positive M2-like macrophages. Conversely, low grade MLPS tissues were infiltrated by a discrete amount of CD3, CD4, and CD8 positive T lymphocytes and a scarce amount of CD163 positive macrophages. Kaplan-Meier analysis revealed a shorter Progression Free Survival in MLPS patients whose tumor tissues were highly vascularized and heavily infiltrated by CD163 positive macrophages, indicating a clear-cut link between M2-like macrophage abundance and poor prognosis in patients. Moreover, we documented that, in co-culture, soluble factors produced by primary human MLPS cells induce macrophage polarization toward an M2-like phenotype which, in turn, increases MLPS cell capability to spread into extracellular matrix and to cross endothelial monolayers. The identification of M2-like polarization factors secreted by MLPS cells may allow to develop novel targeted therapies counteracting MLPS progression.

Outcome in dedifferentiated chondrosarcoma for patients treated with multimodal therapy: Results from the EUROpean Bone Over 40 Sarcoma Study.

INTRODUCTION: The role of chemotherapy for patients with dedifferentiated chondrosarcoma (DDCS) is still under discussion. Here, we present the outcome in patients with DDCS treated with intensive chemotherapy from the EUROpean Bone Over 40 Sarcoma Study. MATERIALS AND METHODS: The chemotherapy regimen included doxorubicin, ifosfamide and cisplatin. Postoperative methotrexate was added in case of poor histological response. Toxicity was graded based on the National Cancer Institute expanded common toxicity criteria, version 2.0, and survival was analysed using Kaplan-Meier curves, log-rank tests and univariate Cox regression models. RESULTS: Fifty-seven patients with DDCS (localised, 34 [60%]; metastatic, 23 [40%]) aged 42-65 years were included. Surgical complete remission (SCR) was achieved in 36 (63%) patients. The median overall survival (OS) was 24 months (95% confidence interval, 22-25), and the 5-year OS was 39%. Patients with extremity localisation had a 5-year OS of 49% compared with 29% in patients with a central tumour (P = 0.08). Patients with localised disease had a 5-year OS of 46%, whereas patients with metastatic disease had a 5-year OS of 29% (P = 0.12). Patients in SCR had a 5-year OS of 49%, whereas patients not in SCR had a 5-year OS of 23% (P = 0.004). Chemotherapy toxicity was considerable but manageable. There was no treatment-related death, and 39 (70%) patients received ≥6 cycles of the planned nine chemotherapy cycles. CONCLUSIONS: Adding intensive chemotherapy to surgery for treatment of DDCS is feasible and shows favourable survival data compared with previous reports. With the limitations of data from a non-controlled trial, we conclude that chemotherapy could be considered in the management of patients aged >40 years.

Inhibiting Monocyte Recruitment to Prevent the Pro-Tumoral Activity of Tumor-Associated Macrophages in Chondrosarcoma.

Chondrosarcomas (CHS) are malignant cartilaginous neoplasms with diverse morphological features, characterized by resistance to chemo- and radiation therapies. In this study, we investigated the role of tumor-associated macrophages (TAM)s in tumor tissues from CHS patients by immunohistochemistry. Three-dimensional organotypic co-cultures were set up in order to evaluate the contribution of primary human CHS cells in driving an M2-like phenotype in monocyte-derived primary macrophages, and the capability of macrophages to promote growth and/or invasiveness of CHS cells. Finally, with an in vivo model of primary CHS cells engrafted in nude mice, we tested the ability of a potent peptide inhibitor of cell migration (Ac-d-Tyr-d-Arg-Aib-d-Arg-NH2, denoted RI-3) to reduce recruitment and infiltration of monocytes into CHS neoplastic lesions. We found a significant correlation between alternatively activated M2 macrophages and intratumor microvessel density in both conventional and dedifferentiated CHS human tissues, suggesting a link between TAM abundance and vascularization in CHS. In 3D and non-contact cu-culture models, soluble factors produced by CHS induced a M2-like phenotype in macrophages that, in turn, increased motility, invasion and matrix spreading of CHS cells. Finally, we present evidence that RI-3 successfully prevent both recruitment and infiltration of monocytes into CHS tissues, in nude mice.

Cell invasiveness in sarcomas: a possibly useful clinical correlation.

AIMS AND BACKGROUND: The prognosis of each individual patient affected by sarcoma, including those with low histopathologic grading, cannot be reliably predicted at the time of surgery. We have developed an in vitro cell invasion assay on early primary cell cultures derived from surgically removed sarcomas. METHODS: Primary cell cultures were subjected to in vitro cell invasion assays by using Boyden chambers, filters coated with matrigel and fetal bovine serum as a source of chemoattractant. For each primary cell culture, the sarcoma cell invasion index was determined in comparison with the percentage of human fibrosarcoma HT1080 cell invasion extent. The cell invasion index of 7 different sarcomas was evaluated in respect to the outcome of the disease, after a follow-up ranging from 14 to 48 months. RESULTS: Data evidenced that a low cell invasion index (39.7% +/- 8.9) was retained by tumor cells derived from patients with no progression of the disease and with a longer interval of disease-free survival (21 +/- 0.8 months). However, an increase in cell invasion index (61% +/- 5) was retained by tumor cells derived from patients with progression of the disease and with a shorter disease-free survival (9 +/- 3 months). Overall, although only 7 cases were analyzed, a statistically significant correlation was found between disease-free survival and cell invasion index (P = 0.003). CONCLUSIONS: Our data support the possibility that cell invasion assays performed in vitro on cells derived from human sarcomas may be predictive of a more aggressive form of the disease.

Fine needle aspiration of metastatic epithelioid angiosarcoma: a report of 2 cases.

BACKGROUND: Epithelioid angiosarcomas (EAs) are uncommon mesenchymal tumors occurring in the thyroid, deep-seated soft tissues, parenchymal organs and, more rarely, superficial soft tissues of the head and neck. Due to their cytologic and immunocytochemical presentation on fine needle aspiration cytology (FNAC) samples, these neoplasms may closely mimic a number of different tumors, potentially causing an erroneous cytopathologic diagnosis unless immunophenotypical markers of vascular differentiation are sought in the cellular material. CASES: A 68-year-old man with a 1-year history of total thyroidectomy for EA presented with a suspicious right neck node and underwent FNA. A 63-year-old woman with a history of recurring multiple scalp nodules diagnosed as EA ultimately developed small multiple, bilateral lymph nodes in the neck and underwent FNA. In both cases a cytopathologic diagnosis of metastatic EA was made. CONCLUSION: The cytopathologic diagnosis of EA is a challenge. Knowledge of the clinical history is of great help in diagnosing metastatic lesions. The cytopathologicpicture of metastases is a useful way for cytopathologists to gain confidence with presentaton of this rare entity in primary sites on FNAC samples. Cytopathologic hints of vascular differentiation should be sought in the cytopathologic material when a diagnosis of EA is entertained.

Intracardiac metastasis originated from chondrosarcoma.

Primary cardiac tumors are extremely rare. By comparison, metastatic involvement of the heart is over 20 times more common and has been reported in autopsy series in up to one in five patients dying of cancer. Cardiac metastasis of chondrosarcoma is absolutely not frequent. In the recent literature, a cardiac metastasis from chondrosarcoma has never been described. We report the case of an 18-year-old man with a diagnosis of cardiac metastasis that originated from a left scapular chondrosarcoma. Chondrosarcoma is a skeletal tumor with various grades of malignancy, rapidly evolving, and with a strong tendency to metastasize, with low responsiveness to chemotherapy. The onset of characteristic systemic symptoms in the late stage of the disease led to the diagnosis of a mass localized in the right atrium. Management and differential diagnosis of infective heart lesions were also very complex in a rapidly evolving life-threatening condition.

New emerging drugs in soft tissue sarcoma.

Doxorubicin and ifosfamide are the two most active drugs in the treatment of patients with advanced, soft tissue sarcoma (STS) of most histologic subtypes, aside from gastrointestinal stromal tumor (GIST). However, after failure of these drugs, alone or in combination, patients with advanced STS have few therapeutic options and the search for new active drugs is well worth pursuing. ET-743, a DNA minor groove binder, which blocks cell cycle progression in G2/M phase through a p53-independent apoptotic process, represents the most promising among novel compounds in STS, since recently completed phase II trials have consistently shown high survival, in spite of the relatively low incidence of major objective responses. The potential for combination with other active compounds further increases the appeal of ET-743. Imatinib mesylate is being tested also in STS other than GIST, which can overexpress one or more of the tyrosine kinases inhibited by imatinib; however, negative data have recently been presented. Clinical studies with a number of other compounds are ongoing or planned. However, investigators involved in the management of patients with advanced STS are to be increasingly aware of the emergence of new molecular targets and genetic profiles in different histologic subtypes, according to which treatment strategies should be adapted.

Expression of transcription factor Yin Yang 1 in human osteosarcomas.

The transcription factor Yin Yang 1 (YY1) is known to be present in some human cancer cell lines and its expression correlates with immune-mediated apoptosis. By using Western blot analysis, we have shown that the YY1 protein is strongly expressed in human osteosarcoma cells and localised mainly in the nucleus. Moreover, by using immunohistochemistry and RT-PCR techniques, we have analysed the expression of YY1 protein in biopsies from human osteosarcomas. The YY1 protein was not detectable by immunohistochemistry in osteoid tissue. However, its expression was restricted to osteosarcoma tissues. These data were confirmed by densitometric analysis of RT-PCR for YY1 expression. Thus, YY1 gene activation appears to be an early event in the process of osteoblastic transformation and its detection may represent, together with the analysis of other established markers, a useful diagnostic tool in human osteosarcomas.

Primary gastrointestinal stromal tumor of the liver with lung metastases successfully treated with STI-571 (imatinib mesylate).

We report a case of a primary malignant GIST of the liver metastatic to the lung in a 37 years-old man. The liver tumor showed histological feature of a GIST and expressed vimentin, and diffusely exhibited CD117. One year after the resection of the liver mass, the patient developed multiple small lung metastases which completely disappeared with STI-571 (imatinib mesylate--Gleevec) therapy. C.T. or PET did not show any mass in the abdomen. These findings suggest that the liver mass was a primary rather than a metastatic tumour. They also support the hypothesis that GIST could originate from undifferentiated mesenchymal cells capable to differentiate toward a pacemaker cell phenotype, which are present in sites other than the G.I. tract.

Adjuvant treatment of high-risk adult soft tissue sarcomas: a survey by the Italian Sarcoma Group.

AIMS AND BACKGROUND: After the first adjuvant study on adult soft tissue sarcomas was concluded, the participating institutions continued to select and treat patients according to that protocol. The aim of this study was to test the protocol reproducibility when applied as a standard practice. METHODS: A call for retrospective data was launched in June 1999 (self-referral of consecutive unregistered patients); thereafter, a prospective follow-up was performed. The treatment regimen consisted of epirubicin (60 mg/m2 days 1 and 2), ifosfamide (3 g/m2/die for 3 days) and equimolar doses of 6-mercapto-ethansulfonate (MESNA), with 300 microg G-CSF administered subcutaneously from day +8 until recovery, every 3 weeks for a total of 5 cycles. RESULTS: From November 1996 to June 1999, 55 high-risk, adult patients were treated. The average median dose intensity was 89% of the planned program. Grade 3-4 toxicities were leukopenia (49%), thrombocytopenia (14%), transfusion requiring anemia in 7 patients (16%), and alopecia in all patients (100%). After a median follow-up of 70 months, 23 patients (41.8%) relapsed and 19 died. Median disease-free, local disease-free and overall survival rates have not yet been reached. The disease-free survival rates at 2 and 4 years were 73% and 57%, respectively; the corresponding overall survival rates were 91% and 70%, respectively. CONCLUSIONS: The feasibility and reproducibility of the original protocol were confirmed, since disease-specific overall survival and disease-free survival rates at the same period of observation and with the same prolonged follow-up did not differ.

Confirmed Activity and Tolerability of Weekly Paclitaxel in the Treatment of Advanced Angiosarcoma.

Background. In several prospective and retrospective studies, weekly paclitaxel showed promising activity in patients with angiosarcoma. Patients and Methods. Our study was originally designed as a prospective, phase II multicenter trial for patients younger than 75, with ECOG performance status 0-2, affected by locally advanced or metastatic angiosarcoma. Patients received paclitaxel 80 mg/m(2) intravenously, at days 1, 8, and 15 every 4 weeks, until disease progression or unacceptable toxicity. Primary endpoint was objective response. Results. Eight patients were enrolled but, due to very slow accrual, the trial was prematurely stopped and further 10 patients were retrospectively included in the analysis. Out of 17 evaluable patients, 6 patients obtained an objective response (5 partial, 1 complete), with an objective response rate of 35% (95% confidence interval 17%-59%). Of note, five responses were obtained in pretreated patients. In the paper, details of overall survival, progression-free survival, and tolerability are reported. Conclusions. In this small series of patients with locally advanced or metastatic angiosarcoma, weekly paclitaxel was confirmed to be well tolerated and active even in pretreated patients.

Biological prognostic factors in adult soft tissue sarcomas.

Adult soft tissue sarcomas (STSs) are a rare group of highly heterogeneous neoplasms arising in different tissues. They are locally aggressive and can produce recurrence and distant metastasis. The most common metastatic sites are lung, lymph nodes, liver, bone and soft tissues. Staging for STSs has been based on some prognostic information: grade (low vs. intermediate/high grade), size (small vs. large tumors), depth of infiltration (superficial vs. deep neoplasms) and presence or not of distant metastasis. In the last 10 years, a plethora of new markers (proliferation markers and DNA alteration, P-gp, p53, TLS-CHOP, cyclins, survivin, TERT, PAX3-PAX7/FKHR, SYT-SSX1/2, VEGF, E-cadherin and beta-catenin, nm23, SKP-2, p27, CD40) has been studied with regard to their role in promoting progression (in a laboratory setting) and then determining prognosis and therapy (in a clinical setting). In the present survey, we focused on the role of new biological prognostic factors in STSs and also reported the quality of such studies with an ad hoc designed questionnaire.

Prognostic value of CD40 in adult soft tissue sarcomas.

PURPOSE: The purpose is to evaluate the expression of CD40, a membrane protein predominantly expressed on B cells, dendritic cells, and macrophages, in a series of adult soft tissue sarcomas and to test its possible prognostic value. EXPERIMENTAL DESIGN: CD40 expression was studied by immunohistochemistry. Correlations with other baseline characteristics of patients and tumors were analyzed with chi(2) test. The prognostic value was studied with univariable and multivariable analysis adjusted by age, sex, tumor size, grade, location, and distant metastases. RESULTS: Eighty-two patients, between January 1994 and May 2001, were analyzed. Membrane or cytoplasmic staining for CD40 protein was absent in 30% of the tumors but present in <10% of cells in 22 (27%), in 10% to 50% in 23 (28%), and in >50% of cells in 12 (15%) tumors. There was no correlation between CD40 expression and age, sex, size, grade, and location of the primary tumor and distant metastases. With 61 patients (74.4%) progressed and 31 (37.8%) dead, CD40 expression was a significant prognostic factor for disease-free and overall survival at univariable and multivariable analysis. Patients with tumors expressing CD40 in >50% of cells had a dramatically unfavorable prognosis with median disease-free and overall survival of 7 and 17 months, respectively, and hazard ratios of relapse and death as compared with patients with CD40-negative tumors of 2.89 (95% confidence interval: 1.26-6.60) and 6.92 (95% confidence interval: 2.18-22.0), respectively. CONCLUSIONS: These data suggest that expression of CD40 protein in >50% of cells might indicate an unfavorable prognosis in adult soft tissue sarcomas.

An unusual association of malignant gastrointestinal neuroectodermal tumor (clear cell sarcoma-like) and Ewing sarcoma.

Very recently a new designation of "Malignant Neuroectodermal Gastrointestinal Tumor" has been proposed for an aggressive form of neuroectodermal tumor with features similar to that of Clear Cell Sarcoma of Soft Tissue, however without a melanocytic differentiation. Also known as "clear cell sarcoma-like tumors of the gastrointestinal tract", these tumors show some features strongly suggesting an origin from a gastrointestinal neuroectodermal precursor cell unable to differentiate along the melanocytic lineage. They occur mainly in young and middle-aged adults, and have a poor prognosis with a high rate of liver and lymphnode metastases. Histologically they are composed of epithelioid or oval-to spindle cells with a sheet-like or nested pattern of growth, strongly positive for neural markers (S-100, SOX10, and vimentin) and negative for the melanocytic ones. EWSR1 gene rearrangements including EWSR1-ATF1 or EWSR1-CREB1 GENE fusions are typically assessed in these tumors. Here we report a case of malignant neuroectodermal gastrointestinal tumor which immunophenotypically unusually expressed FLI-1, occurring in a 29-year-old man with a previous medical history of Ewing sarcoma. We finally suggest that this case might be a further evidence of a link between these two entities.

In vitro and in vivo expression of somatostatin receptors in intermediate and malignant soft tissue tumors.

BACKGROUND: Previous studies showed that the subtype 2 of somatostatin receptors (sstr2) is generally expressed by soft tissue sarcomas. MATERIALS AND METHODS: Using reverse transcription-polymerase chain reaction (RT-PCR), the present study evaluated the expression of sstr mRNA in 31 human intermediate and malignant soft tissue tumors. In 8 patients somatostatin receptor scintigraphy was performed to detect soft tissue tumor sites and visualize in vivo sstr expression. RESULTS: Somatostatin receptors were identified in 84% of the tumors analyzed by RT-PCR analysis. sstr1 and sstr2 were the receptors most frequently detected. Somatostatin receptor scintigraphy was able to identify primary and/or metastatic sites in 7 out of 8 patients, with an overall sensitivity per site of 87%. Concordant results were found between in vitro and in vivo techniques. CONCLUSION: The wide expression of sstrs in soft tissue tumors suggest a relevant role for these receptors in diagnosis and may have therapeutic applications.