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There is considerable controversy about the treatment of asymptomatic ventricular arrhythmias in patients with congestive heart failure [1]. Antiarrhythmic therapy has been reported either to prolong survival and decrease the incidence of sudden death (SD) [2], or only to reduce mortality [3]. Patients with dilated cardiomyopathy (DC) and complex ventricular arrhythmias have been treated successfully with amiodarone and no patient has died suddenly during therapy [4]. Others have underlined that the evidence for results is still lacking [5]. We report the results of our study on the efficacy of amiodarone for the prevention of SD in patients with DC and ventricular tachycardia (VT).

The correlation between intracavitary thrombosis detected by cross sectional echocardiography and systemic embolism was studied in 126 consecutive patients with idiopathic dilated cardiomyopathy who were examined from January 1980 to September 1987. A total of 1041 serial echocardiograms were obtained with 3.5 and 5 MHz transducers. The mean follow up period was 41.2 months. The survival rate was 88% at two years and 56% at five years. Echocardiography showed intracavitary thrombi in 14 (11.1%) patients; 13 were mural and 11 were localised at the apex of the left ventricle. Twelve patients (8.4%) had systemic emboli; this corresponded to an incidence of new embolic events of 1.4 for 100 patient-years. Patients with intracavitary thrombi or systemic emboli were treated with oral anticoagulants, as were nine in functional class IV of the New York Heart Association, for 61 patient-years. The cumulative observation period for the whole population study was 418 patient-years. None of the patients with intracavitary thrombosis had embolic complications and none of those with embolism had intracavitary thrombi. Rates of intracavitary thrombosis and systemic embolism in this series were low and there was no overlap between the two events. This may have been because the patients did not have severe dilated cardiomyopathy, because echocardiography did not detect all the thrombi, or because patients were treated with oral anticoagulants. The presence of intracardiac thrombosis detected by cross sectional echocardiography is not predictive of systemic embolism in patients with idiopathic dilated cardiomyopathy. Criteria for the use of the anticoagulant treatment remain largely empirical in these cases.

In these last few years novel approaches to the treatment of solid tumours have been proposed. Therapeutic agents addressed to specific functions of the neoplastic cells seems to be very promising tools, with a low grade of toxicities. These agents are the basis of the so called targeted therapies. Small molecules inhibiting the proliferative cascade of the cancer cells and monoclonal specific antibodies against growth factor or vascular endothelial growth factor have been claimed as the promise in cancer therapy. Unfortunately, the very good results obtained in preclinical experiments have not been completely confirmed in the clinical practice. A selection of patients who could have beneficial effects from the novel agents is mandatory to avoid inappropriate therapies and also unjustified expenses.

112 consecutive asymptomatic patients who assumed alcohol in excess (1-2 g/kg/die) for 5 years or more were admitted to our hospital for detoxication. They were examined both clinically and with chest x-rays, ecg, phonocardiography, external pulse recording, and M-mode/2-D echocardiography to detect myocardial involvement. Heart disease not related to alcohol abuse was found in 6 cases. In the remaining 106/112 patients electrocardiographic abnormalities (aspecific ST-T changes, left bundle branch block, intraventricular conduction defects, left ventricular strain pattern and atrial fibrillation) were present in 18 per cent of cases. PEP, LVET intervals and PEP/LVET, were calculated only in 39/106 patients and did not differ significantly from the control group. The echocardiographic study showed hypokinesis and left ventricular dilatation in 9/106 patients. In other 5 cases echocardiographic findings were at upper limits of normal for left ventricular dimension and motility. Therefore in 13 per cent of cases a dilated cardiomyopathy was revealed by the echocardiographic study. In 6 of these 13/106 patients ecg was either normal or showed only aspecific ST-T changes. Echocardiography failed to confirm augmented left ventricular thickness and mass as reported in asymptomatic alcoholic patients in the literature. Probably several factors (different interval of time between the interruption of the alcoholic abuse and the time of examination, the quantity of alcohol in excess and the echocardiographic technique) may influence the results of such studies. The present report nevertheless points out to the validity of the echocardiographic study in the detection of subclinical myocardial involvement in alcoholic patients and should be performed in such cases.

Ice sounding radar from high altitudes is compromised by off-nadir ice surface reflections (clutter), which overlays the nadir signal of interest originating from the bedrock and/or internal ice layers. Multi-aperture antenna radar systems were developed to mitigate the impact of surface clutter allowing spatially variant digital beamforming (DBF) processing of the data received from the individual spatially separated apertures. This paper investigates four different beamforming algorithms: conventional beamsteering, nulling of clutter angles, optimum beamformer and the MVDR beamformer. Comparisons are performed based on simulations for an airborne ice sounding scenarios. In addition, real echograms are computed from data acquired by the P-band POLARIS sensor. Relevant conclusions are drawn with respect to the implementation of a future space-based ice sounding mission.

Loss of function of the succinate dehydrogenase complex characterizes 20–40% of all KIT/PDGFRA-negative GIST. Approximately half of SDH-deficient GIST patients lack SDHx mutations and are caused by a hypermethylation of the SDHC promoter, which causes the repression of SDHC transcription and depletion of SDHC protein levels through a mechanism described as epimutation. The remaining 50% of SDH-deficient GISTs have mutations in one of the SDH subunits and SDHA mutations are the most common (30%), with consequent loss of SDHA and SDHB protein expression immunohistochemically. SDHB, SDHC, and SDHD mutations in GIST occur in only 20–30% of cases and most of these SDH mutations are germline. More recently, germline mutations in SDHA have also been described in several patients with loss of function of the SDH complex. SDHA-mutant patients usually carry two mutational events at the SDHA locus, either the loss of the wild type allele or a second somatic event in compound heterozygosis. This review provides an overview of all data in the literature regarding SDHA-mutated GIST, especially focusing on the prevalence of germline mutations in SDH-deficient GIST populations who harbor SDHA somatic mutations, and offers a view towards understanding the importance of genetic counselling for SDHA-variant carriers and relatives.

Gastrointestinal stromal tumors; MiRNAs; MicroRNAs Tumores del estroma gastrointestinal; MiARN; MicroARN Tumors de l'estroma gastrointestinal; MiARN; MicroARN Gastrointestinal stromal tumors (GISTs) harboring mutations in the PDGFRA gene occur in only about 5–7% of patients. The most common PDGFRA mutation is exon 18 D842V, which is correlated with specific clinico-pathological features compared to the other PDGFRA mutated GISTs. Herein, we present a miRNA expression profile comparison of PDGFRA D842V mutant GISTs and PDGFRA with mutations other than D842V (non-D842V). miRNA expression profiling was carried out on 10 patients using a TLDA miRNA array. Then, miRNA expression was followed by bioinformatic analysis aimed at evaluating differential expression, pathway enrichment, and miRNA-mRNA networks. We highlighted 24 differentially expressed miRNAs between D842V and non-D842V GIST patients. Pathway enrichment analysis showed that deregulated miRNAs targeted genes that are mainly involved in the immune response pathways. The miRNA-mRNA networks highlighted a signature of miRNAs/mRNA that could explain the indolent behavior of the D842V mutated GIST. The results highlighted a different miRNA fingerprint in PDGFRA D842V GISTs compared to non-D842Vmutated patients, which could explain the different biological behavior of this GIST subset. The study was supported by a financial contribution of the Department of Pharmacy and Biotechnology (RFO) to SA and of the AIG (Associazione Italiana GIST) to MA.

Myopericytoma is a rare tumor generally arising from skin and soft tissues of extremities, trunk, head, and neck regions, rarely from visceral sites. An intrathoracic visceral localization may carry a broad differential diagnosis including primary lung, pleura and chest wall lesions, or metastatic lesions. To date, any radiological features have been recognized and diagnosis of myopericytoma with intrathoracic localization remains still challenging. Here, we describe the case of a subpleural lesion incidentally diagnosed in an older adult affected by gastric cancer. Radiological features did not allow a differential diagnosis between a benign lesion, a primary tumor, or a metastasis. After resection, the histological examination showed histopathological features congruent with the diagnosis of myopericytoma. This unusual presentation reflects the need to share clinical, radiological, and histopathological data about this uncommon but frequently misdiagnosed disease.

Simple Summary Uterine sarcomas can affect patients of reproductive age. In this setting, the chance of a fertility-sparing treatment would allow women to become pregnant. In the literature, only a few experiences of fertility-sparing treatment of uterine sarcomas have been reported; however, the oncological safety and reproductive outcomes remain unclear. The aim of this systematic review is to report and summarize all the published evidence about the fertility-sparing approach in these rare and heterogenous tumors, and to help physicians in making clinical decisions. Abstract Uterine sarcomas are rare cancers, sometimes diagnosed in women of childbearing age. Hysterectomy is the standard treatment in early stages. The option of lesion removal to save fertility is described in the literature, but it is still considered experimental. The objective of this systematic review is to report on the available evidence on the reproductive and oncological outcomes of fertility-sparing treatment in women with uterine sarcomas. PubMed, Scopus and Cochrane Central Register of Controlled Trials were searched between 1 January 2011 and 21 June 2021 for publications in English about women with uterine sarcoma treated with a fertility-sparing intervention. Thirty-seven studies were included for a total of 210 patients: 63 low-grade endometrial stromal sarcomas, 35 embryonal rhabdomyosarcomas of the cervix, 19 adenosarcomas, 7 leiomyosarcomas and 2 uterine tumors resembling an ovarian sex cord. Conservative treatment ensured pregnancy in 32% of cases. In terms of oncological outcomes, relapse was related to histology and the worst prognosis was reported for leiomyosarcoma, followed by low-grade endometrial stromal sarcoma, which relapsed in 71% and 54% of cases, respectively. The highest death rate was associated with leiomyosarcoma (57.1%). This study demonstrated that fertility-sparing treatments may be employed in selected cases of early stage uterine sarcoma.

Somatic malignant transformation in a germ cell tumor (GCT) is the development of non-germ malignancies; much of available literature refers to teratoma with malignant transformation (TMT). There are various transformation histologies such as sarcoma, adenocarcinoma, primitive neuroectodermal tumors, and more rarely carcinoid tumors, hemangioendothelioma, lymphoma, or nephroblastoma. The treatments of these entities include surgery and/or chemotherapy. A standard approach in choosing chemotherapy in TMT cases has not yet been established. Many authors suggest using chemotherapeutic agents based on the transformed histology, while others recommend GCT-oriented therapy combined with surgery as the primary treatment, reserving histology-driven chemotherapies for metastatic relapse. We report the clinical findings and the genomic profile of a mixed GCT case with somatic-type malignancy of sarcoma type. We achieved a complete radiological response with GCT-oriented chemotherapy performed as salvage therapy after sarcoma-histology therapy. In addition, molecular profiles with RNA-sequencing and exome sequencing analyses of the primary tumor and the tumor with somatic-type malignancy of sarcoma type were explored.

Background: Recently, artificial intelligence (AI) with computerized imaging analysis is attracting the attention of clinicians, in particular for its potential applications in improving cancer diagnosis. This review aims to investigate the contribution of radiomics and AI on the radiological preoperative assessment of patients with uterine sarcomas (USs). Methods: Our literature review involved a systematic search conducted in the last ten years about diagnosis, staging and treatments with radiomics and AI in USs. The protocol was drafted according to the systematic review and meta-analysis preferred reporting project (PRISMA-P) and was registered in the PROSPERO database (CRD42021253535). Results: The initial search identified 754 articles; of these, six papers responded to the characteristics required for the revision and were included in the final analysis. The predominant technique tested was magnetic resonance imaging. The analyzed studies revealed that even though sometimes complex models included AI-related algorithms, they are still too complex for translation into clinical practice. Furthermore, since these results are extracted by retrospective series and do not include external validations, currently it is hard to predict the chances of their application in different study groups. Conclusion: To date, insufficient evidence supports the benefit of radiomics in USs. Nevertheless, this field is promising but the quality of studies should be a priority in these new technologies.

In coastal marine ecosystems coralline algae often create biogenic reefs. These calcareous algal reefs affect their associated invertebrate communities via diurnal oscillations in photosynthesis, respiration and calcification processes. Little is known about how these biogenic reefs function and how they will be affected by climate change. We investigated the winter response of a Mediterranean intertidal biogenic reef, Ellissolandia elongata exposed in the laboratory to reduced pH conditions (i.e. ambient pH – 0.3, RCP 8.5) together with an extreme heatwave event (+1.4 °C for 15 days). Response variables considered both the algal physiology (calcification and photosynthetic rates) and community structure of the associated invertebrates (at taxonomic and functional level). The combination of a reduced pH with a heatwave event caused Ellisolandia elongata to significantly increase photosynthetic activity. The high variability of calcification that occurred during simulated night time conditions, indicates that there is not a simple, linear relationship between these two and may indicate that it will be resilient to future conditions of climate change. In contrast, the associated fauna were particularly negatively affected by the heatwave event, which impoverished the communities as opportunistic taxa became dominant. Local increases in oxygen and pH driven by the algae can buffer the microhabitat in the algal fronds, thus favouring the survival of small invertebrates.

Background: About 20–40% of gastrointestinal stromal tumors (GISTs) lacking KIT/PDGFRA mutations show defects in succinate dehydrogenase (SDH) complex. This study uncovers the gene expression profile (GEP) of SDH-deficient GIST in order to identify new signaling pathways or molecular events actionable for a tailored therapy. Methods: We analyzed 36 GIST tumor samples, either from formalin-fixed, paraffin-embedded by microarray or from fresh frozen tissue by RNA-seq, retrospectively collected among KIT-mutant and SDH-deficient GISTs. Pathway analysis was performed to highlight enriched and depleted transcriptional signatures. Tumor microenvironment and immune profile were also evaluated. Results: SDH-deficient GISTs showed a distinct GEP with respect to KIT-mutant GISTs. In particular, SDH-deficient GISTs were characterized by an increased expression of neural markers and by the activation of fibroblast growth factor receptor signaling and several biological pathways related to invasion and tumor progression. Among them, hypoxia and epithelial-to-mesenchymal transition emerged as features shared with SDH-deficient pheochromocytoma/paraganglioma. In addition, the study of immune landscape revealed the depletion of tumor microenvironment and inflammation gene signatures. Conclusions: This study provides an update of GEP in SDH-deficient GISTs, highlighting differences and similarities compared to KIT-mutant GISTs and to other neoplasm carrying the SDH loss of function. Our findings add a piece of knowledge in SDH-deficient GISTs, shedding light on their putative histology and on the dysregulated biological processes as targets of new therapeutic strategies.

The medical management of advanced gastrointestinal stromal tumors (GIST) has improved with the development of tyrosine kinase inhibitors (TKIs) targeting KIT and PDGFRA mutations. However, approximately 5–10% of GIST lack KIT and PDGFRA mutations, and about a half are deficient in succinate dehydrogenase ( SDH) that promotes carcinogenesis by the cytoplasmic accumulation of succinate. This rare group of GIST primarily occurs in the younger patients than other subtypes, and is frequently associated with hereditary syndromes. The role of TKIs in patients with SDH-deficient GIST is controversial, with conflicting results; thus, there is an urgent need to uncover the disease mechanisms, treatment patterns, and responses to systemic therapy among these patients. Here, based on an extensive literature search, we have provided a rigorous overview of the current evidence on the medical treatment of SDH-deficient GIST.

Background This case represents the first report of malignant primary cardiac tumour in a patient with Lynch Syndrome associated with MSH2 pathogenic variant. Case presentation A 57-year-old woman with previous ovarian cystadenocarcinoma was admitted to the emergency room for hematic pericardial effusion. Multimodal diagnostic imaging revealed two solid pericardial vascularized masses. After pericardiectomy, the final histological diagnosis was poorly differentiated pleomorphic sarcomatoid carcinoma. During follow-up she developed an ampulla of Vater adenocarcinoma. Genetic analysis identified an MSH2 pathogenic variant. Conclusion This case contributes to expand the tumour spectrum of Lynch syndrome, suggesting that MSH2 pathogenic variants cause a more complex multi-tumour cancer syndrome than the classic Lynch Syndrome. In MSH2 variant carriers, symptoms such as dyspnoea and chest discomfort might alert for rare tumours and a focused cardiac evaluation should be considered.

Background: Primary soft tissue sarcomas arising from the male urinary and genital tract are rare tumors, only accounting for 1% to 2% of all malignancies of the genitourinary tract. Clinical management of advanced disease is lacking in standardized recommendations due to the rarity of the disease. To date, complete and extensive surgery represents the only curative and standardized approach for localized disease, while the impact of retroperitoneal lymphadenectomy and adjuvant treatments on clinical outcomes are still unclear. Similarly, a standardized systemic treatment for advanced metastatic disease is still missing. Cases Presentation: Four out of 274 patients have been identified in our sarcoma population. The mean age was 54 years (range = 45-73). The histotypes showed liposarcoma in 2 cases and leiomyosarcoma in the remaining 2 cases. In all 4 cases, the disease was localized at presentation, patients underwent complete surgery, and no adjuvant treatments were done. Three cases presented a recurrence of disease at a mean follow-up of 86 months (range = 60-106 months), more than 7 years. Two cases were treated with a second surgery and chemotherapy and 1 case only with chemotherapy. Discussion and Conclusions: Sharing data about clinical management of paratesticular mesenchymal tumors is a key issue due to the rarity of this tumor’s subtype. In this article, we report the clinical history of 4 patients affected by paratesticular mesenchymal tumor. In particular, main issues of interest are the decision of postoperative treatment and systemic treatment at time of disease recurrence.

Background Despite its proven activity as third-line treatment in gastrointestinal stromal tumors (GIST), regorafenib can present a poor tolerability profile which often leads to treatment modifications and transient or permanent discontinuation; thus, in clinical practice physicians usually adopt various dosing and interval schedules to counteract regorafenib-related adverse events and avoid treatment interruption. The aim of this real-world study was to investigate the efficacy and safety of personalized schedules of regorafenib in patients with metastatic GIST, in comparison with the standard schedule (160 mg daily, 3-weeks-on, 1-week-off). Patients and methods Institutional registries across seven Italian reference centers were retrospectively reviewed and data of interest retrieved to identify patients with GIST who had received regorafenib from February 2013 to January 2021. The Kaplan–Meier method was used to estimate survival and the log-rank test to make comparisons. Results Of a total of 152 patients with GIST, 49 were treated with standard dose, while 103 received personalized schedules. At a median follow-up of 36.5 months, median progression-free survival was 5.6 months [95% confidence interval (CI) 3.73-11.0 months] versus 9.7 months (95% CI 7.9-14.5 months) in the standard-dose and the personalized schedule groups, respectively [hazard ratio (HR) 0.51; 95% CI 0.34-0.75; P = 0.00052]. Median overall survival was 16.6 months (95% CI 14.1-21.8 months) versus 20.5 months (95% CI 15.0-25.4 months), respectively (HR 0.75; 95% CI 0.49-1.22; P = 0.16). Conclusions Regorafenib-personalized schedules are commonly adopted in daily clinical practice of high-volume GIST expert centers and correlate with significant improvement of therapeutic outcomes. Therefore, regorafenib treatment optimization in patients with GIST may represent the best strategy to maximize long-term therapy., Highlights • Regorafenib-personalized schedules are commonly adopted in daily clinical practice. • Regorafenib-personalized schedules correlate with statistically significant improvement of therapeutic outcomes. • A prompt personalization of regorafenib could help clinicians avoid early treatment discontinuation due to adverse events. • A patient-tailored approach could be applied to other metastatic solid tumors treated with regorafenib.

Background: The recurrence rate, related to the unpredictable behavior of gastrointestinal stromal tumors (GISTs), continues to be a major topic of investigation, since no actual risk evaluation scales have proven to be exceedingly effective in predicting prognosis. We therefore focus in this study on investigating the predictive variables of disease recurrence. Methods: Between September 2004 and January 2011, 34 patients, 18 males and 16 females with a median age of 62 (range, 27-87) years, underwent operations for primary, localized and advanced GISTs. Immunohistochemical profile, KIT and the platelet-derived growth factor receptor-alpha (PDGFR-α) gene mutations, tumor size, tumor site, mitotic index, synchronous tumors, adjuvant therapy, symptoms and gender were considered and analyzed as predictive variables. The receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off value for tumor dimension to predict recurrence. Results: The median follow-up (FU) was 20 months (range, 6-86 months). A first-line adjuvant therapy was performed in nine patients. Disease relapse occurred in five cases. The tumor size and the mitotic index were the strongest predictive factors (P

Herein is described the case of a 64-year-old patient affected by metastatic clear-cell carcinoma, with exclusive bone disease, subjected after the initial cytoreductive nephrectomy to 3 successive lines of medical treatment (sunitinib, everolimus, and sorafenib) and multiple locoregional treatments (spinal surgery, radiation therapy, and selective arterial embolization), resulting in a surprisingly long survival of over 75 months. In the era of target therapy, integration strategies, including additional locoregional treatment to medical therapy, are essential to optimize the clinical benefit, to maximize treatment duration overcoming focal progressive disease, and to improve the quality of life. In this context, we would highlight that selective transcatheter embolization of bone metastases from renal cell carcinoma should be considered as an effective and safe option in the palliative setting for patients with bone metastasis, especially for pain relief.

Recent advances in molecular biology have revolutionized the concept of KIT/PDGFRA wild type (WT) gastrointestinal stromal tumors (GIST) than the past. Indeed, from being defined as GIST without KIT or PDGFRA mutations, we are now faced with the opposite scenario, where KIT/PDGFRA WT GIST are “positively” defined according to their specific molecular alterations. In particular, if until recently KIT/PDGFRA GIST without abnormalities of KIT, PDGFRA, SDH, and the RAS signaling pathway were referred as quadruple WT GIST, today also this small subset of GIST is emerging out as a group of heterogeneous distinct entities with multiple different molecular alterations. Therefore, given this still growing and rapidly evolving scenario, the progressive molecular fragmentation may inevitably lead over the time to the disappearance of KIT/PDGFRA WT GIST, destined to be singularly defined by their molecular fingerprint.

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No abstract available

[Introduction] Desmoid tumour (DT) is a locally aggressive fibroblastic proliferative disease representing the most common extraintestinal manifestation of familial adenomatosis polyposis (FAP). As data on the activity of chemotherapy in these patients are limited, we examined the outcomes of patients treated with low-dose methotrexate (MTX)+vinca alkaloids (vinorelbine or vinblastine)., [Patients and methods] We retrospectively reviewed clinical and outcome data from all patients with confirmed FAP-associated DTs treated with weekly MTX+vinca alkaloids in seven European sarcoma reference centres between January 2000 and December 2018. Radiological responses were assessed using RECIST V.1.0 and V.1.1. The Kaplan-Meier method associated to the log-rank test was used to estimate and compare survival curves., [Results] We identified 37 patients (median age 29 years, range 7–44). According to RECIST, 20/37 (54.1%) patients achieved partial response (PR), 15/37 (40.5%) patients had stable disease and 2/37 (5.4%) had progressive disease as best response. Overall, the median progression-free survival (PFS) was 6.5 years (range, 0.3–12.1 years). In the subset of patients achieving PR as best response, the median PFS was not reached. In a subset of 11 patients with progressive disease offered MTX+vinca alkaloids rechallenge (after chemotherapy withdrawal following prolonged disease control), the disease control rate was 100%, resulting in a median PFS after rechallenge of 5.8 years., [Conclusions] This is the largest series on the activity of low-dose chemotherapy in patients with FAP-related DT. In this population, MTX+vinca alkaloids is an active combination, as already reported in patients with sporadic DT.

Gastrointestinal stromal tumours that are wild type for KIT and PDGFRA are referred to as WT GISTs. Of these tumours, SDH-deficient (characterized by the loss of SDHB) and quadruple WT GIST (KIT/PDGFRA/SDH/RAS-P WT) subgroups were reported to display a marked overexpression of FGF4, identifying a putative common therapeutic target for the first time. In SDH-deficient GISTs, methylation of an FGF insulator region was found to be responsible for the induction of FGF4 expression. In quadruple WT, recurrent focal duplication of FGF3/FGF4 was reported; however, how it induced FGF4 expression was not investigated. To assess whether overexpression of FGF4 in quadruple WT could be driven by similar epigenetic mechanisms as in SDH-deficient GISTs, we performed global and locus-specific (on FGF4 and FGF insulator) methylation analyses. However, no epigenetic alterations were detected. Conversely, we demonstrated that in quadruple WT GISTs, FGF4 expression and the structure of the duplication were intimately connected, with the copy of FGF4 closer to the ANO1 super-enhancer being preferentially expressed. In conclusion, we demonstrated that in quadruple WT GISTs, FGF4 overexpression is not due to an epigenetic mechanism but rather to the specific genomic structure of the duplication. Even if FGF4 overexpression is driven by different molecular mechanisms, these findings support an increasing biologic relevance of the FGFR pathway in WT GISTs, both in SDH-deficient and quadruple WT GISTs, suggesting that it may be a common therapeutic target.

Platelet Derived Growth Factor Receptor Alpha (PDGFRA) mutations occur in only about 5-7% of gastrointestinal stromal tumors (GIST), notably with alterations on exons 12/14/18. The most frequent PDGFRA mutation is the exon 18 D842V, which is correlated to specific clinico-pathological features, such as primary imatinib resistance and higher indolence. Here, we present a gene expression profile (GEP) comparison of D842V vs. PDGFRA with mutations other than D842V (non-D842V). GEP was followed by in silico bioinformatic analysis aimed at evaluating differential expression, tumor microenvironment composition and pathway enrichment. We found a large set of oncogenes, transcription factors and nuclear receptors downregulated in the D842V mutant. Conversely, D842V showed a significant enrichment of immune- and interferon- related gene signatures. Differences in tumor microenvironment composition were also highlighted, including a higher abundance of CD8+ T-cells and an overexpression of the T cell-inflamed signature in the D842V mutant subgroup, which is predictive of immunotherapy response. PDGFRA D842V vs. non-D842V GIST display a different expression profile, with a prominent immunological signature, that could represent a proof of principle for testing immunotherapeutic strategies in this drug-orphan subset of GIST.