HMGA1 regulates trabectedin sensitivity in advanced soft-tissue sarcoma (STS): A Spanish Group for Research on Sarcomas (GEIS) study

HMGA1 is a structural epigenetic chromatin factor that has been associated with tumor progression and drug resistance. Here, we reported the prognostic/predictive value of HMGA1 for trabectedin in advanced soft-tissue sarcoma (STS) and the effect of inhibiting HMGA1 or the mTOR downstream pathway in trabectedin activity. The prognostic/predictive value of HMGA1 expression was assessed in a cohort of 301 STS patients at mRNA (n = 133) and protein level (n = 272), by HTG EdgeSeq transcriptomics and immunohistochemistry, respectively. The effect of HMGA1 silencing on trabectedin activity and gene expression profiling was measured in leiomyosarcoma cells. The effect of combining mTOR inhibitors with trabectedin was assessed on cell viability in vitro studies, whereas in vivo studies tested the activity of this combination. HMGA1 mRNA and protein expression were significantly associated with worse progression-free survival of trabectedin and worse overall survival in STS. HMGA1 silencing sensitized leiomyosarcoma cells for trabectedin treatment, reducing the spheroid area and increasing cell death. The downregulation of HGMA1 significantly decreased the enrichment of some specific gene sets, including the PI3K/AKT/mTOR pathway. The inhibition of mTOR, sensitized leiomyosarcoma cultures for trabectedin treatment, increasing cell death. In in vivo studies, the combination of rapamycin with trabectedin downregulated HMGA1 expression and stabilized tumor growth of 3-methylcholantrene-induced sarcoma-like models. HMGA1 is an adverse prognostic factor for trabectedin treatment in advanced STS. HMGA1 silencing increases trabectedin efficacy, in part by modulating the mTOR signaling pathway. Trabectedin plus mTOR inhibitors are active in preclinical models of sarcoma, downregulating HMGA1 expression levels and stabilizing tumor growth.

ETV6::NTRK3 Fusion-Positive Wild-Type Gastrointestinal Stromal Tumor (GIST) with Abundant Lymphoid Infiltration (TILs and Tertiary Lymphoid Structures): A Report on a New Case with Therapeutic Implications and a Literature Review

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, with proto-oncogene, receptor tyrosine kinase (c-kit), or PDGFRα mutations detected in around 85% of cases. GISTs without c-kit or platelet-derived growth factor receptor alpha (PDGFRα) mutations are considered wild-type (WT), and their diverse molecular alterations and biological behaviors remain uncertain. They are usually not sensitive to tyrosine kinase inhibitors (TKIs). Recently, some molecular alterations, including neurotrophic tyrosine receptor kinase (NTRK) fusions, have been reported in very few cases of WT GISTs. This novel finding opens the window for the use of tropomyosin receptor kinase (TRK) inhibitor therapy in these subtypes of GIST. Herein, we report a new case of NTRK-fused WT high-risk GIST in a female patient with a large pelvic mass (large dimension of 20 cm). The tumor was removed, and the histopathology displayed spindle-predominant morphology with focal epithelioid areas, myxoid stromal tissue, and notable lymphoid infiltration with tertiary lymphoid structures. Ten mitoses were quantified in 50 high-power fields without nuclear pleomorphism. DOG1 showed strong and diffuse positivity, and CD117 showed moderate positivity. Succinate dehydrogenase subunit B (SDHB) was retained, Pan-TRK was focal positive (nuclear pattern), and the proliferation index Ki-67 was 7%. Next-generation sequencing (NGS) detected an ETV6::NTRK3 fusion, and this finding was confirmed by fluorescence in situ hybridization (FISH), which showed NTRK3 rearrangement. In addition, an RB1 mutation was found by NGS. The follow-up CT scan revealed peritoneal nodules suggestive of peritoneal dissemination, and Entrectinib (a TRK inhibitor) was administered. After 3 months of follow-up, a new CT scan showed a complete response. Based on our results and the cases from the literature, GISTs with NTRK fusions are very uncommon so far; hence, further screening studies, including more WT GIST cases, may increase the possibility of finding additional cases. The present case may offer new insights into the potential introduction of TRK inhibitors as treatments for GISTs with NTRK fusions. Additionally, the presence of abundant lymphoid infiltration in the present case may prompt further research into immunotherapy as a possible additional therapeutic option.

A Descriptive Study of 103 Primary Cutaneous B-Cell Lymphomas: Clinical and Pathological Characteristics and Treatment from the Spanish Lymphoma Oncology Group (GOTEL)

Primary cutaneous B-cell lymphomas (PCBCLs) are B-cell lymphomas that can occur in the skin without evidence of extracutaneous involvement. The 2005 WHO/EORTC classification of cutaneous lymphomas and its 2018 update have distinguished three main categories based on clinicopathological, immunohistochemical, and genetic characteristics: primary cutaneous marginal zone lymphoma (PCMZL), primary cutaneous follicle centre lymphoma (PCFCL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT). PCMZL and PCFCL are clinically indolent, while PCDLBCL-LT is an aggressive lymphoma. Due to its low incidence and lack of prospective studies, it is difficult to establish a standard treatment for each subgroup. The objective of our study was to describe the clinical and pathological characteristics of 103 patients with cutaneous B-cell lymphoma from 12 centres belonging to the Spanish Lymphoma Oncology Group. The median age was 53 years (40-65). According to skin extension, 62% had single-site lymphoma, 17% had regional lymphoma, and 20% had multifocal lymphoma. Histology: 66% had PCMZL, 26% had PCFCL, and 8% had PCDLBCL-LT. Twenty-three percent of the patients were treated exclusively with surgery, 26% with radiotherapy only, 21% with surgery plus radiotherapy, 10% with polychemotherapy, and 5% with rituximab monotherapy. Overall, 96% of patients achieved a complete response, and 44% subsequently relapsed, most of them relapsing either locally or regionally. The 10-year OS was 94.5% for the entire cohort, 98% for the PCMZL cohort, 95% for the PCFCL cohort, and 85.7% for the PCDLBCL-LT cohort. Our data are comparable to those of other published series, except for the high frequency of PCMZL. The expected heterogeneity in therapeutic management has been observed.

Solitary fibrous tumor: Can the new Huang risk stratification system for orbital tumors improve prognostic accuracy in other tumor locations?

Solitary fibrous tumors (SFTs) are known for their heterogeneous morphology, characterized by a variety of cell shapes and different growth patterns. They can also arise in various anatomical locations, most commonly in extremities and deep soft tissues. Despite this diversity in morphology and location, all SFTs share a common molecular signature involving the NAB2::STAT6 gene fusion. Due to their unpredictable clinical behavior, establishing prognostic factors is crucial. This study aims to evaluate an orbital risk stratification system (RSS) proposed by Huang et al. for use in extraorbital SFTs using a database of 97 cases. The Huang model takes into consideration tumor size, mitotic figures, Ki-67 index, and dominant constituent cell (DCC) as key variables. Survival analysis confirmed the model's predictive value, with higher-risk scores being associated with poorer outcomes. However, in contrast to the orbital SFTs studied by Huang et al., our study did not find a correlation between tumor size and recurrence in extraorbital cases. While the Huang model performs slightly better than other RSS, it falls short on achieving statistical significance in distinguishing recurrence risk groups in extraorbital locations. In conclusion, this study validates the Huang RSS for use in extraorbital SFTs and underscores the importance of considering DCC, mitotic count, and Ki-67 together. However, we found that including tumor size in this model did not improve prognostic significance in extraorbital SFTs. Despite the benefits of this additional RSS, vigilant monitoring remains essential, even in cases classified as low-risk due to the inherent unpredictability of SFT clinical outcomes.

Soft Tissue Sarcomas with Chromosomal Alterations in the 12q13-15 Region: Differential Diagnosis and Therapeutic Implications

The chromosomal region 12q13-15 is rich in oncogenes and contains several genes involved in the pathogenesis of various mesenchymal neoplasms. Notable genes in this region include MDM2, CDK4, STAT6, DDIT3, and GLI1. Amplification of MDM2 and CDK4 genes can be detected in various mesenchymal and nonmesenchymal neoplasms. Therefore, gene amplification alone is not entirely specific for making a definitive diagnosis and requires the integration of clinical, radiological, morphological, and immunohistochemical findings. Neoplasms with GLI1 alterations may exhibit either GLI1 rearrangements or amplifications of this gene. Despite the diagnostic implications that the overlap of genetic alterations in neoplasms with changes in genes within the 12q13-15 region could create, the discovery of coamplifications of MDM2 with CDK4 and GLI1 offers new therapeutic targets in neoplasms with MDM2/CDK4 amplification. Lastly, it is worth noting that MDM2 or CDK4 amplification is not exclusive to mesenchymal neoplasms; this genetic alteration has also been observed in other epithelial neoplasms or melanomas. This suggests the potential use of MDM2 or CDK4 inhibitors in neoplasms where alterations in these genes do not aid the pathological diagnosis but may help identify potential therapeutic targets. In this review, we delve into the diagnosis and therapeutic implications of tumors with genetic alterations involving the chromosomal region 12q13-15, mainly MDM2, CDK4, and GLI1.

Extra-meningeal solitary fibrous tumor: an evolving entity with chameleonic morphological diversity, a hallmark molecular alteration and unresolved issues in risk stratification assessment

Solitary fibrous tumor (SFT) is a rare type of mesenchymal lesion with variable clinical presentation in which specific clinicopathologic factors have been related to patient outcome. SFT shares an important morphologic and immunohistochemical overlap with other sarcomas, hence the differential diagnosis is challenging. Although molecular studies provide significant clues, especially in the differential diagnosis with other neoplasms, a thorough hematoxylin and eosin analysis and the integration of phenotypical, clinical, and radiological features remain an essential tool in SFT diagnosis. In this review, we discuss some emerging issues still under debate in SFT.

REGISTRI: Regorafenib in first-line of KIT/PDGFRA wild type metastatic GIST: a collaborative Spanish (GEIS), Italian (ISG) and French Sarcoma Group (FSG) phase II trial

BACKGROUND

Approximately 15% of adult GIST patients harbor tumors that are wild-type for KIT and PDGFRα genes (KP-wtGIST). These tumors usually have SDH deficiencies, exhibit a more indolent behavior and are resistant to imatinib. Underlying oncogenic mechanisms in KP-wtGIST include overexpression of HIF1α high IGFR signaling through the MAPK pathway or BRAF activating mutation, among others. As regorafenib inhibits these signaling pathways, it was hypothesized that it could be more active as upfront therapy in advanced KP-wtGIST.

METHODS

Adult patients with advanced KP-wtGIST after central confirmation by NGS, naïve of systemic treatment for advanced disease, were included in this international phase II trial. Eligible patients received regorafenib 160 mg per day for 21 days every 28 days. The primary endpoint was disease control rate (DCR), according to RECIST 1.1 at 12 weeks by central radiological assessment.

RESULTS

From May 2016 to October 2020, 30 patients were identified as KP-wtGIST by Sanger sequencing and 16 were confirmed by central molecular screening with NGS. Finally, 15 were enrolled and received regorafenib. The study was prematurely closed due to the low accrual worsened by COVID outbreak. The DCR at 12 weeks was 86.7% by central assessment. A subset of 60% experienced some tumor shrinkage, with partial responses and stabilization observed in 13% and 87% respectively, by central assessment. SDH-deficient GIST showed better clinical outcome than other KP-wtGIST.

CONCLUSIONS

Regorafenib activity in KP-wtGIST compares favorably with other tyrosine kinase inhibitors, especially in the SDH-deficient GIST subset and it should be taken into consideration as upfront therapy of advanced KP-wtGIST.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02638766.

Tumor Microenvironment and Its Clinicopathologic and Prognostic Association in Cutaneous and Noncutaneous Angiosarcomas

OBJECTIVES

We explored features of the angiosarcoma (AS) tumor microenvironment to discover subtypes that may respond to immunotherapy.

METHODS

Thirty-two ASs were included. Tumors were studied by histology, immunohistochemistry (IHC), and gene expression profile using the HTG EdgeSeq Precision Immuno-Oncology Assay.

RESULTS

Comparing cutaneous and noncutaneous ASs, the second group showed 155 deregulated genes, and unsupervised hierarchical clustering (UHC) delineated two groups: the first mostly cutaneous AS and the second mainly noncutaneous AS. Cutaneous ASs showed a significantly higher proportion of T cells, natural killer cells, and naive B cells. ASs without MYC amplification revealed a higher immunoscore in comparison with ASs with MYC amplification. PD-L1 was significantly overexpressed in ASs without MYC amplification. UHC showed 135 deregulated genes differentially expressed when comparing ASs from the non-head and neck area with patients who had AS in the head and neck area. ASs from the head and neck area showed high immunoscore. PD1/PD-L1 content was significantly more highly expressed in ASs from the head and neck area. IHC and HTG gene expression profiling revealed a significant correlation between PD1, CD8, and CD20 protein expression but not PD-L1.

CONCLUSIONS

Our HTG analyses confirmed a high degree of tumor and microenvironment heterogeneity. Cutaneous ASs, ASs without MYC amplification, and ASs located in the head and neck area seem to be the most immunogenic subtypes in our series.

A randomized phase II study comparing the efficacy and safety of the glyco-optimized anti-EGFR antibody tomuzotuximab against cetuximab in patients with recurrent and/or metastatic squamous cell cancer of the head and neck - the RESGEX study

Background

The aim of the RESGEX study was to compare the efficacy and safety of the anti-epidermal growth factor receptor (anti-EGFR) antibody tomuzotuximab against cetuximab both in combination with chemotherapy in patients with recurrent and/or metastatic squamous cell cancer of the head and neck in the first-line treatment.

Patients and methods

In this phase II trial 240 patients were equally randomized for six cycles to receive either tomuzotuximab (initial dose 990 mg then 720 mg) weekly and cisplatin 100 mg/m² and fluorouracil (5-FU; 1000 mg/m²/day, days 1-4) every 3 weeks or cetuximab (400 mg/m² subsequent 250 mg/m²) weekly with the same chemotherapeutic backbone followed by antibody maintenance treatment. The primary endpoint was progression-free survival.

Results

Median progression-free survival was 6.5 months [95% confidence interval (CI) 5.9-7.9 months] in the tomuzotuximab group and 6.2 months (95% CI 5.8-7.3 months) in the cetuximab group (P = 0.86). The median overall survival (OS) estimate was 11.6 months (95% CI 9.5-17.2 months) in the tomuzotuximab group and 13.8 months (95% CI 12.3-16.4 months) in the cetuximab group (P = 0.96). In an exploratory analysis a small subgroup of p16-positive patients had a significantly longer OS compared with p16-negative patients (hazard ratio 1.860, 95% CI 1.09-3.16, P = 0.02).

Conclusions

The glyco-engineered antibody tomuzotuximab failed to demonstrate improved efficacy with a chemotherapeutic backbone in the first-line treatment of recurrent or metastatic head and neck squamous cell carcinoma. It remains a so far unanswered question whether such antibody would partner better with different drugs such as checkpoint inhibitors.

•

Tomuzotuximab has a potential higher antibody-dependent cell cytotoxicity than other EGFR-directed antibodies.

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Comparison of two anti-EGFR antibodies combined with chemotherapy in patients with squamous cell cancer of head and neck.

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Efficacy, safety, and tolerability of tomuzotuximab and cetuximab in combination with chemotherapy were similar.

Solitary Fibrous Tumor: Integration of Clinical, Morphologic, Immunohistochemical and Molecular Findings in Risk Stratification and Classification May Better Predict Patient outcome

Although solitary fibrous tumors (SFTs) have an unpredictable evolution, some specific clinicopathologic factors have been associated with the final outcome. We retrieved clinical, pathological and molecular data of 97 patients with a histological diagnosis of SFT and Signal transducer and activator of transcription 6 (STAT6) positivity. We retrospectively studied the pathological factors predictive of recurrence/metastasis and compared them with the clinical outcome. A wide immunohistochemical study and molecular analysis to detect NAB2/STAT6 gene fusion, tumor protein-53 (TP53) and/or (telomerase reverse transcriptase) TERT promotor mutation were performed. The risk of metastasis was calculated using the Demicco risk stratification system (RSS). The results were combined and examined to assess the accuracy of risk stratification and classification. The most common location was in non-extremities; 66% were located in soft tissue or subcutaneous areas and 92.8% in deep locations. On microscopic analysis, 38.1% of tumors revealed hypercellularity with a predominant patternless and/or hemangiopericytic growth pattern; 13.4% had ≥4 mitoses/10HPF; 16.5% showed necrosis, and almost half the tumors showed at least focal myxoid areas. Dedifferentiation was observed in three tumors. Immunomarker expression in SFTs was as follows: CD34 92.9%, CD99 57.1%, Bcl2 67.9%, neuroendocrine markers (at least 1) 25.7%, Desmin 14.3%, CK(AE1/AE3) 3%, Apoptotic Protease Activating Factor (APAF-1) 87% and finally Ki-67 ≥ 10% in 14.4%. The NAB2/STAT6 gene fusion was detected in 50 tumors. After a median follow-up of 90 months, 9.3% recurred, 11.3% metastasized, 10.3% died of disease and 76.2% were free of disease. TERT mutations were detected in 40.6% of the SFTs; the TP53 mutation was detected in 17%, and only 9.3% showed both mutations. According to the Demicco RSS, 6.1%, 11.3% and 82.4% of the tumors were classified as high, intermediate or low-risk of metastasis, respectively. All high-risk tumors had ≥4 mitoses/10HPF, necrosis, Ki-67 ≥ 10, HTER and/or TP53 mutation and poor evolution. The intermediate risk SFTs with worse evolution displayed the HTER mutation. Almost all low-risk tumors had a favorable evolution, although four showed at least one adverse factor (Ki-67 ≥ 10, ≥4 mitoses/10HPF or high tumor size) and had a worse evolution. An integration of clinical, morphologic, immunohistochemical and molecular findings may improve risk stratification and classification and better predict patient outcome. The unfavorable course seems to be more frequent in high-risk SFTs, although it is not exceptional in low-risk SFTs either; hence, a long-term follow-up is required independently of the assigned risk stratification score. The inclusion of molecular findings in risk stratification systems could improve the precision in the classification of SFTs, especially those of intermediate risk. Future studies will be required to determine the most effective way to incorporate molecular analyses into RSS on SFTs. The coexistence of several adverse factors such as ≥4 mitoses/10HPF, necrosis, Ki-67 ≥ 10%, mutations in HTER and/or p53 may suggest a closer clinical follow-up regardless of the histological appearance of the tumor.

Ki-67 immunoexpression and radiological assessment of necrosis improves accuracy of conventional and modified core biopsy systems in predicting the final grade assigned to adult-soft tissue sarcomas. An international collaborative study

Based on the French Federation Nationale des Centers de Lutte Contre le Cancer (FNCLCC) grading system, this study assesses the accuracy of conventional and modified core biopsy (CB) systems in predicting the final grade (low vs high) assigned to the resected specimen. Substituting Ki-67 immunoexpression for mitotic count, and radiological for histological assessment of necrosis, we used two modified FNCLCC CB grading systems: (1) Ki-67 immunoexpression alone, and (2) Ki-67 plus radiological assessment of necrosis. We graded 199 soft tissue sarcomas (STS) from nine centers, and compared the results for the conventional (obtained from local histopathology reports) and modified CB systems with the final FNCLCC grading of the corresponding resected specimens. Due to insufficient sample quality or lack of available radiologic data, five cases were not evaluated for Ki67 or radiological assessment of necrosis. The conventional FNCLCC CB grading system accurately identified 109 of the 130 high-grade cases (83.8%). The CB grading matched the final FNCLCC grading (low vs high) in 175 (87.9%) of the 199 resected tumors; overestimating the final grade in three cases and underestimating in 21 cases. Modified system 1 (Ki-67) accurately identified 117 of the 130 high-grade cases (90.0%). The CB grading matched the final FNCLCC grading (low vs high) in 175 (89.7%) of the 195 evaluated cases; overestimating seven and underestimating 13 cases. Modified system 2 (Ki-67 plus radiological necrosis) accurately identified 120 of the 130 high-grade cases (92.3%). This last matched the final FNCLCC grading (low vs high) in 177 (91.2%) of the 194 evaluated cases; overestimating seven and underestimating 10 cases. Modified system 2 obtained highest area under ROC curves, although not statistically significant. Underestimated CB grades did not correlate with histological subtypes, although many of the discrepant cases were myxoid tumors (myxofibrosarcomas or myxoid liposarcomas), leiomyosarcomas or undifferentiated pleomorphic/spindle cell sarcomas. Using modified FNCLCC CB grading systems to replace conventional mitotic count and histologic assessment of necrosis may improve the distinction between low and high-grade STS on CB. Our study confirms that classifying grade 1 as low grade and grades 2 and 3 as high grade improves correlation between CB and final grade by up to 21%, irrespective of CB system used. A higher than expected Ki-67 score in a low-grade sarcoma diagnosed on CB should raise concern that a higher-grade component may not have been sampled. Furthermore, correlation of all clinicopathological and radiological findings at multidisciplinary meetings is essential to assess the histological grade on CB as accurately as possible.

A DNA damage repair gene-associated signature predicts responses of patients with advanced soft-tissue sarcoma to treatment with trabectedin

Predictive biomarkers of trabectedin represent an unmet need in advanced soft‐tissue sarcomas (STS). DNA damage repair (DDR) genes, involved in homologous recombination or nucleotide excision repair, had been previously described as biomarkers of trabectedin resistance or sensitivity, respectively. The majority of these studies only focused on specific factors (ERCC1, ERCC5, and BRCA1) and did not evaluate several other DDR‐related genes that could have a relevant role for trabectedin efficacy. In this retrospective translational study, 118 genes involved in DDR were evaluated to determine, by transcriptomics, a predictive gene signature of trabectedin efficacy. A six‐gene predictive signature of trabectedin efficacy was built in a series of 139 tumor samples from patients with advanced STS. Patients in the high‐risk gene signature group showed a significantly worse progression‐free survival compared with patients in the low‐risk group (2.1 vs 6.0 months, respectively). Differential gene expression analysis defined new potential predictive biomarkers of trabectedin sensitivity (PARP3 and CCNH) or resistance (DNAJB11 and PARP1). Our study identified a new gene signature that significantly predicts patients with higher probability to respond to treatment with trabectedin. Targeting some genes of this signature emerges as a potential strategy to enhance trabectedin efficacy.

Advanced systemic amyloidosis secondary to metastatic renal cell carcinoma

Secondary amyloidosis is a rare complex complication related to chronic inflammatory disease. This complication is sparsely associated to malignant neoplasms. Renal cell carcinoma (RCC) is the most common solid organ malignancy related with this paraneoplastic syndrome. Some case reports have described stabilisation or even remission of amyloidosis with cytoreductive nephrectomy. Majority of those reports were based on locally advanced RCC. We report the first case of early aggressive systemic secondary amyloidosis in high-volume metastatic RCC. The subject was diagnosed with metastatic RCC within 6 months of secondary amyloidosis; on month 5 of initiation of targeted therapy (pazopanib) developed nephrotic syndrome with a heavy proteinuria (>18 g/day), severe hypoalbuminaemia (1.53 g/dL), intense and progressive oedema, severe pancolitis and mild dyspnoea with hypotension. A colon biopsy and the immunohistochemistry confirmed the histological diagnosis of a secondary amyloidosis. The multidisciplinary tumour board decided to perform cytoreductive nephrectomy in order to reduce the pro-inflammatory status. Pathology report showed a complete resection of clear cell RCC plus renal amyloid deposits. The patient died within 4 days of surgery due to multiorgan failure.

Angiosarcomas: histology, immunohistochemistry and molecular insights with implications for differential diagnosis

Angiosarcomas (AS) represent a heterogenous group of tumors with variable clinical presentation. AS share an important morphologic and immunohistochemical overlap with other sarcomas, hence the differential diagnosis is challenging, especially in poorly-differentiated tumors. Although molecular studies provide significant clues, especially in the differential diagnosis with other vascular neoplasms, a thorough hematoxylin and eosin analysis remains an essential tool in AS diagnosis. In this review, we discuss pathological and molecular insights with emphasis on implications for differential diagnosis in cutaneous, breast, soft tissue and visceral AS.

PROCLAIM-CX-072: Analysis of patients with advanced solid tumors receiving long-term treatment with CX-072, a PD-L1 probody therapeutic, as a single agent or in combination with ipilimumab

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Background: Monotherapy with immune checkpoint inhibitors (ICIs) has demonstrated efficacy in many cancers. Combining ICIs PD-L1 + CTLA-4 enhanced efficacy but worsened toxicity vs monotherapy; therefore, CTLA-4 dose modifications are often needed, despite a dose-response effect having been shown for efficacy. CX-072 is an investigational PD-L1 PROBODY therapeutic that is preferentially activated in the tumor microenvironment (TME); localized activation may reduce immune-related AEs (irAEs). PROCLAIM-CX-072-001 identified 10 mg/kg Q2W (Mono10) as the recommended monotherapy dose. Here we provide data for Mono10 and for dose escalation of CX-072 in combination with IPI (Combo), with a focus on long-term (≥6 mo) therapy. Methods: Mono10 was evaluated in multiple tumor types. Combo doses evaluated were CX-072 0.3–10 mg/kg and IPI 3–10 mg/kg Q3W. Patients (pts) with ≥6 mo treatment duration (≥6M-TD) were compared to those with < 6 mo of treatment ( < 6M-TD) as of November 30, 2019. Results: Disease control rates (DCR = CR+PR+SD) were 41% for Mono10 (n = 47 of 114; 10 PRs) and 37% for Combo (n = 10 of 27; 1CR + 4 PRs (1CR and 3PRs at 3 mg/kg IPI [IPI3]). Additional results are shown in the table. No treatment-related adverse events (TRAEs) led to death. The most common reason for discontinuation (dc) in all groups was disease progression. Conclusions: CX-072 monotherapy demonstrated durable responses consistent with activation of the PROBODY therapeutic in the TME. The safety profile supports the tolerability of CX-072 as monotherapy and when combined with IPI3. CX-072 + IPI3 demonstrated activity in heavily pretreated pts with various tumors. The safety profile of the combination of CX-072 with IPI3 compares favorably to historical data (grade ≥3 TRAEs 55% and leading to dc in 36%; Larkin J, et al. N Engl J Med. 2015;373:23-34). CX-072 + IPI3 is being explored in a phase 2 study in 2L melanoma Clinical trial information: NCT03993379 . [Table: see text]

Controversial issues in soft tissue solitary fibrous tumors: A pathological and molecular review

The clinical evolution of solitary fibrous tumor (SFT) remains unclear. Although various clinical, morphological and molecular criteria may indicate increased risk of malignancy, some SFT can still progress despite having a clearly benign appearance. Various risk stratification systems have been proposed, but unfortunately they are not sufficient to precisely determine the malignant potential. In this review, we discuss current knowledge on SFT, focusing on the following controversial issues: (i) the diverse morphologic spectrum: 'the great simulator;' (ii) malignant transformation or dedifferentiation; (iii) current risk stratification systems; and (iv) molecular factors associated with clinical evolution. The morphological spectrum of SFT and the list of differential diagnoses continue to expand. Both have increased considerably since the first descriptions of specific molecular alterations. A classification of malignant SFT should not be based on histology alone. The correlation of all pathological and molecular factors is recommended; its inclusion in risk stratification systems may help to improve diagnosis and prognosis.

Correction to: Solitary fibrous tumor: a case series identifying pathological adverse factors-implications for risk stratification and classification

In Tables 4 and 5, there were entries that were not properly aligned on its designated rows. The correct tables are presented in this article.].

CX-072, a PD-L1 Probody therapeutic, as monotherapy in patients with advanced solid tumors: Preliminary results of PROCLAIM-CX-072

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Background: Anti-programmed cell death ligand 1 (PD-L1) immunotherapies have improved survival in many cancers, but immune-related adverse events (irAEs) have been observed, especially in combination therapy. CX-072 is an investigational Probody therapeutic directed against PD-L1, designed to be preferentially activated in the tumor microenvironment and to reduce irAEs. Methods: This is an ongoing phase 1/2a study (PROCLAIM-CX-072; NCT03013491) evaluating CX-072 in patients (pts) with metastatic or unresectable solid tumors with no further standard curative treatment options and with no prior anti-PD1, PD-L1 or anti-CTLA4 treatment. Pts were unselected for PD-L1 expression. We report preliminary results from expansion cohorts in anal squamous cell carcinoma (SCCA), cutaneous squamous cell carcinoma (cSCC), small bowel adenocarcinoma (SBA), triple-negative breast cancer with skin lesions (TNBC), or undifferentiated pleomorphic sarcoma (UPS). Pts were treated with CX-072 monotherapy 10 mg/kg intravenously every 14 days. Results: As of 30 Nov 2018, 51 pts received CX-072 10 mg/kg monotherapy: SCCA (n = 9), cSCC (n = 5), SBA (n = 9), TNBC (n = 9), and UPS (n = 19). Median age was 63 y (range, 32-80), 67% were female, and pts had a median of 3 prior regimens (range, 1-12). Median treatment duration was 1.8 mo (range, 0.3-14.7). A grade 3/4 treatment-related adverse event (AE) was observed in 1 pt (2%; gr 3 generalized rash). No grade 3/4 irAEs were observed. Two pts discontinued treatment due to AEs: nausea (pt with SCCA) and sepsis (pt with SBA), neither treatment-related. Partial responses (confirmed and unconfirmed) were observed in cSCC (n = 1), TNBC (n = 2), and UPS (n = 1) (Table). Conclusions: CX-072 10 mg/kg monotherapy demonstrated anticancer activity in heavily pretreated pts with advanced solid tumors, including responses in cSCC, TNBC with skin lesions, and UPS, with a safety profile that compares favorably to historical controls. Clinical trial information: NCT03013491. [Table: see text]

Clinicopathological and Molecular Characterization of Metastatic Gastrointestinal Stromal Tumors with Prolonged Benefit to Frontline Imatinib

BACKGROUND

Oncogenic KIT/PDGFRA signaling inhibition with imatinib achieves disease control in most patients with advanced/metastatic gastrointestinal stromal tumor (GIST), but resistance eventually develops after 20-24 months. Notably, a small subset of these patients obtain durable benefit from imatinib therapy.

METHODS

We analyzed clinical, pathological, and molecular characteristics and long-term outcomes in patients with metastatic GIST treated with continuous daily dosing of frontline imatinib in a cohort of patients benefiting for ≥5 years. A control group was obtained from the national Spanish Group for Sarcoma Research database and used as comparator.

RESULTS

Sixty-four imatinib long-term responders (LTRs) and 70 control cases were identified. Compared with controls, LTRs at baseline had better performance status (PS) 0-1 (100% vs. 81%), lower mitotic count (median, 8 vs. 15), and tumor burden (number of metastases, 3 vs. 7). KIT exon 11 was the only region found mutated in LTRs. LTRs achieved 34% complete responses and a median progression-free survival of 11 years, compared with 4% and 2 years, respectively, in the control cohort. Prognostic factors that independently predicted long-term benefit with imatinib were PS, number of metastases prior to imatinib, and response to imatinib. Fifteen LTR patients developed new side effects attributable to imatinib after ≥5 years of continuous treatment. No resistance mutations were found in metastatic samples from three patients progressing on imatinib.

CONCLUSION

GISTs in LTRs are a distinctive entity with less aggressive behavior and marked sensitivity to KIT inhibition. Patients reaching 5 or more years on imatinib have a higher chance of remaining progression free over time.

IMPLICATIONS FOR PRACTICE

This work demonstrates that clinical and inherent tumor characteristics define a subset of patients with gastrointestinal stromal tumor (GIST) with increased likelihood to achieve durable response to first-line imatinib therapy. Patients reaching ≥5 years on imatinib have a greater chance of remaining progression free over time, although the disease is unlikely to be cured. Imatinib is well tolerated for >5 years, and emergent toxicities are overall manageable. Resistance to imatinib emerging in patients with GISTs after long-term imatinib treatment does not involve polyclonal expansion of KIT secondary mutations.

Phase II trial of ifosfamide in combination with the VEGFR inhibitor sorafenib in advanced soft tissue sarcoma: a Spanish group for research on sarcomas (GEIS) study

Background Sorafenib is a potent targeted-therapy that blockades angiogenesis and has demonstrated activity against some sarcoma subtypes. Preclinical studies suggested that treatment with sorafenib plus cytotoxic agents could result in additive efficacy. Methods Patients with advanced soft tissue sarcoma, with or without anthracycline pretreatment were included. Patients received oral sorafenib 400 mg twice daily starting on Day +2, ifosfamide 2.0 g/m2 iv infusion lasting 4 h on days 1, 2 and 3 with concurrent mesna 400 mg/m² every three weeks until disease progression or unacceptable toxicity or up to a maximum of 6 cycles of ifosfamide (sorafenib could be continued until progressive disease or unacceptable toxicity). Primary objective was progression-free rate (PFR) at 3 and 6 months; secondary objectives were overall response rate (ORR), Progression-free survival (PFS), Overall survival (OS) and safety. This article reports the phase II part of a phase I/II clinical trial. Results Thirty-five patients were enrolled. PFR at 3 and 6 months was 66% (95% CI 48-81) and 37% (95% CI 22-55). Six patients (17%) achieved partial response and 17 (49%) stable disease. Median PFS was 4.8 months (CI 95% 1.94-6.36) and overall survival 16.2 months (95% CI 8.75-NA). Conclusion Treatment with sorafenib plus ifosfamide achieved a significant clinical benefit with an acceptable safety profile in patients with advanced soft tissue sarcoma resistant to anthracyclines, which warrants a more detailed study in randomized clinical trials.

Efficacy and safety of CetuGEX in recurrent/metastatic squamous cell carcinoma of the head and neck (RM-HNSCC): Results from the randomized phase II RESGEX study

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Background: Standard treatment for RM-HNSCC is a combination of cisplatin (P), 5-FU (F), and the epidermal growth factor receptor (EGFR) blocking monoclonal antibody cetuximab. CetuGEX is a new monoclonal antibody sharing the identical EGFR-binding domain with cetuximab, but a modified Fc part by a proprietary glycosylation method to optimize antibody dependent cellular cytotoxicity (ADCC). Methods: Patients with RM-HNSCC without relevant comorbidities were randomized to receive up to 6 cycles of P 100 mg/m2, F 4 x 1000 mg/m2/24hrs and CetuGEX vs. cetuximab. Initial dose of cetuximab was 400mg/m2, followed by weekly 250 mg/m2. CetuGEX was given as 990 mg, followed by weekly 720 mg. After end of combination treatment, patients received single agent antibody maintenance until disease progression or intolerable toxicity. Stratification factors included FcγRIIIa status, primary tumor site, EGFR pretreatment vs. naïve, and recurrent vs. metastatic disease. Primary endpoint was progression-free survival (PFS) by immune related response criteria (irRC). Secondary endpoints included objective response rate (ORR), clinical benefit rate (CBR) and overall survival (OS) as well as safety and QoL. Results: During Jan 2014 and Feb 2016, 240 patients were accrued in 34 European centers, of which 123 received cetuximab and 117 CetuGEX. The median follow-up was 15 month until May 2017. No difference was observed for the primary endpoint of PFS by irRC [median 27.7 (CetuGEX) and 26.4 (cetuximab) weeks; HR 1.003; 95%-CI 0.738 – 1.363; p = 0.98]. No advantage of CetuGEX over cetuximab was observed for all other secondary efficacy endpoints and subgroup analyses by stratification factors. Infusion related reactions (IRR) were higher for CetuGEX (38.8%) than for cetuximab (5.7%) (Pearson chi2= 37.08; p < 0.0001), but without sequelae. Conclusions: The RESGEX study is the first head-to-head comparison of an ADCC-optimized to a conventional EGFR-directed antibody. The study failed to show superior efficacy of CetuGEX over cetuximab. Both compounds appear to have the same efficacy and a similar safety profile. Glycosylation changes in the Fc part induced more IRRs. Clinical trial information: NCT02052960.

Review with novel markers facilitates precise categorization of 41 cases of diagnostically challenging, "undifferentiated small round cell tumors". A clinicopathologic, immunophenotypic and molecular analysis

BACKGROUND

Despite extensive immunohistochemical (IHC) and molecular studies combined with morphologic findings, a group of round/ovoid cell tumors histologically similar to Ewing sarcomas (ES) but lacking EWSR1-rearrangements may remain unclassifiable.

DESIGN

We retrospectively analyzed 41 Ewing-like tumors (formalin-fixed, paraffin-embedded) previously determined as negative or non-informative for EWSR1-rearrangements by FISH and/or RT-PCR. A new histopathology revision and additional IHC and molecular analyses were carried out in order to investigate whether additional IHC and/or molecular testing in combination with the morphological findings may help in reaching a definitive diagnosis.

RESULTS

Almost all the tumors (n=40) involved soft tissue and/or bone and half the patients died of disease. In the archival cases all diagnoses were Ewing sarcoma (ES), Ewing-like sarcoma (ELS), myoepithelial tumor and undifferentiated sarcoma (US). In the new review all the tumors were re-classified as, ES (n=16), Ewing-like tumor with EWSR1 rearrangement and amplification and possible EWSR1-NFATC2 gene fusion (n=1), CIC-rearranged sarcomas or undifferentiated sarcoma, most consistent with CIC-rearranged sarcoma (n=7), sarcoma with BCOR-alteration or undifferentiated sarcoma, consistent with BCOR-associated sarcoma (n=3), neuroblastoma (n=2), unclassifiable neoplasm with neuroblastic differentiation (n=1), malignant rhabdoid tumor (n=2), lymphoblastic lymphoma (n=1), clear cell sarcoma of the gastrointestinal tract (n=1), small cell carcinoma (n=1), sclerosing rhabdomyosarcoma (n=1), desmoplastic small round cell tumor (n=1), malignant peripheral sheath nerve tumor (n=1), poorly-differentiated synovial sarcoma (n=1), Possible gastrointestinal stromal tumor/GIST with predominant round cells (n=1) and possible SMARCA4-deficient-sarcoma (n=1). NKX2.2, ETV4 and BCOR immunoreactivity was observed in all ES, CIC-rearranged sarcomas and sarcomas with BCOR alteration, respectively. CIC-rearrangement by FISH was observed in many of the CIC-rearranged sarcomas.

CONCLUSION

Our analysis of 41 Ewing-like tumors confirms that there may be a significant pathological and IHC overlap among Ewing-like tumors, with prognostic and therapeutic impacts. Additional IHC (NKX2.2, ETV4 and BCOR) and molecular studies including FUS, CIC or BCOR analysis may support the final diagnosis when FISH or RT-PCR fail to detect EWSR1-rearrangements. Any molecular findings should always be interpreted in relation to the specific clinical and pathological context.

Mutational profile of primary breast diffuse large B-cell lymphoma

Primary breast lymphoma is a rare form of extra-nodal lymphoid neoplasm. The most common histological type is the diffuse large B-cell lymphoma, which represents 60–80% of all the cases. Our study analyzes the mutational profile of the primary lymphoma of the breast through targeted massive sequencing with a panel of 38 genes in a group of 17 patients with primary breast diffuse large B-cell lymphoma. Seventy-point-five percent of the patients presented with stage IE and 29.5% with stage IIE. 44% of the cases correspond to lymphomas with germinal center phenotype and 33.3% to activated B-cell. The genes with a higher mutational frequency include PIM1 (in 50% of the analyzed samples), MYD88 (39%), CD79B, PRDM1 and CARD11 (17%), KMT2D, TNFIAP3 and CREBBP (11%). The profile of mutant genes involves mostly the NFκB signaling pathway. The high frequency of mutations in PIM1 compared with other lymphomas may have implications in the clinical presentation and evolution of this type of lymphoma.

Prognostic value of event-free survival at 12 and 24 months and long-term mortality for non-Hodgkin follicular lymphoma patients: A study report from the Spanish Lymphoma Oncology Group

BACKGROUND

Relatively few studies have analyzed the mortality of follicular lymphoma (FL) patients in comparison with a sex- and age-matched general population. This study analyzed the overall survival (OS) of patients with FL and compared their survival with the expected survival of a general population.

METHODS

Patients diagnosed with FL were prospectively enrolled from 1980 to 2013. Standardized mortality ratios (SMRs) were obtained from yearly sex- and age-specific mortality rates in Spain, and OS was compared with age- and sex-matched general population data.

RESULTS

A total of 1074 patients with newly diagnosed FL were enrolled. The median OS was 231 months (95% confidence interval [CI], 195-267 months). Event-free survival at 12 months (EFS12) and event-free survival at 24 months (EFS24) were associated with an increased probability of early death, with an SMR of 10.27 (95% CI, 8.26-12.77) for EFS12. The overall SMR, including all causes of death, was 2.55 (95% CI, 2.23-2.92), and it was higher for women (SMR, 3.02; 95% CI, 2.48-3.67) and young adults (SMR, 6.01; 95% CI, 3.13-11.55). More than 10 years after the diagnosis, mortality rates for FL patients were lower than those for the general population (SMR, 0.47; 95% CI, 0.28-0.78). When FL was excluded as a cause of death, the overall SMR was 1.35 (95% CI, 1.11-1.65) without a statistically significant mortality increase in the >60-year-old group in comparison with age- and sex-matched general population data. More than 15% of the patients included in the study (n = 158) had more than 10 years of follow-up.

CONCLUSIONS

EFS12 and EFS24 predict an early increase in mortality. The long-term SMR, over the course of 10 years of follow-up, shows that patients with FL have a risk of dying similar to that of a sex- and age-matched general population. Cancer 2017;123:3709-3716. © 2017 American Cancer Society.

Correlation between a new growth modulation index (GMI)-based Geistra score and efficacy outcomes in patients (PTS) with advanced soft tissue sarcomas (ASTS) treated with trabectedin (T): A Spanish group for research on sarcomas (GEIS-38 study)

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Background: The GMI is a marker of drug activity and represents an intra-patient comparison of successive time to progression (TTP), defined as the TTP ratio between the second (or later) line (TTPn) of therapy divided by the prior line (TTPn−1). Defining a clinical profile of pts with GMI >1.33 could help to identify pts who can gain greater benefit from T. Methods: We retrospectively evaluated the concordance between the GMI and the efficacy outcomes and clinical profiles of 198 pts with ASTS treated with trabectedin 1.5 mg/m² (24-h infusion q3w) as a 2nd or further-line treatment from Jan 2007 to Jun 2016. Results: After a median follow-up of 58 months (m; range: 18-172) median overall survival from ASTS diagnosis (MOS) and from T (MT-OS) were 27.5 m (23-32.1) and 10.8 m (8.9-12.7), respectively, while median TTP from T (MT-TTP) and T-1 were 3.4 m (2.8-4) and 3.5 m (2.8-4.2). Overall, 106 pts (53%) had a GMI <1; 22 (11%) a GMI=1-1.33 and 70 pts (35%) a GMI >1.33. A high GMI (<1.33 vs >1.33) correlated with favorable efficacy outcomes: MT-OS: 23 vs 36 m (p<0.001), MT-TTP 2.3 vs 8.2 m (p<0.001) and clinical benefit (objective response + stable disease) 23% vs 68% (p=0.001). The multivariate analysis identified L-type sarcoma (Odds ratio: 1.99, 95% CI 1.06-3.71), metastatic free interval (MFI) from initial diagnosis > 8.1 m (2.24, 95%CI 1.19-4.18) and Karnofsky >80 (2.3, 95%CI 1.00-5.28) as factors independently associated to GMI> 1.33. Based on these 3 variables we defined a new GEISTRA score assigning 1 point for each adversely affected variable: non L-Sarcoma, MFI<8.1m or Karnofsky <80. This score showed a strong correlation with MT-TTP (p<0.001) and MT-OS (p<0.001). Conclusions: Based on the high GMI we defined a new GEISTRA score, which is strongly associated with favorable efficacy outcomes in pts with ASTS treated with T. Thus, GEISTRA score could be a potentially useful predictable clinical tool for T benefit. [Table: see text]

Impact of treatment in long-term survival patients with follicular lymphoma: A Spanish Lymphoma Oncology Group registry

BACKGROUND

Follicular lymphoma is the second most common non-Hodgkin lymphoma in the United States and Europe. However, most of the prospective randomized studies have very little follow-up compared to the long natural history of the disease. The primary aim of this study was to investigate the long-term survival of our series of patients with follicular lymphoma.

PATIENTS AND METHODS

A total of 1074 patients with newly diagnosed FL were enrolled. Patients diagnosed were prospectively enrolled from 1980 to 2013.

RESULTS

Median follow-up was 54.9 months and median overall survival is over 20 years in our series. We analyzed the patients who are still alive beyond 10 years from diagnosis in order to fully assess the prognostic factors that condition this group. Out of 166 patients who are still alive after more than 10 years of follow-up, 118 of them (73%) are free of evident clinical disease. Variables significantly associated with survival at 10 years were stage < II (p <0.03), age < 60 years (p <0.0001), low FLIPI (p <0.002), normal β2 microglobulin (p <0.005), no B symptoms upon diagnosis (p <0.02), Performance Status 0-1 (p <0.03) and treatment with anthracyclines and rituximab (p <0.001), or rituximab (p <0.0001).

CONCLUSIONS

A longer follow-up and a large series demonstrated a substantial population of patients with follicular lymphoma free of disease for more than 10 years.

Malignant PEComa With Metastatic Disease at Diagnosis and Resistance to Several Chemotherapy Regimens and Targeted Therapy (m-TOR Inhibitor)

Perivascular epithelioid cell tumors (PEComas) are infrequent neoplasms with peculiar myomelanocytic differentiation. The aggressive abdominopelvic variant is rare, with only a small number of published cases. We present an additional case of this unusual variant, which showed an aggressive histologic and clinical behavior with multiple liver metastases and resistance to several therapies. We also discuss the histological and immunohistochemical profiles as well as the differential diagnosis.

Cutaneous Angiosarcoma: Clinical and Pathology Study of 16 Cases

INTRODUCTION AND OBJECTIVES

Primary cutaneous angiosarcoma is one of the most aggressive skin tumors and carries a very poor prognosis. Its initially indolent clinical presentation explains the frequently late diagnosis that, together with its typically multifocal pattern and poor delimitation, often makes surgery difficult. The low incidence of primary cutaneous angiosarcoma means that few large single-center series have been published. We review the clinical and pathologic characteristics of cutaneous angiosarcomas treated in our hospital, looking for prognostic factors and for possible diagnostic traits that could facilitate early diagnosis.

MATERIAL AND METHODS

This was a retrospective observational study including all patients diagnosed with cutaneous angiosarcoma in Instituto Valenciano de Oncología in Valencia, Spain between January 2000 and December 2015. We recorded 16 clinical parameters, including age, sex, type of angiosarcoma, site, size, and time since diagnosis, and 8 histopathologic parameters.

RESULTS

We identified 16 patients (11 women and 5 men) with cutaneous angiosarcoma. Their mean age was 67 years (median, 71 years). The most common site was the trunk (10 cases), followed by the head and neck (5 cases). The mean size of the tumor was 10cm (median, 6.5cm). Fourteen patients underwent surgical excision. Six of the 16 patients were alive at the end of the study, after a mean follow-up period of 42.5 months.

CONCLUSIONS

The major determinants of survival among patients with cutaneous angiosarcoma are tumor size and patient age. Other characteristics associated with a poor prognosis were infiltration of deep planes (muscle), a predominantly solid histologic pattern, and a larger number of mitoses.

Primary Breast Lymphoma: Analysis of 55 Cases of the Spanish Lymphoma Oncology Group

INTRODUCTION

Primary breast lymphoma is a rare form of localized extranodal lymphoma, which affects the mammary glands unilaterally or bilaterally, and can also affect the regional lymph nodes.

MATERIALS AND METHODS

We reviewed 55 patients, with disease stages IE and IIE, diagnosed in 16 Spanish institutions between 1989 and 2016. A serial of clinical variables and treatment were collected, and overall survival (OS) and progression-free survival (PFS) were calculated.

RESULTS

Of the 55 patients, 96.4% were women with an average age of 69 years. A total of 53 patients corresponded to non-Hodgkin lymphoma (NHL), of whom 36.3% had lymph node involvement upon diagnosis. Of the patients, 58.2% were stage IE, and 41.8% were stage IIE. Treatments received included radiotherapy (36.3%), chemotherapy (85.5%), and rituximab (in 38 of the 45 patients with NHL treated with chemotherapy). In all, 82.2% of complete responses were achieved. OS and progression-free survival at 5 years in NHL patients was 76% and 73%, respectively.

CONCLUSION

Current treatments (chemotherapy, immunotherapy, and radiotherapy) achieve good control of the disease, with an OS of 5 years in 80% of the patients, although there is no consensus in treatment, given the scarce incidence of these lymphomas.

Malignant Peripheral Nerve Sheath Tumor With Osseous Heterologous Differentiation in Uncommon Locations (Heart and Retropharynx)

We report two cases of malignant peripheral nerve sheath tumor (MPNST) in an uncommon location (heart and retropharynx) both with divergent osseous heterologous differentiation. We present the pathological and immunohistochemical studies that confirmed the neurogenic origin. The histopathology of the tumor arising in the retropharynx showed a transition from a neurofibroma to MPNST, making this a new report of an MPNST arising from a plexiform neurofibroma without neurofibromatosis. Primary cardiac MPNST with osseous differentiation has never been reported before. In conclusion, the histology of MPNSTs is very heterogeneous, showing no specific diagnostic immunoprofile or genetic alteration. Thus, it is important to rule out other histologically similar tumors, particularly in cases arising in uncommon locations or tumors with divergent heterologous differentiation.

Diagnostic and therapeutic update of mantle cell lymphoma (MCL): analysis of seven cases treated in a centre in one year

Mantle cell lymphoma (MCL) is an infrequent subtype of non-Hodgkin’s lymphoma (NHL) and represents between 4–8% of adult lymphomas. Recently an increase in its incidence to 1–2 cases/100,000 inhabitants/year has been observed. The first line of treatment is based on chemoimmunotherapy and depends on age and the initial stage at diagnosis. There are no second line or successive treatments. There are currently several drugs available that provide acceptable results.