Gastrointestinal stromal tumors (GIST) are rare mesenchymal tumors characterized by KIT or PDGFRA mutations. Over three decades, significant changes in drug discovery and loco-regional (LR) ...procedures have impacted treatment strategies. We assessed the evolution of treatment strategies for metastatic GIST patients treated in the three national coordinating centers of NetSarc, the French network of sarcoma referral centers endorsed by the National Institute of Cancers, from 1990 to 2018. The primary objective was to describe the clinical and biological profiles as well as the treatment modalities of patients with metastatic GIST in a real-life setting, including access to clinical trials and LR procedures in the metastatic setting. Secondary objectives were to assess (1) patients’ outcome in terms of time to next treatment (TNT) for each line of systemic treatment, (2) patients’ overall survival (OS), (3) evolution of patients’ treatment modalities and OS according to treatment access: <2002 (pre-imatinib approval), 2002–2006 (pre-sunitinib approval), 2006–2014 (pre-regorafenib approval), post 2014, and (4) the impact of clinical trials and LR procedures on TNT and OS in the metastatic setting. 1038 patients with a diagnosis of GIST made in one of the three participating centers between 1990 and 2018 were included in the national prospective database. Among them, 492 patients presented metastasis, either synchronous or metachronous. The median number of therapy lines in the metastatic setting was 3 (range 0–15). More than half of the patients (55%) participated in a clinical trial during the course of their metastatic disease and half (51%) underwent additional LR procedures on metastatic sites. The median OS in the metastatic setting was 83.4 months (95%CI 72.7; 97.9). The median TNT was 26.7 months (95%CI 23.4; 32.3) in first-line, 10.2 months (95%CI 8.6; 11.8) in second line, 6.7 months (95%CI 5.3; 8.5) in third line, and 5.5 months (95%CI 4.3; 6.7) in fourth line, respectively. There was no statistical difference in OS in the metastatic setting between the four therapeutic periods (log rank, p = 0.18). In multivariate analysis, age, AFIP Miettinen classification, mutational status, surgery of the primary tumor, participation in a clinical trial in the first line and LR procedure to metastatic sites were associated with longer TNT in the first line, whereas age, mitotic index, mutational status, surgery of the primary tumor and LR procedure to metastatic sites were associated with longer OS. This real-life study advocates for early reference of metastatic GIST patients to expert centers to orchestrate the best access to future innovative clinical trials together with LR strategies and further improve GIST patients’ survival.
Background
Rhabdomyosarcoma (RMS) in infants is a particular entity with various clinical presentations and outcomes. To better understand the clinical heterogeneity of RMS in infants, an integrative ...clinical, histological, and molecular analysis was performed.
Methods
From 1989 to 2015, 37 infants aged less than 6 months with a diagnosis of RMS and archival tumor materials were identified in France. Clinical data, central pathologic review, and molecular profile including RNA sequencing were analyzed.
Results
Nineteen patients (51%) had embryonal RMS (ERMS) (including three highly differentiated ERMS with PTCH deletion), eight (22%) had spindle cell RMS (SRMS) (three VGLL2‐, one NTRK‐, and two (B)RAF‐fusions), six (16%) had alveolar RMS (ARMS) (all FOXO1‐ or PAX3‐fusion), two had unclassified RMS, and two poorly differentiated RMS were retrospectively diagnosed as rhabdoid tumors (RT) with loss of INI1 expression. The two RT patients died of rapid disease progression. Five‐year event‐free (EFS) and overall survival (OS) for RMS were 62% (95%CI, 47‐82) and 52% (95%CI, 37‐72). Eleven patients (31%) relapsed and four (11%) had primary refractory disease (all ERMS). In univariate analysis, EFS and OS were only associated with histology subtype, with 100% survival of known fusion‐positive SRMS. RNA cluster expression showed three main clusters: ARMS, ERMS, and “VGLL2‐fusion” cluster, consisting of SRMS and ERMS.
Conclusions
Biopathology findings from this study support the different prognosis of infantile RMS. New fusion‐positive SRMS has a very good outcome which may allow more conservative treatment in the future.
This study reported integrative clinical, histological, and molecular analysis of infants with RMS. Biopathology findings support the different prognosis of infantile RMS with new fusion‐positive spindle cell RMS having a very good outcome which may allow more conservative treatment in the future.
A biopsy is a prerequisite for the diagnosis and evaluation of musculoskeletal tumors. It is considered that surgical biopsy provides a more reliable diagnosis because it can obtain more tumor ...material for pathological analysis. However, it is often associated with a significant complication rate. Imaging-guided percutaneous core needle biopsy (PCNB) is now widely used as an alternative to surgical biopsy; it appears to be minimally invasive, possibly with lower complication rates. This study evaluates the diagnostic yield of the preferred use of PCNB in a referral center, its accuracy, and its complication rate. The data relating to the biopsy and the histological analysis were extracted from the database of a bone tumor reference center where PCNB of bone tumors was discussed as a first-line option. 196 bone tumors were biopsied percutaneously between 2016 and 2020. They were located in the axial skeleton in 21.4% (42) of cases, in the lower limb in 58.7% (115), and in the upper limb in 19.9% (39) cases. We obtained a diagnosis yield of 84.7% and a diagnosis accuracy of 91.7%. The overall complication rate of the percutaneous biopsies observed was 1.0% (n = 2), consisting of two hematomas. PCNB performed in a referral center is a safe, precise procedure, with a very low complication rate, and which avoids the need for first-line open surgical biopsy. The consultation between pathologist, radiologist, and clinician in an expert reference center makes this technique an effective choice as a first-line diagnosis tool.
Background
Metastatic soft tissue sarcomas (STS) are a group of rare and heterogeneous mesenchymal tumors with a poor prognosis. The aim of this study was to evaluate the incidence of long‐term ...survivors and describe their presentation and management in a large cohort of patients with metastatic STS.
Methods
We collected information of patients with metastatic STS managed in Centre Leon Berard between 1985 and 2015 aiming to compare the group of patients alive 5 years after the diagnosis of metastases vs the others. Prognostic factors of patients and tumors characteristics were investigated by logistic regression analysis. For “long‐term survivors,” we explored therapeutic strategies at metastatic stage.
Results
Out of 436 patients enrolled, 39 (9%) were still alive 5 years after diagnostic of metastases with a median survival of 146 months (12 years). This “long‐term survivors” group included more female and younger patients, with better performance status, more synovial sarcoma or endometrial stromal sarcoma, more patients with simple genomic sarcomas, lower tumor grade, smaller tumor, and longer disease‐free interval. In multivariate analysis, age below 55 at metastatic stage (P = 0.0002) and grade 1 tumor (P < 0.0001) were significantly associated with the “long‐term survivors.” Their therapeutic management was usually aggressive (intensified or polychemotherapy, repeated local treatment of metastases), leading to 62% of complete response in first‐line setting.
Conclusions
Very long‐term survivors are observed in metastatic STS. Selection of patients in good condition with less aggressive tumor and administration of intensive treatment may lead to obtain these motivating results in a poor prognosis disease.
Metastatic STS remains an incurable disease, but a significant proportion of patients can achieve long‐term survival and even a very long‐term survival with a 12 years median overall survival. Administration of intensive treatment combining systemic therapy and locoregional destruction of metastases in selected young patients with good performance status and slowly progressive disease may lead to obtain these motivating results in a poor prognosis disease. Identification of such factors is essential for patient management and may contribute further to a more individualized strategy of metastatic STS patients.
BCOR‐ITD tumours form an emerging family of aggressive entities with an internal tandem duplication (ITD) in the last exon of the BCOR gene. The family includes cerebral tumours, termed central ...nervous system BCOR‐ITD (CNS BCOR‐ITD), and sarcomatous types described in the kidney as clear cell sarcoma of the kidney (CCSK), in the endometrium as high‐grade endometrial stromal sarcoma, and in the bone and soft tissue as undifferentiated round cell sarcoma or primitive myxoid mesenchymal tumour of infancy. Based on a series of 33 retrospective cases, including 10 CNS BCOR‐ITD and 23 BCOR‐ITD sarcomas, we interrogated the homogeneity of the entity regarding clinical, radiological, and histopathological findings, and molecular signatures. Whole‐transcriptomic sequencing and DNA methylation profiling were used for unsupervised clustering. BCOR‐ITD tumours mostly affected young children with a median age at diagnosis of 2.1 years (range 0–62.4). Median overall survival was 3.9 years and progression‐free survival was 1.4 years. This dismal prognosis is shared among tumours in all locations except CCSK. Histopathological review revealed marked differences between CNS BCOR‐ITD and BCOR‐ITD sarcomas. These two groups were consistently segregated by unsupervised clustering of expression (n = 22) and DNA methylation (n = 21) data. Proximity between the two groups may result from common somatic changes within key pathways directly related to the novel activity of the ITD itself. Conversely, comparison of gene signatures with single‐cell RNA‐Seq atlases suggests that the distinction between BCOR‐ITD sarcomas and CNS BCOR‐ITD may result from differences in cells of origin.
Risk assessment of gastrointestinal stromal tumor (GIST) according to the AFIP/Miettinen classification and mutational profiling are major tools for patient management. However, the AFIP/Miettinen ...classification depends heavily on mitotic counts, which is laborious and sometimes inconsistent between pathologists. It has also been shown to be imperfect in stratifying patients. Molecular testing is costly and time-consuming, therefore, not systematically performed in all countries. New methods to improve risk and molecular predictions are hence crucial to improve the tailoring of adjuvant therapy. We have built deep learning (DL) models on digitized HES-stained whole slide images (WSI) to predict patients' outcome and mutations. Models were trained with a cohort of 1233 GIST and validated on an independent cohort of 286 GIST. DL models yielded comparable results to the Miettinen classification for relapse-free-survival prediction in localized GIST without adjuvant Imatinib (C-index=0.83 in cross-validation and 0.72 for independent testing). DL splitted Miettinen intermediate risk GIST into high/low-risk groups (p value = 0.002 in the training set and p value = 0.29 in the testing set). DL models achieved an area under the receiver operating characteristic curve (AUC) of 0.81, 0.91, and 0.71 for predicting mutations in KIT, PDGFRA and wild type, respectively, in cross-validation and 0.76, 0.90, and 0.55 in independent testing. Notably, PDGFRA exon18 D842V mutation, which is resistant to Imatinib, was predicted with an AUC of 0.87 and 0.90 in cross-validation and independent testing, respectively. Additionally, novel histological criteria predictive of patients' outcome and mutations were identified by reviewing the tiles selected by the models. As a proof of concept, our study showed the possibility of implementing DL with digitized WSI and may represent a reproducible way to improve tailoring therapy and precision medicine for patients with GIST.
Chordomas are rare, slow-growing tumors of the axial skeleton. These tumors are locally aggressive and refractory to conventional therapies. Radical surgery and radiation remain the first-line ...treatments. Despite these aggressive treatments, chordomas often recur and second-line treatment options are limited. The mechanisms underlying chordoma radioresistance remain unknown, although several radioresistant cancer cells have been shown to respond favorably to aldehyde dehydrogenase (ALDH) inhibition. The study of chordoma has been delayed by small patient cohorts and few available models due to the scarcity of these tumors. We thus created cellular 3D models of chordoma by using low-adherence culture systems. Then, we evaluated their radiosensitivity using colony-forming and spheroid size assays. Finally, we determined whether pharmacologically inhibiting ALDH increased their radiosensitivity. We found that 3D cellular models of chordoma (derived from primary, relapse, and metastatic tumors) reproduce the histological and gene expression features of the disease. The metastatic, relapse, and primary spheroids displayed high, medium, and low radioresistance, respectively. Moreover, inhibiting ALDH decreased the radioresistance in all three models.
Background: Leiomyosarcoma (LMS) and liposarcoma (LPS) are ultra-rare sarcomas in pediatric (0–18 years) and young adult (19−30) populations. We aimed to analyze their clinical characteristics at ...these young ages and to determine whether they should be considered with the same therapeutic strategy in both populations. Methods: National retrospective multicenter study of all young patients (0–30 years) included in the sarcoma database “ConticaBase”, treated for LMS or LPS between 2010 and 2019 via the national NETSARC+ network, with available pathology/biology review. Findings: A total of 218 patients were identified, 34 children (nine LMS, 25 LPS) and 184 young adults (58 LMS, 126 LPS). Myxoid/Round Cell LPS (M/RC-LPS) was the most frequent LPS subtype (72 %). All children had localized LMS and LPS, versus 52/58 and 116/126 respectively in adults. Clinical presentation of LMS and all LPS subtypes was comparable in both populations, except for a preferential limb location of LMS in children. The therapeutic strategy was mainly based on primary surgery in LMS (9/9 children, 52/58 adults) and for LPS (respectively 25/25 and 122/126), exclusively or with adjuvant radiotherapy and systemic treatment. With a median follow-up of 62.4 months (range, 2.5–146), 5-year overall survival was respectively 83 % 95 % CI, 58–100 in children and 73 % 61–88 in young adults for LMS, 100 % 100 vs 92 % 87–99 for M/RC-LPS and 25 % 5–100 vs 60 % 29–100 for pleomorphic LPS. Interpretation: LMS and all LPS subtypes appear to display comparable behavior in children and young adults. The authors propose that the same therapeutic strategy should be considered for both groups.
Malignant Peripheral Nerve Sheath Tumors (MPNST) are very rare and aggressive tumors, which can affect children, adolescents, and young adults. These tumors are frequently associated with type 1 ...neurofibromatosis (NF1). This study aims to determine prognostic factors in unselected pediatric MPNST to specify the risk stratification strategy.
A national multicenter retrospective study encompassing all French pediatric patients (0–18 years) treated for MPNST, confirmed by a pathology review, from 1995 to 2017.
Overall, 66 patients (median age 13.0 years range, 0.1–18.0) developed a MPNST located in the limbs (36%), trunk (27%), head and neck (21%) and para-vertebral area (15%). Forty-eight percent of patients had NF1, 50% had a histologic grade III tumor and 77% a large tumor (>5 cm), including 30% very large (>10 cm). Most patients (94%) had localized tumors. After a median follow-up of 7.6 years range, 0.4–18.7, the 5-year overall (OS) and event-free (EFS) survivals were 46.7% 95%CI, 35.8–60.8 and 40.8% 95%CI, 30.3–54.9, respectively. On multivariate analysis were found to be associated with a worse outcome (OS): metastatic disease (HR (Hazard-Ratio) 6.4 1.8; 22.0), grade 3 FNCLCC (HR 4.77 1.4; 15.8),> 10-cm size (HR 2.3 1.1; 4.8) and the presence of NF1 (HR 2.2 1.1; 4.4). Histologic subtypes of MPNST (classical, malignant Triton or epithelioid tumor) were not correlated with outcome.
The overall outcome of MPNST was poor in patients with NF1 and in high grade, very large and metastatic tumors. The identification of these risk factors allows us to define adapted risk stratification to propose new therapeutic strategies for high-risk cases.
•The prognosis of Pediatric MPNST is poor: 5y-OS 46.7% (95%CI, 35.8–60.8).•Type 1 neurofibromatosis is an independent risk factor in pediatric patients.•High grade, large and metastatic tumors are other major risk factors.•Histological subtype, such as malignant triton tumor, is not correlate with survival.
Survival rate for Chondrosarcoma (CHS) is at a standstill, more effective treatments are urgently needed. Consequently, a better understanding of CHS biology and its immune environment is crucial to ...identify new prognostic factors and therapeutic targets.
Here, we exhaustively describe the immune landscape of conventional and dedifferentiated CHS. Using IHC and molecular analyses (RT-qPCR), we mapped the expression of immune cell markers (CD3, CD8, CD68, CD163) and immune checkpoints (ICPs) from a cohort of 27 conventional and 49 dedifferentiated CHS. The impact of the density of tumor-infiltrating lymphocytes (TILs), tumor-associated macrophages (TAMs) and immune checkpoints (ICPs) on clinical outcome were analyzed.
We reveal that TAMs are the main immune population in CHS. Focusing on dedifferentiated CHS, we found that immune infiltrate composition is correlated with patient outcome, a high CD68+/CD8+ ratio being an independent poor prognostic factor (p < 0.01), and high CD68+ levels being associated with the presence of metastases at diagnosis (p < 0.05). Among the ICPs evaluated, CSF1R, B7H3, SIRPA, TIM3 and LAG3 were expressed at the mRNA level in both CHS subtypes. Furthermore, PDL1 expression was confirmed by IHC exclusively in dedifferentiated CHS (42.6% of the patients) and CSF1R was expressed by TAMs in 89.7% of dedifferentiated CHS (vs 62.9% in conventional).
Our results show that the immune infiltrate of CHS is mainly composed of immunosuppressive actors favoring tumor progression. Our results indicate that dedifferentiated CHS could be eligible for anti-PDL1 therapy and more importantly immunomodulation through CSF1R + macrophages could be a promising therapeutic approach for both CHS subtypes.
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