Artificial intelligence large language model ChatGPT: is it a trustworthy and reliable source of information for sarcoma patients?

Introduction: Since its introduction in November 2022, the artificial intelligence large language model ChatGPT has taken the world by storm. Among other applications it can be used by patients as a source of information on diseases and their treatments. However, little is known about the quality of the sarcoma-related information ChatGPT provides. We therefore aimed at analyzing how sarcoma experts evaluate the quality of ChatGPT's responses on sarcoma-related inquiries and assess the bot's answers in specific evaluation metrics. Methods: The ChatGPT responses to a sample of 25 sarcoma-related questions (5 definitions, 9 general questions, and 11 treatment-related inquiries) were evaluated by 3 independent sarcoma experts. Each response was compared with authoritative resources and international guidelines and graded on 5 different metrics using a 5-point Likert scale: completeness, misleadingness, accuracy, being up-to-date, and appropriateness. This resulted in maximum 25 and minimum 5 points per answer, with higher scores indicating a higher response quality. Scores ≥21 points were rated as very good, between 16 and 20 as good, while scores ≤15 points were classified as poor (11-15) and very poor (≤10). Results: The median score that ChatGPT's answers achieved was 18.3 points (IQR, i.e., Inter-Quartile Range, 12.3-20.3 points). Six answers were classified as very good, 9 as good, while 5 answers each were rated as poor and very poor. The best scores were documented in the evaluation of how appropriate the response was for patients (median, 3.7 points; IQR, 2.5-4.2 points), which were significantly higher compared to the accuracy scores (median, 3.3 points; IQR, 2.0-4.2 points; p = 0.035). ChatGPT fared considerably worse with treatment-related questions, with only 45% of its responses classified as good or very good, compared to general questions (78% of responses good/very good) and definitions (60% of responses good/very good). Discussion: The answers ChatGPT provided on a rare disease, such as sarcoma, were found to be of very inconsistent quality, with some answers being classified as very good and others as very poor. Sarcoma physicians should be aware of the risks of misinformation that ChatGPT poses and advise their patients accordingly.

Effect of radiotherapy on local recurrence, distant metastasis and overall survival in 1200 extremity soft tissue sarcoma patients. Retrospective analysis using IPTW-adjusted models.

BACKGROUND AND PURPOSE: Neoadjuvant (NRTX) and adjuvant radiotherapy (ARTX) reduce local recurrence (LR) risk in extremity soft tissue sarcoma (eSTS), yet their impact on distant metastasis (DM) and overall survival (OS) is less well defined. This study aimed at analysing the influence of NRTX/ARTX on all three endpoints using a retrospective, multicentre eSTS cohort. MATERIALS AND METHODS: 1200 patients (mean age: 60.7 ± 16.8 years; 44.4 % females) were retrospectively included, treated with limb sparing surgery and curative intent for localised, high grade (G2/3) eSTS. 194 (16.2 %), 790 (65.8 %), and 216 (18.0 %) patients had received NRTX, ARTX and no RTX, respectively. For the resulting three groups (no RTX vs. NRTX, no RTX vs. ARTX, NRTX vs. ARTX) Fine&Gray models for LR and DM, and Cox-regression models for OS were calculated, with IPTW-modelling adjusting for imbalances between groups. RESULTS: In the IPTW-adjusted analysis, NRTX was associated with lower LR-risk in comparison to no RTX (SHR [subhazard ratio]: 0.236; p = 0.003), whilst no impact on DM-risk (p = 0.576) or OS (p = 1.000) was found. IPTW-weighted analysis for no RTX vs. ARTX revealed a significant positive association between ARTX and lower LR-risk (SHR: 0.479, p = 0.003), but again no impact on DM-risk (p = 0.363) or OS (p = 0.534). IPTW-weighted model for NRTX vs. ARTX showed significantly lower LR-risk for NRTX (SHR for ARTX: 3.433; p = 0.003) but no difference regarding DM-risk (p = 1.000) or OS (p = 0.639). CONCLUSION: NRTX and ARTX are associated with lower LR-risk, but do not seem to affect DM-risk or OS. NRTX may be favoured over ARTX as our results indicate better local control rates.

Prognostic Impact of Pulmonary Metastasectomy in Bone Sarcoma Patients: A Retrospective, Single-Centre Study.

This retrospective study aimed at analyzing the impact of metastasectomy on post-metastasis survival (PMS) in bone sarcoma patients with lung metastases. Altogether, 47 bone sarcoma patients (24 males, median age at diagnosis of lung metastases: 21.8 (IQR: 15.6-47.3) years) with primary (n = 8) or secondary (n = 39) lung metastases treated at a single university hospital were retrospectively included. Based on a propensity score, inverse probability of treatment weight (IPTW) was calculated to account for selection bias whether patients had undergone metastasectomy or not. The most common underlying histology was osteosarcoma (n = 37; 78.7%). Metastasectomy was performed in 39 patients (83.0%). Younger patients (p = 0.025) with singular (p = 0.043) and unilateral lesions (p = 0.024), as well as those with an interval ≥ 9 months from primary diagnosis to development of lung metastases (p = 0.024) were more likely to undergo metastasectomy. Weighted 1- and 3-year PMS after metastasectomy was 80.8% and 58.3%, compared to 88.5% and 9.1% for patients who did not undergo metastasectomy. Naive Cox-regression analysis demonstrated a significantly prolonged PMS for patients with metastasectomy (HR: 0.142; 95%CI: 0.045-0.450; p = 0.001), which was confirmed after IPTW-weighting (HR: 0.279; 95%CI: 0.118-0.662; p = 0.004), irrespective of age, time to metastasis, and the number of lesions. In conclusion, metastasectomy should be considered in bone sarcoma patients with lung metastases, after carefully considering the individual risks, to possibly improve PMS.

Controversies in the management of patients with soft tissue sarcoma: Recommendations of the Conference on State of Science in Sarcoma 2022.

BACKGROUND: Owing to the rarity and heterogeneity in biology and presentation, there are multiple areas in the diagnosis, treatment and follow-up of soft tissue sarcoma (STS), with no, low-level or conflicting evidence. METHODS: During the first Consensus Conference on the State of Science in Sarcoma (CSSS), we used a modified Delphi process to identify areas of controversy in the field of sarcoma, to name topics with limited evidence-based data in which a scientific and knowledge gap may remain and a consensus statement will help to guide patient management. We determined scientific questions which need to be addressed in the future in order to generate evidence and to inform physicians and caregivers in daily clinical practice in order to improve the outcomes of patients with sarcoma. We conducted a vote on STS key questions and controversies prior to the CSSS meeting, which took place in May 2022. RESULTS: Sixty-two European sarcoma experts participated in the survey. Sixteen strong consensus (≥95%) items were identified by the experts, as well as 30 items with a ≥75% consensus on diagnostic and therapeutic questions. Ultimately, many controversy topics remained without consensus. CONCLUSIONS: In this manuscript, we summarise the voting results and the discussion during the CSSS meeting. Future scientific questions, priorities for clinical trials, registries, quality assurance, and action by stakeholders are proposed. Platforms and partnerships can support innovative approaches to improve management and clinical research in STS.

Targeting epigenetic features in clear cell sarcomas based on patient-derived cell lines.

BACKGROUND: Clear cell sarcomas (CCSs) are translocated aggressive malignancies, most commonly affecting young adults with a high incidence of metastases and a poor prognosis. Research into the disease is more feasible when adequate models are available. By establishing CCS cell lines from a primary and metastatic lesion and isolating healthy fibroblasts from the same patient, the in vivo process is accurately reflected and aspects of clinical multistep carcinogenesis recapitulated. METHODS: Isolated tumor cells and normal healthy skin fibroblasts from the same patient were compared in terms of growth behavior and morphological characteristics using light and electron microscopy. Tumorigenicity potential was determined by soft agar colony formation assay and in vivo xenograft applications. While genetic differences between the two lineages were examined by copy number alternation profiles, nuclear magnetic resonance spectroscopy determined arginine methylation as epigenetic features. Potential anti-tumor effects of a protein arginine N-methyltransferase type I (PRMT1) inhibitor were elicited in 2D and 3D cell culture experiments using cell viability and apoptosis assays. Statistical significance was calculated by one-way ANOVA and unpaired t-test. RESULTS: The two established CCS cell lines named MUG Lucifer prim and MUG Lucifer met showed differences in morphology, genetic and epigenetic data, reflecting the respective original tissue. The detailed cell line characterization especially in regards to the epigenetic domain allows investigation of new innovative therapies. Based on the epigenetic data, a PRMT1 inhibitor was used to demonstrate the targeted antitumor effect; normal tissue cells isolated and immortalized from the same patient were not affected with the IC50 used. CONCLUSIONS: MUG Lucifer prim, MUG Lucifer met and isolated and immortalized fibroblasts from the same patient represent an ideal in vitro model to explore the biology of CCS. Based on this cell culture model, novel therapies could be tested in the form of PRMT1 inhibitors, which drive tumor cells into apoptosis, but show no effect on fibroblasts, further supporting their potential as promising treatment options in the combat against CCS. The data substantiate the importance of tailored therapies in the advanced metastatic stage of CCS.

Impact of allogeneic red blood cell transfusion on prognosis in soft tissue sarcoma patients. A single-centre study.

BACKGROUND: Perioperatively administered (leukocyte reduced) allogeneic red blood cell transfusions (lrRBCTs) may lead to transfusion-related immunomodulation and reduced overall survival (OS) in cancer patients. Herein, the effect of lrRBCT on local recurrence (LR), distant metastasis (DM), and OS in soft tissue sarcoma (STS) patients was analysed. METHODS: Retrospective study on 432 STS patients (mean age: 60.0 ± 17.8 years; 46.1% female), surgically treated at a tertiary tumour centre. Uni- and multivariate survival models were calculated to analyse impact of perioperative lrRBCTs on LR, DM, OS. RESULTS: Perioperatively, 75 patients (17.4%) had received lrRBCTs. Older patients, deep, large, lower limb STS rather required lrRBCTs (all p < 0.05). No significant association between lrRBCT administration and LR- (p = 0.582) or DM-risk (p = 0.084) was observed. LrRBCT was associated with worse OS in univariate analysis (HR: 2.222; p < 0.001), with statistical significance lost upon multivariate analysis (HR: 1.658; p = 0.059; including age, histology, size, grading, amputation, depth). Adding preoperative haemoglobin in subgroup of 220 patients with laboratory parameters revealed significant negative impact of low haemoglobin on OS (p = 0.014), whilst effect of lrRBCT was further diminished (p = 0.167). CONCLUSION: Unfavourable prognostic factors prevail in STS patients requiring lrRBCTs. Low haemoglobin levels rather than lrRBCT seem to reduce OS.

Implementation of Copy Number Variations-Based Diagnostics in Morphologically Challenging EWSR1/FUS::NFATC2 Neoplasms of the Bone and Soft Tissue.

In the last decade, new tumor entities have been described, including EWSR1/FUS::NFATC2-rearranged neoplasms of different biologic behavior. To gain further insights into the behavior of these tumors, we analyzed a spectrum of EWSR1/FUS::NFATC2-rearranged neoplasms and discuss their key diagnostic and molecular features in relation to their prognosis. We report five patients with EWSR1/FUS::NFATC2-rearranged neoplasms, including one simple bone cyst (SBC), two complex cystic bone lesions lacking morphological characteristics of SBC, and two sarcomas. In three cases, fluorescence in situ hybridization (FISH) and in all cases copy number variation (CNV) profiling and fusion analyses were performed. All patients were male, three cystic lesions occurred in children (aged 10, 14, and 17 years), and two sarcomas in adults (69 and 39 years). Fusion analysis revealed two FUS::NFATC2 rearrangements in two cystic lesions and three EWSR1::NFATC2 rearrangements in one complex cystic lesion and two sarcomas. EWSR1 FISH revealed tumor cells with break-apart signal without amplification in one complex cystic lesion and EWSR1 amplification in both sarcomas was documented. CNV analysis showed simple karyotypes in all cystic lesions, while more complex karyotypes were found in NFATC2-rearranged sarcomas. Our study supports and expands previously reported molecular findings of EWSR1/FUS::NFATC2-rearranged neoplasms. The study highlights the importance of combining radiology and morphologic features with molecular aberrations. The use of additional molecular methods, such as CNV and FISH in the routine diagnostic workup, can be crucial in providing a correct diagnosis and avoiding overtreatment.

Keeping up the 'race pace' in a patient with nonuterine leiomyosarcoma.

The most common site of involvement of leiomyosarcoma is the retroperitoneum, accounting for approximately 50% of all cases. The case study presented herein describes the journey of a man with a grade 2 retroperitoneal leiomyosarcoma at the time of diagnosis. The patient received first-line doxorubicin (six cycles) and evofosfamide (11 cycles) during participation in the phase III, randomized, double-blind SARC021 trial and achieved stable disease. Upon progression, he received 24 cycles of second-line trabectedin with stable disease, then third-line pazopanib for 14 months with stable disease. Finally, he received fourth-line gemcitabine monotherapy for 5 months until disease progression, which was followed by death. Notably, trabectedin provided long-term disease control and maintained the patient's functional performance throughout treatment.

Clinical implementation of plasma cell-free circulating tumor DNA quantification by digital droplet PCR for the monitoring of Ewing sarcoma in children and adolescents.

Background: Treatment stratification and response assessment in pediatric sarcomas has relied on imaging studies and surgical/histopathological evidence of vital tumor cells. Such studies and evidence collection processes often involve radiation and/or general anesthesia in children. Cell-free circulating tumor DNA (ctDNA) detection in blood plasma is one available method of so-called liquid biopsies that has been shown to correlate qualitatively and quantitatively with the existence of vital tumor cells in the body. Our clinical observational study focused on the utility and feasibility of ctDNA detection in pediatric Ewing sarcoma (EWS) as a marker of minimal residual disease (MRD). Patients and methods: We performed whole genome sequencing (WGS) to identify the exact breakpoints in tumors known to carry the EWS-FLI1 fusion gene. Patient-specific fusion breakpoints were tracked in peripheral blood plasma using digital droplet PCR (ddPCR) before, during, and after therapy in six children and young adults with EWS. Presence and levels of fusion breakpoints were correlated with clinical disease courses. Results: We show that the detection of ctDNA in the peripheral blood of EWS patients (i) is feasible in the clinical routine and (ii) allows for the longitudinal real-time monitoring of MRD activity in children and young adults. Although changing ctDNA levels correlated well with clinical outcome within patients, between patients, a high variability was observed (inter-individually). Conclusion: ctDNA detection by ddPCR is a highly sensitive, specific, feasible, and highly accurate method that can be applied in EWS for follow-up assessments as an additional surrogate parameter for clinical MRD monitoring and, potentially, also for treatment stratification in the near future.

Survival Prediction in Patients Treated Surgically for Metastases of the Appendicular Skeleton-An External Validation of 2013-SPRING Model.

INTRODUCTION: The aim of this study was to externally validate the 2013-SPRING model, a survival prediction tool for patients treated surgically for bone metastases in a retrospective patient cohort from a single institution. Moreover, subgroup analyses on patients treated with (A) endoprostheses or (B) osteosynthesis, as well as (C) upper limb and (D) lower limb metastases, were performed. METHODS: Altogether, 303 cancer patients (mean age: 67.6 ± 11.1 years; 140 males (46.2%)) with bone metastases to the extremities, treated surgically between March 2000 and June 2018 at a single tertiary sarcoma centre, were retrospectively included. Median follow-up amounted to 6.3 (interquartile range (IQR): 2.3-21.8) months, with all patients followed-up for at least one year or until death. The 2013-SPRING model was applied to assess the prognostication accuracy at 3, 6 and 12 months. Models were validated with area under the curve receiver operator characteristic (AUC ROC; the higher the better), as well as Brier score. RESULTS: Of the 303 patients, 141 had been treated with osteosynthesis (46.5%), and the remaining 162 patients with endoprosthesis (53.5%). Sixty-five (21.5%) metastases were located in the upper limbs, and two hundred and thirty-eight (78.5%) in the lower limbs. Using the 2013-SPRING model for the entire cohort, the accuracy of risk of death prediction at 3, 6 and 12 months, determined by the AUC ROC, was 0.782 (95% CI: 0.729-0.843), 0.810 (95% CI: 0.763-0.858) and 0.802 (95% CI: 0.751-0.854), respectively. Corresponding Brier scores were 0.170, 0.178 and 0.169 at 3, 6 and 12 months. In the subgroup analyses, predictive accuracy of the 2013-SPRING model was likewise encouraging, albeit being slightly higher in the osteosynthesis subgroup as compared with the endoprosthesis subgroup, and also higher in the upper limb in comparison to the lower limb metastasis subgroup. CONCLUSIONS: The current validation study of the 2013-SPRING model shows that this model is clinically relevant to use in an external cohort, also after stratification for surgical procedure and metastasis location.

Patterns of Peripheral Blood B-Cell Subtypes Are Associated With Treatment Response in Patients Treated With Immune Checkpoint Inhibitors: A Prospective Longitudinal Pan-Cancer Study.

Background: Immune checkpoint inhibitors (ICIs) have revolutionized systemic anti-tumor treatments across different types of cancer. Nevertheless, predictive biomarkers regarding treatment response are not routinely established yet. Apart from T-lymphocytes, the humoral immunity of B-lymphocytes is studied to a substantially lesser extent in the respective setting. Thus, the aim of this study was to evaluate peripheral blood B-cell subtypes as potential predictors of ICI treatment response. Methods: Thirty-nine cancer patients receiving ICI therapy were included into this prospective single-center cohort study. All had a first blood draw at the date before treatment initiation and a second at the time of first response evaluation (after 8-12 weeks). Seven different B-cell subtypes were quantified by fluorescence-activated cell sorting (FACS). Disease control- (DCR) and objective response rate (ORR) were co-primary study endpoints. Results: Overall, DCR was 48.7% and ORR was 25.6%, respectively. At baseline, there was no significant association of any B-cell subtype with neither DCR nor ORR. At the first response evaluation, an increase in the frequency of CD21- B-cells was a statistically significant negative predictor of response, both regarding DCR (OR=0.05, 95%CI=0.00-0.67, p=0.024) and ORR (OR=0.09, 95%CI=0.01-0.96, p=0.046). An increase of the frequency of switched memory B-cells was significantly associated with reduced odds for DCR (OR=0.06, 95%CI=0.01-0.70, p=0.025). Patients with an increased frequency of naïve B-cells were more likely to benefit from ICI therapy as indicated by an improved DCR (OR=12.31, 95%CI=1.13-134.22, p=0.039). Conclusion: In this study, certain B-cell subpopulations were associated with ICI treatment response in various human cancer types.

Evaluation of autoantibodies as predictors of treatment response and immune-related adverse events during the treatment with immune checkpoint inhibitors: A prospective longitudinal pan-cancer study.

BACKGROUND: The presence of autoantibodies in the serum of cancer patients has been associated with immune-checkpoint inhibitor (ICI) therapy response and immune-related adverse events (irAEs). A prospective evaluation of different autoantibodies in different cancer entities is missing. MATERIALS AND METHODS: In this prospective cohort study, we included a pan-cancer cohort of patients undergoing ICI treatment and measured a comprehensive panel of autoantibodies at treatment start and at the time point of first response evaluation. The presence and induction of autoantibodies (ANA, ENA, myositis, hepatopathy, rheumatoid arthritis) in different cancer entities were assessed and the association between autoantibodies and disease control rate (DCR), objective response rate (ORR), and progression-free survival (PFS), as well as the development of grade 3 or higher irAEs were evaluated by logistic regression models, cox proportional hazard models, and Kaplan-Meier estimators. RESULTS: Of 44 patients with various cancer entities, neither the presence of any positive autoantibody measurement nor the presence of positive antinuclear antibodies (ANA) [≥1:80] at baseline was associated with the examined clinical endpoints (DCR, ORR, PFS) in univariable and multivariable analyses. After 8-12 weeks of ICI treatment, DCR, ORR, and PFS did not significantly differ between patients with and without any positive autoantibody measurement or positive ANA titers. The frequency of irAEs did not differ depending on autoantibody status of the patients. CONCLUSION: Autoantibodies at treatment initiation or induction after 8-12 weeks of ICI treatment are not associated with treatment efficacy as indicated by DCR, ORR, and PFS or higher grade irAEs.

Molecular profiling of soft-tissue sarcomas with FoundationOne® Heme identifies potential targets for sarcoma therapy: a single-centre experience.

BACKGROUND: Molecular diagnosis has become an established tool in the characterisation of adult soft-tissue sarcomas (STS). FoundationOne® Heme analyses somatic gene alterations in sarcomas via DNA and RNA-hotspot sequencing of tumour-associated genes. METHODS: We evaluated FoundationOne® Heme testing in 81 localised STS including 35 translocation-associated and 46 complex-karyotyped cases from a single institution. RESULTS: Although FoundationOne® Heme achieved broad patient coverage and identified at least five genetic alterations in each sample, the sensitivity for fusion detection was rather low, at 42.4%. Nevertheless, potential targets for STS treatment were detected using the FoundationOne® Heme assay: complex-karyotyped sarcomas frequently displayed copy-number alterations of common tumour-suppressor genes, particularly deletions in TP53, NF1, ATRX, and CDKN2A. A subset of myxofibrosarcomas (MFS) was amplified for HGF (n = 3) and MET (n = 1). PIK3CA was mutated in 7/15 cases of myxoid liposarcoma (MLS; 46.7%). Epigenetic regulators (e.g. MLL2 and MLL3) were frequently mutated. CONCLUSIONS: In summary, FoundationOne® Heme detected a broad range of genetic alterations and potential therapeutic targets in STS (e.g. HGF/MET in a subset of MFS, or PIK3CA in MLS). The assay's sensitivity for fusion detection was low in our sample and needs to be re-evaluated in a larger cohort.

T-regulatory cells predict clinical outcome in soft tissue sarcoma patients: a clinico-pathological study.

BACKGROUND: Soft tissue sarcomas (STS) are generally considered non-immunogenic, although specific subtypes respond to immunotherapy. Antitumour response within the tumour microenvironment relies on a balance between inhibitory and activating signals for tumour-infiltrating lymphocytes (TILs). This study analysed TILs and immune checkpoint molecules in STS, and assessed their prognostic impact regarding local recurrence (LR), distant metastasis (DM), and overall survival (OS). METHODS: One-hundred and ninety-two surgically treated STS patients (median age: 63.5 years; 103 males [53.6%]) were retrospectively included. Tissue microarrays were constructed, immunohistochemistry for PD-1, PD-L1, FOXP3, CD3, CD4, and CD8 performed, and staining assessed with multispectral imaging. TIL phenotype abundance and immune checkpoint markers were correlated with clinical and outcome parameters (LR, DM, and OS). RESULTS: Significant differences between histology and all immune checkpoint markers except for FOXP3+ and CD3-PD-L1+ cell subpopulations were found. Higher levels of PD-L1, PD-1, and any TIL phenotype were found in myxofibrosarcoma as compared to leiomyosarcoma (all p < 0.05). The presence of regulatory T cells (Tregs) was associated with increased LR risk (p = 0.006), irrespective of margins. Other TILs or immune checkpoint markers had no significant impact on outcome parameters. CONCLUSIONS: TIL and immune checkpoint marker levels are most abundant in myxofibrosarcoma. High Treg levels are independently associated with increased LR risk, irrespective of margins.

Treatment of Angiosarcoma with Pazopanib and Paclitaxel: Results of the EVA (Evaluation of Votrient® in Angiosarcoma) Phase II Trial of the German Interdisciplinary Sarcoma Group (GISG-06).

We aimed to evaluate the efficacy and toxicity of paclitaxel combined with pazopanib in advanced angiosarcoma (AS). The primary end point was progression-free survival (PFS) rate at six months (PFSR6). Planned accrual was 44 patients in order to detect a PFSR6 of >55%, with an interim futility analysis of the first 14 patients. The study did not meet its predetermined interim target of 6/14 patients progression-free at 6 months. At the time of this finding, 26 patients had been enrolled between July 2014 and April 2016, resulting in an overrunning of 12 patients. After a median follow-up of 9.5 (IQR 7.7-15.4) months, PFSR6 amounted to 46%. Two patients had a complete and seven patients a partial response. Patients with superficial AS had a significantly higher PFSR6 (61% vs. 13%, p = 0.0247) and PFS (11.3 vs. 2.7 months, p < 0.0001) compared to patients with visceral AS. The median overall survival in the entire cohort was 21.6 months. A total of 10 drug-related serious adverse effects were reported in 5 patients, including a fatal hepatic failure. Although our study did not meet its primary endpoint, the median PFS of 11.6 months in patients with superficial AS appears to be promising. Taking recent reports into consideration, future studies should evaluate the safety and efficacy of VEGFR and immune checkpoint inhibitors with or without paclitaxel in a randomized, multiarm setting.

Comparison of the 7th and 8th version of the AJCC classification system for soft tissue sarcomas of extremities and trunk in patients with localised, intermediate or high-grade disease treated at European tertiary sarcoma centres.

BACKGROUND: The updated 8th version of the AJCC-staging system for soft tissue sarcomas (STS) has been criticised for omitting tumour depth as category-defining variable and eventually not improving prognostic accuracy in comparison to the 7th version. This study aimed at investigating the prognostic accuracy of both AJCC-versions in STS-patients treated at European tertiary sarcoma centres. METHODS: 1032 patients (mean age: 60.7 ± 16.3 years; 46.0% [n = 475] females; median follow-up: 38.6 months), treated at five tertiary sarcoma centres for localised, intermediate or high-grade STS of extremities and trunk were retrospectively included. Uni- and multivariate Cox-regression models and Harrell's C-indices were calculated to analyse prognostic factors for overall survival (OS) and assess prognostic accuracy. RESULTS: In univariate analysis, prognostic accuracy for OS was comparable for both AJCC-versions (C-index: 0.620 [8th] vs. 0.614 [7th]). By adding margins, age, gender, and histology to the multivariate models, prognostic accuracy of both versions could be likewise improved (C-index: 0.714 [8th] vs. 0.705 [7th]). Moreover, tumour depth did not significantly contribute to prognostic accuracy of the 8th version's multivariate model (C-index for both models: 0.714). Stratification into four main T-stages based on tumour size only, as implemented in the 8th version, significantly improved prognostic accuracy between each category. However, T-stages as defined in the 7th version had poorer discriminatory power (C-index: 0.625 [8th] vs. 0.582 [7th]). CONCLUSION: Both AJCC-versions perform equally well regarding prognostic accuracy. Yet, simplification of the 8 th version by omitting tumour depth as T-stage-defining parameter, whilst emphasizing the importance of tumour size, should be considered advantageous.

Influence of tumor-infiltrating immune cells on local control rate, distant metastasis, and survival in patients with soft tissue sarcoma.

Soft tissue sarcomas (STS) are considered non-immunogenic, although distinct entities respond to anti-tumor agents targeting the tumor microenvironment. This study's aims were to investigate relationships between tumor-infiltrating immune cells and patient/tumor-related factors, and assess their prognostic value for local recurrence (LR), distant metastasis (DM), and overall survival (OS). One-hundred-eighty-eight STS-patients (87 females [46.3%]; median age: 62.5 years) were retrospectively analyzed. Tissue microarrays (in total 1266 cores) were stained with multiplex immunohistochemistry and analyzed with multispectral imaging. Seven cell types were differentiated depending on marker profiles (CD3+, CD3+ CD4+ helper, CD3+ CD8+ cytotoxic, CD3+ CD4+ CD45RO+ helper memory, CD3+ CD8+ CD45RO+ cytotoxic memory T-cells; CD20 + B-cells; CD68+ macrophages). Correlations between phenotype abundance and variables were analyzed. Uni- and multivariate Fine&Gray and Cox-regression models were constructed to investigate prognostic variables. Model calibration was assessed with C-index. IHC-findings were validated with TCGA-SARC gene expression data of genes specific for macrophages, T- and B-cells. B-cell percentage was lower in patients older than 62.5 years (p = .013), whilst macrophage percentage was higher (p = .002). High B-cell (p = .035) and macrophage levels (p = .003) were associated with increased LR-risk in the univariate analysis. In the multivariate setting, high macrophage levels (p = .014) were associated with increased LR-risk, irrespective of margins, age, gender or B-cells. Other immune cells were not associated with outcome events. High macrophage levels were a poor prognostic factor for LR, irrespective of margins, B-cells, gender and age. Thus, anti-tumor, macrophage-targeting agents may be applied more frequently in tumors with enhanced macrophage infiltration.

Olaratumab plus anthracyline in advanced/metastatic soft tissue sarcoma : Data of real-world utilization in Austria.

BACKGROUND: Olaratumab is a humanized monoclonal antiplatelet-derived growth factor receptor alpha antibody that has been approved in combination with doxorubicin for the treatment of patients with metastatic soft tissue sarcoma (STS). The purpose of this retrospective study was to assess the clinical efficacy in STS patients treated with olaratumab in a real-world setting in Austria. METHODS: Retrospectively collected longitudinal data from patients treated between November 2016 and September 2018 at 9 Austrian centers were obtained from the respective medical charts. All patients who received at least one dose of olaratumab were eligible. Parameters of most interest were response rates, progression-free survival (PFS) and overall survival (OS). RESULTS: Altogether 55 patients were included in the analysis. The median age was 58 years. In total, 65.5% (n = 36), 21.8% (n = 12) and 12.7% (n = 7) received olaratumab as first, second or ≥third line treatment, respectively. Olaratumab was administered either in combination with doxorubicin (81.8%, n = 45) or liposomal doxorubicin (16.4%, n = 9); one patient received olaratumab as upfront monotherapy. The median PFS and OS were 2.6 and 11.4 months, respectively. The objective response rate was 11.4% and the disease control rate was 40.9%. CONCLUSION: In this real-world analysis the outcome was less pronounced compared to the results of both the phase Ib/II approval trial and the confirmatory phase III trial. The latter failed to show an improvement in OS and PFS for the doxorubicin/olaratumab combination. As such, olaratumab should not be used anymore in patients with STS.

Broadening the spectrum of NTRK rearranged mesenchymal tumors and usefulness of pan-TRK immunohistochemistry for identification of NTRK fusions.

Fusions involving NTRK1, NTRK2, and NTRK3 are oncogenic drivers occurring in a spectrum of mesenchymal neoplasms ranging from benign to highly malignant tumors. To gain further insights into the staining profile with the pan-TRK assay, we analyzed a large number of soft tissue sarcomas and correlated our findings with molecular testing. Additionally, we expand the spectrum of NTRK-fusion tumors by reporting a mesenchymal lesion in the lung as well as a mesenchymal skin lesion in the spectrum of benign fibrous histiocytoma with NTRK-fusion. We retrospectively reviewed soft tissue sarcomas diagnosed at the Diagnostic and Research Institute of Pathology, Medical University of Graz, between 1999 and 2019, and cases from the consultation files of one of the authors (BLA). In total, 494 cases were analyzed immunohistochemically with pan-TRK antibody (clone EPR17341, RTU, Roche/Ventana) and positive cases (defined as any cytoplasmic/nuclear staining in more than 1% of tumor cells) underwent next-generation sequencing (NGS). Immunohistochemical staining was observed in 16 (3.2%) cases. Eleven cases with focal weak and moderate cytoplasmic/membranous or focal moderate to strong nuclear staining did not harbor an NTRK-fusion (three synovial sarcomas, three leiomyosarcomas, two extraskeletal myxoid chondrosarcomas, and one each: dedifferentiated liposarcoma, pleomorphic liposarcoma, and myxofibrosarcoma). Four cases showed strong diffuse nuclear and/or cytoplasmatic staining, and one case showed diffuse, but weak cytoplasmic staining. All these cases demonstrated an NTRK-fusion (LMNA-NTRK1, IRF2BP2-NTRK1, TMB3-NTRK1, ETV6-NTRK3, RBPMS-NTRK3). Pan-TRK assay (clone EPR17341, RTU, Roche, Ventana) immunohistochemistry serves as a reliable diagnostic marker that can also be expressed in non-NTRK-rearranged mesenchymal neoplasms. It can be used as a surrogate marker for identification of NTRK fusion, nevertheless, an RNA-based NGS for detection of the specific fusion should be performed to confirm the rearrangement, if patients are undergoing targeted therapy. Additionally, we identified NTRK-fusion-positive, primary mesenchymal tumors of the lung and the skin.