Outcome Analysis of Treatment Modalities for Thoracic Sarcomas.

BACKGROUND: Primary chest wall sarcomas are a rare and heterogeneous group of chest wall tumors that require multimodal oncologic and surgical therapy. The aim of this study was to review our experience regarding the surgical treatment of chest wall sarcomas, evaluating the short- and long-term results. METHODS: In this retrospective single-center study, patients who underwent surgery for soft tissue and bone sarcoma of the chest wall between 1999 and 2018 were included. We analyzed the oncologic and surgical outcomes of chest wall resections and reconstructions, assessing overall and recurrence-free survival and the associated clinical factors. RESULTS: In total, 44 patients underwent chest wall resection for primary chest wall sarcoma, of which 18 (41%) received surgery only, 10 (23%) received additional chemoradiotherapy, 7% (3) received surgery with chemotherapy, and 30% (13) received radiotherapy in addition to surgery. No perioperative mortality occurred. Five-year overall survival was 51.5% (CI 95%: 36.1-73.4%), and median overall survival was 1973 days (CI 95% 1461; -). As determined in the univariate analysis, the presence of metastasis upon admission and tumor grade were significantly associated with shorter survival (p = 0.037 and p < 0.01, respectively). Five-year recurrence-free survival was 71.5% (95% CI 57.6%; 88.7%). Tumor resection margins and metastatic disease upon diagnosis were significantly associated with recurrence-free survival (p < 0.01 and p < 0.01, respectively). CONCLUSION: Surgical therapy is the cornerstone of the treatment of chest wall sarcomas and can be performed safely. Metastasis and high tumor grade have a negative influence on overall survival, while tumor margins and metastasis have a negative influence on local recurrence.

Unravelling homologous recombination repair deficiency and therapeutic opportunities in soft tissue and bone sarcoma.

Defects in homologous recombination repair (HRR) in tumors correlate with poor prognosis and metastases development. Determining HRR deficiency (HRD) is of major clinical relevance as it is associated with therapeutic vulnerabilities and remains poorly investigated in sarcoma. Here, we show that specific sarcoma entities exhibit high levels of genomic instability signatures and molecular alterations in HRR genes, while harboring a complex pattern of chromosomal instability. Furthermore, sarcomas carrying HRDness traits exhibit a distinct SARC-HRD transcriptional signature that predicts PARP inhibitor sensitivity in patient-derived sarcoma cells. Concomitantly, HRDhigh sarcoma cells lack RAD51 nuclear foci formation upon DNA damage, further evidencing defects in HRR. We further identify the WEE1 kinase as a therapeutic vulnerability for sarcomas with HRDness and demonstrate the clinical benefit of combining DNA damaging agents and inhibitors of DNA repair pathways ex vivo and in the clinic. In summary, we provide a personalized oncological approach to treat sarcoma patients successfully.

Mutational Landscape and Expression of PD-L1 in Patients with Non-Small Cell Lung Cancer Harboring Genomic Alterations of the MET gene.

BACKGROUND: Mesenchymal-to-epithelial transition (MET) exon 14 skipping mutations and MET gene amplification occur in 3-5% of non-small cell lung cancer (NSCLC) patients. Tyrosine kinase inhibitors (TKIs) targeting MET alterations have shown promising results in these patients. OBJECTIVE: The aim of this study was to describe the genomic profile, PD-L1 expression and clinicopathological features of MET dysregulated NSCLC. PATIENTS AND METHODS: We identified 188 patients with advanced-stage NSCLC with data on MET expression by immunohistochemistry (IHC). IHC for PD-L1 expression was performed in 131 patient samples, and next-generation sequencing (NGS) analysis was performed in 109 patient samples. RESULTS: MET exon 14 skipping alterations were identified in 16 (14.7%) samples, MET amplifications with cut-off ≥4 copy number variations were identified in 11 (10.1%) samples, and an oncogenic MET mutation (MET p.D1228N) was identified in 1 (0.9%) sample. 12/15 tumors (80.0%) harboring MET exon 14 alterations and 7/11 (63.6%) MET-amplified tumors expressed PD-L1 in ≥1% of tumor cells. Tumors harboring MET exon 14 skipping alterations expressed PD-L1 more frequently than MET wild-type IHC-positive tumors (p = 0.045). Twenty-five percent of MET exon 14-altered cases and 33% of MET-amplified cases harbored potentially targetable oncogenic co-mutations in KRAS, BRAF, and EGFR. The most frequent co-occurring mutations in all MET-altered tumors were TP53, KRAS, BRAF, and CDK4. CONCLUSIONS: We demonstrated that MET exon 14 skipping alterations and MET amplification are not mutually exclusive to other oncogenic co-mutations, and report the association of genomic MET alterations with PD-L1 expression. Since genomic MET alterations are emerging targets requiring upfront treatment, optimal understanding of the co-mutational landscape for this patient population is needed.

Comprehensive Statistical Exploration of Prognostic (Bio-)Markers for Responses to Immune Checkpoint Inhibitor in Patients with Non-Small Cell Lung Cancer.

Metastatic non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs) may suffer from heavy side effects and not all patients benefit from the treatment. We conducted a comprehensive statistical analysis to identify promising (bio-)markers for treatment response. We analyzed retrospective data from NSCLC patients treated with ICIs in first- or further-line therapy settings at the University Hospital Zurich. We investigated 16 possible prognostic markers with respect to overall survival, tumor size reduction, and the development of an immune-related adverse event (irAE) and assessed the robustness of our results. For the further-line patient group, the most significant result was that increased basophil counts were associated with increased odds of tumor size reduction within three months and with the development of an irAE. For the first-line patient group, the most significant results were that increased lymphocyte counts, the histology of adenocarcinoma, and the intake of non-steroidal anti-rheumatic drugs (NSAR) were associated with decreased hazards of dying. Our study yielded new hypotheses for predictive (bio-)markers for response to ICIs in NSCLC patients. The possibly beneficial role of high basophil counts is a particularly interesting finding. Our results should be tested on independent data in a prospective fashion.

18F-FET PET for Diagnosis of Pseudoprogression of Brain Metastases in Patients With Non-Small Cell Lung Cancer.

PURPOSE: To evaluate whether F-fluoroethyltyrosine (FET) PET can discriminate progression from pseudoprogression of brain metastases in patients with non-small cell lung cancer undergoing immunotherapy and radiotherapy to the brain. METHODS: Retrospective analysis of F-FET PET scans in cases with documented progression of brain metastases on MRI in a cohort of 53 patients with non-small cell lung cancer receiving immune-checkpoint inhibitors and radiotherapy of brain metastases at the University Hospital of Zürich from June 2015 until January 2019. Response to radiotherapy was assessed by MRI. In case of equivocal findings and/or radiological progression in clinically asymptomatic patients, further assessment with F-FET PET was performed. RESULTS: From the cohort of 53 patients, the restaging MRI showed in 30 patients (56.6%) progression of at least 1 treated metastasis. Thereof, F-FET PET was performed in 11 patients, based on the absence of neurological symptoms or presence of systemic response and physicians' decision. F-FET PET correctly identified pseudoprogression in 9 of 11 patients (81.8%). In patients who did not undergo F-FET PET, 5 of 19 (26.3%) were diagnosed with pseudoprogression. CONCLUSIONS: Pseudoprogression of brain metastases occurred in 50% of patients diagnosed with progression on MRI. F-FET PET may help differentiate pseudoprogression from real progression in order to avoid discontinuation of effective therapy or unneeded interventions.

Reversal of tumor acidosis by systemic buffering reactivates NK cells to express IFN-γ and induces NK cell-dependent lymphoma control without other immunotherapies.

Like other immune cells, natural killer (NK) cells show impaired effector functions in the microenvironment of tumors, but little is known on the underlying mechanisms. Since lactate acidosis, a hallmark of malignant tissue, was shown to contribute to suppression of effective antitumor immune responses, we investigated the impact of tissue pH and lactate concentration on NK-cell functions in an aggressive model of endogenously arising B-cell lymphoma. The progressive loss of IFN-γ production by NK cells observed during development of this disease could be ascribed to decreased pH values and lactate accumulation in the microenvironment of growing tumors. Interestingly, IFN-γ expression by lymphoma-derived NK cells could be restored by transfer of these cells into a normal micromilieu. Likewise, systemic alkalization by oral delivery of bicarbonate to lymphoma-developing mice was capable of enhancing IFN-γ expression in NK cells and increasing the NK-cell numbers in the lymphoid organs where tumors were growing. By contrast, NK-cell cytotoxicity was dampened in vivo by tumor-dependent mechanisms that seemed to be different from lactate acidosis and could not be restored in a normal milieu. Most importantly, alkalization and the concomitant IFN-γ upregulation in NK cells were sufficient to significantly delay tumor growth without any other immunotherapy. This effect was strictly dependent on NK cells.

A novel CXCL10-based GPI-anchored fusion protein as adjuvant in NK-based tumor therapy.

BACKGROUND: Cellular therapy is a promising therapeutic strategy for malignant diseases. The efficacy of this therapy can be limited by poor infiltration of the tumor by immune effector cells. In particular, NK cell infiltration is often reduced relative to T cells. A novel class of fusion proteins was designed to enhance the recruitment of specific leukocyte subsets based on their expression of a given chemokine receptor. The proteins are composed of an N-terminal chemokine head, the mucin domain taken from the membrane-anchored chemokine CX3CL1, and a C-terminal glycosylphosphatidylinositol (GPI) membrane anchor replacing the normal transmembrane domain allowing integration of the proteins into cell membranes when injected into a solid tumor. The mucin domain in conjunction with the chemokine head acts to specifically recruit leukocytes expressing the corresponding chemokine receptor. METHODOLOGY/PRINCIPAL FINDINGS: A fusion protein comprising a CXCL10 chemokine head (CXCL10-mucin-GPI) was used for proof of concept for this approach and expressed constitutively in Chinese Hamster Ovary cells. FPLC was used to purify proteins. The recombinant proteins efficiently integrated into cell membranes in a process dependent upon the GPI anchor and were able to activate the CXCR3 receptor on lymphocytes. Endothelial cells incubated with CXCL10-mucin-GPI efficiently recruited NK cells in vitro under conditions of physiologic flow, which was shown to be dependent on the presence of the mucin domain. Experiments conducted in vivo using established tumors in mice suggested a positive effect of CXCL10-mucin-GPI on the recruitment of NK cells. CONCLUSIONS: The results suggest enhanced recruitment of NK cells by CXCL10-mucin-GPI. This class of fusion proteins represents a novel adjuvant in cellular immunotherapy. The underlying concept of a chemokine head fused to the mucin domain and a GPI anchor signal sequence may be expanded into a broader family of reagents that will allow targeted recruitment of cells in various settings.