Prognostic Significance of Immunohistochemical Markers and Genetic Alterations in Malignant Peripheral Nerve Sheath Tumors: A Systematic Review

Background: Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas with dis

Management of Soft Tissue Sarcomas in Extremities

Background: This study aimed to provide an insight into clinical decision-making and surveillance strategy of sarcoma specialists for patients with primary soft tissue sarcoma of the extremities (eSTS). The secondary aim was to quantify the role of patient- and tumor-specific factors in the perioperative management. Methods: Members of sarcoma societies were sent a Web-based 21-item survey about eSTS management. The survey concerned only primary resectable high-grade eSTS in adults. Results: The study enrolled 396 respondents. The majority of the surgical specialists thought the evidence for perioperative chemotherapy (CTX) for high-grade eSTS was insufficient. Radiotherapy (RTX) was less frequently offered in Asia than in North America and Europe. The specialties and continents also differed regarding the importance of patient and tumor characteristics influencing RTX and CTX recommendation. For surveillance after initial treatment outpatient visits, chest computed tomography (CT) scans, and magnetic resonance images of the extremity were the methods primarily used. The specialists in North America preferred chest CT scan over chest x-ray, whereas those in Asia and Europe had no clear preference. Discussion: Specialty and continent are important factors contributing to the variation in clinical practice, treatment recommendations, and surveillance of patients with primary resectable high-grade eSTS.</p

VISTA Expression on Cancer-Associated Endothelium Selectively Prevents T-cell Extravasation

Cancers evade T-cell immunity by several mechanisms such as secretion of anti-inflammatory cytokines, down regulation of antigen presentation machinery, upregulation of immune checkpoint molecules, and exclusion of T cells from tumor tissues. The distribution and function of immune checkpoint molecules on tumor cells and tumor-infiltrating leukocytes is well established, but less is known about their impact on intratumoral endothelial cells. Here, we demonstrated that V-domain Ig suppressor of T-cell activation (VISTA), a PD-L1 homolog, was highly expressed on endothelial cells in synovial sarcoma, subsets of different carcinomas, and immune-privileged tissues. We created an ex vivo model of the human vasculature and demonstrated that expression of VISTA on endothelial cells selectively prevented T-cell transmigration over endothelial layers under physiologic flow conditions, whereas it does not affect migration of other immune cell types. Furthermore, endothelial VISTA correlated with reduced infiltration of T cells and poor prognosis in metastatic synovial sarcoma. In endothelial cells, we detected VISTA on the plasma membrane and in recycling endosomes, and its expression was upregulated by cancer cell–secreted factors in a VEGF-A–dependent manner. Our study reveals that endothelial VISTA is upregulated by cancer-secreted factors and that it regulates T-cell accessibility to cancer and healthy tissues. This newly identified mechanism should be considered when using immunotherapeutic approaches aimed at unleashing T cell–mediated cancer immunity.</p

VISTA Expression on Cancer-Associated Endothelium Selectively Prevents T-cell Extravasation

Cancers evade T-cell immunity by several mechanisms such as secretion of anti-inflammatory cytokines, down regulation of antigen presentation machinery, upregulation of immune checkpoint molecules, and exclusion of T cells from tumor tissues. The distribution and function of immune checkpoint molecules on tumor cells and tumor-infiltrating leukocytes is well established, but less is known about their impact on intratumoral endothelial cells. Here, we demonstrated that V-domain Ig suppressor of T-cell activation (VISTA), a PD-L1 homolog, was highly expressed on endothelial cells in synovial sarcoma, subsets of different carcinomas, and immune-privileged tissues. We created an ex vivo model of the human vasculature and demonstrated that expression of VISTA on endothelial cells selectively prevented T-cell transmigration over endothelial layers under physiologic flow conditions, whereas it does not affect migration of other immune cell types. Furthermore, endothelial VISTA correlated with reduced infiltration of T cells and poor prognosis in metastatic synovial sarcoma. In endothelial cells, we detected VISTA on the plasma membrane and in recycling endosomes, and its expression was upregulated by cancer cell–secreted factors in a VEGF-A–dependent manner. Our study reveals that endothelial VISTA is upregulated by cancer-secreted factors and that it regulates T-cell accessibility to cancer and healthy tissues. This newly identified mechanism should be considered when using immunotherapeutic approaches aimed at unleashing T cell–mediated cancer immunity.</p