Publications by authors named "Andrew D Tieniber"

Article Synopsis
  • Gastrointestinal stromal tumors (GISTs) are the most prevalent type of sarcoma in humans, predominantly occurring in the stomach or small intestine, with over 5000 new cases diagnosed annually in the USA.
  • A study investigated the presence of bacteria within GISTs by analyzing 25 tumor samples from 24 patients using advanced genetic sequencing techniques.
  • Results showed that most samples had negligible bacterial presence, while two samples indicated normal intestinal bacteria, but only in tumors where the mucosal lining was disrupted.
View Article and Find Full Text PDF

γδ T cells are a rare but potent subset of T cells with pleiotropic functions. They commonly reside within tumors but the response of γδ T cells to tyrosine kinase inhibition is unknown. To address this, we studied a genetically engineered mouse model of gastrointestinal stromal tumor (GIST) driven by oncogenic Kit signaling that responds to the Kit inhibitor imatinib.

View Article and Find Full Text PDF

Gastrointestinal stromal tumor (GIST) is the most common human sarcoma and is typically driven by a single mutation in the Kit or PDGFRA receptor. While highly effective, tyrosine kinase inhibitors (TKIs) are not curative. The natural ligand for the Kit receptor is Kit ligand (KitL), which exists in both soluble and membrane-bound forms.

View Article and Find Full Text PDF

Gastrointestinal (GI) cancers include esophageal, gastric, pancreatic, hepatobiliary, and colorectal malignancies. Immunotherapy has proved to be an important treatment method for cancer, and its use for a wide range of GI malignancies has been evaluated recently. This article discusses the type and mechanism of various immunotherapies under investigation in GI cancer.

View Article and Find Full Text PDF

Targeted therapy with a tyrosine kinase inhibitor (TKI) such as imatinib is effective in treating gastrointestinal stromal tumor (GIST), but it is rarely curative. Despite the presence of a robust immune CD8+ T-cell infiltrate, combining a TKI with immune-checkpoint blockade (ICB) in advanced GIST has achieved only modest effects. To identify limitations imposed by imatinib on the antitumor immune response, we performed bulk RNA sequencing (RNA-seq), single-cell RNA-seq, and flow cytometry to phenotype CD8+ T-cell subsets in a genetically engineered mouse model of GIST.

View Article and Find Full Text PDF

Gastrointestinal stromal tumor (GIST) is the most common human sarcoma and is typically driven by a single mutation in the KIT receptor. Across tumor types, numerous mouse models have been developed in order to investigate the next generation of cancer therapies. However, in GIST, most in vivo studies use xenograft mouse models which have inherent limitations.

View Article and Find Full Text PDF

Background: Nodal observation is safe for patients with microscopic melanoma metastasis in a sentinel lymph node (LN). Complete LN dissection (CLND) remains the standard of care for patients with clinically evident LN (cLN) metastases, even though about 40% have only one pathologic LN (pLN). We sought to identify clinical features associated with having one pLN among patients with cLNs.

View Article and Find Full Text PDF

Background: Immune checkpoint and BRAF-targeted inhibitors have demonstrated significant survival benefits for advanced melanoma patients within the context of clinical trials. We sought to determine their impact on overall survival (OS) at a population level in order to better understand the current landscape for patients diagnosed with clinical stage III melanoma.

Methods: A retrospective study was performed using the National Cancer Database.

View Article and Find Full Text PDF

Background: Complex cancer operations performed at high-volume and teaching hospitals have been associated with better outcomes. The purpose of this study was to determine the national trends in the performance of these operations at large teaching hospitals.

Methods: Patients who underwent elective esophagectomies, gastrectomies, pancreatectomies, and hepatectomies for cancer (2003-2015) were identified using the National Inpatient Sample.

View Article and Find Full Text PDF

Background: Clinically relevant postoperative pancreatic fistula and delayed gastric emptying cause substantial morbidity after pancreatoduodenectomy. Per international guidelines, the placement of jejunostomy tubes may be considered for patients at risk for malnutrition, such as those with a high risk for clinically relevant postoperative pancreatic fistula and related complications. This study determined predictors and postoperative outcomes of jejunostomy tube placement.

View Article and Find Full Text PDF

Background: Methanol fixed and paraffin embedded (MFPE) cellblocks are an essential cytology preparation. However, MFPE cellblocks often contain limited material and their relatively small size has caused them to be overlooked in biomarker discovery. Advances in the field of molecular biotechnology have made it possible to extract proteins from formalin fixed and paraffin embedded (FFPE) tissue blocks.

View Article and Find Full Text PDF