Prolonged activated partial thromboplastin time after prophylactic-dose unfractionated heparin in the post-operative neurosurgical setting: case series and management recommendations.

Primary brain tumors, both benign and malignant, pose a high risk of perioperative venous thromboembolism (VTE) due to the development of a prothrombotic state. Perioperative pharmacologic thromboprophylaxis with subcutaneous (SC) unfractionated heparin (UFH) has significantly reduced VTE associated morbidity. Recent reports suggest an association between prolonged activated partial thromboplastin time (aPTT) due to prophylactic SC UFH and increased bleeding risk. We present three patients with normal baseline coagulation parameters in whom pharmacologic thromboprophylaxis with SC UFH resulted in a marked prolongation of the aPTT, leading to adverse outcomes in two patients. These cases demonstrate the uncertain kinetics of SC UFH and effect on aPTT, suggesting the significance of routine aPTT monitoring in high-risk settings. Given the wide variation in presentations of therapeutic or supratherapeutic values of aPTT in the perioperative neurosurgical setting, we propose a practical standardized approach to the evaluation and management of aPTT prolongation following prophylactic SC UFH administration.

Competition between replicative and translesion polymerases during homologous recombination repair in Drosophila.

In metazoans, the mechanism by which DNA is synthesized during homologous recombination repair of double-strand breaks is poorly understood. Specifically, the identities of the polymerase(s) that carry out repair synthesis and how they are recruited to repair sites are unclear. Here, we have investigated the roles of several different polymerases during homologous recombination repair in Drosophila melanogaster. Using a gap repair assay, we found that homologous recombination is impaired in Drosophila lacking DNA polymerase zeta and, to a lesser extent, polymerase eta. In addition, the Pol32 protein, part of the polymerase delta complex, is needed for repair requiring extensive synthesis. Loss of Rev1, which interacts with multiple translesion polymerases, results in increased synthesis during gap repair. Together, our findings support a model in which translesion polymerases and the polymerase delta complex compete during homologous recombination repair. In addition, they establish Rev1 as a crucial factor that regulates the extent of repair synthesis.

Enhanced Complement Expression in the Tumor Microenvironment Following Neoadjuvant Therapy: Implications for Immunomodulation and Survival in Pancreatic Ductal Adenocarcinoma.

Background: Neoadjuvant therapy (NAT) is increasingly being used for pancreatic ductal adenocarcinoma (PDAC) treatment. However, its specific effects on carcinoma cells and the tumor microenvironment (TME) are not fully understood. This study aims to investigate how NAT differentially impacts PDAC's carcinoma cells and TME. Methods: Spatial transcriptomics was used to compare gene expression profiles in carcinoma cells and the TME between 23 NAT-treated and 13 NAT-naïve PDAC patients, correlating with their clinicopathologic features. Analysis of an online single-nucleus RNA sequencing (snRNA-seq) dataset was performed for validation of the specific cell types responsible for NAT-induced gene expression alterations. Results: NAT not only induces apoptosis and inhibits proliferation in carcinoma cells but also significantly remodels the TME. Notably, NAT induces a coordinated upregulation of multiple key complement genes (C3, C1S, C1R, C4B and C7) in the TME, making the complement pathway one of the most significantly affected pathways by NAT. Patients with higher TME complement expression following NAT exhibit improved overall survival. These patients also exhibit increased immunomodulatory and neurotrophic cancer-associated fibroblasts (CAFs); more CD4+ T cells, monocytes, and mast cells; and reduced immune exhaustion gene expression. snRNA-seq analysis demonstrates C3 complement was specifically upregulated in CAFs but not in other stroma cell types. Conclusions: NAT can enhance complement production and signaling within the TME, which is associated with reduced immunosuppression in PDAC. These findings suggest that local complement dynamics could serve as a novel biomarker for prognosis, evaluating treatment response and resistance, and guiding therapeutic strategies in NAT-treated PDAC patients.

Tumor-immune microenvironment revealed by Imaging Mass Cytometry in a metastatic sarcomatoid urothelial carcinoma with a prolonged response to pembrolizumab.

Sarcomatoid urothelial carcinoma (SUC) is a rare subtype of urothelial carcinoma (UC) that typically presents at an advanced stage compared to more common variants of UC. Locally advanced and metastatic UC have a poor long-term survival following progression on first-line platinum-based chemotherapy. Antibodies directed against the programmed cell death 1 protein (PD-1) or its ligand (PD-L1) are now approved to be used in these scenarios. The need for reliable biomarkers for treatment stratification is still under research. Here, we present a novel case report of the first Imaging Mass Cytometry (IMC) analysis done in SUC to investigate the immune cell repertoire and PD-L1 expression in a patient who presented with metastatic SUC and experienced a prolonged response to the anti-PD1 immune checkpoint inhibitor pembrolizumab after progression on first-line chemotherapy. This case report provides an important platform for translating these findings to a larger cohort of UC and UC variants.

Racial Diversity Among Histology of Renal Cell Carcinoma at an Urban Medical Center.

BACKGROUND: Non-Hispanic blacks (NHB) with renal cell carcinoma (RCC) are more likely to have papillary RCC (pRCC) than non-Hispanic whites (NHW). Data on histologic subtypes in RCC in Hispanics (H) are also sparse. Previous studies have shown that pRCC is more prevalent in NHB than in NHW, but they analyzed predominantly NHW populations. The Montefiore-Einstein Center for Cancer Care (MECC) serves a predominantly NHB and H population in the Bronx, NY. We investigated histologic subtype specific associations with established RCC risk factors in this population. PATIENTS AND METHODS: The MECC tumor registry was used to identify patients ≥ 18 years of age treated with partial or radical nephrectomy between January 2000 and December 2015. An institutional software program and individual chart review were used to obtain demographic data (including self-reported race, age, and sex), pathology data, and RCC risk factors (hypertension, diabetes, renal function, weight). Data were modeled by multinomial logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: A total of 1010 RCC cases were identified. Of these, 232 (23.0%) occurred in NHW, 383 (37.9%) NHB, 181 (17.9%) H, and 214 (21.2%) other. A total of 530 cases (52.5%) were clear cell (ccRCC) histology, 257 (25.4%) pRCC, 100 (9.9%) chromophobe (cRCC), and 123 (12.2%) other. Individuals with pRCC compared to ccRCC were more likely to be NHB than NHW (OR, 4.41; 95% CI, 2.81-6.93) but were less likely to be female (OR, 0.50; 95% CI, 0.35-0.72). Individuals with pRCC were also less likely to be H than NHW (OR, 0.52; 95% CI, 0.27-0.99). Patients with cRCC were also more likely to be NHB than NHW (OR, 2.23; 95% CI, 1.06-4.67). CONCLUSION: In the MECC data set, histology of RCC varies by race, confirming earlier reports that non-ccRCC is more common in NHB than NHW. We also report that pRCC is less common in H than NHW.

The Neutrophil-to-Lymphocyte Ratio is a Prognostic Biomarker in An Ethnically Diverse Patient Population with Advanced Pancreatic Cancer.

PURPOSE: The neutrophil-to-lymphocyte ratio (NLR) is associated with decreased overall survival in patients with pancreatic adenocarcinoma (PAC) in studies including few minority patients. We investigated the association between NLR and survival in patients with advanced PAC in an ethnically diverse population. METHODS: We retrospectively evaluated 226 patients with advanced PAC treated at Montefiore Medical Center between 2006 and 2015. Adjusted Cox proportion hazard regression models were utilized to derive effect estimates for survival duration. RESULTS: Patients with a NLR ≤ 5 (126 patients, median age 66 years) were more likely to be non-Hispanic Black (30.8% vs. 20%), while patients with a NLR > 5 (70 patients, median age 66 years) were more likely to be non-Hispanic White (21.4% vs. 12.2%) or Hispanic (44.3% vs. 34%). A NLR > 5 compared with a NLR ≤ 5 was significantly associated with a worse overall survival when adjusted for a priori and exploratory variables from the univariate analysis (median survival 7.4 vs. 12 months, HR 1.650, 95% CI 1.139, 2.390). CONCLUSIONS: In an ethnically diverse population, elevated NLR is an independent marker of poor prognosis and a potentially valuable factor in driving therapeutic decisions and defining prognosis for patients in the locally advanced or metastatic for PAC setting, meriting investigation in prospective clinical trials.

COVID-19 Severity and Outcomes in Patients With Cancer: A Matched Cohort Study.

PURPOSE: SARS-CoV-2 (COVID-19) is a systemic infection. Patients with cancer are immunocompromised and may be vulnerable to COVID-related morbidity and mortality. The objectives of this study were to determine if patients with cancer have worse outcomes compared with patients without cancer and to identify demographic and clinical predictors of morbidity and mortality among patients with cancer. METHODS: We used data from adult patients who tested positive for COVID-19 and were admitted to two New York-Presbyterian hospitals between March 3 and May 15, 2020. Patients with cancer were matched 1:4 to controls without cancer in terms of age, sex, and number of comorbidities. Using Kaplan-Meier curves and the log-rank test, we compared morbidity (intensive care unit admission and intubation) and mortality outcomes between patients with cancer and controls. Among those with cancer, we identified demographic and clinical predictors of worse outcomes using Cox proportional hazard models. RESULTS: We included 585 patients who were COVID-19 positive, of whom 117 had active malignancy, defined as those receiving cancer-directed therapy or under active surveillance within 6 months of admission. Presenting symptoms and in-hospital complications were similar between the cancer and noncancer groups. Nearly one half of patients with cancer were receiving therapy, and 45% of patients received cytotoxic or immunosuppressive treatment within 90 days of admission. There were no statistically significant differences in morbidity or mortality (P = .894) between patients with and without cancer. CONCLUSION: We observed that patients with COVID-19 and cancer had similar outcomes compared with matched patients without cancer. This finding suggests that a diagnosis of active cancer alone and recent anticancer therapy do not predict worse COVID-19 outcomes and therefore, recommendations to limit cancer-directed therapy must be considered carefully in relation to cancer-specific outcomes and death.

Distinct Colorectal Cancer-Associated APC Mutations Dictate Response to Tankyrase Inhibition.

The majority of colorectal cancers show hyperactivated WNT signaling due to inactivating mutations in the adenomatous polyposis coli (APC) tumor suppressor. Genetically restoring APC suppresses WNT and induces rapid and sustained tumor regression, implying that reengaging this endogenous tumor-suppressive mechanism may be an effective therapeutic strategy. Here, using new animal models, human cell lines, and ex vivo organoid cultures, we show that tankyrase (TNKS) inhibition can control WNT hyperactivation and provide long-term tumor control in vivo, but that effective responses are critically dependent on how APC is disrupted. Mutant APC proteins truncated within the mutation cluster region physically engage the destruction complex and suppress the WNT transcriptional program, while APC variants with early truncations (e.g., Apc Min) show limited interaction with AXIN1 and ß-catenin, and do not respond to TNKS blockade. Together, this work shows that TNKS inhibition, like APC restoration, can reestablish endogenous control of WNT/ß-catenin signaling, but that APC genotype is a crucial determinant of this response. SIGNIFICANCE: This study reveals how subtle changes to the mutations in a critical colorectal tumor suppressor, APC, influence the cellular response to a targeted therapy. It underscores how investigating the specific genetic alterations that occur in human cancer can identify important biological mechanisms of drug response and resistance.This article is highlighted in the In This Issue feature, p. 1325.

Tankyrase inhibition sensitizes cells to CDK4 blockade.

Tankyrase (TNKS) 1/2 are positive regulators of WNT signaling by controlling the activity of the ß-catenin destruction complex. TNKS inhibitors provide an opportunity to suppress hyperactive WNT signaling in tumors, however, they have shown limited anti-proliferative activity as a monotherapy in human cancer cell lines. Here we perform a kinome-focused CRISPR screen to identify potential effective drug combinations with TNKS inhibition. We show that the loss of CDK4, but not CDK6, synergizes with TNKS1/2 blockade to drive G1 cell cycle arrest and senescence. Through precise modelling of cancer-associated mutations using cytidine base editors, we show that this therapeutic approach is absolutely dependent on suppression of canonical WNT signaling by TNKS inhibitors and is effective in cells from multiple epithelial cancer types. Together, our results suggest that combined WNT and CDK4 inhibition might provide a potential therapeutic strategy for difficult-to-treat epithelial tumors.