Neoadjuvant chemotherapy is associated with improved disease-free survival in pancreatic cancer patients undergoing pancreaticoduodenectomy with vascular resection.

BACKGROUND AND OBJECTIVES: Neoadjuvant chemotherapy (NAC) is becoming favored for all pancreatic adenocarcinoma (PDAC). Patients with seemingly resectable disease infrequently still display vascular involvement intraoperatively. Outcomes following NAC versus upfront surgery in patients undergoing pancreaticoduodenectomy (PD) with vascular resection are unknown. METHODS: We performed a retrospective cohort study of PDAC patients who underwent PD with vascular resection between January 1, 2013, to December 31, 2020, within a single academic center. Clinicopathologic characteristics and disease-free survival (DFS) were compared between NAC versus upfront surgery cohorts using the Kaplan-Meier estimate and Cox proportional-hazards regression model. RESULTS: Eighty-one patients who underwent PD with vascular resection for PDAC were included. Forty-six patients (56%) received NAC. The NAC cohort more often had pathologic N0 status (47.8% vs. 8.6%, p < 0.001), had decreased vascular invasion (11% vs. 40%, p = 0.002), and completed chemotherapy (80% vs. 40%, p < 0.01). The NAC cohort demonstrated improved DFS (40.5 vs. 14.3 months, p = 0.007). In multivariable analysis, NAC remained independently associated with increased DFS (HR = 0.48, p = 0.02). CONCLUSIONS: NAC was associated with improved clinicopathologic outcomes and DFS in PD with vascular resection. These findings demonstrate the advantage of NAC in PDAC patients undergoing PD with vascular resection.

Natural History and Genomic Landscape of Chemotherapy-Resistant Muscle-Invasive Bladder Cancer.

PURPOSE: Patients with residual invasive bladder cancer after neoadjuvant chemotherapy (NAC) and radical cystectomy have a poor prognosis. Data on adjuvant therapy for these patients are conflicting. We sought to evaluate the natural history and genomic landscape of chemotherapy-resistant bladder cancer to inform patient management and clinical trials. METHODS: Data were collected on patients with clinically localized muscle-invasive urothelial bladder cancer treated with NAC and cystectomy at our institution between May 15, 2001, and August 15, 2019, and completed four cycles of gemcitabine and cisplatin NAC, excluding those treated with adjuvant therapies. Survival was estimated using the Kaplan-Meier method, and multivariable Cox proportional hazards models were used to identify predictors of recurrence-free survival (RFS). Genomic alterations were identified in targeted exome sequencing (Memorial Sloan Kettering Integrated Mutation Profiling of Actionable Cancer Targets) data from post-NAC specimens from a subset of patients. RESULTS: Lymphovascular invasion (LVI) was the strongest predictor of RFS (hazard ratio, 2.15 [95% CI, 1.37 to 3.39]) on multivariable analysis. Patients with ypT2N0 disease without LVI had a significantly prolonged RFS compared with those with LVI (70% RFS at 5 years). Lymph node yield did not affect RFS. Among patients with sequencing data (n = 101), chemotherapy-resistant tumors had fewer alterations in DNA damage response genes compared with tumors from a publicly available chemotherapy-naïve cohort (15% v 29%; P = .021). Alterations in CDKN2A/B were associated with shorter RFS. PIK3CA alterations were associated with LVI. Potentially actionable alterations were identified in more than 75% of tumors. CONCLUSION: Although chemotherapy-resistant bladder cancer generally portends a poor prognosis, patients with organ-confined disease without LVI may be candidates for close observation without adjuvant therapy. The genomic landscape of chemotherapy-resistant tumors is similar to chemotherapy-naïve tumors. Therapeutic opportunities exist for targeted therapies as adjuvant treatment in chemotherapy-resistant disease.

Implementation and Validation of an Automated, Longitudinal Robotic Surgical Evaluation and Feedback Program at a High-volume Center and Impact on Training.

Background: Surgical education lacks a standardized, proficiency-based approach to evaluation and feedback. Objective: To assess the implementation and reception (ie, feasibility) of an automated, standardized, longitudinal surgical skill assessment and feedback system, and identify baseline trainee (resident and fellow) characteristics associated with achieving proficiency in robotic surgery while learning robotic-assisted laparoscopic prostatectomy. Design setting and participants: A quality improvement study assessing a pilot of a surgical experience tracking program was conducted over 1 yr. Participants were six fellows, eight residents, and nine attending surgeons at a tertiary cancer center. Intervention: Trainees underwent baseline self-assessment. After each surgery, an evaluation was completed independently by the trainee and attending surgeons. Performance was rated on a five-point anchored Likert scale (trainees were considered "proficient" when attending surgeons' rating was ≥4). Technical skills were assessed using the Global Evaluative Assessment of Robotic Skills (GEARS) and Prostatectomy Assessment and Competency Evaluation (PACE). Outcome measurements and statistical analysis: Program success and utility were assessed by evaluating completion rates, evaluation completion times, and concordance rates between attending and trainee surgeons, and exit surveys. Baseline characteristics were assessed to determine associations with achieving proficiency. Results and limitations: Completion rates for trainees and attending surgeons were 72% and 77%, respectively. Fellows performed more steps/cases than residents (median [interquartile range]: 5 [3-7] and 3 [2-4], respectively; p < 0.01). Prior completion of robotics or laparoscopic skill courses and surgical experience measures were associated with achieving proficiency in multiple surgical steps and GEARS domains. Interclass correlation coefficients on individual components were 0.27-0.47 on GEARS domains. Conclusions: An automated surgical experience tracker with structured, longitudinal evaluation and feedback can be implemented with good participation and minimal participant time commitment, and can guide curricular development in a proficiency-based education program by identifying modifiable factors associated with proficiency, individualizing education, and identifying improvement areas within the education program. Patient summary: An automated, standardized, longitudinal surgical skill assessment and feedback system can be implemented successfully in surgical education settings and used to inform education plans and predict trainee proficiency.

Changes in the Perioperative Management and Outcomes of Patients With Upper Tract Urothelial Carcinoma Undergoing Radical Nephroureterectomy at Memorial Sloan Kettering Cancer Center: Over 20 Years of Experience.

INTRODUCTION: We evaluated surgical trends, perioperative management evolution, and oncologic outcomes in patients who underwent radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC) at a tertiary cancer center over a 24-year period. METHODS: Between 1995 and 2018, we evaluated 743 consecutive patients with UTUC who underwent RNU. Generalized additive models were used to estimate the associations between date of surgery and continuous outcomes using a linear model, dichotomous outcomes using a logit link, categorical outcomes using multinomial models, and 2- and 5-year survival outcomes using Cox proportional hazards models. RESULTS: Over the study period, preoperative diagnostic endoscopic biopsies increased from 10% to 66%, along with the proportion of patients who underwent RNU for high-grade disease from 55% to 91%. The rate of open RNU declined from 100% to 56% with a rise in minimally invasive approaches. Median lymph node yield increased with more retroperitoneal lymph node dissections performed. Neoadjuvant chemotherapy utilization increased with a contemporary utilization rate of 32%, coinciding with an increase in pT0 rate from 2% to 8%. Cancer-specific survival probabilities improved over the study period, while metastasis-free and overall survival remained stable. CONCLUSIONS: We found several changes in treatment patterns and outcomes for patients with UTUC over the past 2 decades. How individual alterations in management factors, such as patient selection, perioperative chemotherapy, lymphadenectomy, and salvage therapies, impact patient outcomes is challenging in the setting of multiple overlapping practice changes for this rare disease and warrants further investigation.

Clinical and pathological factors associated with survival in patients with pancreatic cancer who receive adjuvant therapy after neoadjuvant therapy: A retrospective multi-institutional analysis.

BACKGROUND: Neoadjuvant therapy is being increasingly used for patients with pancreatic cancer. The role of adjuvant therapy in these patients is unclear. The purpose of this study was to identify clinical and pathologic characteristics that are associated with longer overall survival in patients with pancreatic cancer who receive adjuvant therapy after neoadjuvant therapy. METHODS: This study was conducted using multi-institutional data. All patients underwent surgery after at least 1 cycle of neoadjuvant therapy for pancreatic cancer. Patients who died within 3 months after surgery and were known to have distant metastasis or macroscopic residual disease were excluded. Mann-Whitney U test, χ2 analysis, Kaplan-Meier plot, and univariate and multivariate Cox regression analysis were performed as statistical analyses. RESULTS: In the present study, 529 patients with resected pancreatic cancer after neoadjuvant therapy were reviewed. For neoadjuvant therapy, 177 (33.5%) patients received neoadjuvant chemotherapy, and 352 (66.5%) patients received neoadjuvant chemoradiotherapy. The median duration of neoadjuvant therapy was 7.0 months (interquartile range, 5.0-8.7). Patients were followed for a median of 23.0 months after surgery. Adjuvant therapy was administered to 297 (56.1%) patients and was not associated with longer overall survival for the entire cohort (24 vs 22 months, P = .31). Interaction analysis showed that adjuvant therapy was associated with longer overall survival in patients who received less than 4 months neoadjuvant therapy (hazard ratio 0.40; 95% confidence interval 0.17-0.95; P = .03) or who had microscopic margin positive surgical resections (hazard ratio 0.56; 95% confidence interval 0.33-0.93; P = .03). CONCLUSION: In this retrospective study, there was a survival benefit associated with adjuvant therapy for patients who received less than 4 months of neoadjuvant therapy or had microscopic positive margins.

Examination of the mechanisms underlying the discriminative stimulus properties of the atypical antipsychotic amisulpride.

Amisulpride is an atypical benzamide antipsychotic/antidepressant, whose mechanism of action is thought to depend mainly on dopamine D2/3 receptor activity, but also with some serotonin 5-HT2B/7 effects. The present study examined the role of D2/3 receptors and 5-HT2B/7 receptors in amisulpride's discriminative stimulus. Selective agonists and antagonists of the above receptors were tested in adult, male C57BL/6 mice trained to discriminate 10 mg/kg amisulpride from vehicle in a two-lever drug discrimination assay. After acquisition of the two-lever discrimination, the amisulpride generalization curve yielded an ED50 = 0.56 mg/kg (95% CI = 0.42-0.76 mg/kg). Substitution tests found that the D2/3 antagonist raclopride (62.7% Drug Lever Responding), D2/3 agonist quinpirole (56.6% DLR), 5-HT7 agonist LP-44 (50.1% DLR) and 5-HT7 antagonist SB-269970 (36.7% DLR) produced various degrees of partial substitution for the amisulpride stimulus, whereas the 5-HT2B agonist BW 723C86 (17.9% DLR) and 5-HT2B antagonist SB-204741 (21.1% DLR) yielded negligible amisulpride-like effects. In combination tests with amisulpride, quinpirole decreased percent responding from 98.3% to 57.0% DLR, LP-44 decreased percent responding from 97.6% to 76.7% DLR, and BW 723C86 reduced percent responding from 95.66% to 74.11% DLR. Taken together, the results from stimulus generalization and antagonism studies suggest that amisulpride has a complex discriminative cue that involves mainly mixed D2/3 receptor antagonist/agonist effects and, to a lesser degree, mixed 5-HT7 receptor agonist/antagonist and perhaps 5-HT2B receptor antagonist effects.

Association of Inpatient Palliative Care Consultation with Clinical and Financial Outcomes for Pancreatic Cancer.

BACKGROUND: Palliative care consultation (PCC) has been shown to improve quality of life and reduce costs for various chronic life-threatening diseases. Despite PCC incorporation into modern pancreatic cancer care guidelines, limited data regarding its specific utilization and impact on resource use is available. METHODS: The 2016-2020 Nationwide Readmissions Database was used to identify all adult hospitalizations entailing pancreatic cancer. Only patients with at least one readmission within 90 days were included to account for uncaptured out-of-hospital mortality. Multivariable regression models were used to ascertain the relationship between inpatient PCC during initial hospitalization and index as well as cumulative costs, overall length of stay (LOS), readmission rate, and number of repeat hospitalizations. RESULTS: Of an estimated 175,805 patients with pancreatic cancer, 11.1% had inpatient PCC during the index admission. PCC utilization significantly increased from 10.5% in 2016 to 11.6% in 2020 (nptrend < 0.001). After adjustment, PCC was associated with reduced index hospitalization costs [ß: - $1100; 95% confidence interval (CI) - 1500, - 800; P < 0.001] and cumulative 90-day costs (ß: - $11,700; 95% CI - 12,700, - 10,000; P < 0.001). PCC was associated with longer index LOS (ß: + 1.12 days, 95% CI 0.92-1.31, P < 0.001) but significantly reduced cumulative LOS (ß: - 3.16 days; 95% CI - 3.67, - 2.65; P < 0.001). Finally, PCC was linked with decreased odds of 30-day nonelective readmission (AOR: 0.48, 95% CI 0.45-0.50, P < 0.001). DISCUSSION: PCC was associated with decreased costs, readmission rates, and number of hospitalizations among patients with pancreatic cancer. Directed strategies to increase utilization and reduce barriers to consultation should be implemented to encourage practitioners to maximize inpatient PCC referral rates.

Machine Learning Based Prediction of Postoperative Pancreatic Fistula Following Pancreaticoduodenectomy.

OBJECTIVE: To develop a novel machine learning (ML) model to predict clinically relevant postoperative pancreatic fistula (CR-POPF) following pancreaticoduodenectomy (PD). SUMMARY BACKGROUND DATA: Accurate prognostication of CR-POPF may allow for risk stratification and adaptive treatment strategies for potential PD candidates. However, antecedent models, such as the modified Fistula Risk Score (mFRS), are limited by poor discrimination and calibration. METHODS: All records entailing PD within the 2014-2018 ACS NSQIP were identified. Additionally, patients undergoing PD at our institution between 2013 and 2021 were queried from our local data repository. An eXtreme Gradient Boosting (XGBoost) model was developed to estimate the risk of CR-POPF using data from the ACS NSQIP and evaluated using institutional data. Model discrimination was estimated using the area under the receiver operating characteristic (AUROC) and precision recall curve (AUPRC). RESULTS: Overall, 12,281 and 445 patients undergoing PD were identified within the 2014-2018 ACS NSQIP and our institutional registry, respectively. Application of the XGBoost and mFRS scores to the internal validation dataset revealed that the former model had significantly greater AUROC (0.72 vs. 0.68, P<0.001) and AUPRC (0.22 vs. 0.18, P<0.001). Within the external validation dataset, the XGBoost model remained superior to the mFRS with an AUROC of 0.79 (95% CI 0.74-0.84) versus 0.75 (95% CI 0.70-0.80, P<0.001). In addition, AUPRC was higher for the XGBoost model, compared to the mFRS. CONCLUSIONS: Our novel ML model consistently outperformed the previously validated mFRS within internal and external validation cohorts, thereby demonstrating its generalizability and utility for enhancing prediction of CR-POPF.

Establishing a mouse model of lung metastases using ultrasound-guided right heart ventricle injection.

We report a technique to generate a murine model of lung metastases by selectively injecting tumor cells into the right heart ventricle under ultrasound guidance. First, we describe cell preparation and reference animal preparation as previously described. We then detail the technique using a previously described 3D-printed instrument stabilization device. Finally, we describe tumor growth surveillance using bioluminescent imaging. For complete details on the use and execution of this protocol, please refer to Labora et al.1.

Development of a Novel CLDN18.2-directed Monoclonal Antibody and Antibody-Drug Conjugate for Treatment of CLDN18.2-Positive Cancers.

Gastric and pancreatic cancers are malignancies of high unmet clinical need. Expression of CLDN18.2 in these cancers, coupled with it's absence from most normal tissues, provides a potential therapeutic window against this target. We present preclinical development and characterization of a novel therapeutic mAb and antibody-drug conjugate (ADC) targeting CLDN18.2. A humanized CLDN18.2 specific mAb, CLDN18.2-307-mAb, was generated through immunization in mice followed by full humanization of the mouse mAb sequences. Antibody clones were screened by flow cytometry for selective binding to membrane bound CLDN18.2. A CLDN18.2-directed ADC (CLDN18.2-307-ADC) was also generated by conjugating MMAE to CLDN18.2 mAb using a cleavable linker. Tissue expression of CLDN18.2 was determined by IHC assay using a CLDN18.2-specific mAb. CLDN18.2-307-mAb binds with high affinity to CLDN18.2-positive (CLDN18.2+) cells and induces antibody-dependent cell-mediated cytotoxicity (ADCC). Treatment with this CLDN18.2-mAb blocked the growth of CLDN18.2+ gastric and pancreas cancer cell line xenograft (CDX) models. Upon binding to the extracellular domain of this target, the CLDN18.2-ADC/CLDN18.2 protein was internalized and subsequently localized to the lysosomal compartment inducing complete and sustained tumor regressions in CLDN18.2+ CDXs and patient-derived pancreatic cancer xenografts (PDX). A screen of human cancer tissues, by IHC, found 58% of gastric, 60% of gastroesophageal junction, and 20% of pancreatic adenocarcinomas to be positive for membrane expression of CLDN18.2. These data support clinical development of the CLDN18.2-307-mAb and CLDN18.2-307-ADC for treatment of CLDN18.2+ cancers. Both are now being investigated in phase I clinical studies.

Feasibility and tissue concordance of genomic sequencing of urinary cytology in upper tract urothelial carcinoma.

BACKGROUND: There is limited ability to accurately diagnose and clinically stage patients with upper tract urothelial carcinoma (UTUC). The most easily available and widely used urinary biomarker is urine cytology, which evaluates cellular material yet lacks sensitivity. We sought to assess the feasibility of performing next-generation sequencing (NGS) on urine cytology specimens from patients with UTUC and evaluate the genomic concordance with tissue from primary tumor. METHODS: In this retrospective study, we identified 48 patients with a diagnosis of UTUC treated at Memorial Sloan Kettering Cancer Center (MSK) between 2019 and 2022 who had banked or fresh urine samples. A convenience cohort of matching, previously sequenced tumor tissue was used when available. Urine specimens were processed and the residual material, including precipitated cell-free DNA, was sequenced using our tumor-naïve, targeted exome sequencing platform that evaluates 505 cancer-related genes (MSK-IMPACT). The primary outcome was at least 1 detectable mutation in urinary cytology specimens. The secondary outcome was concordance to matched tissue (using ANOVA or Chi-Square, as indicated). RESULTS: Genomic sequencing was successful for 45 (94%) of the 48 urinary cytology patient samples. The most common mutations identified were TERT (62.2%), KMT2D (46.7%), and FGFR3 (35.6%). All patients with negative urine cytology and low-grade tissue had successful cytology sequencing. Thirty-six of the 45 patients had matching tumor tissue available; concordance to matched tissue was 55% overall (131 of the total 238 oncogenic or likely oncogenic somatic mutations identified). However, in 94.4% (n = 34/36) of patients, the cytology had at least 1 shared mutation with tissue. Eleven (30.6%) patients had 100% concordance between cytology and tissue. CONCLUSIONS: Sequencing urinary specimens from selective UTUC cytology is feasible in nearly all patients with UTUC. Prospective studies are underway to investigate a clinical role for this promising technology.

Ampullary Adenocarcinoma, Version 1.2023, NCCN Clinical Practice Guidelines in Oncology.

Ampullary cancers refer to tumors originating from the ampulla of Vater (the ampulla, the intraduodenal portion of the bile duct, and the intraduodenal portion of the pancreatic duct), while periampullary cancers may arise from locations encompassing the head of the pancreas, distal bile duct, duodenum, or ampulla of Vater. Ampullary cancers are rare gastrointestinal malignancies, and prognosis varies greatly based on factors such as patient age, TNM classification, differentiation grade, and treatment modality received. Systemic therapy is used in all stages of ampullary cancer, including neoadjuvant therapy, adjuvant therapy, and first-line or subsequent-line therapy for locally advanced, metastatic, and recurrent disease. Radiation therapy may be used in localized ampullary cancer, sometimes in combination with chemotherapy, but there is no high-level evidence to support its utility. Select tumors may be treated surgically. This article describes NCCN recommendations regarding management of ampullary adenocarcinoma.

Learning Curves in Establishing a New Minimally Invasive Pancreas Program.

INTRODUCTION: Robotic pancreaticoduodenectomy (rPD) is a complex operation with a reported learning curve of 80 cases. Two recent graduates of a formal robotic complex general surgical oncology training program have been performing rPD at our institution since 2016, which had no previous institutional experience with rPD. OBJECTIVE: To evaluate the learning curve associated with developing a new robotic pancreaticoduodenectomy (rPD) program by fellowship trained surgeons with institutional support. METHODS: Sixty patients undergoing rPD from 2016 to 2022 were reviewed for and compared with proficiency benchmarks set by the University of Pittsburg experience. RESULTS: By 30 cases, operative time met the proficiency benchmark of 391 minutes. Additionally, the entire cohort had comparable rates of clinically relevant postoperative pancreatic fistula (6.7% vs 3%, P = .6), 30-day mortality (0% vs 3%, P = .18), major complications (Clavien >2; 23% vs 17%, P = .14), and length of stay (6 vs 7 days, P = .49) when compared to the benchmark. CONCLUSION: Perioperative outcomes were comparable to proficiency benchmarks from initiation of the new rPD program, and operative time reached proficiency benchmark by 30 cases. This data suggests that graduates of formal rPD training programs can safely establish new minimally invasive pancreas programs at sites with no previous institutional rPD experience.

MEK Inhibition Sensitizes Pancreatic Cancer to STING Agonism by Tumor Cell-intrinsic Amplification of Type I IFN Signaling.

PURPOSE: Stimulator of interferon genes (STING) agonists are currently in development for treatment of solid tumors, including pancreatic ductal adenocarcinoma (PDAC). Response rates to STING agonists alone have been promising yet modest, and combination therapies will likely be required to elicit their full potency. We sought to identify combination therapies and mechanisms that augment the tumor cell-intrinsic effect of therapeutically relevant STING agonists apart from their known effects on tumor immunity. EXPERIMENTAL DESIGN: We screened 430 kinase inhibitors to identify synergistic effectors of tumor cell death with diABZI, an intravenously administered and systemically available STING agonist. We deciphered the mechanisms of synergy with STING agonism that cause tumor cell death in vitro and tumor regression in vivo. RESULTS: We found that MEK inhibitors caused the greatest synergy with diABZI and that this effect was most pronounced in cells with high STING expression. MEK inhibition enhanced the ability of STING agonism to induce type I IFN-dependent cell death in vitro and tumor regression in vivo. We parsed NFκB-dependent and NFκB-independent mechanisms that mediate STING-driven type I IFN production and show that MEK signaling inhibits this effect by suppressing NFκB activation. CONCLUSIONS: Our results highlight the cytotoxic effects of STING agonism on PDAC cells that are independent of tumor immunity and that these therapeutic benefits of STING agonism can be synergistically enhanced by MEK inhibition.

Higher Numbers of Examined Lymph Nodes Are Associated with Increased Survival in Resected, Treatment-Naïve, Node-Positive Esophageal, Gastric, Pancreatic, and Colon Cancers.

BACKGROUND OR PURPOSE: The role of extended lymphadenectomy as part of resection for lymph node (LN)-positive gastrointestinal (GI) malignancies remains controversial with no clear clinical guidance. The purpose of this retrospective study is to determine whether the number of LNs examined as part of GI malignancy resections affects overall survival (OS) among patients with node-positive esophageal, gastric, pancreatic, and colon cancers. METHODS: Participants with LN-positive GI cancers who were diagnosed between 2004 and 2015 and underwent oncologic resections were selected from National Cancer Database (NCDB). The primary predictor was the number of examined LNs categorized in tertiles. The effect on OS was measured by hazard ratio (HR) derived from multivariate Cox regression analyses. RESULTS: From 2004 to 2015, 1877, 10,086, 18,193, and 102,500 patients with LN-positive esophageal, gastric, pancreatic, and colon adenocarcinomas who did not receive neoadjuvant treatment and underwent oncologic tumor resection were registered in the NCDB. Using multivariate Cox proportional hazard modeling, greater LNs examined in surgically resected LN-positive GI cancers were found to be associated with increased OS for all histologies. This association was the strongest (as compared to the lowest tertile) for gastric cancer (middle tertile: HR = 0.91, 95% CI, 0.86-0.96, p = 0.001; highest tertile: HR = 0.73, 95% CI, 0.69-0.78, p < 0.001), followed by colon (highest tertile: HR = 0.86, 95% CI, 0.84-0.88, p < 0.001), esophageal (highest tertile: HR = 0.83, 95% CI, 0.72-0.95, p = 0.01), and pancreatic (highest tertile: HR = 0.93, 95% CI, 0.89-0.98, p = 0.002) cancers. DISCUSSION AND CONCLUSION: In patients with surgically resected node-positive GI malignancies who did not receive neoadjuvant systemic therapy, a higher number of examined LNs is associated with increased OS. This association is the strongest for gastric cancer, followed by colon, esophageal, and pancreatic cancers respectively.

Generation of liver metastases in a mouse model using ultrasound-guided intravenous injection.

Here, we present a protocol to generate a murine model of liver metastasis by directly injecting tumor cells into the portal vein under ultrasound guidance. We describe steps for animal and cell preparation and two techniques for injecting tumor cells. One technique is freehand, while the other technique is device-assisted using a 3D-printed prototype device. Finally, we describe tumor surveillance with bioluminescent imaging.