Prospective Evaluation of Circulating Tumor DNA using Next Generation Sequencing as a Biomarker during Neoadjuvant Chemotherapy in Localized Pancreatic Cancer.

OBJECTIVE: In this prospective study, we aim to characterize the prognostic value of circulating tumor DNA (ctDNA) by next-generation-sequencing (NGS) in patients undergoing neoadjuvant chemotherapy (NAC) for pancreatic ductal adenocarcinoma (PDAC). SUMMARY BACKGROUND DATA: Circulating tumor DNA is a promising blood-based biomarker that is prognostic in several malignancies. Detection of ctDNA by NGS may provide insights regarding the mutational profiles in PDAC to help guide clinical decisions for patients in a potentially curative setting. However, the utility of ctDNA as a biomarker in localized PDAC remains unclear. METHODS: Patients with localized PDAC were enrolled in a prospective study at Northwestern Medicine between October 2020 and October 2022. Blood samples were collected to perform targeted tumor agnostic NGS utilizing the Tempus x|F 105 gene panel at three timepoints: pre-therapy (at diagnosis), post-NAC, and after local therapy, including surgery. The relationship between ctDNA detection and CA19-9, and the prognostic significance of ctDNA detection were analyzed. RESULTS: 56 patients were included in the analysis. ctDNA was detectable in 48% at diagnosis, 33% post-NAC, and 41% after local therapy. After completion of NAC, patients with detectable ctDNA had higher CA19-9 levels versus those without (78.4 vs. 30.0, P=0.02). The presence of baseline ctDNA was associated with a CA19-9 response; those without ctDNA had a significant CA19-9 response following NAC (109.0 U/mL vs. 31.5 U/mL; P=0.01), while those with ctDNA present at diagnosis did not (198.1 U/mL vs. 113.8 U/mL; P=0.77). In patients treated with NAC, the presence of KRAS ctDNA at diagnosis was associated with and independently predicted worse progression-free-survival. CONCLUSION: This report demonstrates the prognostic value of ctDNA analysis with NGS in localized PDAC. NGS ctDNA is a biomarker of treatment response to NAC. KRAS ctDNA at diagnosis independently predicts worse survival in patients treated with NAC.

Gastrointestinal Malignancies: Pancreatic Cancer Clinical Trials in Neoadjuvant Chemotherapy.

Surgical resection is the only known treatment associated with long-term survival in pancreatic adenocarcinoma. While adjuvant therapy has shown a clear survival benefit, neoadjuvant chemotherapy has gained interest due to its ability to prioritize the treatment of micrometastatic disease prior to resection and improve chemotherapy tolerance prior to a major operation. Investigations have focused on evaluating the survival benefit of neoadjuvant therapy using single and combination chemotherapy as well as radiation therapy. Landmark trials in localized pancreatic cancer have paved the way for the standard use of neoadjuvant therapy for pancreatic adenocarcinoma.

Comparison of perioperative and histopathologic outcomes among neoadjuvant treatment strategies for locoregional gastric cancer.

BACKGROUND AND OBJECTIVES: Neoadjuvant chemotherapy (NAC) and chemoradiation (NCRT) have demonstrated improved survival for gastric cancer. However, the optimal neoadjuvant treatment remains unclear. We sought to evaluate perioperative and histopathologic outcomes among neoadjuvant treatments for locoregional gastric cancer. METHODS: The National Cancer Database queried patients who received NAC or NCRT followed by resection for T2-T4 and/or node-positive gastric cancer (2006-2018). Logistic and Poisson regression assessed perioperative (30-day readmission, 30- and 90-day mortality, length of stay [LOS]) and histopathologic outcomes (pathologic complete response [PCR], margin status, and negative pathologic lymph nodes [ypN0]). Kaplan-Meier methods and Cox regression assessed overall survival (OS). RESULTS: Of 9831 patients, 4221 (42.9%) received NAC and 5610 (57.1%) NCRT. There were no differences in perioperative outcomes, apart from patients treated with NCRT exhibiting increased LOS (incidence rate ratio 1.09, 95% confidence interval [CI] 1.03-1.16). Patients who received NCRT were more likely to achieve PCR, margin-negative resection, and ypN0 (all p < 0.05). Median OS was 36.8 months for NAC and 33.6 months for NCRT (p < 0.001). NCRT independently predicted worse OS (vs. NAC, hazard ratio 1.10, 95% CI 1.03-1.18). CONCLUSION: NCRT was associated with better histologic tumor response although NAC was associated with improved OS. Better understanding prognostication through histologic assessment following neoadjuvant therapy is needed.

Utilization and survival outcomes of neoadjuvant chemotherapy for early-stage gastric cancer.

BACKGROUND AND OBJECTIVES: Given increased utilization of neoadjuvant therapy (NAT) for gastric adenocarcinoma, practice patterns deviating from standard of care (upfront resection) remain unknown. We sought to identify factors associated with NAT use and survival outcomes among early-stage gastric cancers. METHODS: The National Cancer Database identified patients with early-stage (T1N0M0) gastric cancer (2010-2020). Multivariable logistic regression assessed characteristics associated with NAT utilization compared to upfront surgery. After 1:1 propensity score matching, Kaplan-Meier methods and Cox regression assessed overall survival (OS). RESULTS: Of 6452 patients with early-stage gastric cancer, 626 (9.7%) received NAT. Patients who received NAT were more likely treated at community hospitals, had moderate to poorly differentiated disease, and tumors located in the cardia (all p < 0.05). After propensity score matching, 1,248 patients remained. Median OS for NAT was 37.1 months (IQR 20.2-64.0) versus 45.6 months (IQR 22.5-72.8) for resection (p < 0.001). Treatment with NAT remained independently predictive of worse OS on Cox regression (hazard ratio 1.19; 95% confidence interval 1.05-1.34). CONCLUSIONS: Although patients who received NAT had more aggressive prognostic features, NAT was associated with worse OS despite accounting for this selection bias. These results highlight the importance of adhering to guidelines, regardless of differing disease characteristics, which has significant implications on outcomes.

Weight loss during neoadjuvant chemotherapy impacts perioperative outcomes in patients undergoing surgery for pancreatic cancer.

BACKGROUND: While use of neoadjuvant chemotherapy (NAC) in pancreatic adenocarcinoma (PDAC) downstages cancers to be eligible for resection, weight loss during the neoadjuvant period due to cancer progression, gastric outlet obstruction, or neoadjuvant therapy itself is an area of concern. The goal of this study is to determine the effect of weight loss during NAC on perioperative outcomes of pancreatectomies. METHODS: The NSQIP database 2014-2019 was utilized to study patients who received NAC for PDAC and underwent significant weight loss, defined as at least 10 % body weight loss in the six months prior to surgery. Univariate and multivariate analyses were conducted using Fisher's Exact Test, Pearson's Chi-squared Test, and logistic regression. RESULTS: Of the 5590 PDAC patients who received NAC, 913 (16%) experienced significant weight loss. Patients who experienced significant weight loss were more likely to experience at least one complication compared to those who did not undergo weight loss (42.2% vs. 38.7%, p = 0.023). Those who had significant weight loss were more likely to undergo unplanned intubation postoperatively (3.8% vs 2.2 %, p = 0.004), have postoperative ventilator need >48 h (3.7% vs 1.8%, p < 0.001), have postoperative septic shock (3.9% vs 1.8 %, p < 0.001), and undergo reoperation (6.0% vs 4.3%, p = 0.027). However, there were no differences for pancreatic fistula (7.7% vs 9.3 %, p = 0.15), readmission rates (15% vs 15 %, p = 0.7), or 30-day mortality (1.5% vs 1.2%, p = 0.5). Utilizing logistic regression, BMI (OR: 1.05, p = 0.032), significant weight loss (OR = 1.18, p = 0.025), sex (OR = 1.26 with female baseline, p < 0.001), history of COPD (OR = 1.39, p = 0.012), hypertensive medication use (OR = 1.18, p = 0.004), and pancreatic radiotherapy (OR = 1.16, p = 0.010) were independent preoperative predictors of a post-operative complication. CONCLUSIONS: Nutritional measures to stabilize weight during NAC should be considered to decrease post-pancreatectomy complications.

The differential effect of neoadjuvant chemotherapy and chemoradiation on nodal downstaging in pancreatic adenocarcinoma.

BACKGROUND/OBJECTIVES: Neoadjuvant chemotherapy (NCT) and chemoradiotherapy (NCRT) enhance resectability in patients with pancreatic adenocarcinoma (PDAC). This study compares the effect of NCT and NCRT on lymph nodal downstaging and survival. METHODS: The 2004-2016 National Cancer Database Pancreas Participant User File was used to identify patients who underwent surgery for PDAC. Fisher's exact, Wilcoxon rank-sum, multivariate logistic regression, and log-rank were used. Downstaging was defined as clinically node-positive patients who demonstrated node-negativity on pathology. RESULTS: Of 42,545 patients meeting criteria, 3311 received NCT and 1511 received NCRT. After surgery for clinically node-positive disease, 23.3% of NCT patients and 41.3% of NCRT patients demonstrated nodal downstaging. Younger age and lower tumor grade independently predicted downstaging. Downstaging after neoadjuvant therapy was associated with improved survival versus no nodal treatment response (29.8 vs. 22.8 months, p < 0.001). Downstaging by NCT was associated with improved overall survival versus downstaging by NCRT (37.5 vs. 26.6 months, p = 0.001). No survival difference existed between those with no nodal response after NCT or NCRT (p = 0.101). CONCLUSIONS: Although nodal downstaging is more likely post-NCRT, survival is superior in those downstaged post-NCT. Overall survival is determined by the systemic burden of disease. Post-therapy histologic analysis may be less prognostic post-NCRT.

The inaccuracies of gastric adenocarcinoma clinical staging and its predictive factors.

INTRODUCTION: Accurate clinical staging (CS) of gastric adenocarcinoma is important to guide treatment planning. Our objectives were to (1) assess clinical to pathologic stage migration patterns for patients with gastric adenocarcinoma, (2) identify factors associated with inaccurate CS, and (3) evaluate the association of understaging with survival. METHODS: The National Cancer Database was queried for patients who underwent upfront resection for stage I-III gastric adenocarcinoma. Multivariable logistic regression was used to detect factors associated with inaccurate understaging. Kaplan-Meier analyses and cox proportional hazards regression were performed to assess overall survival (OS) for patients with inaccurate CS. RESULTS: Of 14 425 analyzed patients, 5781 (40.1%) patients were inaccurately staged. Factors associated with understaging included treatment at a Comprehensive Community Cancer Program, presence of lymphovascular invasion, moderate to poor differentiation, large tumor size, and T2 disease. Based on overall CS, median OS was 51.0 months for accurately staged patients and 29.5 months for understaged patients (<0.001). CONCLUSION: Clinical T-category, large tumor size, and worse histologic features lead to inaccurate CS for gastric adenocarcinoma, impacting OS. Improvements to staging parameters and diagnostic modalities focusing on these factors may improve prognostication.

Prospective Phase II Trials Validate the Effect of Neoadjuvant Chemotherapy on Pattern of Recurrence in Pancreatic Adenocarcinoma.

OBJECTIVE: The objective of this study was to characterize the patterns of first recurrence after curative-intent resection for pancreatic adenocarcinoma (PDAC). SUMMARY OF BACKGROUND DATA: We evaluated the first site of recurrence after neoadjuvant treatment as locoregional (LR) or distant metastasis (DM). To validate our findings, we evaluated the pattern from 2 phase II clinical trials evaluating neoadjuvant chemotherapy (NAC) in PDAC. METHODS: We identified site of first recurrence from a retrospective cohort of patients from 2011 to 2017 treated with NAC followed by chemoradiation and then an operation or an operation first followed by adjuvant therapy, and 2 separate prospective cohorts of patients derived from 2 phase II clinical trials evaluating patients treated with NAC in borderline-resectable and locally advanced PDAC. RESULTS: In the retrospective cohorts, 160 out of 285 patients (56.1%) recurred after a median disease-free survival (mDFS) of 17.2 months. The pattern of recurrence was DM in 81.9% of patients, versus LR in 11.1%. This pattern was consistent in patients treated with upfront resection and adjuvant chemotherapy (DM 83.0%, LR 16.9%) regardless of margin-involvement (DM 80.1%, LR 19.4%). The use of NAC did not alter pattern of recurrence; 81.7% had DM and 18.3% had LR. This pattern also remained consistent regardless of margin-involvement (DM 94.1%, LR 5.9%). In the Phase II borderline-resectable trial (NCI# 01591733) cohort of 32 patients, the mDFS was 34.2 months. Pattern of recurrence remained predominantly DM (88.9%) versus LR (11.1%). In the Phase II locally-advanced trial (NCI# 01821729) cohort of 34 patients, the mDFS was 30.7 months. Although there was a higher rate of local recurrence in this cohort, pattern of first recurrence remained predominantly DM (66.6%) versus LR (33.3%) and remained consistent independent of margin-status. CONCLUSIONS: The pattern of recurrence in PDAC is predominantly DM rather than LR, and is consistent regardless of the use of NAC and margin involvement.

Identification of high-risk germline variants for the development of pancreatic cancer: Common characteristics and potential guidance to screening guidelines.

Pancreatic cancer (PC) is a product of a variety of environmental and genetic factors. Recent work has highlighted the influence of hereditary syndromes on pancreatic cancer incidence. The purpose of this review is to identify the high-risk syndromes, common variants, and risks associated with PC. The study also elucidates common characteristics of patients with these mutations, which is used to recommend potential changes to current screening protocols for greater screening efficacy. We analyzed 8 syndromes and their respective variants: Hereditary Breast and Ovarian Cancer (BRCA1/2), Familial Atypical Multiple Mole Melanoma Syndrome (CDKN2A), Peutz-Jeghers Syndrome (STK11), Lynch Syndrome (PMS2, MLH1, MSH2, MSH6, EPCAM), Ataxia Telangiectasia (ATM), Li-Fraumeni Syndrome (TP53), Fanconi Anemia (PALB2), and Hereditary Pancreatitis (PRSS1, SPINK1, CFTR). Of 587 studies evaluated, 79 studies fit into our inclusion criteria. Information from each study was analyzed to draw conclusions on these variants as well as their association with pancreatic cancer. Information from this review is intended to improve precision medicine and improve criteria for screening.

Impact of the COVID-19 Pandemic on Cancer Clinical Trials.

The COVID-19 pandemic has had widespread impact on healthcare, resulting in modifications to how we perform cancer research, including clinical trials for cancer. The impact of some healthcare workers and study coordinators working remotely and patients minimizing visits to medical facilities impacted clinical trial participation. Clinical trial accrual dropped at the onset of the pandemic, with improvement over time. Adjustments were made to some trial protocols, allowing telephone or video-enabled consent. Certain study activities were permitted to be performed by local healthcare providers or at local laboratories to maximize patients' ability to continue on study during these challenging times. We discuss the impact of COVID-19 on cancer clinical trials and changes at the local, cooperative group, and national level.

Contemporary trials evaluating neoadjuvant therapy for resectable pancreatic cancer.

While the use of neoadjuvant therapy is well-accepted in the treatment of borderline resectable and locally advanced pancreatic cancers, the benefit of neoadjuvant chemotherapy in patients with resectable disease has been a topic of debate. Recently, key trials evaluating neoadjuvant chemotherapy for resectable pancreatic cancer have reported results. This review describes key clinical trials evaluating the use of preoperative therapy in patients with technically resectable pancreatic cancer with a focus on their contribution to the available evidence.

Pancreatic Cancer: A Review.

Importance: Pancreatic ductal adenocarcinoma (PDAC) is a relatively uncommon cancer, with approximately 60 430 new diagnoses expected in 2021 in the US. The incidence of PDAC is increasing by 0.5% to 1.0% per year, and it is projected to become the second-leading cause of cancer-related mortality by 2030. Observations: Effective screening is not available for PDAC, and most patients present with locally advanced (30%-35%) or metastatic (50%-55%) disease at diagnosis. A multidisciplinary management approach is recommended. Localized pancreas cancer includes resectable, borderline resectable (localized and involving major vascular structures), and locally advanced (unresectable) disease based on the degree of arterial and venous involvement by tumor, typically of the superior mesenteric vessels. For patients with resectable disease at presentation (10%-15%), surgery followed by adjuvant chemotherapy with FOLFIRINOX (fluorouracil, irinotecan, leucovorin, oxaliplatin) represents a standard therapeutic approach with an anticipated median overall survival of 54.4 months, compared with 35 months for single-agent gemcitabine (stratified hazard ratio for death, 0.64 [95% CI, 0.48-0.86]; P = .003). Neoadjuvant systemic therapy with or without radiation followed by evaluation for surgery is an accepted treatment approach for resectable and borderline resectable disease. For patients with locally advanced and unresectable disease due to extensive vascular involvement, systemic therapy followed by radiation is an option for definitive locoregional disease control. For patients with advanced (locally advanced and metastatic) PDAC, multiagent chemotherapy regimens, including FOLFIRINOX, gemcitabine/nab-paclitaxel, and nanoliposomal irinotecan/fluorouracil, all have a survival benefit of 2 to 6 months compared with a single-agent gemcitabine. For the 5% to 7% of patients with a BRCA pathogenic germline variant and metastatic PDAC, olaparib, a poly (adenosine diphosphate [ADB]-ribose) polymerase inhibitor, is a maintenance option that improves progression-free survival following initial platinum-based therapy. Conclusions and Relevance: Approximately 60 000 new cases of PDAC are diagnosed per year, and approximately 50% of patients have advanced disease at diagnosis. The incidence of PDAC is increasing. Currently available cytotoxic therapies for advanced disease are modestly effective. For all patients, multidisciplinary management, comprehensive germline testing, and integrated supportive care are recommended.

The role of oncologic resection and enucleation for small pancreatic neuroendocrine tumors.

BACKGROUND: Surgical management of small pancreatic neuroendocrine tumors (PNETs) is variable. Patients may undergo formal oncologic resection, encompassing regional lymphadenectomy, or enucleation. This study's aim was to understand if enucleation is adequate treatment for PNETs <2 cm METHODS: The US National Cancer Database (NCDB) from 2004 to 2016 was used to identify patients who underwent oncologic resection or enucleation for PNETs <2 cm. Fisher's exact test, log-rank, and logistic regression were used. RESULTS: Of 4083 patients, 75.6% underwent oncologic resection with a median (range) number of 8 (0-99) lymph nodes examined, and 24.1% underwent enucleation. Five-year overall survival rate was 89.7% in node-negative patients versus 82.1% in node-positive patients (p < 0.001). No survival difference existed between patients who underwent enucleation versus oncologic resection (5-yr OS of 88.5% vs 88.2%, p = 0.064). According to AJCC classification, 3776 patients were clinically-staged with evidence of node-negative disease. Of these, 75.1% underwent oncologic resection, of which 9.9% had node-positive disease after resection. Tumor grade and size independently predicted nodal upstaging after oncologic resection. CONCLUSION: One-tenth of patients with clinically node-negative disease were node-positive after surgery. Although this was not reflected in overall survival, patients who receive enucleation with higher grade and larger size may benefit from enhanced surveillance for locoregional recurrence.

Neoadjuvant Therapy is Associated with Improved Survival in Borderline-Resectable Pancreatic Cancer.

BACKGROUND: Neoadjuvant therapy has shown value in various cancer types. The role of neoadjuvant therapy in pancreatic ductal adenocarcinoma (PDAC), however, remains unknown. The aim of the present work is to evaluate the effect of neoadjuvant therapy on the survival of patients with borderline-resectable PDAC. PATIENTS AND METHODS: Between 2004 and 2015, 7730 patients with resectable PDAC and 1980 patients with borderline-resectable PDAC were identified from the National Cancer Database (NCDB). Survival was compared between resectable and borderline-resectable patients. Survival and pathologic characteristics were also compared within borderline-resectable patients who received neoadjuvant therapy and those who received adjuvant therapy alone. Kaplan-Meier method and Cox proportional-hazard models were used for analysis. RESULTS: Median overall survival (mOS) of all patients with resectable PDAC was similar to that of patients with borderline-resectable disease treated with neoadjuvant therapy (26.5 versus 25.7 months, p = 0.78). Patients with borderline-resectable disease treated with neoadjuvant therapy had improved mOS compared with borderline-resectable patients treated with adjuvant therapy alone (25.7 versus 19.6 months, p < 0.0001). When comparing patients with borderline-resectable disease who received neoadjuvant therapy versus those who received adjuvant therapy alone, the former less often had node-positive pancreatic cancer (40.6% versus 76.3%, p < 0.001) and margin-positive resections (17.8% versus 44.4%, p < 0.001). CONCLUSION: Neoadjuvant therapy is associated with enhanced survival in patients with borderline-resectable pancreatic cancer, which may be attributed to tumor downstaging.

Clinical staging in pancreatic adenocarcinoma underestimates extent of disease.

BACKGROUND/OBJECTIVES: We sought to identify the reliability of AJCC clinical staging was in comparison to pathologic staging in surgically resected patients with pancreatic cancer. METHODS: We used the National Cancer Database Pancreas from 2004 to 2016 and evaluated patients who underwent resection for PDAC with all documented components of clinical and pathologic stage. We first evaluated the distribution of overall clinical stage and pathologic stage and then evaluated for stage migration by assessing the number of patients who shifted from a clinical stage group to a respective pathologic stage group. To further characterize the migratory pattern, we assessed the distribution of clinical and pathologic T-stage and N-stage. RESULTS: In our cohort of 28,338 patients who underwent resection for PDAC, AJCC clinical staging did not reliably predict pathologic stage. Stage migration after resection was responsible for discrepancies between the distribution of overall clinical stage and pathologic stage. The predominant migration was from patients with clinical stage I disease to pathologic stage II disease. Most patients with clinical T1 and T2 disease were upstaged to pathologic T3 disease and over half of patients with clinical N0 disease were upstaged to pathologic N1 disease after resection. DISCUSSION: Clinical staging appears to overrepresent early T1, T2, and N0 disease, and underrepresent T3 and N1 disease.

Pancreaticoduodenectomy and metastasectomy for metastatic pancreatic neuroendocrine tumors.

BACKGROUND AND OBJECTIVES: Various treatment options exist for patients with metastatic pancreatic neuroendocrine tumors (PNETs). Surgical resection with pancreaticoduodenectomy (PD) typically reserved for patients with limited disease. Definitive data are lacking to support either the resection of primary PNET in the metastatic setting or for surgical debulking of metastatic lesions. METHODS: We conducted an analysis of the National Cancer Database (NCDB) using the pancreatic cancer Participant User File. Thirty- and 90-day mortality rates and survival rates were determined for patients undergoing PD for primary tumor resection and compared with patients who had no surgery or metastasectomy. The Kaplan-Meier method was used to compare survival time. Cox regression models were used to assess factors independently associated with overall survival time. RESULTS: Resection of the primary tumor or metastatic disease each significantly improved overall survival time compared with no resection. Adding metastasectomy to PD resulted in an incremental increase in overall survival time. Both PD and metastasectomy are independently associated with overall survival time. CONCLUSIONS: Our report highlights the potential for survival time benefit in appropriately selected patients who undergo PD in the setting of metastatic PNET.

Pretherapy neutrophil to lymphocyte ratio and platelet to lymphocyte ratio do not predict survival in resectable pancreatic cancer.

BACKGROUND: Pretherapy serum neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) have both been identified as prognostic in pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to identify the prognostic implication of pretherapy NLR and PLR in patients with resectable PDAC. METHODS: Data were collected retrospectively on patients operated at our institution between 2004 and 2014. A Cox proportional hazards model was used to investigate the relationship between clinical and pathological parameters, NLR and PLR to overall survival (OS). Survival data were analyzed using the Kaplan-Meier method. RESULTS: 217 patients were analyzed with a median overall survival (OS) of 17.5 months. Factors identified as being predictive of OS by univariate analysis included age, receipt of adjuvant therapy, margin positivity, pathologic angiolymphatic invasion, T-stage, and N-stage (P < 0.05). Factors identified as being independently predictive of OS by multivariate analysis included age and angiolymphatic invasion (P < 0.05). NLR and PLR were not predictive of OS. Survival analysis demonstrated no difference in OS in patients who had high or low NLR or PLR. DISCUSSION: Pretherapy NLR and PLR do not predict survival in patients who underwent pancreatectomy for PDAC at our institution.

Neutrophil elastase enhances antigen presentation by upregulating human leukocyte antigen class I expression on tumor cells.

Neutrophil elastase (NE) is an innate immune cell-derived inflammatory mediator that we have shown increases the presentation of tumor-associated peptide antigens in breast cancer. In this study, we extend these observations to show that NE uptake has a broad effect on enhancing antigen presentation by breast cancer cells. We show that NE increases human leukocyte antigen (HLA) class I expression on the surface of breast cancer cells in a concentration and time-dependent manner. HLA class I upregulation requires internalization of enzymatically active NE. Western blots of NE-treated breast cancer cells confirm that the expression of total HLA class I as well as the antigen-processing machinery proteins TAP1, LMP2, and calnexin does not change following NE treatment. This suggests that NE does not increase the efficiency of antigen processing; rather, it mediates the upregulation of HLA class I by stabilizing and reducing membrane recycling of HLA class I molecules. Furthermore, the effects of NE extend beyond breast cancer since the uptake of NE by EBV-LCL increases the presentation of HLA class I-restricted viral peptides, as shown by their increased sensitivity to lysis by EBV-specific CD8+ T cells. Together, our results show that NE uptake increases the responsiveness of breast cancer cells to adaptive immunity by broad upregulation of membrane HLA class I and support the conclusion that the innate inflammatory mediator NE enhances tumor cell recognition and increases tumor sensitivity to the host adaptive immune response.