Aryl hydrocarbon receptor knockout accelerates PanIN formation and fibro-inflammation in a mutant Kras-driven pancreatic cancer model.

OBJECTIVES: The pathogenesis of pancreas cancer (PDAC) remains poorly understood, hindering efforts to develop a more effective therapy for PDAC. Recent discoveries show the aryl hydrocarbon receptor (AHR) plays a crucial role in the development of several cancers, and can be targeted for therapeutic effect. However, its involvement in the pathogenesis of PDAC remains unclear. To address this gap, we evaluated the role of AHR in the development of PDAC pre-cancerous lesions in vivo. METHODS: We created a global AHR-null, mutant Kras-driven PDAC mouse model (A-/-KC) and evaluated the changes in PDAC precursor lesion formation (Pan-IN 1, 2, and 3) and associated fibro-inflammation between KC and A-/-KC at 5 months of age. We then examined the changes in the immune microenvironment followed by single-cell RNA-sequencing analysis to evaluate concomitant transcriptomic changes. RESULTS: We identified a significant increase in PanIN-1 lesion formation and PanIN-1 associated fibro-inflammatory infiltrate in A-/-KC vs KC mice. This was associated with significant changes in the adaptive immune system, particularly a decrease in the CD4+/CD8+ T-cell ratio, as well as a decrease in the T-regulatory/Th17 T-cell ratio suggesting unregulated inflammation. CONCLUSION: These findings show the loss of AHR results in heightened Kras-induced PanIN formation, through modulation of immune cells within the pancreatic tumor microenvironment.

Nanodrug-bacteria conjugates-mediated oncogenic collagen depletion enhances immune checkpoint blockade therapy against pancreatic cancer.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) cancer cells specifically produce abnormal oncogenic collagen to bind with integrin α3ß1 receptor and activate the downstream focal adhesion kinase (FAK), protein kinase B (AKT), and mitogen-activated protein kinase (MAPK) signaling pathway. Collectively, this promotes immunosuppression and tumor proliferation and restricts the response rate of clinical cancer immunotherapies. METHODS: Here, by leveraging the hypoxia tropism and excellent motility of the probiotic Escherichia coli strain Nissle 1917 (ECN), we developed nanodrug-bacteria conjugates to penetrate the extracellular matrix (ECM) and shuttle the surface-conjugated protein cages composed of collagenases and anti-programmed death-ligand 1 (PD-L1) antibodies to PDAC tumor parenchyma. FINDINGS: We found the oncogenic collagen expression in human pancreatic cancer patients and demonstrated its interaction with integrin α3ß1. We proved that reactive oxygen species (ROS) in the microenvironment of PDAC triggered collagenase release to degrade oncogenic collagen and block integrin α3ß1-FAK signaling pathway, thus overcoming the immunosuppression and synergizing with anti-PD-L1 immunotherapy. CONCLUSIONS: Collectively, our study highlights the significance of oncogenic collagen in PDAC immunotherapy, and consequently, we developed a therapeutic strategy that can deplete oncogenic collagen to synergize with immune checkpoint blockade for enhanced PDAC treatment efficacy. FUNDING: This work was supported by the University of Wisconsin Carbone Cancer Center Research Collaborative and Pancreas Cancer Research Task Force, UWCCC Transdisciplinary Cancer Immunology-Immunotherapy Pilot Project, and the start-up package from the University of Wisconsin-Madison (to Q.H.).

Single-cell RNA sequencing of neurofibromas reveals a tumor microenvironment favorable for neural regeneration and immune suppression in a neurofibromatosis type 1 porcine model.

Neurofibromatosis Type 1 (NF1) is one of the most common genetically inherited disorders that affects 1 in 3000 children annually. Clinical manifestations vary widely but nearly always include the development of cutaneous, plexiform and diffuse neurofibromas that are managed over many years. Recent single-cell transcriptomics profiling efforts of neurofibromas have begun to reveal cell signaling processes. However, the cell signaling networks in mature, non-cutaneous neurofibromas remain unexplored. Here, we present insights into the cellular composition and signaling within mature neurofibromas, contrasting with normal adjacent tissue, in a porcine model of NF1 using single-cell RNA sequencing (scRNA-seq) analysis and histopathological characterization. These neurofibromas exhibited classic diffuse-type histologic morphology and expected patterns of S100, SOX10, GFAP, and CD34 immunohistochemistry. The porcine mature neurofibromas closely resemble human neurofibromas histologically and contain all known cellular components of their human counterparts. The scRNA-seq confirmed the presence of all expected cell types within these neurofibromas and identified novel populations of fibroblasts and immune cells, which may contribute to the tumor microenvironment by suppressing inflammation, promoting M2 macrophage polarization, increasing fibrosis, and driving the proliferation of Schwann cells. Notably, we identified tumor-associated IDO1 +/CD274+ (PD-L1) + dendritic cells, which represent the first such observation in any NF1 animal model and suggest the role of the upregulation of immune checkpoints in mature neurofibromas. Finally, we observed that cell types in the tumor microenvironment are poised to promote immune evasion, extracellular matrix reconstruction, and nerve regeneration.

The circadian clock is disrupted in pancreatic cancer.

Disruption of the circadian clock is linked to cancer development and progression. Establishing this connection has proven beneficial for understanding cancer pathogenesis, determining prognosis, and uncovering novel therapeutic targets. However, barriers to characterizing the circadian clock in human pancreas and human pancreatic cancer-one of the deadliest malignancies-have hindered an appreciation of its role in this cancer. Here, we employed normalized coefficient of variation (nCV) and clock correlation analysis in human population-level data to determine the functioning of the circadian clock in pancreas cancer and adjacent normal tissue. We found a substantially attenuated clock in the pancreatic cancer tissue. Then we exploited our existing mouse pancreatic transcriptome data to perform an analysis of the human normal and pancreas cancer samples using a machine learning method, cyclic ordering by periodic structure (CYCLOPS). Through CYCLOPS ordering, we confirmed the nCV and clock correlation findings of an intact circadian clock in normal pancreas with robust cycling of several core clock genes. However, in pancreas cancer, there was a loss of rhythmicity of many core clock genes with an inability to effectively order the cancer samples, providing substantive evidence of a dysregulated clock. The implications of clock disruption were further assessed with a Bmal1 knockout pancreas cancer model, which revealed that an arrhythmic clock caused accelerated cancer growth and worse survival, accompanied by chemoresistance and enrichment of key cancer-related pathways. These findings provide strong evidence for clock disruption in human pancreas cancer and demonstrate a link between circadian disruption and pancreas cancer progression.

Chronic jetlag accelerates pancreatic neoplasia in conditional Kras-mutant mice.

Misalignment of the circadian clock compared to environmental cues causes circadian desynchrony, which is pervasive in humans. Clock misalignment can lead to various pathologies including obesity and diabetes, both of which are associated with pancreatic ductal adenocarcinoma - a devastating cancer with an 80% five-year mortality rate. Although circadian desynchrony is associated with an increased risk of several solid-organ cancers, the correlation between clock misalignment and pancreas cancer is unclear. Using a chronic jetlag model, we investigated the impact of clock misalignment on pancreas cancer initiation in mice harboring a pancreas-specific activated Kras mutation. We found that chronic jetlag accelerated the development of pancreatic cancer precursor lesions, with a concomitant increase in precursor lesion grade. Cell-autonomous knock-out of the clock in pancreatic epithelial cells of Kras-mutant mice demonstrated no acceleration of precursor lesion formation, indicating non-cell-autonomous clock dysfunction was responsible for the expedited tumor development. Therefore, we applied single-cell RNA sequencing over time and identified fibroblasts as the cell population manifesting the greatest clock-dependent changes, with enrichment of specific cancer-associated fibroblast pathways due to circadian misalignment.

Aryl hydrocarbon receptor knockout accelerates PanIN formation and fibro-inflammation in a mutant Kras-driven pancreatic cancer model.

Objectives: The pathogenesis of pancreas cancer (PDAC) remains poorly understood, hindering efforts to develop a more effective therapy for PDAC. Recent discoveries show the aryl hydrocarbon receptor (AHR) plays a crucial role in the pathogenesis of several cancers, and can be targeted for therapeutic effect. However, its involvement in PDAC remains unclear. Therefore, we evaluated the role of AHR in the development of PDAC in vivo. Methods: We created a global AHR-null, mutant Kras-driven PDAC mouse model (A-/-KC) and evaluated the changes in PDAC precursor lesion formation (Pan-IN 1, 2, and 3) and associated fibro-inflammation between KC and A-/-KC at 5 months of age. We then examined the changes in the immune microenvironment followed by single-cell RNA-sequencing analysis to evaluate concomitant transcriptomic changes. Results: We found a significant increase in PanIN-1 lesion formation and PanIN-1 associated fibro-inflammatory infiltrate in A-/-KC vs KC mice. This was associated with significant changes in the adaptive immune system, particularly a decrease in the CD4+/CD8+ T-cell ratio, as well as a decrease in the T-regulatory/Th17 T-cell ratio suggesting unregulated inflammation. Conclusion: These findings show the loss of AHR results in heightened Kras-induced PanIN formation, through modulation of immune cells within the pancreatic tumor microenvironment.

Rethinking Routine Intensive Care After Cytoreductive Surgery With Heated Intraperitoneal Chemotherapy: The Fiscal Argument.

BACKGROUND: Patients undergoing cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) are frequently admitted to the intensive care unit (ICU) for mitigation of potential complications, although ICU length of stay (LOS) is a significant driver of cost. This study asked whether a fiscal argument could be made for the selective avoidance of ICU admission after CRS/HIPEC. METHODS: Prospective data for select low-risk patients (e.g., lower peritoneal cancer index [PCI]) admitted to the intermediate care unit (IMC) instead of the ICU after CRS/HIPEC were matched with a historic cohort routinely admitted to the ICU. Cohort comparisons and the impact of the intervention on cost were assessed. RESULTS: The study matched 81 CRS/HIPEC procedures to form a cohort of 49 pre- and 15 post-intervention procedures for patients with similar disease burdens (mean PCI, 8 ± 6.7 vs. 7 ± 5.1). The pre-intervention patients stayed a median of 1 day longer in the ICU (1 day [IQR, 1-1 day] vs. 0 days [IQR, 0-0 days]) and had a longer LOS (8 days [IQR, 7-11 days] vs. 6 days [IQR, 5.5-9 days]). Complications and complication severity did not differ statistically. The median total hospital cost was lower after intervention ($30,845 [IQR, $30,181-$37,725] vs. $41,477 [IQR, $33,303-$51,838]), driven by decreased indirect fixed cost ($8984 [IQR, $8643-$11,286] vs. $14,314 [IQR, $12,206-$18,266]). In a weighted multiple variable linear regression analysis, the intervention was associated with a savings of $2208.68 per patient. CONCLUSIONS: Selective admission to the IMC after CRS/HIPEC was associated with $2208.68 in savings per patient without added risk. In this era of cost-conscious practice of medicine, these data highlight an opportunity to decrease cost by more than 5% for patients undergoing CRS/HIPEC.

Chronic Jetlag Alters the Landscape of the Pancreatic Lipidome.

OBJECTIVES: The innate biologic clock plays a significant role in lipid metabolism, including the peripheral clock in the pancreas. However, an evaluation of the downstream lipids in the pancreatic lipidome is lacking. We sought to understand the diurnal variations of lipids within the pancreatic lipidome. METHODS: At 4 weeks of age, C57Bl/6J mice were subjected to either normal lighting conditions or a chronic jetlag (CJ) condition known to mimic chronic shiftwork in humans. At 9 months, mice were serially killed at 4-hour intervals for 24 hours. The pancreas was removed and subjected to untargeted liquid chromatography-mass spectrometry to examine the pancreatic lipidome. RESULTS: A total of 4.7% of the pancreatic lipidome was rhythmically expressed, which increased to 12.9% after CJ. After CJ, there was a 4.58-hour shift in the timing of peak 24-hour lipid expression. Chronic jetlag also led to the enrichment of diacylglycerols and triglycerides, while promoting a decrease in lysophosphatidylcholines and 44-carbon acyl chain lipids. CONCLUSIONS: The pancreatic lipidome exhibits diurnal rhythmicity across a broad number of lipid classes. Chronic jetlag led to alterations in lipid composition that mirrored other metabolically active organs. Several of the reported changes may link altered sleep-wake cycles with known circadian disruption-induced pancreatic diseases.

Sex-dependent development of Kras-induced anal squamous cell carcinoma in mice.

Anal squamous cell carcinoma (SCC) will be diagnosed in an estimated 9,080 adults in the United States this year, and rates have been rising over the last several decades. Most people that develop anal SCC have associated human papillomavirus (HPV) infection (~85-95%), with approximately 5-15% of anal SCC cases occurring in HPV-negative patients from unknown etiology. This study identified and characterized the Kras-driven, female sex hormone-dependent development of anal squamous cell carcinoma (SCC) in the LSL-KrasG12D; Pdx1-Cre (KC) mouse model that is not dependent on papillomavirus infection. One hundred percent of female KC mice develop anal SCC, while no male KC mice develop tumors. Both male and female KC anal tissue express Pdx1 and Cre-recombinase mRNA, and the activated mutant KrasG12D gene. Although the driver gene mutation KrasG12D is present in anus of both sexes, only female KC mice develop Kras-mutant induced anal SCC. To understand the sex-dependent differences, KC male mice were castrated and KC female mice were ovariectomized. Castrated KC males displayed an unchanged phenotype with no anal tumor formation. In contrast, ovariectomized KC females demonstrated a marked reduction in anal SCC development, with only 15% developing anal SCC. Finally, exogenous administration of estrogen rescued the tumor development in ovariectomized KC female mice and induced tumor development in castrated KC males. These results confirm that the anal SCC is estrogen mediated. The delineation of the role of female sex hormones in mediating mutant Kras to drive anal SCC pathogenesis highlights a subtype of anal SCC that is independent of papillomavirus infection. These findings may have clinical applicability for the papillomavirus-negative subset of anal SCC patients that typically respond poorly to standard of care chemoradiation.

Chronic jetlag-induced alterations in pancreatic diurnal gene expression.

Cell-autonomous circadian clocks exist in nearly every organ and function to maintain homeostasis through a complex series of transcriptional-translational feedback loops. The response of these peripheral clocks to external perturbations, such as chronic jetlag and shift work, has been extensively investigated. However, an evaluation of the effects of chronic jetlag on the mouse pancreatic transcriptome is still lacking. Herein, we report an evaluation of the diurnal variations encountered in the pancreatic transcriptome following exposure to an established chronic jetlag protocol. We found approximately 5.4% of the pancreatic transcriptome was rhythmic. Following chronic jetlag, we found the number of rhythmic transcripts decreased to approximately 3.6% of the transcriptome. Analysis of the core clock genes, which orchestrate circadian physiology, revealed that nearly all exhibited a shift in the timing of peak gene expression-known as a phase shift. Similarly, over 95% of the rhythmically expressed genes in the pancreatic transcriptome exhibited a phase shift, many of which were found to be important for metabolism. Evaluation of the genes involved in pancreatic exocrine secretion and insulin signaling revealed many pancreas-specific genes were also rhythmically expressed and several displayed a concomitant phase shift with chronic jetlag. Phase differences were found 9 days after normalization, indicating a persistent failure to reentrain to the new light-dark cycle. This study is the first to evaluate the endogenous pancreatic clock and rhythmic gene expression in whole pancreas over 48 h, and how the external perturbation of chronic jetlag affects the rhythmic expression of genes in the pancreatic transcriptome.

Summary perioperative risk metrics within the electronic medical record predict patient-level cost variation in pancreaticoduodenectomy.

BACKGROUND: Automated data extraction from the electronic medical record is fast, scalable, and inexpensive compared with manual abstraction. However, concerns regarding data quality and control for underlying patient variation when performing retrospective analyses exist. This study assesses the ability of summary electronic medical record metrics to control for patient-level variation in cost outcomes in pancreaticoduodenectomy. METHODS: Patients that underwent pancreaticoduodenectomy from 2014 to 2018 at a single institution were identified within the electronic medical record and linked with the National Surgical Quality Improvement Program. Variables in both data sets were compared using interrater reliability. Logistic and linear regression modelling of complications and costs were performed using combinations of comorbidities/summary metrics. Models were compared using the adjusted R2 and Akaike information criterion. RESULTS: A total of 117 patients populated the final data set. A total of 31 (26.5%) patients experienced a complication identified by the National Surgical Quality Improvement Program. The median direct variable cost for the encounter was US$14,314. Agreement between variables present in the electronic medical record and the National Surgical Quality Improvement Program was excellent. Stepwise linear regression models of costs, using only electronic medical record-extractable variables, were non-inferior to those created with manually abstracted individual comorbidities (R2 = 0.67 vs 0.30, Akaike information criterion 2,095 vs 2,216). Model performance statistics were minimally impacted by the addition of comorbidities to models containing electronic medical record summary metrics (R2 = 0.67 vs 0.70, Akaike information criterion 2,095 vs 2,088). CONCLUSION: Summary electronic medical record perioperative risk metrics predict patient-level cost variation as effectively as individual comorbidities in the pancreaticoduodenectomy population. Automated electronic medical record data extraction can expand the patient population available for retrospective analysis without the associated increase in human and fiscal resources that manual data abstraction requires.

All-payer Spending on Common Hospital-based Services in California.

BACKGROUND: Hospital-based care accounts for one third of US health spending or over $1 trillion annually, yet a detailed all-payer assessment of what services contribute to this spending is not available. STUDY DESIGN: Cross-sectional and longitudinal evaluation of hospital financial statements from acute-care general hospitals in California between fiscal years 2007 and 2016. The amounts spent on 41 different revenue centers were included. The primary outcome was state-level and hospital-level spending for each revenue center including decomposing growth trends into changes in volume and prices. RESULTS: The analysis included 2941 annual financial statements from 331 hospitals. Between 2007 and 2016, total spending across all centers increased 66.6% from $43.7B to $72.9B. Five centers-surgery and recovery, drugs sold to patients, acute medical/surgical floor, the clinical laboratory, and emergency services-accounted for over 50% of total spending in 2016. Overall spending growths ranged from 1.1%/y (acute pediatrics) to 17.9%/y (observation). Other revenue centers with large increases in spending included emergency services (164.7%), clinics (on-site 114.5%, satellite 129.7%), anesthesia (119.6%), echocardiography (114.4%), and computed tomography (100.8%). Most services had volume growths within ±2%/y, although there were exceptions (eg, observation hours increased 10.0%/y). Prices grew fastest for echocardiograms (10.5%/y), cardiac catheterization (9.7%/y), therapeutic radiology (8.0%/y), and emergency visits (7.5%/y). In general, median prices for services in 2016 were larger than Medicare allowed amounts. CONCLUSIONS: Overall hospital-based spending increased 66.6% between 2007 and 2016 in California, but there was wide variation in spending growth across revenue centers. Understanding this variation-including the relative contributions of volumes and prices-can guide efforts to curb excessive health care spending and optimize resource dedication to current and future patient care needs.

Natural history and cost analysis of surgical bypass versus endoscopic stenting for the palliative management of malignant gastric outlet obstruction.

BACKGROUND: Malignant gastric outlet obstruction (GOO) is managed with palliative surgical bypass or endoscopic stenting. Limited data exist on differences in cost and outcomes. METHODS: Patients with malignant GOO undergoing palliative gastrojejunostomy (GJ) or endoscopic stent (ES) were identified between 2012 and 2015 using the MarketScan® Database. Median costs (payments) for the index procedure and 90-day readmissions and re-intervention were calculated. Frequency of treatment failure-defined as repeat surgery, stenting, or gastrostomy tube-was measured. RESULTS: A total of 327 patients were included: 193 underwent GJ and 134 underwent ES. Compared to GJ, stenting resulted in lower total median payments for the index hospitalization and procedure-related 90-day readmissions ($18,500 ES vs. $37,200 GJ, p = 0.032). For patients treated with ES, 25 (19%) required a re-intervention for treatment-failure, compared to 18 (9%) patients who underwent GJ (p = 0.010). On multivariable analysis, stenting remained significantly associated with need for secondary re-intervention compared to GJ (HR for ES 2.0 [1.1-3.8], p 0.028). CONCLUSION: In patients with malignant GOO, endoscopic stenting results in significant 90-day cost saving, however was associated with twice the rate of secondary intervention. The decision for surgical bypass versus endoscopic stenting should consider patient prognosis, anticipated cost, and likelihood of needing re-intervention.

National Trends in Centralization of Surgical Care and Multimodality Therapy for Pancreatic Adenocarcinoma.

BACKGROUND: Studies have demonstrated that multimodality therapy and surgery at high volume centers are associated with a longer survival. However, it is unknown if these data have translated into national changes in care delivery. METHODS: Patients with stages I-III pancreatic adenocarcinomas who underwent resections between 2004 and 2010 were identified from the National Cancer Data Base. The primary outcome was a 3-year overall survival. Temporal trends in survival outcomes and treatment variables were measured. A mediation analysis using the Lin method was used to discern the relative contribution of changes in treatment variables towards improvements in survival over time. RESULTS: A total of 22,196 patients were identified. Between 2004 and 2010, a 90-day peri-operative mortality remained unchanged (8.5 % to 8.4 %, p = 0.488), 3-year overall survival improved from 26 to 30% (p < 0.001), use of adjuvant/neoadjuvant chemotherapy increased (51 % to 61 %, p < 0.001), and more cases shifted to high volume centers (46 % at institutions performing > 10 cases/year in 2004 vs. 65 % in 2010, p < 0.001). On multivariable analysis, 32 % of the improvement in survival over time was attributable to receipt of chemotherapy, while 12 % was due to the shift of patients towards high volume centers (p < 0.001). CONCLUSIONS: Over the period from 2004 to 2010, a 3-year survival increased for patients undergoing resection for pancreatic cancer. This survival improvement can be partially attributed to the increasing utilization of chemotherapy and centralization of surgical care at high volume centers. A continued emphasis on these factors will likely result in further prolongation of a survival following resection.

Role of radiation therapy for retroperitoneal sarcomas: An eight-institution study from the US Sarcoma Collaborative.

BACKGROUND: The use of radiation therapy in the treatment of retroperitoneal sarcomas has increased in recent years. Its impact on survival and recurrence is unclear. METHODS: A retrospective propensity score matched (PSM) analysis of patients with primary retroperitoneal soft tissue sarcomas, who underwent resection from 2000 to 2016 at eight institutions of the US Sarcoma Collaborative, was performed. Patients with metastatic disease, desmoid tumors, and palliative resections were excluded. RESULTS: Total 425 patients were included, 56 in the neoadjuvant radiation group (neo-RT), 75 in the adjuvant radiation group (adj-RT), and 294 in the no radiotherapy group (no-RT). Median age was 59.5 years, 186 (43.8%) were male with a median follow up of 31.4 months. R0 and R1 resection was achieved in 253 (61.1%) and 143 (34.5%), respectively. Overall 1:1 match of 46 adj-RT and 59 neo-RT patients was performed using histology, sex, age, race, functional status, tumor size, grade, resection status, and chemotherapy. Unadjusted recurrence-free survival (RFS) was 35.9 months (no-RT) vs 33.5 months (neo-RT) and 27.2 months (adj-RT), P = .43 and P = .84, respectively. In the PSM, RFS was 17.6 months (no-RT) vs 33.9 months (neo-RT), P = .28 and 19 months (no-RT) vs 27.2 months (adj-RT), P = .1. CONCLUSIONS: Use of radiotherapy, both in adjuvent or neoadjuvent setting, was not associated with improved survival or reduced recurrence rate.

Natural History and Treatment Trends in Pancreatic Cancer Subtypes.

BACKGROUND: While pancreatic ductal adenocarcinoma is the most common form of pancreatic cancer, many other histologic forms of pancreatic cancer are also recognized. These histologic variants portray unique characteristics in terms of patient demographics, tumor behavior, survival, and responsiveness to treatments. MATERIALS AND METHODS: Patients who underwent surgical resection of the pancreas for non-metastatic, invasive pancreatic cancer between 2004 and 2014 were selected from the National Cancer Data Base and categorized by histologic variant according to WHO classification guidelines. Patient demographics, tumor variables, treatment characteristics, and survival were compared between histologic groups and subgroups. RESULTS: A total of 57,804 patients met inclusion and exclusion criteria and were grouped into eight major histologic categories. Survival analysis by the histologic group showed median overall survival of 20.2 months for ductal adenocarcinoma, 20.5 months for squamous cell carcinoma, 26.8 months for mixed acinar-neuroendocrine carcinomas, 52.6 months for cystic mucinous neoplasms with an associated invasive carcinoma, 67.5 months for acinar cell carcinoma, and 69.3 months for mesenchymal tumors. Median survival was not reached for neuroendocrine tumors and solid-pseudopapillary neoplasms, with 5-year overall survival rates of 84% and 97% respectively. CONCLUSIONS: Rare subtypes of pancreatic cancer present unique clinicopathologic characteristics and display distinct tumor biologies. This study presents data on demographic, prognostic, treatment, and survival outcomes between rare forms of pancreatic neoplasms in order to aid understanding of the natural history and behavior of these neoplasms, with the hope of serving as a reference in clinical decision-making and ability to provide accurate prognostic information to patients.

Analysis of 90-day cost for open versus minimally invasive distal pancreatectomy.

BACKGROUND: Minimally invasive distal pancreatectomy (MIDP) is associated with improved peri-operative outcomes compared to the open approach, though cost-effectiveness of MIDP remains unclear. METHODS: Patients with pancreatic tumors undergoing open (ODP), robotic (RDP), or laparoscopic distal pancreatectomy (LDP) between 2012-2014 were identified through the Truven Health MarketScan® Database. Median costs (payments) for the index operation and 90-day readmissions were calculated. Multivariable regression was used to predict associations with log 90-day payments. RESULTS: 693 patients underwent ODP, 146 underwent LDP, and 53 RDP. Compared to ODP, LDP and RDP resulted in shorter median length of stay (6 d. ODP vs. 5 d. RDP vs. 4 d. LDP, p<0.01) and lower median payments ($38,350 ODP vs. $34,870 RDP vs. $32,148 LDP, p<0.01) during the index hospitalization. Total median 90-day payments remained significantly lower for both minimally invasive approaches ($40,549 ODP vs. $35,160 RDP vs. $32,797 LDP, p<0.01). On multivariable analysis, LDP and RDP resulted in 90-day cost savings of 21% and 25% relative to ODP, equating to an amount of $8,500-$10,000. CONCLUSION: MIDP is associated with >$8,500 in lower cost compared to the open approach. Quality improvement initiatives in DP should ensure that lack of training and technical skill are not barriers to MIDP.

The Impact of Hospital Neoadjuvant Therapy Utilization on Survival Outcomes for Pancreatic Cancer.

BACKGROUND: Many surgeons advocate the use of neoadjuvant treatment for resectable pancreatic cancer, however little is known about variation in the utilization of neoadjuvant therapy (NAT) at the hospital level. METHODS: The National Cancer Data Base was used to identify patients undergoing resection for pancreatic cancer between 2006 and 2014 at high-volume centers. Hospitals were grouped by NAT utilization using standard deviations (SD) from the mean as follows: high neoadjuvant utilizers (> 2 SDs above the mean, > 40% of patients receiving NAT); medium-high (1-2 SDs, 27-40%), medium (0-1 SD, 14-26%); or low (- 1.1 to 0 SDs, < 14%). Overall survival (OS) was compared across NAT utilization groups. RESULTS: Among 107 high-volume centers, 20,119 patients underwent resection. The proportion of patients receiving NAT varied widely among hospitals, ranging from 0 to 74%, with only five centers using NAT in > 40% of patients. These five hospitals had the longest median OS at 28.9 months, compared with 21.1 months for low neoadjuvant utilizers (p < 0.001). On multivariable analysis, high and medium-high NAT utilization predicted improved OS, with a hazard ratio (HR) of 0.68 (95% confidence interval [CI] 0.56-0.83, p < 0.001) and 0.80 (95% CI 0.68-0.95, p = 0.010), respectively, compared with low utilizers. After excluding patients who underwent NAT, there remained an association of improved OS with high NAT utilization (HR 0.74, 95% CI 0.60-0.93, p = 0.009). CONCLUSION: High-volume hospitals that more commonly utilize NAT demonstrated longer survival for all patients treated at those centers. In addition to altering patient selection for surgery, high neoadjuvant utilization may be a marker of institutional factors that contribute to improved outcomes.

Personalized therapy in hepatocellular carcinoma: Molecular markers of prognosis and therapeutic response.

Hepatocellular carcinoma (HCC) represents a growing worldwide health crisis with rising incidence, limited effective therapies and persistently poor prognosis. Five-year survival remains less than 20% despite decades of research. One byproduct of research efforts is the identification of numerous biomarkers of disease. From prognosis to therapeutic response, biomarker identification parallels a deeper molecular understanding of the disease that to date has generated limited gain in clinical outcomes. As one example, the classical prognostic biomarkers of tumor Ki-67 protein expression and TP53 gene mutation have been repeatedly demonstrated to correlate with poor prognosis. There have been several studies throughout the past two decades identifying other gene-based biomarkers of prognosis. Critically, translation into the clinic has been slow and focus has shifted to a search for markers of therapeutic response in hopes of generating novel approaches to the disease. With this focus, many of the correlates are based on retrospective review of sorafenib effectiveness. Sorafenib, an oral targeted multi-kinase inhibitor, is currently the standard of care systemic agent for non-resectable disease. The Wnt-pathway, particularly when activated, is the most commonly cited molecular marker of sorafenib responsiveness. Additional work has identified a profile of genes involved in drug absorption, processing, and elimination that also appears to increase responsiveness. Overall, despite promising clinical data the use of biomarkers in the clinic for HCC is limited. In this piece, progress and opportunities for future work "beyond the genome" are highlighted, including metabolomic, epigenetic, and non-coding RNA studies. Additionally, barriers to the implementation of personalized therapeutic selection in HCC are reviewed.

Epigenetic therapy and chemosensitization in solid malignancy.

Epigenetic modifications result in dynamic shifts between transcriptionally active and suppressed states. The potentially reversible nature of epigenetic changes underlies the concept of epigenetic therapy, which serves to reprogram cancer cells as opposed to inducing cytotoxicity that occurs with standard chemotherapeutics. There are numerous enzymes involved in epigenetic changes and each can be potentially targetable. Although many investigations have evaluated the clinical potential of the various epigenetic therapies, currently only histone deacetylase inhibitors and DNA methyltransferase inhibitors are approved for use in specific hematologic malignancies. Use of epigenetic therapy coincident with cytotoxic or targeted systemic therapy appears to derive a benefit due to chemosensitization. Trials demonstrating efficacy from combination therapy have been performed in various diseases such as NSCLC, ovarian cancer and breast cancer. Furthermore, there are patient subsets in certain solid tumors in which epigenetic therapy provide durable response, such as patients with NSCLC and specific hypermethylation patterns. The encouraging results from combination therapy identified in these trials built upon prior investigations and have provided a foundation for ensuing trials seeking to evaluate epigenetic therapy.