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BACKGROUND: The role of postoperative chemotherapy in patients with resected pancreatic cancer who receive neoadjuvant treatment is unknown. Clinicians use changes in CA19-9 and histopathologic scores to assess treatment response. We sought to investigate if CA19-9 normalization in response to NAT can help guide the need for postoperative treatment. METHODS: Patients with elevated baseline CA19-9 (CA19-9 > 37U/mL) who received NAT followed by surgery between 2011 and 2019 were retrospectively reviewed. Treatment response was determined by CA19-9 normalization following NAT and histopathologic scoring. The role of postoperative chemotherapy was analyzed in light of CA19-9 normalization and histopathologic response. RESULTS: We identified and included 345 patients. Following NAT, CA19-9 normalization was observed in 125 patients (36.2%). CA19-9 normalization was associated with a favorable histopathologic response (41.6% vs 23.2%, p < 0.001) and a lower ypT (p < 0.001) and ypN stage (p = 0.003). Receipt of adjuvant chemotherapy was associated with improved overall survival in patients in whom CA19-9 did not normalize following NAT (26.8 vs 16.4 months, p = 0.008). In patients who received 5FU-based NAT and in whom CA19-9 did not normalize, receipt of 5FU-based adjuvant chemotherapy was associated with improved OS (p = 0.014). CONCLUSION: CA19-9 normalization in response to NAT was associated with favorable outcomes and can serve as a biomarker for treatment response. In patients where CA19-9 did not normalize, receipt of postoperative chemotherapy was associated with improved OS. These patients also benefited from additional 5FU-based postoperative chemotherapy following 5FU-based NAT.

IMPORTANCE: The use of neoadjuvant therapy (NAT) in resectable pancreatic ductal adenocarcinoma (PDAC) remains controversial. A favorable pathologic response (complete or marked tumor regression) to NAT is associated with better outcomes in patients with resected PDAC. The role of NAT for early systemic control compared with immediate surgical resection for PDAC is under investigation. In the era of precision medicine, biomarkers for patient selection and prediction of therapy response are crucial. OBJECTIVE: To evaluate the use of assessment for protein expression on fine-needle aspiration (FNA) biopsy specimens in predicting pathologic response to NAT in treatment-naive patients. DESIGN, SETTING, AND PARTICIPANTS: This was a single-institution prognostic study from a high-volume center for pancreatic cancer. All specimens were obtained between January 1, 2009, and December 31, 2018, with a median (SE) follow-up of 20.2 (1.4) months. Analysis of the data was performed from October 1, 2019, to April 30, 2021. Targeted RNA sequencing of frozen FNA biopsy specimens from a discovery cohort of 23 patients was performed to identify genes with aberrant expression that was associated with patients’ pathologic response to NAT. Immunohistochemical staining was performed on an additional 80 FNA biopsy specimens to assess expression of matrix metalloproteinase 7 (MMP-7) and its association with pathologic response. Receiver operating characteristic curves for prediction of favorable pathologic response were determined. RESULTS: In the discovery cohort (12 [52.1%] male; 3 [13.0%] Black and 20 [86.9%] White), RNA sequencing showed that lower MMP-7 expression was associated with favorable pathologic response (College of American Pathologists system scores of 0 [complete response] and 1 [marked response]). In the validation cohort (40 [50.0%] female; 9 [11.3%] Black and 71 [88.7%] White), patients with negative MMP-7 expression were significantly more likely to have a favorable pathologic response (odds ratio, 21.25; 95% CI, 6.19-72.95; P = .001). Receiver operating characteristic curves for prediction of favorable pathologic response from multivariable Cox proportional hazards regression modeling showed that MMP-7 expression increased the area under the curve from 0.726 to 0.906 (P

BACKGROUND: Main-duct (MD) intraductal papillary mucinous neoplasm (IPMN) is associated with malignancy risk. There is a lack of consensus on treatment (partial or total pancreatectomy) when the MD is diffusely involved. We sought to characterize the pancreatic remnant fate after partial pancreatectomy for non-invasive diffuse MD-IPMN. METHODS: Consecutive patients with partial pancreatectomy for non-invasive MD-IPMN from 2004 to 2016 were analyzed. Diffuse MD-IPMN was defined by preoperative imaging as dilation of the MD in the head of the pancreas more than 5mm and involving the whole gland. RESULTS: Of 127 patients with resected non-invasive MD-IPMN, 47 (37%) had diffuse MD involvement. Eleven of 47(23%) patients developed imaging evidence of progression or new cystic disease in the pancreatic remnant. Patients with diffuse MD-IPMN were older (73yrs vs 67yrs, p=0.009), more likely to receive a pancreaticoduodenectomy (96% vs 56%, p

Purpose:Patient-derived organoids (PDO) are a promising technology to support precision medicine initiatives for patients with pancreatic ductal adenocarcinoma (PDAC). PDOs may improve clinical next-generation sequencing (NGS) and enable rapid ex vivo chemotherapeutic screening (pharmacotyping).Experimental Design:PDOs were derived from tissues obtained during surgical resection and endoscopic biopsies and studied with NGS and pharmacotyping. PDO-specific pharmacotype is assessed prospectively as a predictive biomarker of clinical therapeutic response by leveraging data from a randomized controlled clinical trial.Results:Clinical sequencing pipelines often fail to detect PDAC-associated somatic mutations in surgical specimens that demonstrate a good pathologic response to previously administered chemotherapy. Sequencing the PDOs derived from these surgical specimens, after biomass expansion, improves the detection of somatic mutations and enables quantification of copy number variants. The detection of clinically relevant mutations and structural variants is improved following PDO biomass expansion. On clinical trial, PDOs were derived from biopsies of treatment-naïve patients prior to treatment with FOLFIRINOX (FFX). Ex vivo PDO pharmacotyping with FFX components predicted clinical therapeutic response in these patients with borderline resectable or locally advanced PDAC treated in a neoadjuvant or induction paradigm. PDO pharmacotypes suggesting sensitivity to FFX components were associated with longitudinal declines of tumor marker, carbohydrate-antigen 19–9 (CA-19–9), and favorable RECIST imaging response.Conclusions:PDOs established from tissues obtained from patients previously receiving cytotoxic chemotherapies can be accomplished in a clinically certified laboratory. Sequencing PDOs following biomass expansion improves clinical sequencing quality. High in vitro sensitivity to standard-of-care chemotherapeutics predicts good clinical response to systemic chemotherapy in PDAC.See related commentary by Zhang et al., p. 3176

Supplementary Figure from Precision Medicine in Pancreatic Cancer: Patient-Derived Organoid Pharmacotyping Is a Predictive Biomarker of Clinical Treatment Response

Supplementary Table from Precision Medicine in Pancreatic Cancer: Patient-Derived Organoid Pharmacotyping Is a Predictive Biomarker of Clinical Treatment Response

Supplementary Data from Precision Medicine in Pancreatic Cancer: Patient-Derived Organoid Pharmacotyping Is a Predictive Biomarker of Clinical Treatment Response

This document provides detailed captions for figures S1-S8.

This file contains Figures S1-S8. Figure S1 shows examples of representative images used to score p120 catenin expression in human TMAs and pancreatic histology of mice with loss of p120 catenin. Figure S2 depicts recruitment of inflammation and a unique stromal composition in KCiMist1; p120f/wt and KCiMist1; p120f/f pancreata. Figure S3 shows that prominent basal epithelial cell extrusion in pancreata of KCiMist1; p120f/f mice is not associated with incomplete EMT. Figure S4 shows that pancreatic loss of p120 catenin in a mouse model of acute pancreatitis delays regeneration and results in significant recruitment of inflammation, observations which are mediated at least in part through activation of NF-kB. Figure S5 illustrates that a subset of epithelial cells extruding apically in KCiMist1; p120wt/wt, KCiMist1; p120f/wt, and KCiMist1; p120f/f pancreata express cleaved Caspase-3, while epithelial cells extruding basally do not express cleaved Caspase-3. Figure S6 depicts an analysis of chromosome content using Feulgen stain, which showed abnormal DNA content and aneuploidy in a subset of basally extruded epithelial cells in KCiMist1; p120f/f pancreata. Figure S7 shows mislocalized p120 catenin expression in greater than 95% isolated epithelial cells in human PDA. Figure S8 illustrates IPA results of microarray performed on GFP+ pancreatic cells of KCiMist1G; p120wt/wt and KCiMist1G; p120f/f mice as well as IHC of select targets identified from IPA results.

This table provides a description of antibodies used in this study.

Aberrant regulation of cellular extrusion can promote invasion and metastasis. Here, we identify molecular requirements for early cellular invasion using a premalignant mouse model of pancreatic cancer with conditional knockout of p120 catenin (Ctnnd1). Mice with biallelic loss of p120 catenin progressively develop high-grade pancreatic intraepithelial neoplasia (PanIN) lesions and neoplasia accompanied by prominent acute and chronic inflammatory processes, which is mediated, in part, through NF-κB signaling. Loss of p120 catenin in the context of oncogenic Kras also promotes remarkable apical and basal epithelial cell extrusion. Abundant single epithelial cells exit PanIN epithelium basally, retain epithelial morphology, survive, and display features of malignancy. Similar extrusion defects are observed following p120 catenin knockdown in vitro, and these effects are completely abrogated by the activation of S1P/S1pr2 signaling. In the context of oncogenic Kras, p120 catenin loss significantly reduces expression of genes mediating S1P/S1pr2 signaling in vivo and in vitro, and this effect is mediated at least, in part, through activation of NF-κB. These results provide insight into mechanisms controlling early events in the metastatic process and suggest that p120 catenin and S1P/S1pr2 signaling enhance cancer progression by regulating epithelial cell invasion. Cancer Res; 76(11); 3351–63. ©2016 AACR.

Purpose: Patient-derived organoids (PDO) are a promising technology to support precision medicine initiatives for patients with pancreatic ductal adenocarcinoma (PDAC). PDOs may improve clinical next-generation sequencing (NGS) and enable rapid ex vivo chemotherapeutic screening (pharmacotyping). Experimental Design: PDOs were derived from tissues obtained during surgical resection and endoscopic biopsies and studied with NGS and pharmacotyping. PDO-specific pharmacotype is assessed prospectively as a predictive biomarker of clinical therapeutic response by leveraging data from a randomized controlled clinical trial. Results: Clinical sequencing pipelines often fail to detect PDAC-associated somatic mutations in surgical specimens that demonstrate a good pathologic response to previously administered chemotherapy. Sequencing the PDOs derived from these surgical specimens, after biomass expansion, improves the detection of somatic mutations and enables quantification of copy number variants. The detection of clinically relevant mutations and structural variants is improved following PDO biomass expansion. On clinical trial, PDOs were derived from biopsies of treatment-naïve patients prior to treatment with FOLFIRINOX (FFX). Ex vivo PDO pharmacotyping with FFX components predicted clinical therapeutic response in these patients with borderline resectable or locally advanced PDAC treated in a neoadjuvant or induction paradigm. PDO pharmacotypes suggesting sensitivity to FFX components were associated with longitudinal declines of tumor marker, carbohydrate-antigen 19–9 (CA-19–9), and favorable RECIST imaging response. Conclusions: PDOs established from tissues obtained from patients previously receiving cytotoxic chemotherapies can be accomplished in a clinically certified laboratory. Sequencing PDOs following biomass expansion improves clinical sequencing quality. High in vitro sensitivity to standard-of-care chemotherapeutics predicts good clinical response to systemic chemotherapy in PDAC. See related commentary by Zhang et al., p. 3176

Background Lymph node (LN) metastasis is associated with decreased survival following resection for pancreatic ductal adenocarcinoma (PDAC). In N0 disease, increasing total evaluated LN (ELN) correlates with improved outcomes suggesting patients may be understaged when LNs are undersampled. We aim to assess the optimal number of examined lymph nodes (ELN) following pancreatectomy. Methods Data from 1837 patients undergoing surgery were prospectively collected. The binomial probability law was utilized to analyze the minimum number of examined LNs (minELN) and accurately characterize each histopathologic stage. LN ratio (LNR) was compared to American Joint Committee on Cancer (AJCC) guidelines. Results As ELN total increased, the likelihood of finding node positive disease increased. An evaluation based upon the binomial probability law suggested an optimal minELN of 12 for accurate AJCC N staging. As the number of ELNs increased, the discriminatory capacity of alternative strategies to characterize LN disease exceeded that offered by AJCC N stage. Conclusion This is the first study dedicated to optimizing histopathologic staging in PDAC using models of minELN informed by the binomial probability law. This study highlights two separate cutoffs for ELNs depending upon prognostic goal and validates that 12 LNs are adequate to determine AJCC N stage for the majority of patients.

The aim of this study was to determine the incidence of high-grade dysplasia (HGD) or invasive carcinoma in patients with small branch duct intraductal papillary mucinous neoplasms (BD-IPMNs).923 patients who underwent surgical resection for an IPMN were identified. Sendai-negative patients were identified as those without history of pancreatitis or jaundice, main pancreatic duct size (MPD)5 mm, cyst size3 cm, no mural nodules, negative cyst fluid cytology for adenocarcinoma, or serum carbohydrate antigen 19-9 (CA 19-9)37 U/L.BD-IPMN was identified in 388 (46.4%) patients and 89 (22.9%) were categorized as Sendai-negative. Overall, 68 (17.5%) of BD-IPMN had HGD and 62 (16.0%) had an associated invasive-carcinoma. Among the 89 Sendai-negative patients, 12 (13.5%) had IPMNs with HGD and only one patient (1.1%) had invasive-carcinoma. Of note, older age (OR 1.13, 95% CI 1.03-1.23; P = 0.008) and minimal dilation of MPD (OR 11.3, 95% CI 2.40-53.65; P = 0.002) were associated with high-risk disease in Sendai-negative patients after multivariable risk adjustment.The risk of harboring a high-risk disease remains low in small BD-IPMNs. However, Sendai-negative patients who are older than 65 years old and those with minimal dilation of MPD (3-5 mm) are at greater risk of high-risk lesions and should be given consideration to be included as a "worrisome feature" in a future guidelines update.

BACKGROUND AND OBJECTIVES: Tumor location (peritoneal vs hepatic) has been incorporated in the 8th edition of the American Joint Committee on Cancer Staging system for gallbladder cancer. However, larger studies are needed to confirm the prognostic impact of tumor location. METHODS: Patients with pathologically-confirmed gallbladder cancer with information on primary tumor location were included from the National Cancer Database (2009–2012). We compared patients with hepatic-side tumors to those on the peritoneal side. Survival data were plotted using the Kaplan-Meier method. Prognostic factors were modeled with a multivariate Cox Proportional Hazards Model. Primary outcome was overall survival (OS). RESULTS: A total of 1251 patients were included. In comparison to patients with peritoneal-sided tumors, patients with hepatic-sided tumors were more likely to: be of higher pT stage (pT3: 49% vs 24%; P < .001); node positive (31% vs 24%; P = .016); undergo liver resection (53% vs 25%; P < .001); or have positive margins (29% vs 16%; P < .001). However, on multivariate analysis, there was no difference in OS between the groups (HR, 0.97; 95% CI, 0.79–1.18; P = .753). Liver resection was associated with improved survival regardless of tumor location in pT2 tumors (peritoneal: HR, 0.57; P = .034; hepatic: HR, 0.67; P < .001). CONCLUSIONS: This study failed to demonstrate the independent prognostic value of primary tumor location in patients with gallbladder cancer.

Pancreatic ductal adenocarcinoma (PDAC) is increasing in incidence and is projected to become the second leading cause of cancer death in the United States. Despite significant advances in understanding the disease, there has been minimal increase in PDAC patient survival. PDAC tumors are unique in the fact that there is significant desmoplasia. This generates a large stromal compartment composed of immune cells, inflammatory cells, growth factors, extracellular matrix, and fibroblasts, comprising the tumor microenvironment (TME), which may represent anywhere from 15% to 85% of the tumor. It has become evident that the TME, including both the stroma and extracellular component, plays an important role in tumor progression and chemoresistance of PDAC. This review will discuss the multiple components of the TME, their specific impact on tumorigenesis, and the multiple therapeutic targets.

Computed tomography (CT) image-guided procedures including biopsy, drug delivery, and ablation are gaining increasing application in medicine. Robotic technology holds the promise for allowing surgeons, and other proceduralists, access to such CT guided procedures by potentially shortening training, improving accuracy, decreasing needle passes, and reducing radiation exposure. We evaluated surgeon learning and proficiency for image-guided needle placement with an FDA-cleared robotic arm. Five out of six surgeons had no prior CT guided procedural experience, while one had prior experience with freehand CT guided needle placement. All surgeons underwent a 60-minute training with the MAXIO robot (Perfint Healthcare, Redmond, WA). The robot was used to place needles into three different pre-specified targets on a spine model. Performance time, procedural errors, and needle placement accuracy were recorded. All participants successfully placed needles into the targets using the robotic arm. The average time for needle placement was 3:44 ± 1:43 minutes. Time for needle placement decreased with subsequent attempts, with average third placement taking 2:29 ± 1:51 minutes less than the first attempt. The average vector distance from the target was 2.3 ± 1.2 mm. One error resulted in the need for reimaging by CT scan. No errant needle placement occurred. Surgeons (attending fellows and residents) without previous experience and minimal training could successfully place percutaneous needles under CT guidance quickly, accurately, and reproducibly using a robotic arm. This suggests that robotic technology may be used to facilitate surgeon adoption of CT image-guided needle-based procedures in the future.

Colorectal cancer is the third most common cancer diagnosis in the world, and the second most common cause of cancer-related deaths. Despite significant progress in management strategies for colorectal cancer over the last several decades, metastatic disease remains difficult to treat and is often considered incurable. However, for patients with colorectal liver metastases (CRLM), surgical resection offers the best opportunity for survival, can be curative, and remains the gold standard. Unfortunately, surgical treatment options are underutilized. Misperceptions regarding resectable and unresectable CRLM likely play a role in this. The assessment of factors that impact resectability status like medical fitness, technical considerations, and disease biology can be difficult, necessitating careful multidisciplinary input and discussion. The identification of ideal operative time windows that align with the multimodal management of these patients can also be perplexing. For all patients with CRLM it may therefore be advantageous to obtain surgical evaluation at the time of discovering liver metastases to mitigate these challenges and minimize the risk of undertreatment. In this review we summarize current surgical management strategies for CRLM and discuss factors to be considered when determining resectability.

BACKGROUND: Food deserts are neighborhoods with low access to healthy foods and are associated with poor health metrics. We investigated association of food desert residence and cancer outcomes. METHODS: In this population-based study, data from the 2000–2012 California Cancer Registry was used to identify patients with stage II/III breast or colorectal cancer. Patient residence at time of diagnosis was linked by census tract to food desert using the USDA Food Access Research Atlas. Treatment and outcomes were compared by food desert residential status. RESULTS: Among 64,987 female breast cancer patients identified, 66.8% were

Nerves are a notable feature of the tumor microenvironment in some epithelial tumors, but their role in the malignant progression of pancreatic ductal adenocarcinoma (PDAC) is uncertain. Here, we identify dense innervation in the microenvironment of precancerous pancreatic lesions, known as pancreatic intraepithelial neoplasms (PanIN), and describe a unique subpopulation of neuroendocrine PanIN cells that express the neuropeptide substance P (SP) receptor neurokinin 1-R (NK1-R). Using organoid culture, we demonstrated that sensory neurons promoted the proliferation of PanIN organoids via SP-NK1-R signaling and STAT3 activation. Nerve-responsive neuroendocrine cells exerted trophic influences and potentiated global PanIN organoid growth. Sensory denervation of a genetically engineered mouse model of PDAC led to loss of STAT3 activation, a decrease in the neoplastic neuroendocrine cell population, and impaired PanIN progression to tumor. Overall, our data provide evidence that nerves of the PanIN microenvironment promote oncogenesis, likely via direct signaling to neoplastic neuroendocrine cells capable of trophic influences. These findings identify neuroepithelial cross-talk as a potential novel target in PDAC treatment. Cancer Res; 77(8); 1868–79. ©2017 AACR.

Older adults undergoing cancer surgery are at greater risk for poor postoperative outcomes. Caregivers also endure significant burden. Participation in perioperative physical activity may improve physical functioning and enhance overall well-being for both patients and caregivers. In this study, we assessed the feasibility of a personalized telehealth intervention to enhance physical activity for older (≥ 65 years) gastrointestinal (GI) and lung cancer surgery patients/caregivers. Participants completed four telehealth sessions with physical therapy/occupational therapy (PT/OT) before surgery and up to 2 weeks post-discharge. Outcomes included preop geriatric assessment, functional measures, and validated measures for symptoms and psychological distress. Pre/post-intervention trends/trajectories for outcomes were explored. Thirty-four patient/caregiver dyads (16, GI; 18, lung) were included. Accrual rate was 76% over 8 months; retention rate was 88% over 2 months. Median for postop of a 6-min walk test, timed up and go, and short physical performance battery test scores improved from baseline to postop. Participant satisfaction scores were high. Our conceptually based, personalized, multimodal, telehealth perioperative physical activity intervention for older patient/caregiver dyads is feasible and acceptable. It offers an opportunity to improve postoperative outcomes by promoting functional recovery through telehealth, behavior change, and self-monitoring approaches. ClinicalTrials.gov Identifier: NCT03267524

BACKGROUND. No guidelines exist for surveillance following cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) for appendiceal and colorectal cancer. The primary objective was to define the optimal surveillance frequency after CRS/HIPEC. METHODS. The U.S. HIPEC Collaborative database (2000–2017) was reviewed for patients who underwent a CCR0/1 CRS/HIPEC for appendiceal or colorectal cancer. Radiologic surveillance frequency was divided into two categories: low-frequency surveillance (LFS) at q6–12mos or high-frequency surveillance (HFS) at q2–4mos. Primary outcome was overall survival (OS). RESULTS. Among 975 patients, the median age was 55 year, 41% were male: 31% had non-invasive appendiceal (n = 301), 45% invasive appendiceal (n = 435), and 24% colorectal cancer (CRC; n = 239). With a median follow-up time of 25 mos, the median time to recurrence was 12 mos. Despite less surveillance, LFS patients had no decrease in median OS (non-invasive appendiceal: 106 vs. 65 mos, p < 0.01; invasive appendiceal: 120 vs. 73 mos, p = 0.02; colorectal cancer [CRC]: 35 vs. 30 mos, p = 0.8). LFS patients had lower median PCI scores compared with HFS (non-invasive appendiceal: 10 vs. 19; invasive appendiceal: 10 vs. 14; CRC: 8 vs. 11; all p < 0.01). However, on multivariable analysis, accounting for PCI score, LFS was still not associated with decreased OS for any histologic type (non-invasive appendiceal: hazard ratio [HR]: 0.28, p = 0.1; invasive appendiceal: HR: 0.73, p = 0.42; CRC: HR: 1.14, p = 0.59). When estimating annual incident cases of CRS/HIPEC at 375 for noninvasive appendiceal, 375 invasive appendiceal and 4410 colorectal, LFS compared with HFS for the initial two postoperative years would potentially save $13–19 M/year to the U.S. healthcare system. CONCLUSIONS. Low-frequency surveillance after CRS/HIPEC for appendiceal or colorectal cancer is not associated with decreased survival, and when considering decreased costs, may optimize resource utilization.

Aberrant regulation of cellular extrusion can promote invasion and metastasis. Here, we identify molecular requirements for early cellular invasion using a premalignant mouse model of pancreatic cancer with conditional knockout of p120 catenin (Ctnnd1). Mice with biallelic loss of p120 catenin progressively develop high-grade pancreatic intraepithelial neoplasia (PanIN) lesions and neoplasia accompanied by prominent acute and chronic inflammatory processes, which is mediated, in part, through NF-κB signaling. Loss of p120 catenin in the context of oncogenic Kras also promotes remarkable apical and basal epithelial cell extrusion. Abundant single epithelial cells exit PanIN epithelium basally, retain epithelial morphology, survive, and display features of malignancy. Similar extrusion defects are observed following p120 catenin knockdown in vitro, and these effects are completely abrogated by the activation of S1P/S1pr2 signaling. In the context of oncogenic Kras, p120 catenin loss significantly reduces expression of genes mediating S1P/S1pr2 signaling in vivo and in vitro, and this effect is mediated at least, in part, through activation of NF-κB. These results provide insight into mechanisms controlling early events in the metastatic process and suggest that p120 catenin and S1P/S1pr2 signaling enhance cancer progression by regulating epithelial cell invasion. Cancer Res; 76(11); 3351–63. ©2016 AACR.

Pancreatic cancer is one of the most lethal malignancies, with virtually all patients eventually succumbing to their disease. Mutations in p53 have been documented in >50% of pancreatic cancers. Owing to the high incidence of p53 mutations in PanIN 3 lesions and pancreatic tumors, we interrogated the comparative ability of adult pancreatic acinar and ductal cells to respond to oncogenic Kras and mutant Tp53(R172H) using Hnf1b:CreER(T2) and Mist1:CreER(T2) mice. These studies involved co-activation of a membrane-tethered GFP lineage label, allowing for direct visualization and isolation of cells undergoing Kras and mutant p53 activation. Kras activation in Mist1(+) adult acinar cells resulted in brisk PanIN formation, whereas no evidence of pancreatic neoplasia was observed for up to 6 months following Kras activation in Hnf1beta(+) adult ductal cells. In contrast to the lack of response to oncogenic Kras alone, simultaneous activation of Kras and mutant p53 in adult ductal epithelium generated invasive PDAC in 75% of mice as early as 2.5 months after tamoxifen administration. These data demonstrate that pancreatic ductal cells, whereas exhibiting relative resistance to oncogenic Kras alone, can serve as an effective cell of origin for pancreatic ductal adenocarcinoma in the setting of gain-of-function mutations in p53.

Minimally invasive hepatobiliary surgery began in 1987 with the first laparoscopic cholecystectomy (1,2). Over the next two decades, the use of laparoscopy in liver resection was reported on by multiple groups (3-5). However, it was not until 2008, when the first consensus guidelines for laparoscopic liver surgery were published, that these new minimally invasive techniques were standardized (6). Despite advances in instrumentation including laparoscopic staplers and energy devices, laparoscopic liver resections were still limited by the rigid instruments and 2D vision. While the laparoscopic techniques were maturing, the first robotic cholecystectomies were performed by Himpens (7) and Gagner (8) in the early 1990s. This was followed by the release of the da Vinci robotic surgical system in Europe in 1999 and its approval by the Food and Drug Administration (FDA) in the United States in 2000.

Colorectal cancer affects over one million people worldwide annually, with the liver being the most common site of metastatic spread. Adequate resection of hepatic metastases is the only chance for a cure in a subset of patients, and five-year survival increases to 35% with complete resection. Traditionally, computed tomographic imaging (CT) was utilized for staging and to evaluate metastases in the liver. Recently, the introduction of hepatobiliary contrast-enhanced magnetic resonance imaging (MRI) agents including gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Eovist in the United States, Primovist in Europe, or Gd-EOB-DTPA) has proved to be a sensitive method for detection of hepatic metastases. Accurate detection of liver metastases is critical for staging of colorectal cancer as well as preoperative planning.

Fibrolamellar carcinoma (FLC) is a variant of hepatocellular carcinoma (HCC), which comprises ∼1%-9% of all HCCs. Although FLC is a variant of HCC, it is distinct from HCC in that it most often affects younger patients (10-35 years of age) with no underlying liver disease. FLC often presents with vague abdominal pain, nausea, abdominal fullness, malaise, and weight loss. Surgery is the current mainstay of treatment for FLC and remains the only potentially curative option. While FLCs are considered less responsive to chemotherapy than their classic HCC counterparts, there have been suggestions that multimodality treatments may be effective, especially in advanced cases. Further research is necessary to determine effective systemic therapies as an adjunct to surgery for FLC.

Post-hepatectomy liver failure (PHLF) is a major source of morbidity and mortality in patients undergoing liver resection. The aim of this review is to summarize the recent literature available on PHLF including its definition, predictive factors, preoperative risk assessment, severity grading, preventative measures, and management strategies. A systematic literature search was carried out with the search engines PubMed, Medline, and Cochrane Database using the keywords related to “liver failure”, “posthepatectomy”, and “hepatic resection”. Liver resection is a curative treatment of liver tumors. However, it leads to concurrent death and regeneration of the remaining hepatocytes. Factors related to the patient, liver parenchyma and the extent of surgery can inhibit regeneration leading to PHLF. Given its resistance to treatment and the high postoperative mortality associated with PHLF, great effort has been put in to both accurately identify patients at high risk and to develop strategies that can help prevent its occurrence.

Background: The “cell of origin” for pancreatic “ductal” neoplasia remains uncertain. Selective activation of Kras in the acinar cell compartment robustly generates mPanIN lesions, while similar activation in pancreatic ductal epithelial cells produces minimal change. These differences are notable considering in human tumorigenesis, mutational oncogene activation is postulated to occur in either single cells or small numbers of cells, followed by clonal expansion and tumor initiation. We have interrogated the comparative ability of adult pancreatic acinar and duct cells to respond to oncogenic Kras using Hnf1b:CreERT2 and Mist1:CreERT2 mice, and applied comprehensive bioinformatics analysis to identify mechanisms of duct cell-specific Kras resistance. Hypothesis and Methods: We hypothesized that duct cell-specific changes in gene expression would mediate the relative resistance of ductal epithelial cells to Kras-mediated transformation. To identify these changes, we studied the initiation and progression of pancreatic cancer with unprecedented temporal and spatial resolution. Our approach allows for the direct visualization and FACS-based isolation of specific cell populations in which oncogenic Kras has been activated. We have activated KrasG12D and a membrane-tethered GFP in a number of adult pancreatic cell types including the acinar, ductal and centroacinar cells. Using FACS-based isolation and visualization, we have generated whole transcriptome signatures of how the different cell types respond to Kras over time. Our comprehensive bioinformatic approach involves the identification of genes that are increased or decreased at different time points after the induction of oncogenic Kras expression. Results: Kras activation in the adult acinar cells resulted in brisk PanIN formation, while no evidence of pancreatic neoplasia was observed for up to 6 months following isolated Kras activation in Hnf1b+ duct cells. By comparing gene expression changes occurring following Kras activation in acinar vs. duct cells, we identified a panel of candidate duct cell-specific Kras resistance genes. These included Bcl-2, p21, Stk3, Plkha1, Slc9a9 and Pdcd10. Identification of upregulated Bcl-2 and p21 expression following Kras activation in duct cells, but not acinar cells, suggested involvement of the p53 pathway as a cell type-specific suppressor of pancreatic neoplasia. We recently published that biallelic expression of mutant p53R172H in cooperation with KrasG12D led to the development of pancreatic cancer from ductal cells. We are now investigating both autocrine and paracrine signaling mechanisms of mutant p53 oncogenic transformation in human derived ductal epithelial cells. This abstract is also being presented as Poster A17 Citation Format: Kishore Polireddy, Audrey Hendley, Melissa A. Pruski, Kelly Lafaro, Mamoun Younes, Anirban Maitra, Florencia McAllister, Christine A. Iacobuzio-Donahue, Wasim A. Dar, John S. Bynon, Steven D. Leach, Jennifer M. Bailey.{Authors}. Mutant p53 promotes adenocarcinoma in pancreatic ductal cells. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr PR03.

In human tumorigenesis, mutational oncogene activation is postulated to occur in either single cells or small numbers of cells, followed by clonal expansion and tumor initiation. In the field of pancreatic cancer research, transgenic animal models mimicking the human disease have contributed to major advancements in our understanding of pancreatic cancer biology. These models have allowed the effects of oncogenic Kras (KrasG12D) activation to be evaluated in different pancreatic compartments using Cre/Lox technology. When oncogenic Kras is expressed under the control of endogenous Kras regulatory elements and selectively activated in embryonic pancreatic epithelium using either Pdx-1:Cre, Ptf1a:Cre or Nestin:Cre driver lines, the KrasG12D allele induces murine pancreatic intraepithelial neoplastic lesions (mPanIN) at as early as two weeks of age. In adult pancreas, selective activation of oncogenic Kras in the acinar cell compartment using either tamoxifen-regulated Elastase (Ela):CreERT2, Mist1:CreERT2 or Ptf1:CreER driver lines also leads to effective mPanIN formation, supporting the possibility that adult acinar cells may serve as the cell type of origin for “ductal” neoplasia. In comparison, activation of oncogenic Kras in Sox9-expressing ductal epithelium leads to only low frequency mPanIN formation (Kopp et al, 2012), indicating that Sox9-expressing duct cells may be more resistant to transformation by oncogenic Kras. We have thoroughly interrogated the ability of the pancreatic ductal epithelium to respond to oncogenic Kras using the HNF1β:CreERT2 transgenic mouse. Our unpublished data support the findings of Kopp et al., as activation of Kras fails to induce mPanIN up to six months after the induction of recombination. Furthermore, combined KrasG12D activation and loss of the potent tumor suppressor p53 also fails to induce mPanIN formation from the HNF1β ductal compartment. In order to better understand the differential responsiveness of adult acinar and ductal cells to oncogenic Kras, we have FACS sorted acinar cells from PanIN-forming Mist1:CreERT2;LsL-Kras;mTmG mice and duct cells from non-PanIN forming HNF1β:CreERT2;LsL-Kras;mTmG mice at 0, 1 and 3 weeks following tamoxifen administration, and prior to the onset of any morphologic change. Following FACS-based cell isolation, we have performed whole genome transcriptional profiling to identify candidate genes mediating differential responsiveness to oncogenic Kras. This approach has identified a panel of candidate genes mediating Kras resistance in ductal cells, and a corresponding panel of candidate genes mediating Kras sensitivity in acinar cells. Genes potentially mediating Kras resistance in the ductal compartment include Plkha1, Slc9a9 and Pdcd10, while the loss of Gmnn and Med6 in the acinar cells appears to be associated with cell type-specific sensitivity to oncogenic Kras. Functional interrogation of identified genes is currently underway. Citation Format: Jennifer M. Bailey, Janivette Alsina, Florencia McAllister, Audrey Hendley, Kelly Lafaro, Anzer Habibulla, Luigi Marchionni, Anirban Maitra, Steven Leach. In search of Kras resistance genes: Whole transcriptome analysis identifies critical pathways mediating resistance and sensitivity to oncogenic Kras. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr A10.

Pancreatic cancer is the fourth most common cause of cancer death in the United States. It remains a highly lethal malignancy despite surgical and chemotherapeutic advances. In spite of progress made delineating the mechanisms underlying pancreatic cancer, there has been little improvement in survival rates over the past fifty years. Copy number analysis of human invasive pancreatic ductal adenocarcinoma (PDAC) revealed massively rearranged cellular karyotypes as well as significant clonal complexity. Given the genetic complexity of already invasive PDAC, we believe it will be important to understand earlier events in pancreatic cancer, i.e. PanIN formation and progression. We hypothesized that stage-specific bottlenecks may lead to clonal selection during pancreatic intraepithelial neoplasia (PanIN) formation and progression. In order to test this hypothesis, we examined evolving clonal complexity during the progression of pancreatic intraepithelial neoplasia in the Mist1Tg/wt; LSL-KrasG12D (KCiMist1) mouse model of pancreatic cancer. Following KrasG12D activation in adult acinar cells, these mice develop acinar to ductal metaplasia (ADM) and preinvasive PanIN 1 - PanIN 3 lesions in a manner that faithfully recapitulates the human disease. Our strategy involves crossing MistTg/wt; LSL-KrasG12D to Brainbow2.1Tg/Tg “Confetti” mice, in which individual cells undergo stochastic recombination of the Confetti reporter to activate expression of either nuclear GFP, membrane-associated CFP, cytoplasmic RFP or cytoplasmic YFP. Following tamoxifen induction, mice were given cerulein injections to increase PanIN density, and sacrificed at four and nine weeks post-tamoxifen. Following additional immunofluorescent labeling with EpCAM to demarcate individual cells, confocal imaging was performed. Lesions were characterized by grade (ADM, early PanIN and late PanIN), and the number of clones, defined as adjacent cells sharing an identical fluorescent protein signature, was compared at 4 and 9 weeks. For AMDs, early PanIN and late PanIN, we observe both monoclonal and polyclonal lesions. Our analysis of evolving clonal complexity over time is ongoing, but preliminary data suggests a time-dependent decrease in clonal complexity. The average number of clones seen in individual ADM and late PanIN lesions decreased in the mice sacrificed at nine week post tamoxifen induction compared to those sacrificed at four weeks post tamoxifen induction (1.5 +/- 0.52 clones per lesion vs. 2.29 +/- 1.14 clones per lesion for ADM and 2.5 +/- 1.29 vs. 3.75 +/- 1.89 clones per lesion for late PanIN). In contrast, there was little difference in clonal complexity noted for early PanINs at 4 vs. 9 weeks (2.17 +/- 1.19 clones per lesion in the four week cohort vs. 2.42 +/- 1.24 clones per lesion in the nine week time point). These preliminary data suggest an overall trend towards decreased clonal complexity of PanIN lesions over time, suggesting significant selective pressure at even the earliest stages of pancreatic cancer. This abstract is also presented as Poster A62. Citation Format: Kelly J. Lafaro, Audrey Hendley, Jennifer Bailey, Steven Leach. Clonal composition and clonal selection during PanIN progression. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr PR04.

BACKGROUND: Reciprocal molecular signaling between pancreatic ductal adenocarcinoma (PDAC) and nerves may promote perineural invasion (PNI) and tumor growth. The identity and function of sensory neuropeptides in the tumor microenvironment are unknown. We hypothesized that sensory neurons play an important role in tumor progression and that substance P (SP) is a candidate neuropeptide for mediating this effect. AIMS:1) to characterize SP receptor (NK1R) expression in PanIN epithelium 2) to determine NK1R expression in human PDAC cell lines 3) to study effects of sensory denervation on pancreatic intraepithelial neoplasia (PanIN) initiation and progression in the KPC ( Pdx1-Cre; LSL-Kras; LSLTrp53) mouse model. METHODS: KPC mice were injected with the sensory neurotoxin resiniferatoxin (RTX; Sigma) or control solution on postnatal day 7. Pancreata from 8and 12-week-old mice were fixed and subject to HE Santa Cruz). Images were taken with a Nikon Camera or Zeiss LSM 510 Meta microscope. PanINs were graded as early (grade 1) or advanced (grades 2 and 3). PanIN burden was calculated by the percentage of total surface area occupied in 5 random views per HE p = 0.02). All analyzed human PDAC cell lines expressed the NK1R. In vivo studies revealed axons in close proximity to PanIN epithelium (Fig.1). RTX-treated mice had a 50% decrease in pancreatic sensory axonal density when compared to control mice at 8 and 12 weeks (p < 0.05). RTX-treated mice had a significant reduction in advanced PanINs compared to control mice at both 8 weeks (0.05% versus 0.9%; p < 0.05) and 12 weeks (0.3% versus 8%; p < 0.05). CONCLUSIONS: The NK1R is expressed in distinct cells within the PanIN epithelium and the percentage of NK1R+ cells increases with PanIN grade. Human PDAC cell lines express the NK1R. Sensory denervation is associated with a significant reduction in progression from early to advanced PanIN in the KPC model. Sensory nerves are likely an important part of the PanIN microenvironment and may affect tumorigenesis via the NK1R. This study provides new insight into the pathogenesis and potential therapeutic targets in PDAC.