National clinical and financial outcomes associated with acute kidney injury following esophagectomy for cancer.

BACKGROUND: Esophagectomy is a complex oncologic operation associated with high rates of postoperative complications. While respiratory and septic complications have been well-defined, the implications of acute kidney injury (AKI) remain unclear. Using a nationally representative database, we aimed to characterize the association of AKI with mortality, resource use, and 30-day readmission. METHODS: All adults undergoing elective esophagectomy with a diagnosis of esophageal or gastric cancer were identified in the 2010-2019 Nationwide Readmissions Database. Study cohorts were stratified based on presence of AKI. Multivariable regressions and Royston-Parmar survival analysis were used to evaluate the independent association between AKI and outcomes of interest. RESULTS: Of an estimated 40,438 patients, 3,210 (7.9%) developed AKI. Over the 10-year study period, the incidence of AKI increased from 6.4% to 9.7%. Prior radiation/chemotherapy and minimally invasive operations were associated with reduced odds of AKI, whereas public insurance coverage and concurrent infectious and respiratory complications had greater risk of AKI. After risk adjustment, AKI remained independently associated with greater odds of in-hospital mortality (AOR: 4.59, 95% CI: 3.62-5.83) and had significantly increased attributable costs ($112,000 vs $54,000) and length of stay (25.7 vs 13.3 days) compared to patients without AKI. Furthermore, AKI demonstrated significantly increased hazard of 30-day readmission (hazard ratio: 1.16, 95% CI: 1.01-1.32). CONCLUSIONS: AKI after esophagectomy is associated with greater risk of mortality, hospitalization costs, and 30-day readmission. Given the significant adverse consequences of AKI, careful perioperative management to mitigate this complication may improve quality of esophageal surgical care at the national level.

Association of neighborhood socioeconomic disadvantage with use of minimally invasive resection for non-small cell lung cancer.

OBJECTIVE: Minimally invasive resection for non-small cell lung cancer has been linked to decreased postoperative morbidity. This work sought to characterize factors associated with receiving minimally invasive surgery for surgically resectable non-small cell lung cancer. METHODS: All adults undergoing lobectomy/sublobar resection for stage I non-small cell lung cancer were identified using the 2010-2020 National Cancer Database. Those undergoing thoracoscopic/robotic procedures comprised the minimally invasive resection cohort (others: open). Hospitals were stratified by minimally invasive resection procedure volume, with the top quartile considered high minimally invasive resection volume centers. Multivariable models were constructed to assess the independent association between the patients, diseases, and hospital factors and the likelihood of receiving minimally invasive resection. RESULTS: Of 217,762 patients, 112,304 (52%) underwent minimally invasive resection. The proportion of minimally invasive resection procedures increased from 27% in 2010 to 72% in 2020 (P < .001). After adjustment, several factors were independently associated with decreased odds of receiving minimally invasive resection, including lower quartiles of median neighborhood income (51st-75th percentile adjusted odds ratio, 0.92, 95% CI, 0.89-0.94; 26th-50th percentile adjusted odds ratio, 0.86, CI, 0.83-0.89; 0-25th percentile adjusted odds ratio, 0.78, CI, 0.75-0.81; reference: 76th-100th percentile income) and care at community hospitals (adjusted odds ratio, 0.70, CI, 0.68-0.71; reference: academic centers). Among patients receiving care at high minimally invasive resection volume centers, lowest income remained linked with reduced likelihood of undergoing minimally invasive resection from 2010 to 2015 (adjusted odds ratio, 0.85, CI, 0.77-0.94), but did not alter the odds of minimally invasive resection in later years (adjusted odds ratio, 1.01, CI, 0.87-1.16; reference: highest income). CONCLUSIONS: This study identified significant community income-based disparities in the likelihood of undergoing minimally invasive resection as definitive surgical treatment. Novel interventions are warranted to expand access to high-volume minimally invasive resection centers and ensure equitable access to minimally invasive surgery.

The majority of patients with resectable incidental lung cancers are ineligible for lung cancer screening.

Objective: The study objective was to determine what proportion of asymptomatic patients had resectable lung cancer detected through lung cancer screening versus incidentally. Methods: We performed a retrospective study of patients who underwent resection for lung cancer between January 2015 and December 2020. We then assessed whether asymptomatic patients with incidentally found lung cancers were eligible for lung cancer screening using the National Comprehensive Cancer Network, United States Preventive Services Task Force, Centers for Medicare & Medicaid Services, American College of Chest Physicians, American Cancer Society, and American Society of Clinical Oncology guidelines. Results: Of 539 patients who underwent resection for primary lung cancer, 437 (81%) were asymptomatic and 355 (66%) of these patients had lung cancer found discovered incidentally. Of the 355 patients with incidentally detected lung cancer, 10 were excluded for insufficient data. Of the remaining 345 patients, 110 (32%) would have been eligible for screening using National Comprehensive Cancer Network guidelines, 65 (19%) using 2021 United States Preventive Services Task Force guidelines, 53 (15%) using 2013 United States Preventive Services Task Force guidelines, 64 (19%) using 2022 Centers for Medicare & Medicaid Services guidelines, 52 (15%) using 2015 Centers for Medicare & Medicaid Services/American College of Chest Physicians guidelines, and 45 (13%) using American Cancer Society/American Society of Clinical Oncology guidelines. Of the 280 patients who were screen ineligible by 2021 United States Preventive Services Task Force criteria, 143 patients (51%) never smoked, 112 patients (40%) quit smoking more than 15 years ago, 89 patients (32%) did not smoke at least 20 pack-years, and 44 patients (16%) were ineligible due to age. Conclusions: The majority of asymptomatic patients with resectable lung cancers had lung cancer identified incidentally and not through lung cancer screening. Most of these patients were not eligible for screening under current guidelines. This study suggests a need for improved lung cancer screening implementation and further investigation in the identification and assessment of risk factors for lung cancer.

Clinical and financial outcomes of pulmonary resection for lung cancer in safety-net hospitals.

OBJECTIVE: Safety-net hospitals (SNHs) have previously been associated with inferior outcomes and greater resource use. However, this relationship has not been explored in the contemporary setting of pulmonary lobectomy. In the present national study we characterized the association between SNHs and mortality, complications, and resource use. METHODS: All adults (18 years of age or older) who underwent elective lobectomy for lung cancer were identified within the 2010 to 2019 Nationwide Readmissions Database. Hospitals in the highest quartile of safety-net burden were categorized as SNHs, and others non-SNHs. Multivariable regressions were developed to assess the independent association between safety-net status and outcomes of interest. RESULTS: Of an estimated 282,011 patients who met inclusion criteria, 41,015 (14.5%) were treated at SNHs. Patients at SNHs were younger but as commonly female, compared with non-SNHs. After multivariable adjustment, there was no association between SNHs and mortality. However, treatment at SNHs was linked to higher odds of pneumonia (adjusted odds ratio [AOR], 1.11; 95% CI, 1.02-1.21) and prolonged ventilation (AOR, 1.36; 95% CI, 1.11-1.66), as well as infectious (AOR, 1.24; 95% CI, 1.08-1.43), intraoperative (AOR, 1.22; 95% CI, 1.07-1.39), and overall complications (AOR, 1.07; 95% CI, 1.01-1.14). Patients at SNHs also showed a greater need for a blood transfusion (AOR, 1.37; 95% CI, 1.23-1.53). In addition, SNHs were associated with increased length of stay (+0.33 days; 95% CI, 0.17-0.48) and greater costs (+$4130; 95% CI, 3.34-4.92), relative to non-SNHs. CONCLUSIONS: Hospital safety-net status was associated with greater odds of perioperative complications and greater health care expenditure. Further investigation is necessary uncover the mechanisms contributing to these complications and eradicate persistent disparities in lobectomy.

Comparison of Clinical Outcomes of Robot-Assisted, Video-Assisted, and Open Esophagectomy for Esophageal Cancer: A Systematic Review and Meta-analysis.

Importance: The utilization of robot-assisted minimally invasive esophagectomy (RAMIE) for esophageal cancer is increasing, despite limited data comparing RAMIE with other surgical approaches. Objective: To evaluate the literature for clinical outcomes of RAMIE compared with video-assisted minimally invasive esophagectomy (VAMIE) and open esophagectomy (OE). Data Sources: A systematic search of PubMed, Cochrane, Ovid Medline, and Embase databases from January 1, 2013, to May 6, 2020, was performed. Study Selection: Studies that compared RAMIE with VAMIE and/or OE for cancer were included. Data Extraction and Synthesis: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guideline, data were extracted by independent reviewers. A random-effects meta-analysis of 9 propensity-matched studies was performed for the RAMIE vs VAMIE comparison only. A narrative synthesis of RAMIE vs VAMIE and OE was performed. Main Outcomes and Measures: The outcomes of interest were intraoperative outcomes (ie, estimated blood loss [EBL], operative time, lymph node [LN] harvest), short-term outcomes (anastomotic leak, recurrent laryngeal nerve [RLN] palsy, pulmonary and total complications, and 90-day mortality), and long-term oncologic outcomes. Results: Overall, 21 studies (2 randomized clinical trials, 11 propensity-matched studies, and 8 unmatched studies) with 9355 patients were included. A meta-analysis was performed with 9 propensity-matched studies comparing RAMIE with VAMIE. The random-effects pooled estimate found an adjusted risk difference (RD) of -0.06 (95% CI, -0.11 to -0.01) favoring fewer pulmonary complications with RAMIE. There was no evidence of differences between RAMIE and VAMIE in LN harvest (mean difference [MD], -1.1 LN; 95% CI, -2.45 to 0.25 LNs), anastomotic leak (RD, 0.0; 95% CI, -0.03 to 0.03), EBL (MD, -6.25 mL; 95% CI, -18.26 to 5.77 mL), RLN palsy (RD, 0.01; 95% CI, -0.08 to 0.10), total complications (RD, 0.05; 95% CI, -0.01 to 0.11), or 90-day mortality (RD, -0.01; 95% CI, -0.02 to 0.0). There was low certainty of evidence that RAMIE was associated with a longer disease-free survival compared with VAMIE. For OE comparisons (data not pooled), RAMIE was associated with a longer operative time, decreased EBL, and less pulmonary and total complications. Conclusions and Relevance: In this study, RAMIE had similar outcomes as VAMIE but was associated with fewer pulmonary complications compared with VAMIE and OE. Studies on long-term functional and cancer outcomes are needed.

Management of Complications Following Lung Resection.

Lung resections are associated with a variety of potential postoperative complications. Not surprisingly, pulmonary complications are most frequent after lung surgery. Cardiac and thromboembolic complications are also important. It is essential that surgeons anticipate the possibility of these complications and take preventative measures whenever possible. When complications do occur, prompt recognition and treatment is required to assure optimal patient outcomes.

A Prognostic Scoring System for the Prediction of Metastatic Recurrence Following Curative Resection of Pancreatic Neuroendocrine Tumors.

BACKGROUND: Patients with early-stage pancreatic neuroendocrine tumors (PNETs) may develop metastatic recurrences despite undergoing potentially curative pancreas resections. We sought to identify factors predictive of metastatic recurrences and develop a prognostication strategy to predict recurrence-free survival (RFS) in resected PNETs. METHODS: Patients with localized PNETs undergoing surgical resection between 1989 and 2015 were identified. Univariate and multivariate analysis were used to identify potential predictors of post-resection metastasis. A score-based prognostication system was devised using the identified factors. The bootstrap model validation methodology was utilized to estimate the external validity of the proposed prognostication strategy. RESULTS: Of the 140 patients with completely resected early-stage PNETs, overall 5- and 10-year RFS were 84.6% and 67.1%, respectively. The median follow-up was 56 months. Multivariate analysis identified tumor size > 5 cm, Ki-67 index 8-20%, lymph node involvement, and high histologic grade (G3, or Ki-67 > 20%) as independent predictors of post-resection metastatic recurrence. A scoring system based on these factors stratified patients into three prognostic categories with distinct 5-year RFS: 96.9%, 54.8%, and 33.3% (P < 0.0001). The bootstrap model validation methodology projected our proposed prognostication strategy to retain a high predictive accuracy even when applied in an external dataset (validated c-index of 0.81). CONCLUSIONS: The combination of tumor size, LN status, grade, and Ki-67 was identified as the most highly predictive indicators of metastatic recurrences in resected PNETs. The proposed prognostication strategy may help stratify patients for adjuvant therapies, enhanced surveillance protocols and future clinical trials.

Histone deacetylase inhibitors provoke a tumor supportive phenotype in pancreatic cancer associated fibroblasts.

Although histone deacetylase inhibitors (HDACi) are a promising class of anti-cancer drugs, thus far, they have been unsuccessful in early phase clinical trials for pancreatic ductal adenocarcinoma (PDAC). One potential reason for their poor efficacy is the tumor stroma, where cancer-associated fibroblasts (CAFs) are a prominent cell type and a source of resistance to cancer therapies. Here, we demonstrate that stromal fibroblasts contribute to the poor efficacy of HDACi's in PDAC. HDACi-treated fibroblasts show increased biological aggressiveness and are characterized by increased secretion of pro-inflammatory tumor-supportive cytokines and chemokines. We find that HDAC2 binds to the enhancer and promoter regions of pro-inflammatory genes specifically in CAFs and in silico analysis identified AP-1 to be the most frequently associated transcription factor bound in these regions. Pharmacologic inhibition of pathways upstream of AP-1 suppresses the HDACi-induced inflammatory gene expression and tumor-supportive responses in fibroblasts. Our findings demonstrate that the combination of HDACi's with chemical inhibitors of the AP-1 signaling pathway attenuate the inflammatory phenotype of fibroblasts and may improve the efficacy of HDACi in PDAC and, potentially, in other solid tumors rich in stroma.

Association of Histopathologic Phenotype of Periampullary Adenocarcinomas With Survival.

Importance: Patients with periampullary adenocarcinomas have widely variable survival. These cancers are traditionally categorized by their anatomic location of origin, namely, the duodenum, ampulla, distal common bile duct (CBD), or head of the pancreas. However, they can be alternatively subdivided histopathologically into intestinal or pancreaticobiliary (PB) types, which may more accurately estimate prognosis. Objectives: To identify factors associated with survival in patients with periampullary adenocarcinomas and to compare survival between those having intestinal-type or PB-type cancers originating from the duodenum, ampulla, or distal CBD with those having pancreatic ductal adenocarcinoma (PDAC). Design, Setting, and Participants: This study was a retrospective analysis of medical records in a prospectively maintained database. Three pathologists separately evaluated histopathologic phenotypes at a university-based tertiary referral center. Study participants were all patients (N = 510) who underwent pancreatoduodenectomy for adenocarcinoma between January 1995 and December 2014. Main Outcome and Measure: Overall survival. Results: This study identified 510 patients (mean [SD] age, 66.1 [10.9] years; 245 female [48%]) who underwent pancreatoduodenectomy for adenocarcinomas: 13 duodenal, 110 ampullary, 43 distal CBD, and 344 PDAC. The median overall survival was 61.2 (interquartile range [IQR], 22.0-111.0), 70.4 (IQR, 26.7-147.7), 40.6 (IQR, 15.2-59.6), and 31.4 (IQR, 17.3-86.3) months for patients with cancers of the duodenum, ampulla, distal CBD, or pancreas, respectively (P = .01), indicating a significant difference between the 4 tumor anatomic locations. Most duodenal (61.5% [8 of 13]) and ampullary (51.8% [57 of 110]) cancers were intestinal type, and most distal CBD tumors were PB type (86.0% [37 of 43]). Those with intestinal-type duodenal, ampullary, or distal CBD adenocarcinomas had longer median overall survival than those with PB type (71.7 vs 33.3 months, P = .02) or PDAC (31.4 months, P = .003). There was no survival difference between PB-type cancers and PDAC (33.3 vs 31.4 months, P = .66). On multivariable analysis, histologic grade (hazard ratio [HR], 1.98; 95% CI, 1.56-2.52; P < .001), histopathologic phenotype (HR, 1.75; 95% CI, 1.16-2.64; P = .008), and nodal status (HR, 1.45; 95% CI, 1.12-1.87; P = .05) were significantly associated with survival, while anatomic location was not. Conclusions and Relevance: Histopathologic phenotype is a better prognosticator of survival in patients with periampullary adenocarcinomas than tumor anatomic location. Those with PB-type duodenal, ampullary, or distal CBD adenocarcinomas have survival similar to those with PDAC.

Chemotherapy-Induced Inflammatory Gene Signature and Protumorigenic Phenotype in Pancreatic CAFs via Stress-Associated MAPK.

UNLABELLED: Pancreatic ductal adenocarcinoma (PDAC) has a characteristically dense stroma comprised predominantly of cancer-associated fibroblasts (CAF). CAFs promote tumor growth, metastasis, and treatment resistance. This study aimed to investigate the molecular changes and functional consequences associated with chemotherapy treatment of PDAC CAFs. Chemoresistant immortalized CAFs (R-CAF) were generated by continuous incubation in gemcitabine. Gene expression differences between treatment-naïve CAFs (N-CAF) and R-CAFs were compared by array analysis. Functionally, tumor cells (TC) were exposed to N-CAF- or R-CAF-conditioned media and assayed for migration, invasion, and viability in vitro Furthermore, a coinjection (TC and CAF) model was used to compare tumor growth in vivo R-CAFs increased TC viability, migration, and invasion compared with N-CAFs. In vivo, TCs coinjected with R-CAFs grew larger than those accompanied by N-CAFs. Genomic analysis demonstrated that R-CAFs had increased expression of various inflammatory mediators, similar to the previously described senescence-associated secretory phenotype (SASP). In addition, SASP mediators were found to be upregulated in response to short duration treatment with gemcitabine in both immortalized and primary CAFs. Inhibition of stress-associated MAPK signaling (P38 MAPK or JNK) attenuated SASP induction as well as the tumor-supportive functions of chemotherapy-treated CAFs in vitro and in vivo These results identify a negative consequence of chemotherapy on the PDAC microenvironment that could be targeted to improve the efficacy of current therapeutic regimens. IMPLICATIONS: Chemotherapy treatment of pancreatic cancer-associated fibroblasts results in a proinflammatory response driven by stress-associated MAPK signaling that enhances tumor cell growth and invasiveness. Mol Cancer Res; 14(5); 437-47. ©2016 AACR.

p85α is a microRNA target and affects chemosensitivity in pancreatic cancer.

BACKGROUND: We previously identified a correlation between increased expression of the phosphoinositide 3-kinase (PI3K) regulatory subunit p85α and improved survival in human pancreatic ductal adenocarcinoma (PDAC). The purpose of this study was to investigate the impact of changes in p85α expression on response to chemotherapy and the regulation of p85α by microRNA-21 (miR-21). MATERIALS AND METHODS: PDAC tumor cells overexpressing p85α were generated by viral transduction, and the effect of p85α overexpression on sensitivity to gemcitabine was tested by MTT assay. Primary human PDAC tumors were stained for p85α and miR-21 via immunohistochemistry and in situ hybridization, respectively. Additionally, PDAC cells were treated with miR-21 mimic, and changes in p85α and phospho-AKT were assessed by Western blot. Finally, a luciferase reporter assay system was used to test direct regulation of p85α by miR-21. RESULTS: Higher p85α expression resulted in increased sensitivity to gemcitabine (P < 0.01), which correlated with decreased PI3K-AKT activation. Human tumors demonstrated an inverse correlation between miR-21 and p85α expression levels (r = -0.353, P < 0.001). In vitro, overexpression of miR-21 resulted in decreased levels of p85α and increased phosphorylation of AKT. Luciferase reporter assays confirmed the direct regulation of p85α by miR-21 (P < 0.01). CONCLUSIONS: Our results demonstrate that p85α expression is a determinant of chemosensitivity in PDAC. Additionally, we provide novel evidence that miR-21 can influence PI3K-AKT signaling via its direct regulation of p85α. These data provide insight into potential mechanisms for the known relationship between increased p85α expression and improved survival in PDAC.

Low expression of the E3 ubiquitin ligase CBL confers chemoresistance in human pancreatic cancer and is targeted by epidermal growth factor receptor inhibition.

PURPOSE: Expression of CBL, an ubiquitin ligase, is decreased in 60% of human pancreatic ductal adenocarcinomas (PDAC) and is associated with shorter overall survival. We sought to determine how low CBL directly contributes to clinically more aggressive PDAC. EXPERIMENTAL DESIGN: Human PDACs were stained for CBL, pEGFR, and EGFR. CBL-low was modeled in PDAC cells (Panc-1, L3.6pl, and AsPC-1) via transient transfection (siRNA) or stable knockdown (shRNA). Cell viability and apoptosis were measured by MTT assays and FACS. Immunoblot and a phospho-receptor tyrosine kinase (pRTK) array were used to probe signal transduction. NOD-scid-IL2Rγ(null) mice were subcutaneously implanted with PDAC or PDAC(CBL-low) cells on opposite flanks and treated with gemcitabine ± erlotinib for ≥4 weeks. RESULTS: There was an inverse correlation between CBL and pEGFR protein expression in 12 of 15 tumors. CBL knockdown increased PDAC resistance to gemcitabine and 5-fluorouracil (5-FU) by upregulating pEGFR (Y1068), pERK, and pAKT. A pRTK array of PDAC(CBL-low) cells revealed additional activated tyrosine kinases but all to a much lower magnitude than EGFR. Increased chemoresistance from low CBL was abrogated by the EGFR inhibitor erlotinib both in vitro and in vivo. Erlotinib+gemcitabine-treated PDAC(CBL-low) cells exhibited greater apoptosis by cleaved PARP, caspase-3, and Annexin V/PI. CONCLUSIONS: Low CBL causes chemoresistance in PDAC via stress-induced EGFR activation that can be effectively abrogated by EGFR inhibition. These results suggest that dysregulation of ubiquitination is a key mechanism of EGFR hyperactivation in PDAC and that low CBL may define PDAC tumors likely to respond to erlotinib treatment.

Current recommendations for surveillance and surgery of intraductal papillary mucinous neoplasms may overlook some patients with cancer.

BACKGROUND: The 2012 Sendai Criteria recommend that patients with 3 cm or larger branch duct intraductal papillary mucinous neoplasms (BD-IPMN) without any additional "worrisome features" or "high-risk stigmata" may undergo close observation. Furthermore, endoscopic ultrasound (EUS) is not recommended for BD-IPMN <2 cm. These changes have generated concern among physicians treating patients with pancreatic diseases. The purposes of this study were to (i) apply the new Sendai guidelines to our institution's surgically resected BD-IPMN and (ii) reevaluate cyst size cutoffs in identifying patients with lesions harboring high-grade dysplasia or invasive cancer. METHODS: We retrospectively reviewed 150 patients at a university medical center with preoperatively diagnosed and pathologically confirmed IPMNs. Sixty-six patients had BD-IPMN. Pathologic grade was dichotomized into low-grade (low or intermediate grade dysplasia) or high-grade/invasive (high-grade dysplasia or invasive cancers). Fisher's exact test, chi-square test, student's t test, linear regression, and receiver operating characteristic (ROC) analyses were performed. RESULTS: The median BD-IPMN size on imaging was 2.4 cm (interquartile range 1.5-3.0). Fifty-one (77 %) low-grade and 15 (23 %) high-grade/invasive BD-IPMN were identified. ROC analysis demonstrated that cyst size on preoperative imaging is a reasonable predictor of grade with an area under the curve of 0.691. Two-thirds of high-grade/invasive BD-IPMN were <3 cm (n = 10). Compared to a cutoff of 3, 2 cm was associated with higher sensitivity (73.3 vs. 33.3 %) and negative predictive value (83.3 vs. 80 %, NPV) for high-grade/invasive BD-IPMN. Mural nodules on endoscopic ultrasound (EUS) or atypical cells on endoscopic ultrasound-fine needle aspiration (EUS-FNA) were identified in all cysts <2 and only 50 % of those <3 cm. Forty percent of cysts >3 cm were removed based on size alone. DISCUSSION/CONCLUSIONS: Our results suggest that "larger" size on noninvasive imaging can indicate high-grade/invasive cysts, and EUS-FNA may help identify "smaller" cysts with high-grade/invasive pathology.

Stromal microRNA-21 levels predict response to 5-fluorouracil in patients with pancreatic cancer.

BACKGROUND AND OBJECTIVES: MicroRNA-21 (miR-21) is upregulated and inversely associated with survival in many cancer types, including pancreatic ductal adenocarcinoma (PDAC). We studied the predictive value of miR-21 levels for gemcitabine or 5-fluorouracil (5-FU) response in tumor cells (TCs) or cancer associated fibroblasts (CAFs) in a cohort of PDAC patients from the RTOG 9704 trial. METHODS: MiR-21 expression in CAFs and TCs, determined by in situ hybridization, of the 229 PDAC subset from RTOG 9704 was correlated with (i) histopathology characteristics using a chi-square test; and (ii) patient overall survival (OS) using the Cox proportional hazards model. RESULTS: MiR-21 was strongly expressed in TCs and CAFs in 137/182 (75%) and 152/181 (84%) PDACs, respectively. MiR-21 expression in CAFs for the group given 5-FU for OS: (i) approached significance in a univariate analysis (hazard ratio [HR], 1.57; 95% confidence interval [CI], 0.95-2.57; P = 0.07); and (ii) was significant in the multivariate model (HR, 1.70; 95% CI, 1.03-2.82; P = 0.038). CONCLUSIONS: MiR-21 expression in CAFs was associated with decreased OS in PDAC patients who received 5-FU, but not gemcitabine. These findings begin to identify stromal miR-21 as a marker to guide chemotherapy choice in PDAC patients.

Nonfunctional pancreatic neuroendocrine tumors <2 cm on preoperative imaging are associated with a low incidence of nodal metastasis and an excellent overall survival.

BACKGROUND: The optimal surgical management of small nonfunctional pancreatic neuroendocrine tumors (NF-PNETs) remains controversial. We sought to identify (1) clinicopathologic factors associated with survival in NF-PNETs and (2) preoperative tumor characteristics that can be used to determine which lesions require resection and lymph node (LN) harvest. METHODS: The records of all 116 patients who underwent resection for NF-PNETs between 1989 and 2012 were reviewed retrospectively. Preoperative factors, operative data, pathology, surgical morbidity, and survival were analyzed. RESULTS: The overall 5- and 10-year survival rates were 83.9 and 72.8 %, respectively. Negative LNs (p = 0.005), G1 or G2 histology (p = 0.033), and age <60 years (p = 0.002) correlated with better survival on multivariate analysis. The 10-year survival rate was 86.6 % for LN-negative patients (n = 73) and 34.1 % for LN-positive patients (n = 32). Tumor size ≥2 cm on preoperative imaging predicted nodal positivity with a sensitivity of 93.8 %. Positive LNs were found in 38.5 % of tumors ≥2 cm compared to only 7.4 % of tumors <2 cm. CONCLUSIONS: LN status, a marker of systemic disease, was a highly significant predictor of survival in this series. Tumor size on preoperative imaging was predictive of nodal disease. Thus, it is reasonable to consider parenchyma-sparing resection or even close observation for NF-PNETs <2 cm.

MicroRNA-21 in pancreatic ductal adenocarcinoma tumor-associated fibroblasts promotes metastasis.

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) is projected to rise to the second leading cause of U.S. cancer-related deaths by 2020. Novel therapeutic targets are desperately needed. MicroRNAs (miRs) are small noncoding RNAs that function by suppressing gene expression and are dysregulated in cancer. miR-21 is overexpressed in PDAC tumor cells (TC) and is associated with decreased survival, chemoresistance and invasion. Dysregulation of miR regulatory networks in PDAC tumor-associated fibroblasts (TAFs) have not been previously described. In this study, we show that miR-21 expression in TAFs promotes TC invasion. METHODS: In-situ hybridization for miR-21 was performed on the 153 PDAC patient UCLA tissue microarray and 23 patient-matched lymph node metastases. Stromal and TC histoscores were correlated with clinicopathologic parameters by univariate and multivariate Cox regression. miR-21 positive cells were further characterized by immunofluorescence for mesenchymal/epithelial markers. For in vitro studies, TAFs were isolated from freshly resected human PDAC tumors by the outgrowth method. miR-21 was overexpressed/inhibited in fibroblasts and then co-cultured with GFP-MiaPaCa TCs to assess TC invasion in modified Boyden chambers. RESULTS: miR-21 was upregulated in TAFs of 78% of tumors, and high miR-21 significantly correlated with decreased overall survival (P = 0.04). Stromal miR-21 expression was also significantly associated with lymph node invasion (P = 0.004), suggesting that it is driving TC spread. Co-immunofluorescence revealed that miR-21 colocalized with peritumoral fibroblasts expressing α-smooth muscle actin. Moreover, expression of miR-21 in primary TAFs correlated with miR-21 in TAFs from patient-matched LN metastases; evidence that PDAC tumor cells induce TAFs to express miR-21. miR-21 expression in TAFs and TCs promotes invasion of TCs and is inhibited with anti-miR-21. CONCLUSIONS: miR-21 expression in PDAC TAFs is associated with decreased overall survival and promotes TC invasion. Anti-miR-21 may represent a novel therapeutic strategy for dual targeting of both tumor and stroma in PDAC.

Endoscopically acquired pancreatic cyst fluid microRNA 21 and 221 are associated with invasive cancer.

OBJECTIVES: Pancreatic cysts are a group of lesions with heterogeneous malignant potential. Currently, there are no reliable biomarkers to aid in cyst diagnosis and classification. The objective of this study was to identify potential microRNA (miR) biomarkers in endoscopically acquired pancreatic cyst fluid that could be used to distinguish between benign, premalignant, and malignant cysts. METHODS: A list of candidate miRs was developed using a whole-genome expression array analysis of pancreatic cancer (pancreatic ductal adenocarcinoma) and nonmalignant samples overlapped with existing literature and predicted gene targets. Endoscopically acquired pancreatic cyst fluid samples were obtained from a group of 38 patients who underwent cyst fluid aspiration and surgical resection. Selected miR expression levels in cyst fluid samples were assessed by quantitative real-time-PCR. Additionally, in situ hybridization (ISH) on corresponding cyst tissue samples was performed to identify the source and validate the expression level of fluid miRs. RESULTS: Of the six miRs that were profiled in the study, two showed differential expression in malignant cysts. miR-221 was expressed at significantly higher levels in malignant cysts compared with benign or premalignant cysts (P=0.05). miR-21 was also expressed at significantly higher levels in malignant cysts (P<0.01). Additionally, the expression of miR-21 was significantly higher in premalignant cysts than benign cysts (P=0.03). The differential expression of miR-21 among cyst categories was confirmed by ISH. CONCLUSIONS: In this small single-center study, miRs are potential pancreatic cyst fluid diagnostic biomarkers. In particular, miR-21 is identified as a candidate biomarker to distinguish between benign, premalignant, and malignant cysts. Additionally miR-221 may be of use in the identification of more advanced malignant disease.

Intestinal resection induces angiogenesis within adapting intestinal villi.

PURPOSE: Adaptive growth of the intestinal mucosa in response to massive gut loss is fundamental for autonomy from parenteral nutrition. Although angiogenesis is essential for cellular proliferation in other tissues, its relevance to intestinal adaptation is unknown. We tested the hypothesis that resection-induced adaptation is associated with new blood vessel growth. METHODS: Male C57Bl/6 mice underwent either a 50% small bowel resection or a sham (transection and reanastomosis) operation. After 1, 3, or 7 days, capillary density within the intestinal villi was measured using confocal microscopy. A messenger RNA reverse-transcriptase polymerase chain reaction (RT-PCR) array was used to determine angiogenic gene expression during adaptation. RESULTS: Mice that underwent small bowel resection had a significantly increased capillary density compared to sham-operated mice at postoperative day 7. This morphological alteration was preceded by significant alterations in 5 candidate genes at postoperative day 3. CONCLUSION: New vessel blood growth is observed in the adapting intestine after massive small bowel loss. This response appears to follow rather than initiate the adaptive alterations in mucosal morphology that are characteristic of adaptation. A better understanding of this progress and the signaling factors involved may improve therapeutic options for children with short gut syndrome.