Intratumoral Cell Neighborhoods Coordinate Outcomes in Pancreatic Ductal Adenocarcinoma

BACKGROUND & AIMS

Pancreatic ductal adenocarcinoma (PDA) is a highly lethal disease characterized by a spatially heterogeneous tumor microenvironment. Within the PDA microenvironment, cells organize into communities where cell fate is influenced by neighboring cells of diverse ontogeny and function. However, it remains unclear how cell neighborhoods in the tumor microenvironment evolve with treatment and impact clinical outcomes.

METHODS

Here, using automated chromogenic multiplex immunohistochemistry and unsupervised computational image analysis of human PDA tumors, we investigated cell neighborhoods in surgically resected tumors from patients with chemotherapy-naïve PDA (n = 59) and neoadjuvant chemotherapy-treated PDA (n = 57). Single cells were defined by lineage markers (CD3, CD8, Foxp3, CD68, CK19), proliferation (Ki67), and neighboring cells.

RESULTS

Distinct intratumoral immune and tumor cell subsets were defined by neighboring cells. Higher content of stromal-associated macrophages was seen in chemotherapy-naïve tumors from long-term survivors (overall survival >3 years) compared with short-term survivors (overall survival <1 year), whereas immune-excluded tumor cells were higher in short-term survivors. Chemotherapy-treated vs -naïve tumors showed lower content of tumor-associated T cells and macrophages but similar densities of stromal-associated immune cells. However, proliferating tumor cell subsets with immune-rich neighborhoods were higher in chemotherapy-treated tumors. In a blinded analysis of tumors from patients treated with neoadjuvant chemotherapy, a composite index comprising lower quantities of immune-excluded tumor cells and higher spatially distinct immune cell subsets was associated with prolonged survival.

CONCLUSIONS

Together, these data provide new insights into discrete cell communities in PDA and show their clinical relevance.

Multianalyte Serum Biomarker Panel for Early Detection of Pancreatic Adenocarcinoma

PURPOSE

We determined whether a large, multianalyte panel of circulating biomarkers can improve detection of early-stage pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

We defined a biologically relevant subspace of blood analytes on the basis of previous identification in premalignant lesions or early-stage PDAC and evaluated each in pilot studies. The 31 analytes that met minimum diagnostic accuracy were measured in serum of 837 subjects (461 healthy, 194 benign pancreatic disease, and 182 early-stage PDAC). We used machine learning to develop classification algorithms using the relationship between subjects on the basis of their changes across the predictors. Model performance was subsequently evaluated in an independent validation data set from 186 additional subjects.

RESULTS

A classification model was trained on 669 subjects (358 healthy, 159 benign, and 152 early-stage PDAC). Model evaluation on a hold-out test set of 168 subjects (103 healthy, 35 benign, and 30 early-stage PDAC) yielded an area under the receiver operating characteristic curve (AUC) of 0.920 for classification of PDAC from non-PDAC (benign and healthy controls) and an AUC of 0.944 for PDAC versus healthy controls. The algorithm was then validated in 146 subsequent cases presenting with pancreatic disease (73 benign pancreatic disease and 73 early- and late-stage PDAC cases) and 40 healthy control subjects. The validation set yielded an AUC of 0.919 for classification of PDAC from non-PDAC and an AUC of 0.925 for PDAC versus healthy controls.

CONCLUSION

Individually weak serum biomarkers can be combined into a strong classification algorithm to develop a blood test to identify patients who may benefit from further testing.

Diminished Immune Surveillance during Histologic Progression of Intraductal Papillary Mucinous Neoplasms Offers a Therapeutic Opportunity for Cancer Interception

PURPOSE

Intraductal papillary mucinous neoplasms (IPMN) are bona fide precursors to pancreatic ductal adenocarcinoma (PDAC). While genomic alterations during multistep IPMN progression have been well cataloged, the accompanying changes within the tumor immune microenvironment (TIME) have not been comprehensively studied. Herein, we investigated TIME-related alterations during IPMN progression, using multiplex immunofluorescence (mIF) coupled with high-resolution image analyses.

EXPERIMENTAL DESIGN

Two sets of formalin-fixed, paraffin-embedded tissue samples from surgically resected IPMNs were analyzed. The training set of 30 samples consisted of 11 low-grade IPMN (LG-IPMN), 17 high-grade IPMN (HG-IPMN), and 2 IPMN with PDAC, while a validation set of 93 samples comprised of 55 LG-IPMN and 38 HG-IPMN. The training set was analyzed with two panels of immuno-oncology-related biomarkers, while the validation set was analyzed with a subset of markers found significantly altered in the training set.

RESULTS

Cell types indicative of enhanced immune surveillance, including cytotoxic and memory T cells, and antigen-experienced T cells and B cells, were all found at higher densities within isolated LG-IPMNs compared with HG-IPMNs. Notably, the TIME of LG-IPMNs that had progressed at the time of surgical resection (progressor LGD) resembled that of the synchronous HG-IPMNs, underscoring that attenuated immune surveillance occurs even in LG-IPMNs destined for progression.

CONCLUSIONS

Our findings provide a basis for interception of cystic neoplasia to PDAC, through maintenance of sustained immune surveillance using vaccines and other prevention approaches.

Hospital Costs Following Surgical Complications: A Value-driven Outcomes Analysis of Cost Savings Due to Complication Prevention

OBJECTIVE

Surgical complications have substantial impact on healthcare costs. We propose an analysis of the financial impact of postoperative complications.

SUMMARY OF BACKGROUND DATA

Both complications and preoperative patient risk have been shown to increase costs following surgery. The extent of cost increase due to specific complications has not been well described.

METHODS

A single institution's American College of Surgeons National Surgical Quality Improvement Program data was queried from 2012 to 2018 and merged with institutional cost data for each encounter. A mixed effects multivariable generalized linear model was used to estimate the mean relative increase in hospital cost due to each complication, adjusting for patient and procedure-level fixed effects clustered by procedure. Potential savings were calculated based on projected decreases in complication rates and theoretical hospital volume.

RESULTS

There were 11,897 patients linked between the 2 databases. The rate of any American College of Surgeons National Surgical Quality Improvement Program complication was 11.7%. The occurrence of any complication resulted in a 1.5-fold mean increase in direct hospital cost [95% confidence interval (CI) 1.49-1.58]. The top 6 most costly complications were postoperative septic shock (4.0-fold, 95% CI 3.58-4.43) renal insufficiency/failure (3.3-fold, 95% CI 2.91-3.65), any respiratory complication (3.1-fold, 95% CI 2.94-3.36), cardiac arrest (3.0-fold, 95% CI 2.64-3.46), myocardial infarction (2.9-fold, 95% CI 2.43-3.42) and mortality within 30 days (2.2-fold, 95% CI 2.01-2.48). Length of stay (6.5 versus 3.2 days, P < 0.01), readmission rate (29.1% vs 3.1%, P < 0.01), and discharge destination outside of home (20.5% vs 2.7%, P < 0.01) were significantly higher in the population who experienced complications.

CONCLUSIONS

Decreasing complication rates through preoperative optimization will improve patient outcomes and lead to substantial cost savings.

Value Analysis of Methods of Inguinal Hernia Repair

OBJECTIVE

Value is defined as health outcomes important to patients relative to cost of achieving those outcomes: Value = Quality/Cost. For inguinal hernia repair, Level 1 evidence shows no differences in long-term functional status or recurrence rates when comparing surgical approaches. Differences in value reside within differences in cost. The aim of this study is to compare the value of different surgical approaches to inguinal hernia repair: Open (Open-IH), Laparoscopic (Lap-IH), and Robotic (R-TAPP).

METHODS

Variable and fixed hospital costs were compared among consecutive Open-IH, Lap-IH, and R-TAPP repairs (100 each) performed in a university hospital. Variable costs (VC) including direct materials, labor, and variable overhead ($/min operating room [OR] time) were evaluated using Value Driven Outcomes, an internal activity-based costing methodology. Variable and fixed costs were allocated using full absorption costing to evaluate the impact of surgical approach on value. As cost data is proprietary, differences in cost were normalized to Open-IH cost.

RESULTS

Compared to Open-IH, VC for Lap-IH were 1.02X higher (including a 0.81X reduction in cost for operating room [OR] time). For R-TAPP, VC were 2.11X higher (including 1.36X increased costs for OR time). With allocation of fixed cost, a Lap-IH was 1.03X more costly, whereas R-TAPP was 3.18X more costly than Open-IH. Using equivalent recurrence as the quality metric in the value equation, Lap-IH decreases value by 3% and R-TAPP by 69% compared to Open-IH.

CONCLUSIONS

Use of higher cost technology to repair inguinal hernias reduces value. Incremental health benefits must be realized to justify increased costs. We expect payors and patients will incorporate value into payment decisions.

Detection of circulating tumor DNA without a tumor-informed search using next-generation sequencing is a prognostic biomarker in pancreatic ductal adenocarcinoma

The confounding effects of next-generation sequencing (NGS) noise on detection of low frequency circulating tumor DNA (ctDNA) without a priori knowledge of solid tumor mutations has limited the applications of circulating cell-free DNA (ccfDNA) in clinical oncology. Here, we use a 118 gene panel and leverage ccfDNA technical replicates to eliminate NGS-associated errors while also enhancing detection of ctDNA from pancreatic ductal adenocarcinomas (PDACs). Pre-operative ccfDNA and tumor DNA were acquired from 14 patients with PDAC (78.6% stage II-III). Post-operative ccfDNA was also collected from 11 of the patients within 100 days of surgery. ctDNA detection was restricted to variants corresponding to pathogenic mutations in PDAC present in both replicates. PDAC-associated pathogenic mutations were detected in pre-operative ccfDNA in four genes (KRAS, TP53, SMAD4, ALK) from five patients. Of the nine ctDNA variants detected (variant allele frequency: 0.08%-1.59%), five had a corresponding mutation in tumor DNA. Pre-operative detection of ctDNA was associated with shorter survival (312 vs. 826 days; χ2=5.4, P = 0.021). Guiding ctDNA detection in pre-operative ccfDNA based on mutations present in tumor DNA yielded a similar survival analysis. Detection of ctDNA in the post-operative ccfDNA with or without tumor-informed guidance was not associated with outcomes. Therefore, the detection of PDAC-derived ctDNA during a broad and untargeted survey of ccfDNA with NGS may be a valuable, non-invasive, prognostic biomarker to integrate into the clinical assessment and management of patients prior to surgery.

Abstract 580: The broad surveillance and unbiased detection of circulating tumor DNA using next-generation sequencing without a priori knowledge of somatic mutations is a prognostically significant biomarker in pancreatic ductal adenocarcinoma

Background. Detection of low frequency tumor-derived variants in circulating cell-free DNA (ccfDNA; i.e., circulating tumor DNA, ctDNA) without a priori knowledge of mutations in the matched solid tumor is confounded by next-generation sequencing (NGS) noise and constrained by theoretical and practical limitations associated with low DNA yield from plasma. Here, we leverage technical replicates (two libraries prepared and sequenced independently from each extracted ccfDNA sample) to simultaneously suppress NGS-associated errors and improve detection of ctDNA derived from pancreatic ductal adenocarcinomas (PDACs).

Methods. Pre-operative ccfDNA and tumor DNA were acquired from 14 patients with PDAC (78.6% stage II-III) undergoing surgery aimed at complete total resection. For 11 patients, ccfDNA was also collected post-operatively within 100 days of surgery. Two technical replicates of ccfDNA libraries using molecular barcodes were independently generated using 2 mL plasma equivalents of ccfDNA for each library. Subsequently, libraries were capture-enriched using a 118 gene panel (~124 kb) and underwent NGS (paired-end, 125x2; HiSeq 2500). Consensus sequence determination and position-specific error modeling were coupled with restricting variant identification to nonreference alleles present in both patient replicates that corresponded to COSMIC-reported pathogenic mutations in PDAC.

Results. PDAC-associated pathogenic mutations were detected in pre-operative ccfDNA in four genes (KRAS, TP53, SMAD4, ALK) from five patients (35.7%) with a variant allele frequency ranging from 0.08% to 1.59% (median: 0.25%). Of the nine ctDNA variants identified, five (55.6%) had a corresponding mutation in tumor DNA. The estimated median overall survival in patients with and without detection of pre-operative ctDNA was significantly different (312 vs. 826 days, respectively; χ2=5.3, P=0.0207). Using mutations identified in tumor tissue DNA to guide detection of pre-operative ctDNA yielded a similar survival analysis (369 vs 1,011 days, respectively; χ2=5.6, P=0.018). Detection of ctDNA in post-operative ccfDNA with or without guidance from tumor tissue mutations was not associated with outcomes. Applying the noise reduction strategy used to detect ctDNA in PDAC patients eliminated false positives from healthy controls.

Conclusions. Acquisition of NGS data in replicate coupled with in silico error suppression strategies enabled detection of ctDNA without a priori knowledge of tumor variants, which overcomes a major obstacle limiting ccfDNA applications. Pre-operative ctDNA detected during a broad and untargeted survey of ccfDNA with NGS is a non-invasive, prognostic biomarker to help guide PDAC patient management.

Citation Format: Kajsa E. Affolter, Sabine Hellwig, David A. Nix, Mary P. Bronner, Alun Thomas, Carrie L. Fuertes, Cindy L. Hamil, Ignacio Garrido-Laguna, Courtney L. Scaife, Sean J. Mulvihill, Hunter R. Underhill. The broad surveillance and unbiased detection of circulating tumor DNA using next-generation sequencing without a priori knowledge of somatic mutations is a prognostically significant biomarker in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 580.

Immunologic predictors of therapeutic response to neoadjuvant chemotherapy for pancreatic ductal adenocarcinoma (PDA) in SWOG S1505

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Background: A role for the immune system in predicting treatment outcomes in PDA has not been well-studied prospectively, especially in the curative setting. Here, we investigated the capacity of two established chemotherapy regimens to trigger an immune response against PDA when administered as neoadjuvant therapy. Methods: We used available PDA surgical specimens from SWOG S1505 (a randomized phase II trial of perioperative chemotherapy with either mFOLFIRINOX [FFX] or gemcitabine/nab-paclitaxel [GA] for resectable PDA; ASCO 2020 abstr 4504) resected after 3 months of neoadjuvant chemotherapy, and matched untreated controls from the biorepository at the University of Utah. Multiplex immunohistochemistry (IHC) for CD8, CD68, CK19, FOXP3, PDL1, CD3, and Ki67 was performed; regions of interest (ROIs) were transcribed by a central pathologist. ROIs were digitally quantified using custom image analysis algorithms created using Visiopharm Integrator System software to detect and classify cells within superimposed grids for quantification; medians and coefficients of variation (CV) were calculated. Wilcoxon signed-rank test and Cox regression models were used to analyze associations between IHC cell counts and pathologic response (pR) and overall survival (OS), respectively. Results: IHC cell counts varied between treated (Rx) (n = 57; FFX = 34, GA = 23) and control (C) (n = 61) specimens for: CK19 percent area was 7.9 vs 15.6 (p < 0.001); total Ki67/mm2 was 211 vs 400 (p < 0.001); total CD3/mm2 was 376 vs 676 (p < 0.001); Foxp3/mm2 was 81.5 vs 152.8 (p < 0.001); CD8/mm2 was 313 vs 477 (p < 0.001); CD68/mm2 was 507 vs 741 (p = 0.015). PDL1 expression was undetectable in the majority of specimens, both Rx and C. FFX (vs GA) was associated with fewer CK19+Ki67+ cells (459 vs 1026, p = 0.017) but more CD68+ cells (33,241 vs 13,334, p = 0.007) and slightly more CD8+ cells (19,809 vs 14,344, p = 0.049). In all Rx patients, complete/major (n = 19) vs poor/no (n = 36) pR was associated with total CD3/mm2: 461 vs 308 (p = 0.019); the other parameters showed no notable differences. OS showed no remarkable associations with the tested parameters. Conclusions: We have demonstrated: 1) Decreased tumor cells and proliferating cells in Rx vs C samples, as expected. This decrease is more pronounced with FFX compared with GA; 2) Decreased total CD3+ T cells as well as regulatory Foxp3+ T cells in Rx vs C samples, which is unexpected; 3) A reduction in CD68+ myeloid cells in Rx vs C samples, which is expected but more pronounced with GA compared with FFX; 4) Rx samples did not show an increased expression of PDL1, compared with C; and 5) Improved pR was associated with increased T cell infiltrate, pointing toward a possible mechanism. Together, these data support the capacity of neoadjuvant chemotherapy to modulate the immune response to PDA. Therapeutic implications of such changes merit further investigation. Clinical trial information: NCT02562716.

Lymph Node Ratio in Pancreatic Adenocarcinoma After Preoperative Chemotherapy vs. Preoperative Chemoradiation and Its Utility in Decisions About Postoperative Chemotherapy

BACKGROUND

Single-center studies in pancreatic adenocarcinoma have suggested that preoperative chemotherapy (PCT) is associated with higher lymph node ratio (LNR) than preoperative chemoradiation (PCRT). The association of postoperative chemotherapy with overall survival (OS) in patients treated with PCT and PCRT remains unclear. Our objectives were to investigate whether (1) PCT is associated with higher LNR than PCRT and (2) postoperative chemotherapy is associated with longer OS after PCT and PCRT in LNR-stratified cohorts.

METHODS

A retrospective cohort study was performed of patients with pancreatic adenocarcinoma treated with PCT or PCRT followed by resection between 2006 and 2014 in the National Cancer Database. Temporal trends were evaluated with Cuzick's test. OS was evaluated with multivariable Cox regression and inverse probability weighted (IPW) Cox regression.

RESULTS

Of 4187 patients, 1993 (47.6%) received PCT. PCT rates were stable at approximately 30% in 2006-2010 (p = 0.33) but increased to 64.9% by 2014 (p < 0.001). Node positivity rates were higher after PCT than PCRT (62.7 vs. 41.8%, P < 0.001) and mean LNR was higher (0.10 [95% CI 0.096, 0.11] vs. 0.058 [95% CI 0.052, 0.063], P < 0.001). Postoperative chemotherapy was associated with longer OS in patients with LNR 0.01-0.149 after PCT by univariate analysis (median OS 34.5 vs. 26.5 months, P = 0.002), multivariable Cox regression (HR 0.64, 95% CI 0.48, 0.84), and IPW Cox regression (HR 0.72, 95% CI 0.55, 0.94). Postoperative chemotherapy was not associated with longer OS for patients who were node-negative or who had LNR ≥ 0.15 after PCT or for any patient subgroups after PCRT.

CONCLUSIONS

PCT is associated with a higher LNR and higher rates of node positivity than PCRT. Postoperative chemotherapy is associated with longer OS than observation in patients with a LNR of 0.01-0.149 after PCT.

Adrenocorticotropin Hormone Secreting Carcinoma of the Pancreas: A Case Report

Introduction: Adrenocorticotropin hormone (ACTH) secreting pancreatic neuroendocrine neoplasms (pNENs) are rare. The clinical and biological behavior of pNENs is poorly understood. Patients often present at an advanced stage of disease and outcomes remain poor. This report demonstrates a case of ectopic Cushing's syndrome secondary to an ACTH-producing pancreatic neuroendocrine carcinoma (pNEC).

Case report: A 54-year-old woman presented with rapidly progressive Cushing's syndrome complicated by hypertension and acute heart failure. This was ultimately found to be secondary to a metastatic ACTH-producing pNEC. She underwent laparoscopic distal pancreatectomy and splenectomy with hepatic metastasectomy as primary treatment. She had rapid correction of her endocrine abnormalities and associated physiological abnormalities. She had progressive hepatic metastases found on imaging at 3 months, but remained free of significant endocrine abnormalities for 9 months after surgery. Her disease did recur and she died of complications associated with her disease at 1 year after her surgery.

Conclusion: ACTH-producing pNEN is a very rare disease with a poor prognosis. Robust evidence to guide treatment decisions is limited. This report suggests that aggressive surgical management of primary and metastatic lesions for management of this disease is reasonable, consistent with prior case reports. Control of endocrine abnormalities offers the best opportunity for prolonged survival, and an aggressive surgical approach can achieve this goal. The patient presented had control of endocrine abnormalities after surgery for 9 months before symptomatic disease recurrence.

Exosomes harbor B cell targets in pancreatic adenocarcinoma and exert decoy function against complement-mediated cytotoxicity

Although B cell response is frequently found in cancer, there is little evidence that it alters tumor development or progression. The process through which tumor-associated antigens trigger humoral response is not well delineated. We investigate the repertoire of antigens associated with humoral immune response in pancreatic ductal adenocarcinoma (PDAC) using in-depth proteomic profiling of immunoglobulin-bound proteins from PDAC patient plasmas and identify tumor antigens that induce antibody response together with exosome hallmark proteins. Additional profiling of PDAC cell-derived exosomes reveals significant overlap in their protein content with immunoglobulin-bound proteins in PDAC plasmas, and significant autoantibody reactivity is observed between PDAC cell-derived exosomes and patient plasmas compared to healthy controls. Importantly, PDAC-derived exosomes induce a dose-dependent inhibition of PDAC serum-mediated complement-dependent cytotoxicity towards cancer cells. In summary, we provide evidence that exosomes display a large repertoire of tumor antigens that induce autoantibodies and exert a decoy function against complement-mediated cytotoxicity.

Disparities in utilization of treatment for clinical stage I-II pancreatic adenocarcinoma by area socioeconomic status and race/ethnicity

BACKGROUND

Utilization of multimodality therapy for clinical stage I-II pancreatic ductal adenocarcinoma is associated with meaningful prolongation of survival. Although the qualitative existence of disparities in treatment utilization by socioeconomic status and race/ethnicity is well documented, the absolute magnitudes of these disparities have not been previously quantified.

METHODS

The exposures in this retrospective cohort study of the 2010-2015 National Cancer Database were a 7-value area-level socioeconomic status index and race/ethnicity. Main outcomes were surgery, chemotherapy, and multimodality therapy (surgery and chemotherapy). Adjusted rate differences were calculated after logistic regression. Models excluded intermediate variables. Overall survival was evaluated in unadjusted and adjusted analyses.

RESULTS

Of 43,760 patients, 63.4% underwent surgery. Of 39,808 patients without chemotherapy contraindications, refusal, or missing data, 75.1% received chemotherapy and 51.4% received multimodality therapy. Adjusted rate differences for utilization of surgery, chemotherapy, and multimodality therapy in the lowest socioeconomic status patients were -10.0 (95% confidence interval [CI] -12.4 to -7.5), -12.7 (95% CI -16.3 to -9.1), and -15.4 (95% CI -18.8 to -12.0), respectively, versus the highest socioeconomic status patients. Adjusted rate differences for multimodality therapy utilization in non-Hispanic Black and Hispanic patients were -10.1 (95% CI -13.6 to -6.7) and -11.8 (95% CI -14.3 to -9.2), respectively, versus non-Hispanic White patients. Median overall survival increased in a graded fashion from 14.1 (95% CI 13.4-14.8) months in the lowest socioeconomic status patients to 20.2 months (95% CI 19.6-20.8) in the highest socioeconomic status patients. Survival differences were attenuated but not eliminated in multivariable Cox models.

CONCLUSION

Socioeconomic status and race/ethnicity are more powerful determinants of whether patients receive treatment for clinical stage I-II pancreatic ductal adenocarcinoma than previously appreciated. Nationwide quality improvement efforts aimed at addressing these inequities are warranted.

Pancreatic cancer as a sentinel for hereditary cancer predisposition

BACKGROUND

Genes associated with hereditary breast and ovarian cancer (HBOC) and colorectal cancer (CRC) predisposition have been shown to play a role in pancreatic cancer susceptibility. Growing evidence suggests that pancreatic cancer may be useful as a sentinel cancer to identify families that could benefit from HBOC or CRC surveillance, but to date pancreatic cancer is only considered an indication for genetic testing in the context of additional family history.

METHODS

Preliminary data generated at the Huntsman Cancer Hospital (HCH) included variants identified on a custom 34-gene panel or 59-gene panel including both known HBOC and CRC genes for respective sets of 66 and 147 pancreatic cancer cases, unselected for family history. Given the strength of preliminary data and corresponding literature, 61 sequential pancreatic cancer cases underwent a custom 14-gene clinical panel. Sequencing data from HCH pancreatic cancer cases, pancreatic cancer cases of the Cancer Genome Atlas (TCGA), and an unselected pancreatic cancer screen from the Mayo Clinic were combined in a meta-analysis to estimate the proportion of carriers with pathogenic and high probability of pathogenic variants of uncertain significance (HiP-VUS).

RESULTS

Approximately 8.6% of unselected pancreatic cancer cases at the HCH carried a variant with potential HBOC or CRC screening recommendations. A meta-analysis of unselected pancreatic cancer cases revealed that approximately 11.5% carry a pathogenic variant or HiP-VUS.

CONCLUSION

With the inclusion of both HBOC and CRC susceptibility genes in a panel test, unselected pancreatic cancer cases act as a useful sentinel cancer to identify asymptomatic at-risk relatives who could benefit from relevant HBOC and CRC surveillance measures.

Association of adjuvant chemotherapy with overall survival in resected pancreatic adenocarcinoma previously treated with neoadjuvant therapy

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Background: Guidelines for adjuvant chemotherapy in patients with resected pancreatic adenocarcinoma (PDAC) who received neoadjuvant chemotherapy are equivocal. A lymph node ratio (LNR) ≥ 0.15 may predict lack of benefit, but conflicting results are reported. Methods: The National Cancer Database was searched to identify patients who were resected after neoadjuvant chemotherapy in 2006-2013. Exclusions: metastases at surgery, 90-day postoperative mortality, adjuvant radiation, and outlier interval from diagnosis to surgery (<2.5 or >10 months). The association between adjuvant chemotherapy and overall survival (OS) from diagnosis was examined using multivariable Cox regression and inverse propensity of treatment weighted (IPTW) Cox regression. An IPTW based estimator of the average treatment effect (ATE) was used to quantify the population average survival benefit of treatment. Outcomes were examined in all patients and in those with LNR < 0.15 and ≥ 0.15. Results: 681/2488 patients (27%) received adjuvant chemotherapy. In multivariable Cox regression, adjuvant chemotherapy was associated with improved OS in the overall cohort and in patients with LNR < 0.15. A trend towards improved OS was also observed for those with LNR ≥ 0.15. After accounting for indication bias using IPTW, a significant survival benefit for was observed only for patients with LNR < 0.15. The ATE among LNR < 0.15 patients was 3.3 (95% CI 1.0, 5.7) months, indicating that the average survival of the population would be 3.3 months longer if all received treatment. Conclusions: Adjuvant chemotherapy in resected PDAC patients who received neoadjuvant therapy appears to be beneficial in patients with negative lymph nodes or minimal nodal burden. High LNR after neoadjuvant therapy may be an indicator of adverse tumor biology that is less likely to derive a therapeutic benefit. [Table: see text]

Association of time-to-surgery with outcomes in clinical stage I-II pancreatic adenocarcinoma treated with upfront surgery

BACKGROUND

Time-to-surgery from cancer diagnosis has increased in the United States. We aimed to determine the association between time-to-surgery and oncologic outcomes in patients with resectable pancreatic ductal adenocarcinoma undergoing upfront surgery.

METHODS

The 2004-2012 National Cancer Database was reviewed for patients undergoing curative-intent surgery without neoadjuvant therapy for clinical stage I-II pancreatic ductal adenocarcinoma. A multivariable Cox model with restricted cubic splines was used to define time-to-surgery as short (1-14 days), medium (15-42), and long (43-120). Overall survival was examined using Cox shared frailty models. Secondary outcomes were examined using mixed-effects logistic regression models.

RESULTS

Of 16,763 patients, time-to-surgery was short in 34.4%, medium in 51.6%, and long in 14.0%. More short time-to-surgery patients were young, privately insured, healthy, and treated at low-volume hospitals. Adjusted hazards of mortality were lower for medium (hazard ratio 0.94, 95% confidence interval, .90, 0.97) and long time-to-surgery (hazard ratio 0.91, 95% confidence interval, 0.86, 0.96) than short. There were no differences in adjusted odds of node positivity, clinical to pathologic upstaging, being unresectable or stage IV at exploration, and positive margins. Medium time-to-surgery patients had higher adjusted odds (odds ratio 1.11, 95% confidence interval, 1.03, 1.20) of receiving an adequate lymphadenectomy than short. Ninety-day mortality was lower in medium (odds ratio 0.75, 95% confidence interval, 0.65, 0.85) and long time-to-surgery (odds ratio 0.72, 95% confidence interval, 0.60, 0.88) than short.

CONCLUSION

In this observational analysis, short time-to-surgery was associated with slightly shorter OS and higher perioperative mortality. These results may suggest that delays for medical optimization and referral to high volume surgeons are safe.

Sequential Validation of Blood-Based Protein Biomarker Candidates for Early-Stage Pancreatic Cancer

Background

CA19-9, which is currently in clinical use as a pancreatic ductal adenocarcinoma (PDAC) biomarker, has limited performance in detecting early-stage disease. We and others have identified protein biomarker candidates that have the potential to complement CA19-9. We have carried out sequential validations starting with 17 protein biomarker candidates to determine which markers and marker combination would improve detection of early-stage disease compared with CA19-9 alone.

Methods

Candidate biomarkers were subjected to enzyme-linked immunosorbent assay based sequential validation using independent multiple sample cohorts consisting of PDAC cases (n = 187), benign pancreatic disease (n = 93), and healthy controls (n = 169). A biomarker panel for early-stage PDAC was developed based on a logistic regression model. All statistical tests for the results presented below were one-sided.

Results

Six out of the 17 biomarker candidates and CA19-9 were validated in a sample set consisting of 75 PDAC patients, 27 healthy subjects, and 19 chronic pancreatitis patients. A second independent set of 73 early-stage PDAC patients, 60 healthy subjects, and 74 benign pancreatic disease patients (combined validation set) yielded a model that consisted of TIMP1, LRG1, and CA19-9. Additional blinded testing of the model was done using an independent set of plasma samples from 39 resectable PDAC patients and 82 matched healthy subjects (test set). The model yielded areas under the curve (AUCs) of 0.949 (95% confidence interval [CI] = 0.917 to 0.981) and 0.887 (95% CI = 0.817 to 0.957) with sensitivities of 0.849 and 0.667 at 95% specificity in discriminating early-stage PDAC vs healthy subjects in the combined validation and test sets, respectively. The performance of the biomarker panel was statistically significantly improved compared with CA19-9 alone (P < .001, combined validation set; P = .008, test set).

Conclusion

The addition of TIMP1 and LRG1 immunoassays to CA19-9 statistically significantly improves the detection of early-stage PDAC.

A nomogram to predict pathologic lymph node positivity in clinical stage I-II pancreatic adenocarcinoma

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Background: Clinical nodal staging in PDAC is inaccurate. Most pts are cN0, but > 70% are pN+. We hypothesize that preoperative variables are associated with pN+ and could be used to create a predictive nomogram. Methods: The NCDB was reviewed from 2010-13 for pts with clinical stage I-II PDAC. Exclusions were neoadjuvant therapy, < 12 nodes examined, and missing data for clinical/pathologic stage, size, and number of nodes examined/positive. Logistic regression assessed factors associated with pN+ and an interaction was included for extrapancreatic extension and cN stage. A logistic regression based nomogram was constructed and 10-fold cross validation evaluated model discrimination. Results: Of 7,475 pts, 28% were cN+ but 74% were pN+ (P < 0.001). Associations of preoperative factors with pN+ are shown. Size was pathology based. We recommend multiplying imaging based size estimates by 1.33 for use in the nomogram based on studies showing that imaging underestimates size by 25%. Interestingly, extrapancreatic extension was protective for cN0 pts but associated with increased odds of pN+ for cN1 relative to cN0 ps. A nomogram was created to predict pN+ using these variables. The 10-fold cross validated AUC was 0.77. Conclusions: Our nomogram has good discrimination to preoperatively predict lymph node positivity for patients with resectable PDAC. It could potentially be useful in identifying biologically aggressive resectable PDAC pts at higher risk of pN+ in order to select pts for neoadjuvant therapy. [Table: see text]

Biomarkers in pancreatic adenocarcinoma: current perspectives

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, with a 5-year survival rate of 7.7%. Most patients are diagnosed at an advanced stage not amenable to potentially curative resection. A substantial portion of this review is dedicated to reviewing the current literature on carbohydrate antigen (CA 19-9), which is currently the only guideline-recommended biomarker for PDAC. It provides valuable prognostic information, can predict resectability, and is useful in decision making about neoadjuvant therapy. We also discuss carcinoembryonic antigen (CEA), CA 125, serum biomarker panels, circulating tumor cells, and cell-free nucleic acids. Although many biomarkers have now been studied in relation to PDAC, significant work still needs to be done to validate their usefulness in the early detection of PDAC and management of patients with PDAC.

Abstract B23: Plasma basigin as an early detection biomarker for pancreatic adenocarcinoma

Poor survival rates for pancreatic adenocarcinoma (PDAC) are in part due to late presentation. Earlier diagnosis is recognized as a means to improve outcomes by increasing the possibility for potentially curative treatment. Identification of early detection biomarkers is a research priority. The stromal compartment is a potential source for biomarkers as a strong desmoplastic response is a hallmark of PDAC. The interaction of mesenchymal, cancer, and inflammatory cells in the tumor induce secretion of autocrine and paracrine effectors and extracellular matrix remodeling enzymes that contribute to tumor growth, invasion, angiogenesis, and metastasis. Basigin (BSG), a cell surface glycoprotein, plays a role in the interaction of cancer and mesenchymal cells through the stimulation of extracellular matrix remodeling enzymes. Circulating BSG has also been demonstrated as a diagnostic/prognostic biomarker for other cancers. We evaluated the potential utility of plasma BSG as a PDAC diagnostic and prognostic biomarker.

BSG levels were measured by ELISA in plasma from 106 healthy control subjects (mean = 3.29 ng/ml, 95% CI =3.0 – 3.6), 77 patients with chronic pancreatitis (3.72 ng/ml, 3.3 – 4.1 CI), and 112 pre-treatment samples from patients with PDAC (4.19 ng/ml, 3.9 – 4.5 CI). Nonparametric analysis revealed a significant difference for the model (P = 0.02, Wilcoxon). By ANOVA and Tukey-Kramer post-hoc tests, the distributions of BSG levels in PDAC and healthy control subjects were significantly different (P = 0.0003), but the comparison of PDAC to chronic pancreatitis cases was not significant (P = 0.147). A striking difference was noted after separating the PDAC cases into early stage (I-II) and late stage (III-IV) groups. ANOVA indicated that early stage disease (N = 70, 4.61 ng/ml, 4.2 – 5.0 CI) had significantly elevated BSG levels compared to healthy controls (P &lt; 0.0001), chronic pancreatitis cases (P = 0.006), and late stage PDAC cases (P = 0.003, N = 42, 3.48 ng/ml, 2.9 – 3.9 CI). Increased plasma BSG levels were also significantly related to decreased survival in univariate Cox proportional hazards models (P = 0.01) indicating a 14% increase in risk per 1 ng/ml. This relationship remained significant in multivariate models adjusting for stage and post-diagnosis treatments.

The results suggest that circulating BSG is an early stage phenomenon during PDAC development and would apparently be unique in its ability to specifically identify early stage PDAC cases. If validated, this biomarker should substantially contribute to the accuracy of an early detection biomarker panel. Further investigations are warranted into the usefulness of circulating BSG for early detection, selection of patients for surgical resection, identification of recurrence, screening high-risks groups and/or inclusion in panel screens.

Citation Format: Samaa Kamal, Matthew A. Firpo, Courtney L. Scaife, Adler G. Douglas, Kenneth M. Boucher, Sean J. Mulvihill. Plasma basigin as an early detection biomarker for pancreatic adenocarcinoma. [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 B23.

Pancreatic adenocarcinoma, version 2.2014: featured updates to the NCCN guidelines

The NCCN Guidelines for Pancreatic Adenocarcinoma discuss the diagnosis and management of adenocarcinomas of the exocrine pancreas and are intended to assist with clinical decision-making. These NCCN Guidelines Insights summarize major discussion points from the 2014 NCCN Pancreatic Adenocarcinoma Panel meeting. The panel discussion focused mainly on the management of borderline resectable and locally advanced disease. In particular, the panel discussed the definition of borderline resectable disease, role of neoadjuvant therapy in borderline disease, role of chemoradiation in locally advanced disease, and potential role of newer, more active chemotherapy regimens in both settings.

Defective apical extrusion signaling contributes to aggressive tumor hallmarks

When epithelia become too crowded, some cells are extruded that later die. To extrude, a cell produces the lipid, Sphingosine 1-Phosphate (S1P), which activates S1P₂ receptors in neighboring cells that seamlessly squeeze the cell out of the epithelium. Here, we find that extrusion defects can contribute to carcinogenesis and tumor progression. Tumors or epithelia lacking S1P₂ cannot extrude cells apically and instead form apoptotic-resistant masses, possess poor barrier function, and shift extrusion basally beneath the epithelium, providing a potential mechanism for cell invasion. Exogenous S1P₂ expression is sufficient to rescue apical extrusion, cell death, and reduce orthotopic pancreatic tumors and their metastases. Focal Adhesion Kinase (FAK) inhibitor can bypass extrusion defects and could, therefore, target pancreatic, lung, and colon tumors that lack S1P₂ without affecting wild-type tissue.

DOI:http://dx.doi.org/10.7554/eLife.04069.001

Epithelial cells cover the surface of our bodies, line our lungs, stomach and intestines and serve as a protective layer around other organs. If too many epithelial cells die and are not replaced, this protective layer may erode and lead to organ damage. However, if too many new cells grow, tumors can form.

One process that helps to maintain the right number of epithelial cells is called extrusion. When too many epithelial cells are present, the resulting overcrowding triggers this process to squeeze excess cells out of the layer and away from the organ. Usually, these cells quickly die. However, if the pathway that regulates this process—which involves a receptor protein called S1P₂—is disturbed, the cells may instead be pushed into the space between the epithelial layer and the organ. When this happens, the cells are more likely to survive and may then form a tumor that invades the organ.

Gu et al. interfered with extrusion by reducing the levels of the S1P₂ receptor in layers of human epithelial cells grown in the laboratory. Fewer epithelial cells were squeezed out of these cell layers, making the layers up to three times as thick in places. Moreover, mutant zebrafish lacking the S1P₂ receptor also accumulated epithelial masses throughout their bodies.

Gu et al. found that disrupting the extrusion process made the cells resistant to chemotherapy, and that certain hard-to-treat human pancreatic, lung, and colon cancers had lower levels of the S1P₂ receptors. Boosting the activity of S1P₂ receptors helped to restore normal extrusion and reduced the size of pancreatic tumors in mice.

Gu et al. then focused on an enzyme called Focal Adhesion Kinase that helps cells to survive. Treating zebrafish with a drug to block the activity of this enzyme left normal fish unharmed. However, in mutant fish with malfunctioning extrusion pathways, the drug rescued the number of cells that died, reduced the size and number of masses, and cured their leaky skin barrier. If further studies confirm the results, the drug may offer a new, less toxic, treatment for certain cancers that do not respond to currently available treatments.

DOI:http://dx.doi.org/10.7554/eLife.04069.002

Accuracy of diagnosing pancreatic ductal adenocarcinoma by EUS-FNA at a single institution

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Background: Endoscopic ultrasound-directed fine needle aspiration (EUS-FNA) in combination with imaging is currently the standard preoperative diagnostic method for pancreatic ductal adenocarcinoma (PDA). Previous studies have reported sensitivities and specificities ranging from 80%-90% and accuracies of approximately 85%. Our goal was to determine the accuracy of EUS-FNA for detecting PDA in individual patients at our institution. Methods: We conducted a retrospective chart review using the Clinical Cancer Research Database at Huntsman Cancer Institute (HCI). We included all cases in which pancreatic lesions were evaluated by EUS-FNA and a subsequent surgical resection was performed. All patients that met these criteria at HCI between March 1999 and April 2014 were included. Descriptive variables were calculated by comparing EUS-FNA results to final surgical diagnoses. The variables used to determine these values were; false positive = PDA by EUS-FNA and negative at resection, true positive = PDA for both, false negative = negative for PDA at EUS-FNA and positive at resection, true negative = negative for both. We considered atypical cells positive for PDA since their presence mandates aggressive intervention by the treating clinician. Results: Of the 242 patients that met the inclusion criterion, 139 were female with an average age of 58 +/- 15 (mean +/- standard deviation) and 103 were male with an average age of 62 +/- 13. In terms of diagnosing PDA by EUS-FNA we determined the sensitivity 89% (81%-94%; 95% confidence interval), specificity 76% (68%-83%), positive predictive value of 74% (66%-82%), and negative predictive value 89% (82%-94%). Conclusions: Although our findings are relatively consistent with the current literature, there is discernible potential for inappropriate treatment of patients based purely on EUS-FNA evaluation. Limitations of this study are the appraisal at a single institution and the necessity to evaluate only cases that ultimately had surgical resection of the pancreatic lesion.

Value Driven Outcomes (VDO): a pragmatic, modular, and extensible software framework for understanding and improving health care costs and outcomes

OBJECTIVE

To develop expeditiously a pragmatic, modular, and extensible software framework for understanding and improving healthcare value (costs relative to outcomes).

MATERIALS AND METHODS

In 2012, a multidisciplinary team was assembled by the leadership of the University of Utah Health Sciences Center and charged with rapidly developing a pragmatic and actionable analytics framework for understanding and enhancing healthcare value. Based on an analysis of relevant prior work, a value analytics framework known as Value Driven Outcomes (VDO) was developed using an agile methodology. Evaluation consisted of measurement against project objectives, including implementation timeliness, system performance, completeness, accuracy, extensibility, adoption, satisfaction, and the ability to support value improvement.

RESULTS

A modular, extensible framework was developed to allocate clinical care costs to individual patient encounters. For example, labor costs in a hospital unit are allocated to patients based on the hours they spent in the unit; actual medication acquisition costs are allocated to patients based on utilization; and radiology costs are allocated based on the minutes required for study performance. Relevant process and outcome measures are also available. A visualization layer facilitates the identification of value improvement opportunities, such as high-volume, high-cost case types with high variability in costs across providers. Initial implementation was completed within 6 months, and all project objectives were fulfilled. The framework has been improved iteratively and is now a foundational tool for delivering high-value care.

CONCLUSIONS

The framework described can be expeditiously implemented to provide a pragmatic, modular, and extensible approach to understanding and improving healthcare value.

HR-MAS MRS of the pancreas reveals reduced lipid and elevated lactate and taurine associated with early pancreatic cancer

The prognosis for patients with pancreatic cancer is extremely poor, as evidenced by the disease's five-year survival rate of ~5%. New approaches are therefore urgently needed to improve detection, treatment, and monitoring of pancreatic cancer. MRS-detectable metabolic changes provide useful biomarkers for tumor detection and response-monitoring in other cancers. The goal of this study was to identify MRS-detectable biomarkers of pancreatic cancer that could enhance currently available imaging approaches. We used (1) H high-resolution magic angle spinning MRS to probe metabolite levels in pancreatic tissue samples from mouse models and patients. In mice, the levels of lipids dropped significantly in pancreata with lipopolysaccharide-induced inflammation, in pancreata with pre-cancerous metaplasia (4 week old p48-Cre;LSL-Kras(G12D) mice), and in pancreata with pancreatic intraepithelial neoplasia, which precedes invasive pancreatic cancer (8 week old p48-Cre LSL-Kras(G12D) mice), to 26 ± 19% (p = 0.03), 19 ± 16% (p = 0.04), and 26 ± 10% (p = 0.05) of controls, respectively. Lactate and taurine remained unchanged in inflammation and in pre-cancerous metaplasia but increased significantly in pancreatic intraepithelial neoplasia to 266 ± 61% (p = 0.0001) and 999 ± 174% (p < 0.00001) of controls, respectively. Importantly, analysis of patient biopsies was consistent with the mouse findings. Lipids dropped in pancreatitis and in invasive cancer biopsies to 29 ± 15% (p = 0.01) and 26 ± 38% (p = 0.02) of normal tissue. In addition, lactate and taurine levels remained unchanged in inflammation but rose in tumor samples to 244 ± 155% (p = 0.02) and 188 ± 67% (p = 0.02), respectively, compared with normal tissue. Based on these findings, we propose that a drop in lipid levels could serve to inform on pancreatitis and cancer-associated inflammation, whereas elevated lactate and taurine could serve to identify the presence of pancreatic intraepithelial neoplasia and invasive tumor. Our findings may help enhance current imaging methods to improve early pancreatic cancer detection and monitoring.

Screening for pancreatic cancer

Even with improved cancer care generally, the incidence and death rate is increasing for pancreatic cancer. Concern exists that a further increase in deaths caused by pancreatic cancer will be seen as other causes of death, such as heart disease and other cancers, decline. Critical exploration of screening high-risk patients as a tool to reduce deaths from pancreatic cancer should be considered. Technological advances and improved understanding of pancreatic cancer biology provides an opportunity to identify and test a panel of early detection biomarkers easily, accurately, and inexpensively measured in blood, urine, stool, or saliva samples. These biomarkers may have additional usefulness in staging, stratification for treatment, establishing prognosis, and assessing response to therapy in this disease. Screening may prove to be one of several strategies to improve outcomes in a disease that has otherwise been difficult to defeat.

Prospects for developing an accurate diagnostic biomarker panel for low prevalence cancers

BACKGROUND

Early detection screening of asymptomatic populations for low prevalence cancers requires a highly specific test in order to limit the cost and anxiety produced by falsely positive identifications. Most solid cancers are a heterogeneous collection of diseases as they develop from various combinations of genetic lesions and epigenetic modifications. Therefore, it is unlikely that a single test will discriminate all cases of any particular cancer type. We propose a novel, intuitive biomarker panel design that accommodates disease heterogeneity by allowing for diverse biomarker selection that increases diagnostic accuracy.

METHODS

Using characteristics of nine pancreatic ductal adenocarcinoma (PDAC) biomarkers measured in human sera, we modeled the behavior of biomarker panels consisting of a sum of indicator variables representing a subset of biomarkers within a larger biomarker data set. We then chose a cutoff for the sum to force specificity to be high and delineated the number of biomarkers required for adequate sensitivity of PDAC in our panel design.

RESULTS

The model shows that a panel consisting of 40 non-correlated biomarkers characterized individually by 32% sensitivity at 95% specificity would require any 7 biomarkers to be above their respective thresholds and would result in a panel specificity and sensitivity of 99% each.

CONCLUSIONS

A highly accurate blood-based diagnostic panel can be developed from a reasonable number of individual serum biomarkers that are relatively weak classifiers when used singly. A panel constructed as described is advantageous in that a high level of specificity can be forced, accomplishing a prerequisite for screening asymptomatic populations for low-prevalence cancers.

Serum IGFBP2 and MSLN as diagnostic and prognostic biomarkers for pancreatic cancer

BACKGROUND

Identification of diagnostic and prognostic biomarkers is a research priority for the improved management of pancreatic ductal adenocarcinoma (PDAC). Insulin-like growth factor binding protein 2 (IGFBP2) and mesothelin (MSLN) have shown potential as serum biomarkers in other cancers, but have not been adequately studied in PDAC.

METHODS

Serum IGFBP2 and MSLN levels were quantified by enzyme-linked immunosorbent assay (ELISA) in a cohort of 84 PDAC patients, 84 healthy control subjects and 40 chronic pancreatitis (ChPT) patients. Regression models related IGFBP2 and MSLN levels to diagnosis, gender, age, stage and survival.

RESULTS

IGFPB2 and MSLN serum levels were diagnostic for PDAC in age-adjusted models (P = 0.032 and P = 0.002, respectively) when compared with ChPT and healthy control samples. At a 95% specificity threshold, the sensitivity for IGFBP2 was 22% and the sensitivity for MSLN was 17%. Neither protein approached the diagnostic accuracy of CA 19-9. However, IGFBP2 or MSLN or both correctly identified 18 of the 28 samples misidentified by CA 19-9. In age-adjusted models, neither serum IGFBP2 (P = 0.36) nor MSLN (P = 0.29) were significant predictors of survival.

DISCUSSION

Serum IGFBP2 and MSLN are weak diagnostic classifiers individually, but may be useful in a diagnostic biomarker panel.

Does travel distance influence length of stay in elective pancreatic surgery?

BACKGROUND

Length of stay (LoS) following elective surgery is being reported as an outcomes quality measure. Regional referral centres may care for patients travelling significant distances. The effect of travel distance on LoS in pancreatic surgery patients was examined.

METHODS

National Surgical Quality Improvement Program data on pancreatic surgery patients, operated during the period from 2005 to 2011, were reviewed. Demographics, surgical variables and distance travelled were analysed relative to LoS. The LoS was log-transformed in general linear models to achieve normality.

RESULTS

Of the 243 patients, 53% were male. The mean ± standard deviation (SD) age of the total patient sample was 60.6 ± 14 years. The mean ± SD distance travelled was 203 ± 319 miles (326.7 ± 513.4 km) [median: 132 miles (212.4 km); range: 3-3006 miles (4.8-4837.7 km)], and the mean ± SD LoS was 10.5 ± 7 days (range: 1-46 days). Univariate analysis showed a near significant increase in LoS with increased distance travelled (P = 0.05). Significant variables related to LoS were: age (P = 0.002); relative value units (P < 0.001), and preoperative American Society of Anesthesiologists class (P = 0.005). In a general linear model, for every 100 miles (160.9 km) travelled there is an associated 2% increase in LoS (P = 0.031). When the distance travelled is increased by 500 miles (804.7 km), LoS increases by 10.5%.

CONCLUSIONS

Increased travel distance from a patient's home to the hospital was independently associated with an increase in LoS. If LoS is a reportable quality measure in pancreatic surgery, travel distance should be considered in risk adjustments.

Comparison of intraoperative versus delayed enteral feeding tube placement in patients undergoing a Whipple procedure

BACKGROUND

The intraoperative placement of an enteral feeding tube (FT) during pancreaticoduodenectomy (PD) is based on the surgeon's perception of need for postoperative nutrition. Published preoperative risk factors predicting postoperative morbidity may be used to predict FT need and associated intraoperative placement.

METHODS

A retrospective review of patients who underwent PD during 2005-2011 was performed by querying the National Surgical Quality Improvement Program (NSQIP) database with specific procedure codes. Patients were categorized based on how many of 10 possible preoperative risk factors they demonstrated. Groups of patients with scores of ≤ 1 (low) and ≥ 2 (high), respectively, were compared for FT need, length of stay (LoS) and organ space surgical site infections (SSIs).

RESULTS

Of 138 PD patients, 82 did not have an FT placed intraoperatively, and, of those, 16 (19.5%) required delayed FT placement. High-risk patients were more likely to require a delayed FT (29.3%) compared with low-risk patients (9.8%) (P = 0.026). The 16 patients who required a delayed FT had a median LoS of 15.5 days, whereas the 66 patients who did not require an FT had a median LoS of 8 days (P < 0.001).

CONCLUSIONS

In this analysis, subjects considered as high-risk patients were more likely to require an FT than low-risk patients. Assessment of preoperative risk factors may improve decision making for selective intraoperative FT placement.

Serum osteopontin and tissue inhibitor of metalloproteinase 1 as diagnostic and prognostic biomarkers for pancreatic adenocarcinoma

OBJECTIVES

Pancreatic ductal adenocarcinoma (PDAC) has a dismal 5-year survival rate of 5%. There is an urgent need for early detection while the tumors are small and surgically resectable. We assessed serum osteopontin (OPN) and tissue inhibitor of metalloproteinase 1 (TIMP-1) as possible diagnostic and prognostic biomarkers in a novel cohort of patients with pancreatic cancer.

METHODS

Osteopontin and TIMP-1 levels were determined in sera from 86 patients with PDAC, 86 healthy control subjects, and 48 patients with chronic pancreatitis. Regression models were used to relate OPN and TIMP-1 to sex, age, stage, class, and treatment. Survival analyses were performed using univariate and multivariate Cox models.

RESULTS

The serum levels of both OPN and TIMP-1 distinguished PDAC from chronic pancreatitis (P ≤ 0.0001) and healthy control subjects (P < 0.0001). The serum levels of both OPN and TIMP-1 also distinguished early-stage resectable PDAC cases from chronic pancreatitis (P < 0.04) and healthy control subjects (P < 0.01). High serum levels of OPN were significantly correlated with reduced patient survival.

CONCLUSIONS

Serum OPN and TIMP-1 have use as diagnostic biomarkers in PDAC. Our data suggest a potential benefit of using OPN, TIMP-1, and CA 19-9 in a panel to improve diagnostic accuracy in PDAC.

The clinical utility of CA 19-9 in pancreatic adenocarcinoma: diagnostic and prognostic updates

CA 19-9 and CEA are the most commonly used biomarkers for diagnosis and management of patients with pancreatic cancer. Since the original compendium by Steinberg in 1990, numerous studies have reported the use of CA 19-9 and, to a lesser extent, CEA in the diagnosis of pancreatic cancer. Here we update an evaluation of the accuracy of CA 19-9 and CEA, and, unlike previous reviews, focus on discrimination between malignant and benign disease instead of normal controls. In 57 studies involving 3,285 pancreatic carcinoma cases, the combined sensitivity of CA 19-9 was 78.2% and in 37 studies involving 1,882 cases with benign pancreatic disease the specificity of CA 19-9 was 82.8%. From the combined analysis of studies reporting CEA, the sensitivity was 44.2% (1,324 cases) and the specificity was 84.8% (656 cases). These measurements more appropriately reflect the expected biomarker accuracy in the differential diagnosis of patients with periampullary diseases. We also present a summary of the use of CA 19-9 as a prognostic tool and evaluate CA 19-9 diagnostic and prognostic utility in a 10-year, single institution experience.

Effect of venous involvement on survival in locally advanced pancreatic cancer

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Background: Locally advanced pancreatic cancer is defined as tumor that extends beyond the pancreas into surrounding structures. Borderline resectable disease usually includes a description of superior mesenteric vein (SMV) or portal vein (PV) involvement, while the AJCC staging no longer includes venous involvement in the staging system. We reviewed our institutional cancer database to determine if venous involvement affects overall survival and should be included in pancreatic ductal adenocarcinoma (PDA) staging. Methods: A retrospective review was performed of all patients with stage II or III PDA identified through our institutional prospective Clinical Cancer Research Database, between 2007-2012. Patients with superior mesenteric artery (SMA) or celiac artery and/or venous (SMV or PV) involvement were compared to those without. Vascular involvement was defined as either vessel encasement or abutment on endoscopic ultrasound or CT imaging. Survival analysis was performed using the Kaplan-Meier method with log-rank test for comparison of survival curves. Results: A total of 194 patients were identified as having stage II or stage III pancreatic adenocarcinoma, with 85 having evidence of vascular involvement. In our patient population we found that in patients with stage IIA and IIB disease PV or SMV involvement did not portend statistically worse survival (median survival 14 months v 15 months p=0.63). In stage III patients survival was actually longer in patients with PV or SMV involvement, but this was not statistically significant (median survival 13 months v 7.9 months p=.066). When comparing those with PV or SMV involvement versus those with celiac axis or superior mesenteric artery (SMA) involvement in all patients with locally advanced pancreatic cancer (stage II or III), those with celiac or SMA involvement did significantly worse (mean survival 14 months v. 7.9 months p<0.001). Conclusions: Venous involvement does not portend a worse survival in patients with stage II and III pancreatic cancer. The addition of venous involvement to the current AJCC staging scheme would not provide additional survival information.

Toward development of a surface-enhanced Raman scattering (SERS)-based cancer diagnostic immunoassay panel

Proteomic analyses of readily obtained human fluids (e.g., serum, urine, and saliva) indicate that the diagnosis of complex diseases will be enhanced by the simultaneous measurement of multiple biomarkers from such samples. This paper describes the development of a nanoparticle-based multiplexed platform that has the potential for simultaneous read-out of large numbers of biomolecules. For this purpose, we have chosen pancreatic adenocarcinoma (PA) as a test bed for diagnosis and prognosis. PA is a devastating form of cancer in which an estimated 86% of diagnoses resulted in death in the United States in 2010. The high mortality rate is due, in part, to the asymptomatic development of the disease and the dearth of sensitive diagnostics available for early detection. One promising route lies in the development of a serum biomarker panel that can generate a signature unique to early stage PA. We describe the design and development of a proof-of-concept PA biomarker immunoassay array coupled with surface-enhanced Raman scattering (SERS) as a sensitive readout method.

Pancreatic Adenocarcinoma, version 2.2012: featured updates to the NCCN Guidelines

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Pancreatic Adenocarcinoma discuss the workup and management of tumors of the exocrine pancreas. These NCCN Guidelines Insights provide a summary and explanation of major changes to the 2012 NCCN Guidelines for Pancreatic Adenocarcinoma. The panel made 3 significant updates to the guidelines: 1) more detail was added regarding multiphase CT techniques for diagnosis and staging of pancreatic cancer, and pancreas protocol MRI was added as an emerging alternative to CT; 2) the use of a fluoropyrimidine plus oxaliplatin (e.g., 5-FU/leucovorin/oxaliplatin or capecitabine/oxaliplatin) was added as an acceptable chemotherapy combination for patients with advanced or metastatic disease and good performance status as a category 2B recommendation; and 3) the panel developed new recommendations concerning surgical technique and pathologic analysis and reporting.

Pancreatic Adenocarcinoma, version 2.2012: featured updates to the NCCN Guidelines

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Pancreatic Adenocarcinoma discuss the workup and management of tumors of the exocrine pancreas. These NCCN Guidelines Insights provide a summary and explanation of major changes to the 2012 NCCN Guidelines for Pancreatic Adenocarcinoma. The panel made 3 significant updates to the guidelines: 1) more detail was added regarding multiphase CT techniques for diagnosis and staging of pancreatic cancer, and pancreas protocol MRI was added as an emerging alternative to CT; 2) the use of a fluoropyrimidine plus oxaliplatin (e.g., 5-FU/leucovorin/oxaliplatin or capecitabine/oxaliplatin) was added as an acceptable chemotherapy combination for patients with advanced or metastatic disease and good performance status as a category 2B recommendation; and 3) the panel developed new recommendations concerning surgical technique and pathologic analysis and reporting.

Roux-en-Y drainage of a pancreatic fistula for disconnected pancreatic duct syndrome after acute necrotizing pancreatitis

BACKGROUND

After acute necrotizing pancreatitis (ANP), a pancreatic fistula may occur from disconnected pancreatic duct syndrome (DPDS) where a segment of the pancreas is no longer in continuity with the main pancreatic duct.

AIM

To study the outcome of patients treated using Roux-Y pancreatic fistula tract-jejunostomy for DPDS after ANP.

METHODS

Between 2002 and 2011, patients treated for DPDS in the setting of endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopanreatography (MRCP) documented main pancreatic duct disruption with Roux-Y pancreatic fistula tract-jejunostomy.

RESULTS

In all, seven patients with DPDS were treated. The median age was 62 years (range 49-78) and five were men. The cause of ANP was gallstones (2), alcohol (1), ERCP (1) and idiopathic (3). Pancreatic necrosectomy was done in six patients. Time from onset of pancreatitis to fistula drainage was 270 days (164-365). Pancreatic fistulae arose from DPDS in the head/neck (4) and body/tail (3). Patients had a median fistula output of 140 ml (100-200) per day before surgery. The median operative time was 142 min (75-367) and estimated blood loss was 150 ml (25 to 500). Patients began an oral diet on post-operative day 4 (3-6) and were hospitalized for a median of 7 days (5-12). The median follow-up was 264 days (29-740). Subsequently, one patient required a distal pancreatectomy. After surgery, three patients required oral hypoglycaemics. No patient developed pancreatic exocrine insufficiency.

CONCLUSION

Internal surgical drainage using Roux-en-Y pancreatic fistula tract-jejunostomy is a safe and definitive treatment for patients with DPDS.

Stat3 and MMP7 contribute to pancreatic ductal adenocarcinoma initiation and progression

Chronic pancreatitis is a well-known risk factor for pancreatic ductal adenocarcinoma (PDA) development in humans, and inflammation promotes PDA initiation and progression in mouse models of the disease. However, the mechanistic link between inflammatory damage and PDA initiation is unclear. Using a Kras-driven mouse model of PDA, we establish that the inflammatory mediator Stat3 is a critical component of spontaneous and pancreatitis-accelerated PDA precursor formation and supports cell proliferation, metaplasia-associated inflammation, and MMP7 expression during neoplastic development. Furthermore, we show that Stat3 signaling enforces MMP7 expression in PDA cells and that MMP7 deletion limits tumor size and metastasis in mice. Finally, we demonstrate that serum MMP7 level in human patients with PDA correlated with metastatic disease and survival.

A population-based description of familial clustering of pancreatic cancer

BACKGROUND & AIMS

Several familial pancreatic cancer syndromes have been identified. However, the prevalence of familial pancreatic cancers in the general population has not been well defined.

METHODS

We linked pancreatic cancer cases, identified through the Utah Cancer Registry, to the Utah Population Database, which contains genealogic data from Utah pioneers and their descendants. This database includes 1411 pancreatic adenocarcinoma cases with 3 or more generations of Utah pioneer genealogy. We examined the familial clustering of pancreatic cancer by evaluating the relative risk (RR) of pancreatic cancer among relatives of cases. We also used the genealogical index of familiality to test the hypothesis of no excess relatedness among pancreatic cancer cases.

RESULTS

The risk of pancreatic cancer was significantly increased in first-degree (RR, 1.84; 95% confidence interval [CI], 1.47-2.29; P < .0001) and second-degree (RR, 1.59; 95% CI, 1.31-2.91; P < .0001) relatives of individuals with pancreatic cancer. Analysis of case relatedness indicated significant excess relatedness for pancreatic cancer. More than 300 high-risk pedigrees were identified, with from 3-14 cases observed among descendants of pedigree founders.

CONCLUSIONS

This population-based study provides evidence for increased risk of pancreatic cancer among relatives of cases and for a significantly higher average relatedness among cases than expected. These observations support the role of genetic factors in pancreatic cancer.

Serum platelet factor 4 is an independent predictor of survival and venous thromboembolism in patients with pancreatic adenocarcinoma

BACKGROUND

Improved diagnostic, predictive, and prognostic biomarkers for pancreatic ductal adenocarcinoma (PDAC) are urgently needed. Platelet factor 4 (PF4) has been proposed as a diagnostic biomarker for PDAC. We assessed the diagnostic and prognostic potential of serum PF4 levels in PDAC patients.

METHODS

Serum PF4 levels were determined by enzyme-linked immunosorbent assay in an initial cohort of 62 PDAC patients, 62 healthy control subjects, and 34 chronic pancreatitis patients. A second validation set consisted of 71 PDAC patients. Linear regression models were used to relate PF4 to class, gender, age, stage, platelet count, and diagnosis. Survival analyses were done using univariate and multivariate Cox models.

RESULTS

In the initial cohort, serum PF4 levels distinguished PDAC from chronic pancreatitis patients (P = 0.011), but not from healthy control subjects (P = 0.624). In PDAC patients, high serum PF4 level significantly predicted decreased survival independent of all covariates examined (P < 0.01). The prognostic relationship of serum PF4 levels remained significant in the validation set. Venous thromboembolism (VTE) occurred in 20% of the 133 PDAC patients. The VTE risk was higher in subjects with elevated PF4 levels (P = 0.009).

CONCLUSIONS

Serum PF4 is shown for the first time to be prognostic for survival in PDAC patients. High PF4 is associated with an increased risk for the development of VTE.

IMPACT

Serum PF4 levels may be useful for patient stratification and for directing treatment options in patients with pancreatic cancer including anticoagulation prophylaxis. The relationship between high PF4 levels and poorer outcomes requires further study.

Prognostic significance of PINCH signalling in human pancreatic ductal adenocarcinoma

OBJECTIVE

Prognostic markers for pancreatic ductal adenocarcinoma (PDA) have failed to accurately predict patient prognosis. Recently, interest has developed in the accuracy of integrin-associated PINCH protein expression in human cancers as a predictive marker of tumour status. The goal of this study was to define the expression of PINCH protein in PDA.

METHODS

Human PDA samples and orthotopic tumours from a murine model were analysed by immunohistochemistry for PINCH expression. In the animal model, PINCH expression was compared between primary and metastatic tumours. In the human samples, PINCH expression was correlated with stage, nodal involvement, margin status and overall survival.

RESULTS

In the murine model, there was greater PINCH expression in metastatic tumours than in primary tumours. In the human PDA samples, greater staining for PINCH in the tumour cells was correlated with higher T status. Additionally, high PINCH expression in the stroma was associated with decreased overall survival.

CONCLUSIONS

Findings of increased PINCH protein in more advanced stages of human PDA, as well as in metastatic tumours in the animal model, support the hypothesis that PINCH is an important controller of cell survival and migration. Additionally, the importance of the differential expression of PINCH in the human tumour and stroma warrants further evaluation.

ACS-NSQIP has the potential to create an HPB-NSQIP option

BACKGROUND

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) was started in 2004. Presently, 58% of the 198 hospitals participating in ACS-NSQIP are academic or teaching hospitals. In 2008, ACS-NSQIP initiated a number of changes and made risk-adjusted data available for use by participating hospitals. This analysis explores the ACS-NSQIP database for utility in developing hepato-pancreato-biliary (HPB) surgery-specific outcomes (HPB-NSQIP).

METHODS

The ACS-NSQIP Participant Use File was queried for patient demographics and outcomes for 49 HPB operations from 1 January 2005 through 31 December 2007. The procedures included six hepatic, 16 pancreatic and 23 complex biliary operations. Four laparoscopic or open cholecystectomy operations were also studied. Risk-adjusted probabilities for morbidity and mortality were compared with observed rates for each operation.

RESULTS

During this 36-month period, data were accumulated on 9723 patients who underwent major HPB surgery, as well as on 44,189 who received cholecystectomies. The major HPB operations included 2847 hepatic (29%), 5074 pancreatic (52%) and 1802 complex biliary (19%) procedures. Patients undergoing hepatic resections were more likely to have metastatic disease (42%) and recent chemotherapy (7%), whereas those undergoing complex biliary procedures were more likely to have significant weight loss (20%), diabetes (13%) and ascites (5%). Morbidity was high for hepatic, pancreatic and complex biliary operations (20.1%, 32.4% and 21.2%, respectively), whereas mortality was low (2.3%, 2.7% and 2.7%, respectively). Compared with laparoscopic cholecystectomy, the open operation was associated with higher rates of morbidity (19.2% vs. 6.0%) and mortality (2.5% vs. 0.3%). The ratios between observed and expected morbidity and mortality rates were <1.0 for hepatic, pancreatic and biliary operations.

CONCLUSIONS

These data suggest that HPB operations performed at ACS-NSQIP hospitals have acceptable outcomes. However, the creation of an HPB-NSQIP has the potential to improve quality, provide risk-adjusted registries with HPB-specific data and facilitate multi-institutional clinical trials.

Improved diagnosis of pancreatic adenocarcinoma using haptoglobin and serum amyloid A in a panel screen

BACKGROUND

Timely, accurate diagnosis of pancreatic adenocarcinoma (PA) is hampered by the lack of effective circulating biomarkers. No single test has emerged that improves upon the commonly used biomarker cancer antigen 19-9 (CA 19-9) to discriminate PA from benign conditions effectively. The goals of this study were to validate two acute-phase proteins, haptoglobin and serum amyloid A (SAA), as biomarkers for PA and determine if the combination of haptoglobin, SAA, and CA 19-9 would improve PA diagnosis over CA 19-9 alone.

METHODS

Levels of haptoglobin, SAA, and CA 19-9 were measured in pretreatment sera from 75 PA patients, 32 patients with chronic pancreatitis, 42 patients with other benign pancreatic disease or biliary stricture, and 150 healthy control subjects by enzyme-linked immunosorbent assay or colorimetric binding assay. Relative levels of haptoglobin or SAA were compared between groups using analysis of variance. The diagnostic accuracy of serum haptoglobin and SAA levels were investigated using receiver operating characteristics (ROC) analysis. Using classification tree analysis, an algorithm was developed that used haptoglobin, SAA, and CA 19-9 in a diagnostic screening panel.

RESULTS

Both haptoglobin and SAA were significantly elevated in sera from PA patients compared to healthy control subjects (p<0.0001) and patients with chronic pancreatitis (p=0.01). Haptoglobin was significantly elevated in sera from PA patients relative to patients with other benign diseases (p=0.0015), whereas SAA fell short of significance in the same comparison (p=0.0508). ROC analysis indicated that haptoglobin [area under the curve (AUC)=0.792] was a better diagnostic marker than SAA (AUC=0.691) over multiple threshold cutoffs. Using specific cutoffs that minimized overall misclassification, haptoglobin yielded a sensitivity of 82.7% and a specificity of 71.1%, and SAA yielded a sensitivity of 34.7% and a specificity of 90.2% when discriminating PA cases from all non-PA controls. In the same sample set, CA 19-9 yielded a sensitivity of 77.3% and a specificity of 91.1%. Combining data from haptoglobin, SAA, and CA 19-9 in a diagnostic screening panel improved the overall accuracy when compared to CA 19-9 alone, yielding a sensitivity of 81.3% and a specificity of 95.5%.

CONCLUSIONS

These data demonstrate that haptoglobin and SAA are useful for discriminating PA from benign conditions as well as healthy controls when used in a diagnostic screening panel. This study supports the use of combined biomarkers for improved accuracy in the diagnosis of PA.

Synthetic extracellular matrix enhances tumor growth and metastasis in an orthotopic mouse model of pancreatic adenocarcinoma

Individuals with pancreatic cancer have one of the poorest survival rates among the major cancers, suggesting the need to develop new therapeutic approaches. An effective animal model that mimics the progression and metastases of human pancreatic adenocarcinoma does not exist. The goal of this investigation was to develop a model that would compare the growth and metastasis of orthotopically injected pancreatic cancer cells to cells encapsulated within a synthetic extracellular matrix (sECM). The hypotheses tested were that the cells within the sECM would grow more quickly and more frequently develop metastasis to distant organs. MiaPaCa-2 cells expressing red fluorescent protein, either in serum-free media or within a hyaluronan-based hydrogel, were injected into the pancreas of nude mice. Tumors were monitored for 8 weeks via intravital red fluorescent protein imaging. Cells encapsulated within the sECM grew more quickly and produced larger tumors compared with the cells alone. In addition, the cells within the sECM developed metastasis more frequently. Therefore, the encapsulation of human pancreatic cancer cells within an injectable sECM improved the rate of tumor growth and metastasis in an orthotopic mouse model. The advantages of this new approach can be utilized to investigate the mechanisms of tumor progression and test novel therapeutic agents in vivo.