Effects of novel Coronavirus (COVID-19) on presentation, management, and outcomes of acute cholecystitis at an academic tertiary care center cholecystitis management during COVID-19

Background

The COVID-19 pandemic necessitated adjustments to nearly all aspects of healthcare, including surgical care. The effects of these adjustments have not been well studied on acute surgical problems conventionally managed non-electively in large, tertiary care centers.

Methods

A retrospective analysis of admitted patients with acute cholecystitis at a US academic tertiary care center was performed. We compared the presentation, management, and 30-day outcomes of patients admitted during a 2-month time period during early COVID, to a pre-COVID control group of admitted cholecystitis patients over a 2-month span.

Results

The study cohort captured 24 patients, while the control cohort encompassed 53 patients. A non-significant trend toward non-operative management in the COVID cohort is reported. There was no delay in time-to-surgery or complication rate. No surgically managed patient developed COVID within 30 days of operation.

Conclusions

Operative management of acute cholecystitis during the COVID-19 pandemic, with pre-operative testing and personal protective equipment guidelines, remained safe and effective.

Surgical treatment of stage IV gastroenteropancreatic neuroendocrine carcinoma: Experience and outcomes in the United States

BACKGROUND AND OBJECTIVES

Surgery for metastatic gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC) has not been well-studied. This retrospective cohort study describes patients in the United States with stage IV GEP-NEC and their survival outcomes segregated by surgery.

METHODS

Patients diagnosed with stage IV GEP-NEC from 2004 to 2017 in the National Cancer Database were categorized into three groups: no surgery, primary site or metastatic site ("single-site") surgery, and primary site and metastatic site ("multisite") surgery. Factors associated with surgical treatment were identified, and risk-adjusted overall survival of each group was compared.

RESULTS

Of 4171 patients included, 958 (23.0%) underwent single-site surgery and 374 (9.0%) underwent multisite surgery. The strongest predictor of surgery was primary tumor type. Compared with no surgery, the risk-adjusted mortality reduction associated with single-site surgery ranged from 63% for small bowel (HR = 0.37, 0.23-0.58, p < 0.001) NEC to 30% for colon and appendix NEC (HR = 0.70, 0.61-0.80, p < 0.001), while the mortality reduction associated with multisite surgery ranged from 77% for pancreas NEC (HR = 0.23, 0.17-0.33, p < 0.001) to 48% for colon and appendix NEC (HR = 0.52, 0.44-0.63, p < 0.001).

CONCLUSIONS

We observed an association between extent of surgical intervention and overall survival for patients with stage IV GEP-NEC. Surgical resection should be further investigated as a treatment option for highly-selected patients with this aggressive disease.

Impact of COVID-19 on the gastrointestinal surgical oncology patient population

Background

The onset of the COVID-19 pandemic led to substantial alterations in healthcare delivery and access. In this study, we aimed to evaluate the impact of COVID-19 on the presentation and surgical care of patients with gastrointestinal (GI) cancers.

Methods

All patients who underwent GI cancer surgery at a large, tertiary referral center between March 15, 2019 and March 15, 2021 were included. March 15, 2020 was considered the start of the COVID-19 pandemic. Changes in patient, tumor, and treatment characteristics before the pandemic compared to during the pandemic were evaluated.

Results

Of 522 patients that met study criteria, 252 (48.3%) were treated before the COVID-19 pandemic. During the first COVID-19 wave, weekly volume of GI cancer cases was one-third lower than baseline (p = 0.041); during the second wave, case volume remained at baseline levels (p = 0.519). There were no demographic or tumor characteristic differences between patients receiving GI cancer surgery before versus during COVID-19 (p > 0.05 for all), and no difference in rate of emergency surgery (p > 0.9). Patients were more likely to receive preoperative chemotherapy during the first six months of the pandemic compared to the subsequent six months (35.6% vs. 15.5%, p < 0.001). Telemedicine was rapidly adopted at the start of the pandemic, rising from 0% to 47% of GI surgical oncology visits within two months.

Conclusions

The COVID-19 pandemic caused an initial disruption to the surgical care of GI cancers, but did not compromise stage at presentation. Preoperative chemotherapy and telemedicine were utilized to mitigate the impact of a high COVID-19 burden on cancer care.

Ampullary Adenocarcinoma, Version 1.2023, NCCN Clinical Practice Guidelines in Oncology

Ampullary cancers refer to tumors originating from the ampulla of Vater (the ampulla, the intraduodenal portion of the bile duct, and the intraduodenal portion of the pancreatic duct), while periampullary cancers may arise from locations encompassing the head of the pancreas, distal bile duct, duodenum, or ampulla of Vater. Ampullary cancers are rare gastrointestinal malignancies, and prognosis varies greatly based on factors such as patient age, TNM classification, differentiation grade, and treatment modality received. Systemic therapy is used in all stages of ampullary cancer, including neoadjuvant therapy, adjuvant therapy, and first-line or subsequent-line therapy for locally advanced, metastatic, and recurrent disease. Radiation therapy may be used in localized ampullary cancer, sometimes in combination with chemotherapy, but there is no high-level evidence to support its utility. Select tumors may be treated surgically. This article describes NCCN recommendations regarding management of ampullary adenocarcinoma.

Utility of promoter hypermethylation in malignant risk stratification of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs), a type of cystic pancreatic cancer (PC) precursors, are increasingly identified on cross-sectional imaging and present a significant diagnostic challenge. While surgical resection of IPMN-related advanced neoplasia, i.e., IPMN-related high-grade dysplasia or PC, is an essential early PC detection strategy, resection is not recommended for IPMN-low-grade dysplasia (LGD) due to minimal risk of carcinogenesis, and significant procedural risks. Based on their promising results in prior validation studies targeting early detection of classical PC, DNA hypermethylation-based markers may serve as a biomarker for malignant risk stratification of IPMNs. This study investigates our DNA methylation-based PC biomarker panel (ADAMTS1, BNC1, and CACNA1G genes) in differentiating IPMN-advanced neoplasia from IPMN-LGDs.

METHODS

Our previously described genome-wide pharmaco-epigenetic method identified multiple genes as potential targets for PC detection. The combination was further optimized and validated for early detection of classical PC in previous case-control studies. These promising genes were evaluated among micro-dissected IPMN tissue (IPMN-LGD: 35, IPMN-advanced neoplasia: 35) through Methylation-Specific PCR. The discriminant capacity of individual and combination of genes were delineated through Receiver Operating Characteristics curve analysis.

RESULTS

As compared to IPMN-LGDs, IPMN-advanced neoplasia had higher hypermethylation frequency of candidate genes: ADAMTS1 (60% vs. 14%), BNC1 (66% vs. 3%), and CACGNA1G (25% vs. 0%). We observed Area Under Curve (AUC) values of 0.73 for ADAMTS1, 0.81 for BNC1, and 0.63 for CACNA1G genes. The combination of the BNC1/ CACNA1G genes resulted in an AUC of 0.84, sensitivity of 71%, and specificity of 97%. Combining the methylation status of the BNC1/CACNA1G genes, blood-based CA19-9, and IPMN lesion size enhanced the AUC to 0.92.

CONCLUSION

DNA-methylation based biomarkers have shown a high diagnostic specificity and moderate sensitivity for differentiating IPMN-advanced neoplasia from LGDs. Addition of specific methylation targets can improve the accuracy of the methylation biomarker panel and enable the development of noninvasive IPMN stratification biomarkers.

Access to telehealth services for colorectal cancer patients in the United States during the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic yielded rapid telehealth deployment to improve healthcare access, including for surgical patients.

METHODS

We conducted a secret shopper study to assess telehealth availability for new patient and follow-up colorectal cancer care visits in a random national sample of Commission on Cancer accredited hospitals and investigated predictive facility-level factors.

RESULTS

Of 397 hospitals, 302 (76%) offered telehealth for colorectal cancer patients (75% for follow-up, 42% for new patients). For new patients, NCI-designated Cancer Programs offered telehealth more frequently than Integrated Network (OR: 0.20, p = 0.01), Academic Comprehensive (OR: 0.18, p = 0.001), Comprehensive Community (OR: 0.10, p < 0.001), and Community (OR: 0.11, p < 0.001) Cancer Programs. For follow-up, above average timeliness of care hospitals offered telehealth more frequently than average hospitals (OR: 2.87, p = 0.04).

CONCLUSIONS

We identified access disparities and predictive factors for telehealth availability for colorectal cancer care during the COVID-19 pandemic. These factors should be considered when constructing telehealth policies.

Change in Neutrophil-to-Lymphocyte Ratio During Neoadjuvant Treatment Does Not Predict Pathological Response and Survival in Resectable Pancreatic Ductal Adenocarcinoma

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) has been reported as prognostic in pancreatic ductal adenocarcinoma (PDAC). Data about NLR changes during neoadjuvant therapy (NAT) and its relationship with pathological tumor response and survival are lacking.

METHODS

Pancreatic ductal adenocarcinoma patients with NAT followed by resection between 2009 and 2015 were identified from a prospective database. Neutrophil-to-lymphocyte ratio was collected prior to NAT (baseline), on chemotherapy (prior to cycle 3), and prior to surgery. Baseline NLR, and changes in NLR between baseline and on chemotherapy (delta 1) and between baseline and surgery (delta 2) were compared with pathologic response (<90% and ≥90% defined as poor and good), overall (OS), and disease-free survival (DFS) using Wilcoxon rank-sum and Cox proportional hazard models.

RESULTS

Of 93 patients, 17% had good pathological response. Median (interquartile range) NLR at baseline, third cycle, and surgery were 2.7 (2.0-3.7), 2.5 (1.9-4.1), and 3.1 (2.1-5.3), respectively. Median change in NLR from baseline to third cycle was .06 (P = .72), and .6 from baseline to surgery (P < .01). Baseline NLR, delta 1, and delta 2 were not associated with pathological response, OS, or DFS.

DISCUSSION

Neutrophil-to-lymphocyte ratio increased after NAT, but a significant association between NLR and pathological response, OS, and DFS in resected PDAC patients was not observed.

Benefit of Extended Surveillance of Low-Risk Pancreatic Cysts After 5-Year Stability: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Low-risk branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) lacking worrisome features (WF) and high-risk stigmata (HRS) warrant surveillance. However, their optimal duration, especially among cysts with initial 5 years of size stability, warrants further investigation. We systematically reviewed the surveillance of low-risk BD-IPMNs and investigated the incidence of WF/HRS and advanced neoplasia, high-grade dysplasia, and pancreatic cancer during the initial (<5 years) and extended surveillance period (>5-years).

METHODS

A systematic search (CRD42020117120) identified studies investigating long-term IPMN surveillance outcomes of low-risk IPMN among the Cochrane Library, Embase, Google Scholar, Ovid Medline, PubMed, Scopus, and Web of Science, from inception until July 9, 2021. The outcomes included the incidence of WF/HRS and advanced neoplasia, disease-specific mortality, and surveillance-related harm (expressed as percentage per patient-years). The meta-analysis relied on time-to-event plots and used a random-effects model.

RESULTS

Forty-one eligible studies underwent systematic review, and 18 studies were meta-analyzed. The pooled incidence of WF/HRS among low-risk BD-IPMNs during initial and extended surveillance was 2.2% (95% CI, 1.0%-3.7%) and 2.9% (95% CI, 1.0%-5.7%) patient-years, respectively, whereas the incidence of advanced neoplasia was 0.6% (95% CI, 0.2%-1.00%) and 1.0% (95% CI, 0.6%-1.5%) patient-years, respectively. The pooled incidence of disease-specific mortality during initial and extended surveillance was 0.3% (95% CI, 0.1%-0.6%) and 0.6% (95% CI, 0.0%-1.6%) patient-years, respectively. Among BD-IPMNs with initial size stability, extended surveillance had a WF/HRS and advanced neoplasia incidence of 1.9% (95% CI, 1.2%-2.8%) and 0.2% (95% CI, 0.1%-0.5%) patient-years, respectively.

CONCLUSIONS

A lower incidence of advanced neoplasia during extended surveillance among low-risk, stable-sized BD-IPMNs was a key finding of this study. However, the survival benefit of surveillance among this population warrants further exploration through high-quality studies before recommending surveillance cessation with certainty.

Comorbidities Drive the Majority of Overall Mortality in Low-Risk Mucinous Pancreatic Cysts Under Surveillance

BACKGROUND & AIMS

The Charlson Comorbidity Index (CACI) has been suggested as a tool to determine comorbidity burden and guide management for patients with mucinous pancreatic cysts (Intrapapillary Mucinous Neoplasms and Mucinous Cystic Neoplasms), but has not been studied well among "low-risk" mucinous pancreatic cysts i.e. without worrisome features (WF) and high-risk stigmata (HRS). This study sought to determine the comorbidity burden among surveillance population of low-risk pancreatic cysts and provide their follow-up mortality outcomes.

METHODS

A single center study retrospectively reviewed a prospective pancreatic cyst database and included individuals with low-risk cysts undergoing serial imaging during 2016. Electronic medical records were reviewed to determine their baseline age-adjusted CACI (age-CACI). After 4 years, their progression to WF, disease specific (pancreatic malignancy-related, DSM), extra-pancreatic (EPM), and overall mortalities (OM) were determined using Kaplan-Meir Survival Analysis.

RESULTS

502 individuals underwent prospective surveillance. The study included 440 individuals with low-risk suspected or presumed mucinous cysts and excluded 50 and 12 individuals with WF and HRS respectively. Over a median follow-up of 56 months, 12 WF progressions, 2 DSMs, 42 EPMs, and 44 OMs were observed. Baseline age-CACI had good predictive capacity for 4-year EPM (Area-Under Curve: 0.87; p< .0001). The median age-CACI of 4 enabled cohort stratification into Low (age-CACI <4) and High CACI (age-CACI ≥4) groups. A significantly higher OM (p< .001) was observed among the High CACI group as compared to the Low CACI group.

CONCLUSION

Through real-time application of CACI to patient outcomes, our analysis supports incorporation of this comorbidity assessment tool in making shared surveillance decisions among low-risk pancreatic cyst population.

Abstract PO-155: Racial heterogeneity in the molecular landscape of pancreatic adenocarcinoma: A call for action

Background: Pancreatic adenocarcinoma (PDAC) is an aggressive cancer predicted to be the second leading cause of cancer mortality in the next decade. Significant disparities in the incidence rate and outcomes of Black patients with PDAC have recently been reported. Efforts to characterize the molecular landscape of PDAC are ongoing; however, the molecular mechanisms driving cancer in PDAC patients remain largely unexplored with respect to sociocultural race. In this study, we utilized the Cancer Genome Atlas (TCGA) dataset to describe the somatic mutation, DNA methylation and gene expression profiles of PDAC patients with respect to sociocultural race in an effort to elucidate the racial heterogeneity in pancreatic carcinogenesis. Methods: This study involved accessing the public TCGA dataset for all patients with diagnosed PDACs. We filtered this cohort to include only patients with available racial information and matched DNA methylation, mRNA expression and simple somatic mutation data (n = 150). We analyzed the frequency and nature of non-silent simple somatic mutations for our cohort, both combined and separated by sociocultural race, and calculated the top differentially-methylated and differentially-expressed genes, using a maximum p-value of 0.01 for the Benjamini-Hochberg adjustment method as our cut-off. Results: We observed the four previously reported pancreatic adenocarcinoma driver genes (KRAS, TP53, SMAD4, and CDKN2A) to be the genes most frequently mutated in White (n = 132) and Asian (n = 9) PDAC samples. In Black (n = 5) samples, PDAC appears to be only partially driven by mutation of these driver genes. We found Black PDAC samples have a distinct mutational landscape and harbor somatic mutations in additional genes, including: CSMD2 (42.9%), RYR1 (28.6%), CBLL2 (28.6%), ANKRD24 (28.6%), SAMD7 (28.6%). The DNA methylation landscape of PDAC patients is also distinct with respect to sociocultural race, with the majority of differentially-methylated loci present to a greater degree in Black (53.8%) or Asian samples (28.2%), compared to White (17.9%) samples. Gene expression data also follow this trend, with the majority of genes showing the highest degree of differential expression in Black (82.4%) versus Asian (14.7%) or White (2.9%) patients. Conclusion: Our preliminary analyses suggest racial heterogeneity exists at the level of DNA methylation, gene expression and somatic mutation. We discovered that reporting on PDAC driver mutations is likely biased by the overrepresentation of White patient samples in the TCGA dataset – the largest publicly available dataset with data on sociocultural race. Given our preliminary results, further work to describe the DNA methylation and gene expression landscape in PDAC with respect to sociocultural race is imperative. However, until minority representation is improved in such biobanking efforts – the ability to perform molecular profiling of PDAC within those populations experiencing disparate incidence and outcomes remains underpowered.

Citation Format: Haleigh Tianna Larson, Ankit Chhoda, Astrid Hengartner, Nesrin Hasan, Nensi Ruzgar, Sri Yalamanchi, John W. Kunstman, James J. Farrell, Anup Sharma, Nita Ahuja. Racial heterogeneity in the molecular landscape of pancreatic adenocarcinoma: A call for action [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-155.

Methylation-based Cell-free DNA Signature for Early Detection of Pancreatic Cancer

OBJECTIVES

The potential of DNA methylation alterations in early pancreatic cancer (PC) detection among pancreatic tissue cell-free DNA seems promising. This study investigates the diagnostic capacity of the 4-gene methylation biomarker panel, which included ADAMTS1, BNC1, LRFN5, and PXDN genes, in a case-control study.

METHODS

A genome-wide pharmacoepigenetic approach identified ADAMTS1, BNC1, LRFN5, and PXDN genes as putative targets. Tissue samples including stage I-IV PC (n = 44), pancreatic intraepithelial neoplasia (n = 15), intraductal papillary mucinous neoplasms (n = 24), and normal pancreas (n = 8), and cell-free DNA, which was acquired through methylation on beads technology from PC (n = 22) and control patients (n = 10), were included. The 2-∆ct was the outcome of interest and underwent receiver operating characteristic analysis to determine the diagnostic accuracy of the panel.

RESULTS

Receiver operating characteristic analysis revealed an area under the curve of 0.93 among ADAMTS1, 0.76 among BNC1, 0.75 among PXDN, and 0.69 among LRFN5 gene. The combination gene methylation panel (ADAMTS1, BNC1, LRFN5, and PXDN) had an area under the curve of 0.94, with a sensitivity of 100% and specificity of 90%.

CONCLUSIONS

This methylation-based biomarker panel had promising accuracy for PC detection and warranted further validation in prospective PC surveillance trials.

Renalase is a novel tissue and serological biomarker in pancreatic ductal adenocarcinoma

Dysregulated expression of the secretory protein renalase can promote pancreatic ductal adenocarcinoma (PDAC) growth in animal models. We characterized renalase expression in premalignant and malignant PDAC tissue and investigated whether plasma renalase levels corresponded to clinical PDAC characteristics. Renalase immunohistochemistry was used to determine the presence and distribution of renalase in normal pancreas, chronic pancreatitis, PDAC precursor lesions, and PDAC tissues. Associations between pretreatment plasma renalase and PDAC clinical status were assessed in patients with varied clinical stages of PDAC and included tumor characteristics, surgical resection in locally advanced/borderline resectable PDAC, and overall survival. Data were retrospectively obtained and correlated using non-parametric analysis. Little to no renalase was detected by histochemistry in the normal pancreatic head in the absence of abdominal trauma. In chronic pancreatitis, renalase immunoreactivity localized to peri-acinar spindle-shaped cells in some samples. It was also widely present in PDAC precursor lesions and PDAC tissue. Among 240 patients with PDAC, elevated plasma renalase levels were associated with worse tumor characteristics, including greater angiolymphatic invasion (80.0% vs. 58.1%, p = 0.012) and greater node positive disease (76.5% vs. 56.5%, p = 0.024). Overall survival was worse in patients with high plasma renalase levels with median follow-up of 27.70 months vs. 65.03 months (p < 0.001). Renalase levels also predicted whether patients with locally advanced/borderline resectable PDAC underwent resection (AUC 0.674; 95%CI 0.42-0.82, p = 0.04). Overall tissue renalase was increased in both premalignant and malignant PDAC tissues compared to normal pancreas. Elevated plasma renalase levels were associated with advanced tumor characteristics, decreased overall survival, and reduced resectability in patients with locally advanced/borderline resectable PDAC. These studies show that renalase levels are increased in premalignant pancreatic tissues and that its levels in plasma correspond to the clinical behavior of PDAC.

A risk-adjusted analysis of drain use in pancreaticoduodenectomy: Some is good, but more may not be better

BACKGROUND

Intraperitoneal drain placement decreases morbidity and mortality in patients who develop a clinically relevant postoperative pancreatic fistula (CR-POPF) following pancreaticoduodenectomy (PD). It is unknown whether multiple drains mitigate CR-POPF better than a single drain. We hypothesize that multiple drains decrease the complication burden more than a single drain in cases at greater risk for CR-POPF.

METHODS

The Fistula Risk Score (FRS), mitigation strategies (including number of drains placed), and clinical outcomes were obtained from a multi-institutional database of PDs performed from 2003 to 2020. Outcomes were compared between cases utilizing 0, 1, or 2 intraperitoneal drains. Multivariable regression analysis was used to evaluate the optimal drainage approach.

RESULTS

A total of 4,292 PDs used 0 (7.3%), 1 (45.2%), or 2 (47.5%) drains with an observed CR-POPF rate of 9.6%, which was higher in intermediate/high FRS zone cases compared with negligible/low FRS zone cases (13% vs 2.4%, P < .001). The number of drains placed also correlated with FRS zone (median of 2 in intermediate/high vs 1 in negligible/low risk cases). In intermediate/high risk cases, the use of 2 drains instead of 1 was not associated with a reduced rate of CR-POPF, average complication burden attributed to a CR-POPF, reoperations, or mortality. Obviation of drains was associated with significant increases in complication burden and mortality - regardless of the FRS zone.

CONCLUSION

In intermediate/high risk zone cases, placement of a single drain or multiple drains appears to mitigate the complication burden while use of no drains is associated with inferior outcomes.

Pancreatic Adenocarcinoma, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

Pancreatic cancer is the fourth leading cause of cancer-related death among men and women in the United States. A major challenge in treatment remains patients' advanced disease at diagnosis. The NCCN Guidelines for Pancreatic Adenocarcinoma provides recommendations for the diagnosis, evaluation, treatment, and follow-up for patients with pancreatic cancer. Although survival rates remain relatively unchanged, newer modalities of treatment, including targeted therapies, provide hope for improving patient outcomes. Sections of the manuscript have been updated to be concordant with the most recent update to the guidelines. This manuscript focuses on the available systemic therapy approaches, specifically the treatment options for locally advanced and metastatic disease.

A Critical Appraisal of the July Effect: Evaluating Complications Following Pancreaticoduodenectomy

BACKGROUND

Reports of higher rates of medical errors in the month of July have generated concern regarding major surgery at academic institutions early in the yearly promotion cycle. This study was designed to evaluate perioperative outcomes in patients undergoing pancreaticoduodenectomy (PD) at different times of the year.

MATERIALS AND METHODS

Outcomes were retrospectively evaluated for patients treated in July versus the rest of the year and in the first quarter (July-September) versus the remaining quarters. The primary outcome was operative morbidity as measured by Clavien-Dindo grade, a classification system of surgical complications. Secondary outcomes included mortality, operative blood loss, pancreatic fistula formation, delayed gastric emptying, intraabdominal abscess, anastomotic leak, reoperation, and other variables of interest.

RESULTS

From January 2003 to September 2015, 472 patients underwent PD by a single academic surgeon. Overall, 77.1% of PDs were performed for malignancy. The number of patients did not significantly vary by month or by quarter. The incidence of major morbidity (Clavien-Dindo grade ≥ III) in patients who had a PD was 12.2% in July and 17.5% in all other months (P = 0.79). The rate of pancreatic fistula, intraabdominal abscess, reoperation, readmission, and mortality did not differ significantly by month or by quarter (P > 0.05 for all).

CONCLUSIONS

The current study does not find any correlation between time of year and operative morbidity or mortality, suggesting that PD can be safely performed irrespective of timing.

Association of Treatment Inequity and Ancestry With Pancreatic Ductal Adenocarcinoma Survival

Importance

Pancreatic ductal adenocarcinoma (PDAC) has a higher incidence and worse outcomes among black patients than white patients, potentially owing to a combination of socioeconomic, biological, and treatment differences. The role that these differences play remains unknown.

Objectives

To determine the level of survival disparity between black and white patients in a modern PDAC cohort and whether treatment inequity is associated with such a disparity.

Design, Setting, and Participants

This cohort study used data on 278 936 patients with PDAC with database-defined race from the National Cancer Database from January 1, 2004, to December 31, 2015. The median follow-up for censored patients was 24 months. The National Cancer Database, comprising academic and community facilities, includes about 70% of new cancer diagnoses in the United States. Race-stratified receipt of therapy was the primary variable of interest. Multivariable analyses included additional demographic and clinical parameters. Data analysis was initially completed on November 30, 2018, and revised data analysis was completed on June 27, 2019.

Main Outcomes and Measures

Overall survival was the primary outcome, analyzed with Kaplan-Meier and multivariable Cox proportional hazards regression modeling.

Results

The cohort included 278 936 patients (137 121 women and 141 815 men; mean [SD] age, 68.72 [11.57] years); after excluding patients from other racial categories, 243 820 of the 278 936 patients (87.4%) were white and 35 116 of the 278 936 patients (12.6%) were black. Unadjusted median overall survival was longer for white patients than for black patients (6.6 vs 6.0 months; P < .001). Black patients presented at younger ages than white patients (15 819 of 35 116 [45.0%] vs 83 846 of 243 820 [34.4%] younger than 65 years; P < .001) and with more advanced disease (20 853 of 31 600 [66.0%] vs 135 317 of 220 224 [61.4%] with stage III or IV disease; P < .001). Black patients received fewer surgical procedures than white patients for potentially resectable stage II disease (4226 of 8097 [52.2%] vs 39 214 of 65 124 [60.2%]; P < .001) and slightly less chemotherapy for advanced disease (2756 of 4067 [67.8%] vs 17 296 of 25 227 [68.6%] for stage III disease [P = .001]; 8208 of 16 104 [51.0%] vs 58 603 of 105 616 [55.5%] for stage IV disease [P < .001]). Decreased survival for black patients persisted in multivariable modeling controlled for sociodemographic parameters (hazard ratio, 1.04 [95% CI, 1.02-1.05]). Conversely, modeling that controlled specifically for clinical parameters such as disease stage and treatment revealed a modest survival advantage (hazard ratio, 0.94 [95% CI, 0.93-0.96]) among black patients. Resection was the factor most strongly associated with overall survival (hazard ratio, 0.39 [95% CI, 0.38-0.39]).

Conclusions and Relevance

Black patients with PDAC present at younger ages and with more advanced disease than white patients, suggesting that differences in tumor biology may exist. Black patients receive less treatment stage for stage and fewer surgical procedures for resectable cancers than white patients; these findings may be only partly associated with socioeconomic differences. When disease stage and treatment were controlled for, black patients had no decrease in survival.

Outcomes after Pancreatectomy with Routine Pasireotide Use

BACKGROUND

Morbidity after pancreatectomy is commonly due to leakage of exocrine secretions resulting in abscess or pancreatic fistula (PF). Previously, we authored a double-blind randomized controlled trial demonstrating that perioperative pasireotide administration lowers abscess or PF formation by >50%. Accordingly, we adopted pasireotide use as standard practice after pancreatectomy in October 2014 and hypothesized a similar PF/abscess rate reduction would be observed.

STUDY DESIGN

A prospectively maintained database was queried for all patients who underwent pancreatectomy between October 2014 and July 2017. Pasireotide was administered preoperatively and twice daily for 7 days postoperatively or until discharge. The primary end point was clinically relevant PF/abscess requiring procedural intervention, identical to the earlier trial outcomes. Logistic regression was used to compare outcomes with the placebo arm of the earlier randomized trial and to control known PF risk factors.

RESULTS

During the 34-month study period, 652 patients underwent pancreatectomy (211 distal pancreatectomy, 441 pancreaticoduodenectomy). Compared with the historical placebo group (n = 148), the observational group had an increased prevalence of higher American Society of Anesthesiologists scores (69% vs 54%; p < 0.001) and high-risk cases (small duct and soft gland, 47% vs 36%; p = 0.030). The primary end point occurred in 13.3% of patients receiving pasireotide vs 20.9% in the placebo arm of the earlier trial trial (odds ratio 0.58; 95% CI 0.37 to 0.92; p = 0.020). Biliary leakage was lower in those receiving pasireotide (0.6% vs 3.4%; p = 0.014), and other morbidity was unchanged. No subpopulation was identified more likely to benefit from pasireotide.

CONCLUSIONS

At our center, adoption of pasireotide has allowed us to achieve a clinically significant abscess or pancreatic leak rate of 13.3%, approximating the effect observed in the randomized trial of pasireotide during routine surgical practice.

Clonal evolution analysis of paired anaplastic and well-differentiated thyroid carcinomas reveals shared common ancestor

Foci of papillary or follicular thyroid carcinoma are frequently noted in thyroidectomy specimens of anaplastic thyroid carcinoma (ATC). However, whether ATCs evolve from these co-existing well-differentiated thyroid carcinomas (WDTCs) has not been well-understood. To investigate the progression of ATC in patients with co-existing WDTCs, five ATC tumors with co-existing WDTCs and matching normal tissues were whole-exome sequenced. After mapping the somatic alteration landscape, evolutionary lineages were constructed by sub-clone analysis. Though each tumor harbored at least some unique private mutations, all five ATCs demonstrated numerous overlapping mutations with matched WDTCs. Clonal analysis further demonstrated that each ATC/WDTC pair shared a common ancestor, with some pairs diverging early in their evolution and others in which the ATC seems to arise directly from a sub-clone of the WDTC. Though the precise lineal relationship remains ambiguous, based on the genetic relationship, our study clearly suggests a shared origin of ATC and WDTC.

Comprehensive Genetic Analysis of Follicular Thyroid Carcinoma Predicts Prognosis Independent of Histology

CONTEXT

Follicular thyroid carcinoma (FTC) is classified into minimally invasive (miFTC), encapsulated angioinvasive (eaFTC), and widely invasive (wiFTC) subtypes, according to the 2017 World Health Organization guidelines. The genetic signatures of these subtypes may be crucial for diagnosis, prognosis, and treatment but have not been described.

OBJECTIVE

Identify and describe the genetic underpinnings of subtypes of FTC.

METHODS

Thirty-nine tumors, comprising 12 miFTCs, 17 eaFTCs, and 10 wiFTCs, were whole-exome sequenced and analyzed. Somatic mutations, constitutional sequence variants, somatic copy number alterations, and mutational signatures were described. Clinicopathologic parameters and mutational profiles were assessed for associations with patient outcomes.

RESULTS

Total mutation burden was consistent across FTC subtypes, with a median of 10 (range 1 to 44) nonsynonymous somatic mutations per tumor. Overall, 20.5% of specimens had a mutation in the RAS subfamily (HRAS, KRAS, or NRAS), with no notable difference between subtypes. Mutations in TSHR, DICER1, EIF1AX, KDM5C, NF1, PTEN, and TP53 were also noted to be recurrent across the cohort. Clonality analysis demonstrated more subclones in wiFTC. Survival analysis demonstrated worse disease-specific survival in the eaFTC and wiFTC cohorts, with no recurrences or deaths for patients with miFTC. Mutation burden was associated with worse prognosis, independent of histopathological classification.

CONCLUSIONS

Though the number and variety of somatic variants are similar in the different histopathological subtypes of FTC in our study, mutational burden was an independent predictor of mortality and recurrence.

Pancreaticoduodenectomy Can be Performed Safely with Rare Employment of Surgical Drains

Use of drain remains frequent following pancreaticoduodenectomy (PD) due to concern for postoperative pancreatic fistula (POPF) and anastomotic leak development. Despite controversy, a recent randomized trial suggested omitting drainage would result in a large increase in operative mortality. This study sought to comprehensively examine the effects of forgoing drainage in the large cohort of patients undergoing PD. A prospective cohort study of two consecutive groups undergoing PD was constructed. The initial group had operative drains placed in cases subjectively concerning for POPF development; the second cohort did not undergo operative drainage. Outcomes including POPF incidence, need for reintervention, and overall morbidity were examined. A total of 106 patients were evaluated in two consecutive cohorts of 53; in the first group, 30 per cent had operative drains placed; 22.6 per cent developed POPF versus 7.5 per cent of patients in the no drainage group (P = 0.06). Despite this, no significant difference in major morbidity (Clavien ≥3, 20.8% versus 17.0%) or need for procedural reintervention (18.9% versus 15.1%) was observed. A subsequent validation cohort of 237 additional patients where drains were used only in exceptional circumstances was examined. Operative drains were placed in only 3 per cent of patients (n = 7) and 90-day mortality was 1.3 per cent (n = 3). Incidence of POPF was 8.0 per cent and the overall major complication rate was 14.8 per cent. Given such findings, it appears that drainage after PD can be avoided resulting in acceptable operative morbidity and mortality in most cases.

Pancreaticoduodenectomy Can Be Performed Safely with Rare Employment of Surgical Drains

Use of drain remains frequent following pancreaticoduodenectomy (PD) due to concern for postoperative pancreatic fistula (POPF) and anastomotic leak development. Despite controversy, a recent randomized trial suggested omitting drainage would result in a large increase in operative mortality. This study sought to comprehensively examine the effects of forgoing drainage in the large cohort of patients undergoing PD. A prospective cohort study of two consecutive groups undergoing PD was constructed. The initial group had operative drains placed in cases subjectively concerning for POPF development; the second cohort did not undergo operative drainage. Outcomes including POPF incidence, need for reintervention, and overall morbidity were examined. A total of 106 patients were evaluated in two consecutive cohorts of 53; in the first group, 30 per cent had operative drains placed; 22.6 per cent developed POPF versus 7.5 per cent of patients in the no drainage group (P = 0.06). Despite this, no significant difference in major morbidity (Clavien ≥3, 20.8% versus 17.0%) or need for procedural reintervention (18.9% versus 15.1%) was observed. A subsequent validation cohort of 237 additional patients where drains were used only in exceptional circumstances was examined. Operative drains were placed in only 3 per cent of patients (n = 7) and 90-day mortality was 1.3 per cent (n = 3). Incidence of POPF was 8.0 per cent and the overall major complication rate was 14.8 per cent. Given such findings, it appears that drainage after PD can be avoided resulting in acceptable operative morbidity and mortality in most cases.

Novel somatic mutations in primary hyperaldosteronism are related to the clinical, radiological and pathological phenotype

Aldosterone-producing adenomas (APAs) and bilateral adrenal hyperplasia are important causes of secondary hypertension. Somatic mutations in KCNJ5, CACNA1D, ATP1A1, ATP2B3 and CTNNB1 have been described in APAs.

OBJECTIVE

To characterize clinical-pathological features in APAs and unilateral adrenal hyperplasia, and correlate them with genotypes.

DESIGN

Retrospective study.

SUBJECTS AND MEASUREMENTS

Clinical and pathological characteristics of 90 APAs and seven diffusely or focally hyperplastic adrenal glands were reviewed, and samples were examined for mutations in known disease genes by Sanger or exome sequencing.

RESULTS

Mutation frequencies were as follows: KCNJ5, 37·1%; CACNA1D, 10·3%; ATP1A1, 8·2%; ATP2B3, 3·1%; and CTNNB1, 2·1%. Previously unidentified mutations included I157K, F154C and two insertions (I150_G151insM and I144_E145insAI) in KCNJ5, all close to the selectivity filter, V426G_V427Q_A428_L433del in ATP2B3 and A39Efs*3 in CTNNB1. Mutations in KCNJ5 were associated with female and other mutations with male gender (P = 0·007). On computed tomography, KCNJ5-mutant tumours displayed significantly greater diameter (P = 0·023), calculated area (P = 0·002) and lower precontrast Hounsfield units (P = 0·0002) vs tumours with mutations in other genes. Accordingly, KCNJ5-mutant tumours were predominantly comprised of lipid-rich fasciculata-like clear cells, whereas other tumours were heterogeneous (P = 5 × 10(-6) vs non-KCNJ5 mutant and P = 0·0003 vs wild-type tumours, respectively). CACNA1D mutations were present in two samples with hyperplasia without adenoma.

CONCLUSIONS

KCNJ5-mutant tumours appear to be associated with fasciculata-like clear cell predominant histology and tend to be larger with a characteristic imaging phenotype. Novel somatic KCNJ5 variants likely cause adenomas by loss of potassium selectivity, similar to previously described mutations.

Ashley W. Oughterson, MD: Surgeon, Soldier, Leader

Ashley W. Oughterson, MD, (1895-1956) was a longtime faculty surgeon at Yale University. He performed some of the earliest pancreatic resections in the United States. During World War II, Colonel Oughterson was the primary "Surgical Consultant" in the South Pacific and present at nearly every major battle. His meticulously kept diary is regarded as the foremost source detailing wartime surgical care. Colonel Oughterson led the initial Army team to survey Hiroshima and Nagasaki following the nuclear attacks. Thoughout his academic career at Yale, Oughterson was a key leader in several medical and surgical societies. As scientific director of the American Cancer Society, Oughterson lectured widely and guided research priorities in oncology following World War II. Oughterson also authored numerous benchmark papers in surgical oncology that continue to be cited today. These extensive contributions are examined here and demonstrate the wide-ranging impact Oughterson exerted during a formative period of American surgery.

Characterization of the mutational landscape of anaplastic thyroid cancer via whole-exome sequencing

Anaplastic thyroid carcinoma (ATC) is a frequently lethal malignancy that is often unresponsive to available therapeutic strategies. The tumorigenesis of ATC and its relationship to the widely prevalent well-differentiated thyroid carcinomas are unclear. We have analyzed 22 cases of ATC as well as 4 established ATC cell lines using whole-exome sequencing. A total of 2674 somatic mutations (121/sample) were detected. Ontology analysis revealed that the majority of variants aggregated in the MAPK, ErbB and RAS signaling pathways. Mutations in genes related to malignancy not previously associated with thyroid tumorigenesis were observed, including mTOR, NF1, NF2, MLH1, MLH3, MSH5, MSH6, ERBB2, EIF1AX and USH2A; some of which were recurrent and were investigated in 24 additional ATC cases and 8 ATC cell lines. Somatic mutations in established thyroid cancer genes were detected in 14 of 22 (64%) tumors and included recurrent mutations in BRAF, TP53 and RAS-family genes (6 cases each), as well as PIK3CA (2 cases) and single cases of CDKN1B, CDKN2C, CTNNB1 and RET mutations. BRAF V600E and RAS mutations were mutually exclusive; all ATC cell lines exhibited a combination of mutations in either BRAF and TP53 or NRAS and TP53. A hypermutator phenotype in two cases with >8 times higher mutational burden than the remaining mean was identified; both cases harbored unique somatic mutations in MLH mismatch-repair genes. This first comprehensive exome-wide analysis of the mutational landscape of ATC identifies novel genes potentially associated with ATC tumorigenesis, some of which may be targets for future therapeutic intervention.

Whole-exome sequencing characterizes the landscape of somatic mutations and copy number alterations in adrenocortical carcinoma

CONTEXT

Adrenocortical carcinoma (ACC) is a rare and lethal malignancy with a poorly defined etiology, and the molecular genetics of ACC are incompletely understood.

OBJECTIVE

To utilize whole-exome sequencing for genetic characterization of the underlying somatic mutations and copy number alterations present in ACC.

DESIGN

Screening for somatic mutation events and copy number alterations (CNAs) was performed by comparative analysis of tumors and matched normal samples from 41 patients with ACC.

RESULTS

In total, 966 nonsynonymous somatic mutations were detected, including 40 tumors with a mean of 16 mutations per sample and one tumor with 314 mutations. Somatic mutations in ACC-associated genes included TP53 (8/41 tumors, 19.5%) and CTNNB1 (4/41, 9.8%). Genes with potential disease-causing mutations included GNAS, NF2, and RB1, and recurrently mutated genes with unknown roles in tumorigenesis comprised CDC27, SCN7A, and SDK1. Recurrent CNAs included amplification at 5p15.33 including TERT (6/41, 14.6%) and homozygous deletion at 22q12.1 including the Wnt repressors ZNRF3 and KREMEN1 (4/41 9.8% and 3/41, 7.3%, respectively). Somatic mutations in ACC-established genes and recurrent ZNRF3 and TERT loci CNAs were mutually exclusive in the majority of cases. Moreover, gene ontology identified Wnt signaling as the most frequently mutated pathway in ACCs.

CONCLUSIONS

These findings highlight the importance of Wnt pathway dysregulation in ACC and corroborate the finding of homozygous deletion of Wnt repressors ZNRF3 and KREMEN1. Overall, mutations in either TP53 or CTNNB1 as well as focal CNAs at the ZNRF3 or TERT loci denote mutually exclusive events, suggesting separate mechanisms underlying the development of these tumors.

Evaluation of a recently described risk classification scheme for pancreatic fistulae development after pancreaticoduodenectomy without routine post-operative drainage

BACKGROUND

Post-operative pancreatic fistula (POPF) formation occurs frequently after a pancreaticoduodenectomy (PD). Recently, a 10-point Fistula Risk Score (FRS) evaluating the likelihood of clinically relevant POPF (CR-POPF) development has been described and validated. This scheme has yet to be evaluated in PD patients managed without intra-operative drain placement.

METHODS

Among patients undergoing PD at an academic centre since 2003, a retrospective analysis calculating FRS and its correlation with CR-POPF development was evaluated by logistic regression. Secondary analysis examined presentation and management of CR-POPF in undrained PD patients.

RESULTS

FRS was calculated for 265 patients; 97.7% were managed without operative drains. The overall incidence of CR-POPF was 7.9%. Logistic regression revealed a 1.6-fold increase in CR-POPF risk per 1-point increase in FRS [95% confidence interval (CI) 1.2-2.0]. The negative predictive value in patients with FRS <3 was 100%, whereas the positive predictive value of FRS >6 was 16.7%. The median time to CR-POPF diagnosis was 18 days [interquartile range (IQR) 13-23]; 70.0% required readmission and 10.0% required a laparotomy.

CONCLUSIONS

Among patients without operative drainage, CR-POPF often has delayed presentations but most are managed non-operatively. The predictive value of high-risk FRS appears limited; conversely, a low-risk FRS accurately predicts the absence of CR-POPF and seems an appropriate metric for guiding care.

Recurrent activating mutation in PRKACA in cortisol-producing adrenal tumors

Adrenal tumors autonomously producing cortisol cause Cushing syndrome^1–4. Exome sequencing of 25 tumor-normal pairs revealed two groups. Eight tumors (including 3 carcinomas) had many somatic copy number variants (CNV+) with frequent deletion of CDC42 and CDKN2A, amplification of 5q31.2, and protein-altering mutations in TP53 and RB1. Seventeen (all adenomas) had no CNVs (CNV-), TP53 or RB1 mutations. Six of these had known gain of function mutations in CTNNB1^5,6 (beta-catenin) or GNAS^7,8 (Gα_s), Six others had somatic p.Leu206Arg mutations in PRKACA (protein kinase A (PKA) catalytic subunit). Further sequencing identified this mutation in 13 of 63 tumors (35% of adenomas with overt CS). PRKACA, GNAS and CTNNB1 mutations were mutually exclusive. Leu206 directly interacts with PKA’s regulatory subunit, PRKAR1A^9,10. PRKACA^L206R loses PRKAR1A binding, increasing phosphorylation of downstream targets. PKA activity induces cortisol production and cell proliferation^11–15, providing a mechanism for tumor development. These findings define distinct mechanisms underlying adrenal cortisol-producing tumors.

Epigenetic silencing of RASSF1A deregulates cytoskeleton and promotes malignant behavior of adrenocortical carcinoma

Background

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with high mutational heterogeneity and a generally poor clinical outcome. Despite implicated roles of deregulated TP53, IGF-2 and Wnt signaling pathways, a clear genetic association or unique mutational link to the disease is still missing. Recent studies suggest a crucial role for epigenetic modifications in the genesis and/or progression of ACC. This study specifically evaluates the potential role of epigenetic silencing of RASSF1A, the most commonly silenced tumor suppressor gene, in adrenocortical malignancy.

Results

Using adrenocortical tumor and normal tissue specimens, we show a significant reduction in expression of RASSF1A mRNA and protein in ACC. Methylation-sensitive and -dependent restriction enzyme based PCR assays revealed significant DNA hypermethylation of the RASSF1A promoter, suggesting an epigenetic mechanism for RASSF1A silencing in ACC. Conversely, the RASSF1A promoter methylation profile in benign adrenocortical adenomas (ACAs) was found to be very similar to that found in normal adrenal cortex. Enforced expression of ectopic RASSF1A in the SW-13 ACC cell line reduced the overall malignant behavior of the cells, which included impairment of invasion through the basement membrane, cell motility, and solitary cell survival and growth. On the other hand, expression of RASSF1A/A133S, a loss-of-function mutant form of RASSF1A, failed to elicit similar malignancy-suppressing responses in ACC cells. Moreover, association of RASSF1A with the cytoskeleton in RASSF1A-expressing ACC cells and normal adrenal cortex suggests a role for RASSF1A in modulating microtubule dynamics in the adrenal cortex, and thereby potentially blocking malignant progression.

Conclusions

Downregulation of RASSF1A via promoter hypermethylation may play a role in the malignant progression of adrenocortical carcinoma possibly by abrogating differentiation-promoting RASSF1A- microtubule interactions.

Somatic and germline CACNA1D calcium channel mutations in aldosterone-producing adenomas and primary aldosteronism

Adrenal aldosterone-producing adenomas (APAs) constitutively produce the salt-retaining hormone aldosterone and are a common cause of severe hypertension. Recurrent mutations in the potassium channel KCNJ5 that result in cell depolarization and Ca²⁺ influx cause ~40% of these tumors¹. We found five somatic mutations (four altering glycine 403, one altering isoleucine 770) in CACNA1D, encoding a voltage-gated calcium channel, among 43 non-KCNJ5-mutant APAs. These mutations lie in S6 segments that line the channel pore. Both result in channel activation at less depolarized potentials, and glycine 403 mutations also impair channel inactivation. These effects are inferred to cause increased Ca²⁺ influx, the sufficient stimulus for aldosterone production and cell proliferation in adrenal glomerulosa². Remarkably, we identified de novo mutations at the identical positions in two children with a previously undescribed syndrome featuring primary aldosteronism and neuromuscular abnormalities. These findings implicate gain of function Ca²⁺ channel mutations in aldosterone-producing adenomas and primary aldosteronism.

Clinical review: Parathyroid localization and implications for clinical management

CLINICAL CONTEXT

The prevalence of hyperparathyroidism, especially primary hyperparathyroidism, has increased in recent decades due to improvements in diagnostic techniques with a corresponding surge in parathyroid surgery, leading to the development of focused, minimally invasive surgical approaches. Focused parathyroidectomy is predicated on preoperative localization of suspected parathyroid pathology. As a result, there has been a proliferation of parathyroid imaging modalities and protocols, resulting in confusion about their indications and applications.

EVIDENCE ACQUISITION

Bibliographies from clinical trials and review articles published since 2000 were reviewed and supplemented with targeted searches using biomedical databases. We also employed our extensive clinical experience.

EVIDENCE SYNTHESIS

The best-studied modalities for parathyroid localization are nuclear scintigraphy and sonography and are widely applied as initial studies. Multiple variations exist, and several additional noninvasive imaging techniques, such as computed tomography and magnetic resonance, are described. The exquisite anatomical detail of 4-dimensional computed tomography must be balanced with significant radiation exposure to the thyroid gland. Invasive venous PTH sampling and parathyroid arteriography have important roles in remedial cases. Due to considerable heterogeneity in imaging, multidisciplinary collaboration between endocrinologists, surgeons, and radiologists is beneficial.

CONCLUSIONS

Parathyroid localization is indicated in surgical candidates. Crucial considerations when selecting an imaging study include availability, cost, radiation exposure, local expertise, and accuracy. Additional factors include the patient's anticipated pathology and whether it is de novo or refractory disease. An approach to imaging for patients with primary hyperparathyroidism is presented.

Gene expression and regulation in adrenocortical tumorigenesis

Adrenocortical tumors are frequently found in the general population, and may be benign adrenocortical adenomas or malignant adrenocortical carcinomas. Unfortunately the clinical, biochemical and histopathological distinction between benign and malignant adrenocortical tumors may be difficult in the absence of widely invasive or metastatic disease, and hence attention has turned towards a search for molecular markers. The study of rare genetic diseases that are associated with the development of adrenocortical carcinomas has contributed to our understanding of adrenocortical tumorigenesis. In addition, comprehensive genomic hybridization, methylation profiling, and genome wide mRNA and miRNA profiling have led to improvements in our understanding, as well as demonstrated several genes and pathways that may serve as diagnostic or prognostic markers.

Comprehensive analysis of variables affecting delayed gastric emptying following pancreaticoduodenectomy

INTRODUCTION

Delayed gastric emptying (DGE) occurs commonly following pancreaticoduodenectomy (PD), and criteria for its clinical diagnosis have recently been standardized by an international consensus group. We evaluated 24 operative and peri-operative variables to assess which were independent risk factors for DGE development. Secondarily, we also examined DGE incidence over time and evaluated the consensus guidelines' ability to diagnose DGE in patients with complicated post-operative courses.

METHODS

A prospective, single-surgeon database of 235 patients undergoing PD at an academic tertiary center was retrospectively reviewed and DGE was assessed per published guidelines.

RESULTS

DGE occurred in 42 patients overall (17.9 %), with incidence falling from 30.0 to 9.1% during the study period. Post-operative abscess, pancreatic fistula formation, pulmonary comorbidity, and increased intraoperative blood loss were found to be independent risk factors (p<0.05) for DGE on multivariate analysis. Changes in operative technique, such as pylorus preservation, did not associate with DGE. In a separate analysis, when patients with confounding post-operative events such as re-intubation or re-laparotomy were excluded, DGE incidence was 11.9 %.

CONCLUSIONS

Perturbation of the operative bed by a secondary complication seems to be the dominant risk for DGE development. The consensus guidelines for DGE diagnosis, while indispensable, may overestimate DGE incidence.