Race and Odds of Surgery Offer in Small Bowel and Pancreas Neuroendocrine Neoplasms

BACKGROUND

Despite existing society guidelines, management of pancreatic (PanNEN) and small bowel (SBNEN) neuroendocrine neoplasms remains inconsistent. The purpose of this study was to identify patient- and/or disease-specific characteristics associated with increased odds of being offered surgery for PanNEN and SBNEN.

PATIENTS AND METHODS

The Surveillance, Epidemiology, and End Results (SEER) Program database and the National Cancer Database (NCDB) were queried for patients with PanNEN/SBNEN. Demographic and pathologic data were compared between patients who were offered surgery and those who were not. Multivariate logistic regression was performed to identify factors independently associated with being offered surgery.

RESULTS

In SEER, there were 3641 patients with PanNEN (54.7% were offered surgery) and 5720 with SBNEN (86.0% were offered surgery). On multivariate analysis of SEER, non-white race was associated with decreased odds of surgery offer for SBNEN [odds ratio (OR) 0.58, p < 0.001], but not PanNEN (p = 0.187). In NCDB, there were 28,483 patients with PanNEN (57.5% were offered surgery) and 42,675 with SBNEN (86.9% were offered surgery). On multivariate analysis of NCDB, non-white race was also associated with decreased odds of surgery offer for SBNEN (OR 0.61, p < 0.001) but not PanNEN (p = 0.414).

CONCLUSIONS

This study's findings suggest that, in addition to previously reported disparities in surgical resection and surgery refusal rates, racial/ethnic disparities also exist earlier in the course of treatment, with non-white patients being less likely to be offered surgery for SBNEN but not for PanNEN; this is potentially due to discrepancies in rates of referral to academic centers for pancreas and small bowel malignancies.

Area deprivation and rurality impact overall survival and adjuvant therapy administration in patients with pancreatic ductal adenocarcinoma (PDAC)

BACKGROUND

The impact of neighborhood deprivation on outcomes in patients with pancreatic ductal adenocarcinoma (PDAC) is not well-described and represents an area to improve disparities.

METHODS

We retrospectively queried our prospectively maintained database of patients with PDAC (2014-2022). Patients were grouped by Area Deprivation Index (ADI) and rural-urban commuting area (RUCA) codes. Cox proportional hazards models and logistic regressions were used to investigate effect on overall survival (OS) and adjuvant therapy administration.

RESULTS

536 patients were included. High ADI patients (more disadvantaged, n = 184) were more likely to identify as non-Hispanic Black (17.9% vs. 4.8%, p < 0.01) and were more likely to be from rural areas (49.5% vs. 18.5%, p < 0.01). High ADI was independently associated with decreased OS (HR (95% CI): 1.31 (1.01-1.69), p = 0.04). Urban high ADI patients were 3.5 times more likely to receive adjuvant therapy than rural high ADI patients (OR [95% CI]: 3.48 [1.26-9.61], p = 0.02).

CONCLUSION

Patients from the most disadvantaged neighborhoods have decreased OS. Access to adjuvant therapy likely contributes to this disparity in rural areas. Investigation into sources of this OS disparity and identification of barriers to adjuvant therapy will be crucial to improve outcomes in underserved patients with PDAC.

Impact of Prehabilitation on Postoperative Mortality and the Need for Non-Home Discharge in High-Risk Surgical Patients

BACKGROUND

The preoperative period is an important target for interventions (eg Surgical Prehabilitation and Readiness [SPAR]) that can improve postoperative outcomes for older patients with comorbidities.

STUDY DESIGN

To determine whether a preoperative multidisciplinary prehabilitation program (SPAR) reduces postoperative 30-day mortality and the need for non-home discharge in high-risk surgical patients, surgical patients enrolled in a prehabilitation program targeting physical activity, pulmonary function, nutrition, and mindfulness were compared with historical control patients from 1 institution's American College of Surgeons (ACS) NSQIP database. SPAR patients were propensity score-matched 1:3 to pre-SPAR NSQIP patients, and their outcomes were compared. The ACS NSQIP Surgical Risk Calculator was used to compare observed-to-expected ratios for postoperative outcomes.

RESULTS

A total of 246 patients were enrolled in SPAR. A 6-month compliance audit revealed that overall patient adherence to the SPAR program was 89%. At the time of analysis, 118 SPAR patients underwent surgery with 30 days of follow-up. Compared with pre-SPAR NSQIP patients (n = 4,028), SPAR patients were significantly older with worse functional status and more comorbidities. Compared with propensity score-matched pre-SPAR NSQIP patients, SPAR patients had significantly decreased 30-day mortality (0% vs 4.1%, p = 0.036) and decreased need for discharge to postacute care facilities (6.5% vs 15.9%, p = 0.014). Similarly, SPAR patients exhibited decreased observed 30-day mortality (observed-to-expected ratio 0.41) and need for discharge to a facility (observed-to-expected ratio 0.56) compared with their expected outcomes using the ACS NSQIP Surgical Risk Calculator.

CONCLUSIONS

The SPAR program is safe and feasible and may reduce postoperative mortality and the need for discharge to postacute care facilities in high-risk surgical patients.

Postoperative Proton Pump Inhibitors are associated with a significantly higher rate of delayed gastric emptying after pancreatoduodenectomy

BACKGROUND

Proton pump inhibitors (PPIs) are effective in reducing marginal ulcers after pancreatoduodenectomy. However, their impact on perioperative complications has not been defined.

METHODS

We retrospectively analyzed the effect of postoperative PPIs on 90-day perioperative outcomes in all patients who underwent pancreatoduodenectomy at our institution from April 2017 to December 2020.

RESULTS

284 patients were included; 206 (72.5%) received perioperative PPIs, 78 (27.5%) did not. The two cohorts were similar in demographics and operative variables. Postoperatively, the PPI cohort had significantly higher rates of overall complications (74.3% vs. 53.8%) and delayed gastric emptying (28.6% vs. 11.5%), p < 0.05. However, no differences in infectious complications, postoperative pancreatic fistula, or anastomotic leaks were seen. On multivariate analysis, PPI was independently associated with a higher risk of overall complications (OR 2.46, CI 1.33-4.54) and delayed gastric emptying (OR 2.73, CI 1.26-5.91), p = 0.011. Four patients developed marginal ulcers within 90-days postoperatively; all were in the group who received PPIs.

CONCLUSION

Postoperative proton pump inhibitor use was associated with a significantly higher rate of overall complications and delayed gastric emptying after pancreatoduodenectomy.

Piperacillin-Tazobactam Compared With Cefoxitin as Antimicrobial Prophylaxis for Pancreatoduodenectomy: A Randomized Clinical Trial

Importance

Despite improvements in perioperative mortality, the incidence of postoperative surgical site infection (SSI) remains high after pancreatoduodenectomy. The effect of broad-spectrum antimicrobial surgical prophylaxis in reducing SSI is poorly understood.

Objective

To define the effect of broad-spectrum perioperative antimicrobial prophylaxis on postoperative SSI incidence compared with standard care antibiotics.

Design, Setting, and Participants

Pragmatic, open-label, multicenter, randomized phase 3 clinical trial at 26 hospitals across the US and Canada. Participants were enrolled between November 2017 and August 2021, with follow-up through December 2021. Adults undergoing open pancreatoduodenectomy for any indication were eligible. Individuals were excluded if they had allergies to study medications, active infections, chronic steroid use, significant kidney dysfunction, or were pregnant or breastfeeding. Participants were block randomized in a 1:1 ratio and stratified by the presence of a preoperative biliary stent. Participants, investigators, and statisticians analyzing trial data were unblinded to treatment assignment.

Intervention

The intervention group received piperacillin-tazobactam (3.375 or 4 g intravenously) as perioperative antimicrobial prophylaxis, while the control group received cefoxitin (2 g intravenously; standard care).

Main Outcomes and Measures

The primary outcome was development of postoperative SSI within 30 days. Secondary end points included 30-day mortality, development of clinically relevant postoperative pancreatic fistula, and sepsis. All data were collected as part of the American College of Surgeons National Surgical Quality Improvement Program.

Results

The trial was terminated at an interim analysis on the basis of a predefined stopping rule. Of 778 participants (378 in the piperacillin-tazobactam group [median age, 66.8 y; 233 {61.6%} men] and 400 in the cefoxitin group [median age, 68.0 y; 223 {55.8%} men]), the percentage with SSI at 30 days was lower in the perioperative piperacillin-tazobactam vs cefoxitin group (19.8% vs 32.8%; absolute difference, -13.0% [95% CI, -19.1% to -6.9%]; P < .001). Participants treated with piperacillin-tazobactam, vs cefoxitin, had lower rates of postoperative sepsis (4.2% vs 7.5%; difference, -3.3% [95% CI, -6.6% to 0.0%]; P = .02) and clinically relevant postoperative pancreatic fistula (12.7% vs 19.0%; difference, -6.3% [95% CI, -11.4% to -1.2%]; P = .03). Mortality rates at 30 days were 1.3% (5/378) among participants treated with piperacillin-tazobactam and 2.5% (10/400) among those receiving cefoxitin (difference, -1.2% [95% CI, -3.1% to 0.7%]; P = .32).

Conclusions and Relevance

In participants undergoing open pancreatoduodenectomy, use of piperacillin-tazobactam as perioperative prophylaxis reduced postoperative SSI, pancreatic fistula, and multiple downstream sequelae of SSI. The findings support the use of piperacillin-tazobactam as standard care for open pancreatoduodenectomy.

Trial Registration

ClinicalTrials.gov Identifier: NCT03269994.

Video Interviews and Surgical Applicants' Ability to Assess Fit to Residency Programs

INTRODUCTION

Due to the COVID-19 pandemic, the recruitment cycle for the 2021 Match was performed virtually. This Association for Surgical Education (ASE)-sponsored survey set out to study applicants' ability to assess the factors contributing to fit through video interviews.

METHODS

An IRB-approved, online, anonymous survey was distributed to surgical applicants at a single academic institution and through the ASE clerkship director distribution list between the rank order list certification deadline and Match Day. Applicants used 5-point Likert-type scales to rate factors for importance to fit and their ease of assessment through video interviewing. A variety of recruitment activities were also rated by applicants for their perceived helpfulness in assessment of fit.

RESULTS

One hundred and eighty-three applicants responded to the survey. The three most important factors for applicant fit were how much the program cared, how satisfied residents seem with their program, and how well residents get along. Resident rapport, diversity of the patient population, and quality of the facilities were hardest to assess through video interviews. In general, diversity-related factors were more important to female and non-White applicants, but not more difficult to assess. Interview day and resident-only virtual panels were the most helpful recruitment activities, while virtual campus tours, faculty-only panels, and a program's social media were the least helpful.

CONCLUSIONS

This study provides valuable insight into the limitations of virtual recruitment for surgical applicants' perception of fit. These findings and the recommendations herein should be taken into consideration by residency program leadership to ensure successful recruitment of diverse residency classes.

4,300 steps per day prior to surgery are associated with improved outcomes after pancreatectomy

BACKGROUND

Decreased preoperative physical fitness and low physical activity have been associated with preoperative functional reserve and surgical complications. We sought to evaluate daily step count as a measure of physical activity and its relationship with post-pancreatectomy outcomes.

METHODS

Patients undergoing pancreatectomy were given a remote telemonitoring device to measure their preoperative levels of physical activity. Patient activity, demographics, and perioperative outcomes were collected and compared in univariate and multivariate logistic regression analysis.

RESULTS

73 patients were included. 45 (61.6%) patients developed complications, with 17 (23.3%) of those patients developing severe complications. These patients walked 3437.8 (SD 1976.7) average daily steps, compared to 5918.8 (SD 2851.1) in patients without severe complications (p < 0.001). In logistic regression analysis, patients who walked less than 4274.5 steps had significantly higher odds of severe complications (OR = 7.5 (CI 2.1, 26.8), p = 0.002).

CONCLUSION

Average daily steps below 4274.5 before surgery are associated with severe complications after pancreatectomy. Preoperative physical activity levels may represent a modifiable target for prehabilitation protocols.

Applicants' perception of fit to residency programmes in the video-interview era: A large multidisciplinary survey

INTRODUCTION

'Fit' refers to an applicants' perceived compatibility to a residency programme. A variety of structural, identity-related and relational factors contribute to self-assessments of fit. The 2021 residency recruitment cycle in the USA was performed virtually due to the COVID-19 pandemic. Little is known about how video-interviewing may affect residency applicants' ability to gauge fit.

METHODS

A multidisciplinary, anonymous survey was distributed to applicants at a large academic institution between rank order list (ROL) certification deadline and Match Day 2021. Using Likert-type scales, applicants rated factors for importance to 'fit' and their ease of assessment through video-interviewing. Applicants also self-assigned fit scores to the top-ranked programme in their ROL using Likert-type scales with pairs of anchoring statements.

RESULTS

Four hundred seventy-three applicants responded to the survey (25.7% response rate). The three most important factors to applicants for assessment of fit (how much the programme seemed to care, how satisfied residents seem with their programme and how well the residents get along) were also the factors with the greatest discrepancy between importance and ease of assessment through video-interviewing. Diversity-related factors were more important to female applicants compared with males and to non-White applicants compared with White applicants. Furthermore, White male applicants self-assigned higher fit scores compared with other demographic groups.

CONCLUSION

There is a marked discrepancy between the most important factors to applicants for fit and their ability to assess those factors virtually. Minoritised trainees self-assigned lower fit scores to their top-ranked programme, which should raise concern amongst medical educators and highlights the importance of expanding current diversity, equity and inclusion efforts in academic medicine.

Increased Morbidity and Mortality After Hepatectomy for Colorectal Liver Metastases in Frail Patients is Largely Driven by Worse Outcomes After Minor Hepatectomy: It's Not "Just a Wedge"

BACKGROUND

Frailty is associated with postoperative mortality, but its significance after hepatectomy for colorectal liver metastases (CRLM) is poorly defined. This study evaluated the impact of frailty after hepatectomy for CRLM.

METHODS

The study identified 8477 patients in National Surgical Quality Improvement Program databases from 2014 to 2019 and stratified them by frailty score using the risk analysis index as very frail (>90th percentile), frail (75th-90th percentile), or non-frail (< 75th percentile). Multivariate regression models determined the impact of frailty on perioperative outcomes, including by the extent of hepatectomy.

RESULTS

The procedures performed were 2752 major hepatectomies (left hepatectomy, right hepatectomy, trisectionectomy) and 5725 minor hepatectomies (≤2 segments) for 870 (10.3%) very frail, 1680 (19.8%) frail, and 5927 (69.9%) non-frail patients. Postoperatively, the very frail and frail patients experienced more complications (very frail [41.8%], frail [35.1%], non-frail [31.0%]), which resulted in a longer hospital stay (very-frail [5.7 days], frail [5.8 days], non-frail [5.1 days]), a higher 30-day mortality (very-frail [2.2%], frail [1.3%], non-frail [0.5%]), and more discharges to a facility (very frail [6.8%], frail [3.7%], non-frail [2.6%]) (p < 0.05) although they underwent similarly extensive (major vs. minor) hepatectomies. In the multivariate analysis, frailty was independently associated with complications (very-frail [odds ratio {OR}, 1.70], frail [OR, 1.25]) and 30-day mortality (very-frail [OR, 4.24], frail [OR, 2.41]) (p < 0.05). After minor hepatectomy, the very frail and frail patients had significantly higher rates of complications and 30-day mortality than the non-frail patients, and in the multivariate analysis, frailty was independently associated with complications (very frail [OR, 1.97], frail [OR, 1.27]) and 30-day mortality (very frail [OR, 6.76], frail [OR, 3.47]) (p < 0.05) after minor hepatectomy.

CONCLUSIONS

Frailty predicted significantly poorer outcomes after hepatectomy for CRLM, even after only a minor hepatectomy.

Enhanced recovery pathway after open pancreaticoduodenectomy reduces postoperative length of hospital stay without reducing composite length of stay

BACKGROUND/PURPOSE

There is no data regarding the impact of enhanced recovery pathways (ERP) on composite length of stay (CLOS) after procedures with increased risk of morbidity and mortality, such as pancreaticoduodenectomy.

METHODS

Patients undergoing open pancreaticoduodenectomy before and after implementation of ERP were prospectively followed for 90 days after surgery and complications were severity graded using the Modified Accordion Grading System. A retrospective analysis of patient outcomes were compared before and after instituting ERP. 1:1 propensity score matching was used to compare ERP patient outcomes to those of matched pre-ERP patients. CLOS is defined as postoperative length of hospital stay (PLOS) plus readmission length of hospital stay within 90 days after surgery.

RESULTS

494 patients underwent open pancreaticoduodenectomy - 359 pre-ERP and 135 ERP. In a 1:1 propensity-score-matched analysis of 110 matched pairs, ERP patients had significantly decreased superficial surgical site infections (5.5% vs 15.5% p = 0.015) and significantly increased rates of urinary retention (29.1% vs 7.3% p < 0.0001) compared to matched pre-ERP patients. However, overall complication rate and 90-day readmission rate were not significantly different between matched groups. Propensity score-matched ERP patients had significantly decreased PLOS (7 days vs 8 days p = 0.046) compared to matched pre-ERP patients, but CLOS was not significantly different (9 days vs 9.5 days p = 0.615).

CONCLUSION

ERP may reduce PLOS but might not impact the total postoperative time spent in the hospital (i.e. CLOS) within 90 days after pancreaticoduodenectomy.

In silico epitope prediction analyses highlight the potential for distracting antigen immunodominance with allogeneic cancer vaccines

Allogeneic cancer vaccines are designed to induce antitumor immune responses with the goal of impacting tumor growth. Typical allogeneic cancer vaccines are produced by expansion of established cancer cell lines, transfection with vectors encoding immunostimulatory cytokines, and lethal irradiation. More than 100 clinical trials have investigated the clinical benefit of allogeneic cancer vaccines in various cancer types. Results show limited therapeutic benefit in clinical trials and currently there are no FDA approved allogeneic cancer vaccines. We used recently developed bioinformatics tools including the pVAC-seq suite of software tools to analyze DNA/RNA sequencing data from the TCGA to examine the repertoire of antigens presented by a typical allogeneic cancer vaccine, and to simulate allogeneic cancer vaccine clinical trials. Specifically, for each simulated clinical trial we modeled the repertoire of antigens presented by allogeneic cancer vaccines consisting of three hypothetical cancer cell lines to 30 patients with the same cancer type. Simulations were repeated ten times for each cancer type. Each tumor sample in the vaccine and the vaccine recipient was subjected to HLA typing, differential expression analyses for tumor associated antigens (TAAs), germline variant calling, and neoantigen prediction. These analyses provided a robust, quantitative comparison between potentially beneficial TAAs and neoantigens versus distracting antigens present in the allogeneic cancer vaccines. We observe that distracting antigens greatly outnumber shared TAAs and neoantigens, providing one potential explanation for the lack of observed responses to allogeneic cancer vaccines. This analysis provides additional rationale for the redirection of efforts towards a personalized cancer vaccine approach.

Improved outcomes with minimally invasive pancreaticoduodenectomy in patients with dilated pancreatic ducts: a prospective study

Background

Little is known about what factors predict better outcomes for patients who undergo minimally invasive pancreaticoduodenectomy (MIPD) versus open pancreaticoduodenectomy (OPD). We hypothesized that patients with dilated pancreatic ducts have improved postoperative outcomes with MIPD compared to OPD.

Methods

All patients undergoing pancreaticoduodenectomy were prospectively followed over a time period of 47 months, and perioperative and pathologic covariates and outcomes were compared. Ideal outcome after PD was defined as follows: (1) no complications, (2) postoperative length of stay < 7 days, and (3) negative (R0) margins on pathology. Patients with dilated pancreatic ducts (≥ 3 mm) who underwent MIPD were 1:3 propensity score-matched to patients with dilated ducts who underwent OPD and outcomes compared. Likewise, patients with non-dilated pancreatic ducts (< 3 mm) who underwent MIPD were 1:3 propensity score-matched to patients with non-dilated ducts who underwent OPD and outcomes were compared.

Results

371 patients underwent PD—74 (19.9%) MIPD and 297 (80.1%) underwent OPD. Overall, patients who underwent MIPD had significantly less intraoperative blood loss. After 1:3 propensity score matching, patients with dilated pancreatic ducts who underwent MIPD (n = 45) had significantly lower overall complication and 90-day readmission rates compared to matched OPD patients (n = 135) with dilated ducts. Patients with dilated duct who underwent MIPD were more likely to have an ideal outcome than patients with OPD (29 vs 15%, p = 0.035). There were no significant differences in postoperative outcomes among propensity score-matched patients with non-dilated pancreatic ducts who underwent MIPD (n = 29) compared to matched patients undergoing OPD (n = 87) with non-dilated ducts.

Conclusions

MIPD is safe with comparable perioperative outcomes to OPD. Patients with pancreatic ducts ≥ 3 mm appear to derive the most benefit from MIPD in terms of fewer complications, lower readmission rates, and higher likelihood of ideal outcome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08611-x.

Development of a novel intraoperative difficulty score for minimally invasive cholecystectomy

BACKGROUND

The rate of biliary injuries from minimally invasive cholecystectomy has remained high for over two decades. To improve outcomes there are multiple bail-out methods described, including aborting the procedure, converting to open, or performing a sub-total cholecystectomy. However, the intraoperative difficulty threshold for when a bail-out method should be implemented is poorly understood.

METHODS

From 1/2014 to 2/2019 cholecystectomy videos were collected, de-identified, edited to include the 2-3 minutes when the gallbladder was first visualized, and accelerated. They were then rated on a 5-point difficulty scale. Inter-coder reliability was evaluated using Krippendorff's alpha and regression models were used to evaluate the scores ability to predict the need for a bail-out technique.

RESULTS

62 videos were analyzed with a median length after editing of 37.5 (29.0-43.3) seconds. A median time of 46.2 (38.3-53.4) seconds was required for grading. The bail-out rate was 42.9%. The inter-coder reliability between 2 surgeons and 8 non-clinical reviewers was 0.675 with an average difficulty score of 3.0 (SD = 1.01). Regression models showed that the scale was able to significantly predict conversion (β=0.56,p<.01).

CONCLUSION

This novel difficulty score was able to predict conversion to a bail-out technique early in the course of minimally invasive cholecystectomy.

Re-defining a high volume center for pancreaticoduodenectomy

BACKGROUND

The purpose of this study was to re-evaluate the previously utilized definitions of high volume center for pancreaticoduodenectomy to determine/establish an objective, evidence based threshold of hospital volume associated with improvement in perioperative mortality.

METHODS

Patients who underwent pancreaticoduodenectomy were identified using the National Cancer Database from 2004 to 2015. The relationship between hospital volume and 90-day mortality was assessed using a logistic regression model. Receiver Operator Characteristic analysis was performed and Youden's statistic was utilized to calculate the optimal cut offs.

RESULTS

42,402 patients underwent elective Pancreaticoduodenectomy at 1238 unique hospitals. A logistic regression was performed which showed a significant inverse linear association between institutional volume and overall 90 day mortality. The maximum improvement in 90 day mortality is seen if the average annual hospital volume was greater than 9 (OR = 0.647 (0.595-0.702), p < 0.0001). When analysis is limited to hospitals that performed >9 cases per year, the maximum improvement in 90 day mortality was noticed at 36 cases per year (OR = 0.458 (0.399-0.525), p < 0.0001).

CONCLUSIONS

Based on our results, we recommend defining low, medium, and high volume centers for pancreaticoduodenectomy as hospitals with average annual volume less than 9, 9 to 35, and more than 35 cases per year, respectively.

Inability to manage non-severe complications on an outpatient basis increases non-white patient readmission rates after pancreaticoduodenectomy: A large metropolitan tertiary care center experience

BACKGROUND

Pancreaticoduodenectomy (PD) has a high rate of readmission, and racial disparities in care could be an important contributor.

METHODS

Patients undergoing PD were prospectively followed, and their complications graded using the Modified Accordion Grading System (MAGS). Patient factors and perioperative outcomes for patients with and without postoperative readmission were compared in univariate and multivariate analysis by severity.

RESULTS

837 patients underwent PD, the overall 90-day readmission rate was 27.5%. Non-white race was independently associated with readmission (OR 1.83, p = 0.007). 51.3% of readmissions were for non-severe complications (MAGS <3). Non-white race was independently associated with MAGS non-severe readmission (OR 2.13, p = 0.006), but not MAGS severe readmission.

CONCLUSIONS

Non-white patients are more likely to be readmitted, particularly for non-severe complications. Follow up protocols should be tailored to address race disparities in the rates of readmission as readmission for less severe complications could potentially be avoidable.

Care Fragmentation and Mortality in Readmission after Surgery for Hepatopancreatobiliary and Gastric Cancer: A Patient-Level and Hospital-Level Analysis of the Healthcare Cost and Utilization Project Administrative Database

BACKGROUND

Hepatopancreatobiliary (HPB) and gastric oncologic operations are frequently performed at referral centers. Postoperatively, many patients experience care fragmentation, including readmission to "outside hospitals" (OSH), which is associated with increased mortality. Little is known about patient-level and hospital-level variables associated with this mortality difference.

STUDY DESIGN

Patients undergoing HPB or gastric oncologic surgery were identified from select states within the Healthcare Cost and Utilization Project database (2006-2014). Follow-up was 90 days after discharge. Analyses used Kruskal-Wallis test, Youden index, and multilevel modeling at the hospital level.

RESULTS

There were 7,536 patients readmitted within 90 days of HPB or gastric oncologic surgery to 636 hospitals; 28% of readmissions (n = 2,123) were to an OSH, where 90-day readmission mortality was significantly higher: 8.0% vs 5.4% (p < 0.01). Patients readmitted to an OSH lived farther from the index surgical hospital (median 24 miles vs 10 miles; p < 0.01) and were readmitted later (median 25 days after discharge vs 12; p < 0.01). These variables were not associated with readmission mortality. Surgical complications managed at an OSH were associated with greater readmission mortality: 8.4% vs 5.7% (p < 0.01). Hospitals with <100 annual HPB and gastric operations for benign or malignant indications had higher readmission mortality (6.4% vs 4.7%, p = 0.01), although this was not significant after risk-adjustment (p = 0.226).

CONCLUSIONS

For readmissions after HPB and gastric oncologic surgery, travel distance and timing are major determinants of care fragmentation. However, these variables are not associated with mortality, nor is annual hospital surgical volume after risk-adjustment. This information could be used to determine safe sites of care for readmissions after HPB and gastric surgery. Further analysis is needed to explore the relationship between complications, the site of care, and readmission mortality.

Feasibility and safety of non-operative management of portal vein aneurysms: a thirty-five year experience

BACKGROUND

Portal vein aneurysms (PVAs) are rare, though clinically challenging with post-operative mortality approaching 20% and no evidence-based treatment guidelines. We aim to describe our experience with PVAs and recommend optimum management strategies.

METHODS

Demographics and clinical details of patients with PVAs admitted to our institution from 1984 to 2019 were reviewed. Clinical presentation, management and outcomes were analysed.

RESULTS

PVAs were identified in 18 patients (median age 56 years, range 20-101 years; 13 female); 10 were incidental and 8 diagnosed during abdominal pain work-up. Median aneurysm diameter at diagnosis was 3.4 cm (1.8-5.5 cm), remaining unchanged at 3.5 cm (1.9-4.8 cm) during a 3.2-year follow-up (4 months-31 years). Aneurysm sites were the main portal vein (n = 12), porto-splenic-junction (n = 3), splenic-SMV-junction (n = 2) and right portal vein (n = 1). Thrombosis occurred in 4 patients; 3 developed clinically insignificant cavernous transformation. Two patients underwent surgery for abdominal pain. Postoperatively, one developed PV thrombosis and PVA recurrence occurred in the second. No aneurysm ruptures or mortalities occurred during follow-up.

CONCLUSION

PVAs follow a clinically indolent course with structural stability and minimal complications over time. Non-operative management is feasible for most patients. Abdominal pain, large size or thrombosis don't appear to confer additional risks and should not, in isolation, merit surgical intervention.

Thunderbeat™ Integrated Bipolar and Ultrasonic Forceps in the Whipple Procedure: A Prospective Randomized Trial

Thunderbeat™ is a device that uses both ultrasonic and advanced bipolar energies to achieve hemostasis. It has been evaluated in a variety of clinical contexts, but no literature exists regarding its application to pancreatic surgery. Using a prospective, randomized controlled trial, we evaluated its safety and efficacy in the Whipple procedure. Thirty-two participants were enrolled in the study. The Thunderbeat™ device during the Whipple procedure showed similar safety profile compared to standard of care.

Composite Length of Stay, An Outcome Measure of Postoperative and Readmission Length of Stays in Pancreatoduodenectomy

PURPOSE

Postoperative length of stay (PLOS) and readmission rate are pancreatoduodenectomy (PD) outcome measures, which are reported individually but may be interrelated. The purpose of this study was to evaluate how well a composite length of stay measure (CLOS) that included PLOS and readmission length of stay describes outcomes. To do so, we evaluated how well CLOS correlated to postoperative complications absolutely and compared to PLOS.

METHODS

A total of 668 PDs performed between 2011 and 2018 were evaluated. CLOS was calculated from PLOS and readmission length of stay. Complication severity was judged by the Modified Accordion Grading System (MAGS). Multinomial logistical regression models (MLRM) were used to investigate the relationship between either PLOS or CLOS and complications. Multilevel and pairwise area under curves (AUC) using SAS macro %MultAUC were provided for both models.

RESULTS

A total of 432 of 668 patients (65%) developed complications. One hundred seventy-seven patients (27%) were readmitted. Mean PLOS was 10.2 days (7.1 SD) and mean CLOS was 12.3 days (10.1 SD). PLOS and CLOS both were correlated linearly to MAGS grade. Spearman correlation coefficient for CLOS vs. MAGS of 0.68 was higher than that of 0.49 for PLOS vs. MAGS. Multilevel AUC from MLRM using PLOS was 0.66, but multilevel AUC from MLRM using CLOS was 0.71.

DISCUSSION

CLOS provides an accurate estimate of hospital day utilization per patient for PD, reflecting not only the basal hospital recovery time for PD but the added time needed because of readmissions due to complications. It is tightly correlated to number and severity of postoperative complications.

The safety of hepatectomy after transarterial radioembolization: Single institution experience and review of the literature

BACKGROUND AND OBJECTIVES

The liver is a frequent site of malignancy, both primary and metastatic. The treatment goal of patients with liver cancer may include transarterial radioembolization (TARE). There are limited reports on the safety of hepatectomy following TARE. Our study's purpose is to review patients who have received TARE followed by hepatectomy.

METHODS

A retrospective study was performed on patients diagnosed with any liver cancer from 2013 to 2019 who underwent TARE followed by hepatectomy. Postoperative complications were prospectively collected. Descriptive statistics and the Kaplan-Meier test were used to assess survival outcomes.

RESULTS

Twelve patients were treated with a TARE followed by a hepatectomy (nine with ≥4 segments resected). Diagnoses included: six HCC, four cholangiocarcinoma, one metastatic neuroendocrine tumor, and one metastatic colorectal cancer. There were no 90-day post-hepatectomy mortalities and the overall morbidity was 66% (16% severe ≥MAGS 3). Hepatectomy-specific complications after hepatectomy included two (16%) bile leaks and no post-hepatectomy liver failures. The median recurrence free survival was 26 months. Overall survival at 1-year was 78% and at 3 years was 47%.

CONCLUSIONS

Our results support the safety of hepatectomy in select patients after TARE. Additional comparison to patients who receive hepatectomy as a first-line treatment for liver cancers should be investigated.

Less is more in the difficult gallbladder: recent evolution of subtotal cholecystectomy in a single HPB unit

INTRODUCTION

Subtotal cholecystectomy (SC) is a technique to manage the difficult gallbladder and avoid hazardous dissection and biliary injury. Until recently it was used infrequently. However, because of reduced exposure to open total cholecystectomy in resident training, we recently adopted subtotal cholecystectomy as the bail-out procedure of choice for resident teaching. This study reports our experience and outcomes with subtotal cholecystectomy in the years immediately preceding adoption and since adoption.

METHODS

A retrospective analysis was conducted of patients undergoing SC from July 2010 to June 2019. Outcomes, including bile leak, reoperation and need for additional procedures, were analyzed. Complications were graded by the Modified Accordion Grading Scale (MAGS).

RESULTS

1571 cholecystectomies were performed of which 71 were SC. Subtotal cholecystectomy patients had several indicators of difficulty including prior attempted cholecystectomy and previous cholecystostomy tube insertion. The most common indication for SC was marked inflammation in the hepatocystic triangle (51%). As our experience increased, fewer patients required open conversion to accomplish SC and SC was completed laparoscopically, usually subtotal fenestrating cholecystectomy (SFC). Most patients (85%) had a drain placed and 28% were discharged with a drain. The highest MAGS complication observed was grade 3 (11 patients, 15%). Six patients had a bile leak from the cystic duct resolved by ERCP. At mean follow-up of about 1 year no patient returned with recurrent symptoms.

CONCLUSIONS

Subtotal fenestrating cholecystectomy is a useful technique to avoid biliary injury in the difficult gallbladder and can be performed with very satisfactory rates of bile fistula, ERCP, and reoperation.

Long-Term Endocrine and Exocrine Insufficiency After Pancreatectomy

PURPOSE

To identify peri-operative risk factors and time to onset of pancreatic endocrine/exocrine insufficiency.

METHODS

We retrospectively analyzed a single institutional series of patients who underwent pancreaticoduodenectomy (PD) or distal pancreatectomy (DP) between 2000 and 2015. Endocrine/exocrine insufficiencies were defined as need for new pharmacologic intervention. Cox proportional modeling was used to identify peri-operative variables to determine their impact on post-operative pancreatic insufficiency.

RESULTS

A total of 1717 patient records were analyzed (75.47% PD, 24.53% DP) at median follow-up 17.88 months. Average age was 62.62 years, 51.78% were male, and surgery was for malignancy in 74.35% of patients. Post-operative endocrine insufficiency was present in 20.15% (n = 346). Male gender (p = 0.015), increased body mass index (BMI) (p < 0.001), tobacco use (p = 0.011), family history of diabetes (DM) (p < 0.001), personal history of DM (p ≤ 0.001), and DP (p ≤ 0.001) were correlated with increased risk. Mean time to onset was 20.80 ± 33.60 (IQR: 0.49-28.37) months. Post-operative exocrine insufficiency was present in 36.23% (n = 622). Race (p = 0.014), lower BMI (p < 0.001), family history of DM (p = 0.007), steatorrhea (p < 0.001), elevated pre-operative bilirubin (p = 0.019), and PD (p ≤ 0.001) were correlated with increased risk. Mean time to onset was 14.20 ± 26.90 (IQR: 0.89-12.69) months.

CONCLUSIONS

In this large series of pancreatectomy patients, 20.15% and 36.23% of patients developed post-operative endocrine and exocrine insufficiency at a mean time to onset of 20.80 and 14.20 months, respectively. Patients should be educated regarding post-resection insufficiencies and providers should have heightened awareness long-term.

An Update on Technical Aspects of Cholecystectomy

Laparoscopic cholecystectomy has revolutionized the field of surgery, and is currently the gold standard in the treatment for symptomatic cholelithiasis. The goal of every laparoscopic cholecystectomy should be attainment of the critical view of safety before cutting the cystic duct and artery to reduce the risk of bile duct injury. Open cholecystectomy is most commonly performed when laparoscopic cholecystectomy is converted to open or when laparoscopic cholecystectomy is contraindicated. Robotic cholecystectomy is a safe alternative to conventional laparoscopic cholecystectomy, and follows the same basic operative principles.

Targeting both tumour-associated CXCR2+ neutrophils and CCR2+ macrophages disrupts myeloid recruitment and improves chemotherapeutic responses in pancreatic ductal adenocarcinoma

OBJECTIVE

Chemokine pathways are co-opted by pancreatic adenocarcinoma (PDAC) to facilitate myeloid cell recruitment from the bone marrow to establish an immunosuppressive tumour microenvironment (TME). Targeting tumour-associated CXCR2⁺neutrophils (TAN) or tumour-associated CCR2⁺ macrophages (TAM) alone improves antitumour immunity in preclinical models. However, a compensatory influx of an alternative myeloid subset may result in a persistent immunosuppressive TME and promote therapeutic resistance. Here, we show CCR2 and CXCR2 combined blockade reduces total tumour-infiltrating myeloids, promoting a more robust antitumour immune response in PDAC compared with either strategy alone.

METHODS

Blood, bone marrow and tumours were analysed from PDAC patients and controls. Treatment response and correlative studies were performed in mice with established orthotopic PDAC tumours treated with a small molecule CCR2 inhibitor (CCR2i) and CXCR2 inhibitor (CXCR2i), alone and in combination with chemotherapy.

RESULTS

A systemic increase in CXCR2⁺ TAN correlates with poor prognosis in PDAC, and patients receiving CCR2i showed increased tumour-infiltrating CXCR2⁺ TAN following treatment. In an orthotopic PDAC model, CXCR2 blockade prevented neutrophil mobilisation from the circulation and augmented chemotherapeutic efficacy. However, depletion of either CXCR2⁺ TAN or CCR2⁺ TAM resulted in a compensatory response of the alternative myeloid subset, recapitulating human disease. This was overcome by combined CCR2i and CXCR2i, which augmented antitumour immunity and improved response to FOLFIRINOX chemotherapy.

CONCLUSION

Dual targeting of CCR2⁺ TAM and CXCR2⁺ TAN improves antitumour immunity and chemotherapeutic response in PDAC compared with either strategy alone.

Adjuvant therapy is associated with improved survival after curative resection for hilar cholangiocarcinoma: A multi-institution analysis from the U.S. extrahepatic biliary malignancy consortium

BACKGROUND

Curative-intent treatment for localized hilar cholangiocarcinoma (HC) requires surgical resection. However, the effect of adjuvant therapy (AT) on survival is unclear. We analyzed the impact of AT on overall (OS) and recurrence free survival (RFS) in patients undergoing curative resection.

METHODS

We reviewed patients with resected HC between 2000 and 2015 from the ten institutions participating in the U.S. Extrahepatic Biliary Malignancy Consortium. We analyzed the impact of AT on RFS and OS. The probability of RFS and OS were calculated in the method of Kaplan and Meier and analyzed using multivariate Cox regression analysis.

RESULTS

A total of 249 patients underwent curative resection for HC. Patients who received AT and those who did not had similar demographic and preoperative features. In a multivariate Cox regression analysis, AT conferred a significant protective effect on OS (HR 0.58, P = 0.013), and this was maintained in a propensity matched analysis (HR 0.66, P = 0.033). The protective effect of AT remained significant when node negative patients were excluded (HR 0.28, P = 0.001), while it disappeared (HR 0.76, P = 0.260) when node positive patients were excluded.

CONCLUSIONS

AT should be strongly considered after curative-intent resection for HC, particularly in patients with node positive disease.

Utility of a multidisciplinary tumor board in the management of pancreatic and upper gastrointestinal diseases: an observational study

BACKGROUND & OBJECTIVES

Multidisciplinary tumor boards (MDTBs) are frequently employed in cancer centers but their value has been debated. We reviewed the decision-making process and resource utilization of our MDTB to assess its utility in the management of pancreatic and upper gastrointestinal tract conditions.

METHODS

A prospectively-collected database was reviewed over a 12-month period. The primary outcome was change in management plan as a result of case discussion. Secondary outcomes included resources required to hold MDTB, survival, and adherence to treatment guidelines.

RESULTS

Four hundred seventy cases were reviewed. MDTB resulted in a change in the proposed plan of management in 101 of 402 evaluable cases (25.1%). New plans favored obtaining additional diagnostic workup. No recorded variables were associated with a change in plan. For newly-diagnosed cases of pancreatic ductal adenocarcinoma (n = 33), survival time was not impacted by MDTB (p = .154) and adherence to National Comprehensive Cancer Network guidelines was 100%. The estimated cost of physician time per case reviewed was $190.

CONCLUSIONS

Our MDTB influences treatment decisions in a sizeable number of cases with excellent adherence to national guidelines. However, this requires significant time expenditure and may not impact outcomes. Regular assessments of the effectiveness of MDTBs should be undertaken.

Abstract 4150: Blockade of CXCR2 mediated granulocytic MDSC recruitment synergizes with CCR2 inhibition of inflammatory monocytes and restores anti-tumor immunity in pancreatic adenocarcinoma

Introduction: Pancreatic cancer (PC) is characterized by a dense tumor stroma with a heavy leukocytic infiltrate, comprised predominately of immunosuppressive bone marrow (BM) derived cells. We have previously demonstrated in a phase Ib clinical trial that CCR2 inhibition (CCR2i) prevents inflammatory monocyte (IM) recruitment from the BM and results in a significant reduction of tumor associated macrophages (TAM) and an increase in treatment efficacy. However, granulocytic myeloid derived suppressor cells (G-MDSC) remain in the tumor microenvironment (TME) following CCR2i. Herein, we explored the impact of targeting G-MDSC recruitment to PC tumors both alone and in combination with CCR2i.

Methods: Human BM, blood, and tumor was collected under an IRB approved protocol. A tissue microarray (TMA) from resected PC patients was analyzed for immune infiltrate. Mice were injected orthotopically with 2.5×106 syngeneic PC cells. CXCR2 and CCR2 inhibitors (Tocris) were given twice daily. Tumor growth was assessed and specimens obtained for analysis by flow cytometry, RNAseq, and IHC.

Results: Human PC overexpresses CXCL5 and CXCL8, corresponding with an abundance of tumor infiltrating CXCR2+ G-MDSC. Furthermore, the ratio of CD8 to G-MDSC correlates with survival in human PC patients. In an orthotopic murine model that recapitulates human disease, ΣCXCL ligands were also increased. Either Ly6G depletion or targeted blockade with a CXCR2 inhibitor decreased G-MDSC and reduced tumor burden. Intriguingly, blockade of IM from the BM did not reduce G-MDSC and paradoxically resulted in a modest increase in this population within the tumors from human patients following CCR2i. Thus, we explored the combination of CCR2/CXCR2 blockade both with and without FOLFIRINOX chemotherapy. This resulted in a synergistic impact when both BM derived populations were targeted and dual therapy was further enhanced by FOLFIRINOX. RNAseq analysis of tumors following monotherapy or dual inhibition revealed alterations in the TME favoring an anti-tumor immune response. To test the hypothesis that this effect was mediated by restoration of anti-tumor immunity we analyzed the tumor infiltrating lymphocyte (TIL) populations and found a significant increase in the relative and absolute numbers of CD8+ and C4+ TIL. Analysis of the activation status of these cells demonstrated an increase in effector CD8+ T-cell phenotype (IFNγ+, CD69+, CD44+). Using Nur77GFP T-cell receptor reporter mice, we showed an increase in GFP expressing CD8+ TIL following dual blockade. CD8 depletion resulted in a loss of therapeutic efficacy of myeloid blockade, further confirming our hypothesis.

Conclusion: These findings suggest that combinatorial blockade strategies preventing tumor infiltration by myeloid cells may restore anti-tumor immunity in PC.

Citation Format: Timothy M. Nywening, Brian A. Belt, Roheena Z. Panni, Darren Cullinan, Dominic E. Sanford, Ryan C. Fields, William G. Hawkins, David G. DeNardo, William E. Gillanders, Peter Goedegebuure, David C. Linehan. Blockade of CXCR2 mediated granulocytic MDSC recruitment synergizes with CCR2 inhibition of inflammatory monocytes and restores anti-tumor immunity in pancreatic adenocarcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4150.

Targeting tumour-associated macrophages with CCR2 inhibition in combination with FOLFIRINOX in patients with borderline resectable and locally advanced pancreatic cancer: a single-centre, open-label, dose-finding, non-randomised, phase 1b trial

BACKGROUND

In pancreatic ductal adenocarcinoma, the CCL2-CCR2 chemokine axis is used to recruit tumour-associated macrophages for construction of an immunosuppressive tumour microenvironment. This pathway has prognostic implications in pancreatic cancer, and blockade of CCR2 restores anti-tumour immunity in preclinical models. We aimed to establish the safety, tolerability, and recommended phase 2 oral dose of the CCR2 inhibitor PF-04136309 in combination with FOLFIRINOX chemotherapy (oxaliplatin and irinotecan plus leucovorin and fluorouracil).

METHODS

We did this open-label, dose-finding, non-randomised, phase 1b study at one centre in the USA. We enrolled treatment-naive patients aged 18 years or older with borderline resectable or locally advanced biopsy-proven pancreatic ductal adenocarcinoma, an Eastern Cooperative Oncology Group performance status of 1 or less, measurable disease as defined by Response Evaluation Criteria in Solid Tumors version 1.1, and normal end-organ function. Patients were allocated to receive either FOLFIRINOX alone (oxaliplatin 85 mg/m(2), irinotecan 180 mg/m(2), leucovorin 400 mg/m(2), and bolus fluorouracil 400 mg/m(2), followed by 2400 mg/m(2) 46-h continuous infusion), administered every 2 weeks for a total of six treatment cycles, or in combination with oral PF-04136309, administered at a starting dose of 500 mg twice daily in a standard 3 + 3 dose de-escalation design. Both FOLFIRINOX and PF-04136309 were simultaneously initiated with a total treatment duration of 12 weeks. The primary endpoints were the safety, tolerability, and recommended phase 2 dose of PF-04136309 plus FOLFIRINOX, with an expansion phase planned at the recommended dose. We analysed the primary outcome by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01413022.

RESULTS

Between April 19, 2012, and Nov 12, 2014, we treated 47 patients with FOLFIRINOX alone (n=8) or with FOLFIRINOX plus PF-04136309 (n=39). One patient had a dose-limiting toxic effect in the dose de-escalation group receiving FOLFIRINOX plus PF-04136309 at 500 mg twice daily (n=6); this dose was established as the recommended phase 2 dose. We pooled patients in the expansion-phase group (n=33) with those in the dose de-escalation group that received PF-04136309 at the recommended phase 2 dose for assessment of treatment-related toxicity. Six (75%) of the eight patients receiving FOLFIRINOX alone were assessed for treatment toxicity, after exclusion of two (25%) patients due to insurance coverage issues. The median duration of follow-up for treatment toxicity was 72·0 days (IQR 49·5-89·0) in the FOLFIRINOX alone group and 77·0 days (70·0-90·5) in the FOLFIRINOX plus PF-04136309 group. No treatment-related deaths occurred. Two (5%) patients in the FOLFIRINOX plus PF-04136309 group stopped treatment earlier than planned due to treatment-related toxic effects. Grade 3 or higher adverse events reported in at least 10% of the patients receiving PF-04136309 included neutropenia (n=27), febrile neutropenia (n=7), lymphopenia (n=4), diarrhoea (n=6), and hypokalaemia (n=7). Grade 3 or higher adverse events reported in at least 10% of patients receiving FOLFIRINOX alone were neutropenia (n=6), febrile neutropenia (n=1), anaemia (n=2), lymphopenia (n=1), diarrhoea (n=2), hypoalbuminaemia (n=1), and hypokalaemia (n=3). Therapy was terminated because of treatment-related toxicity in one (17%) of the six patients receiving FOLFIRINOX alone. 16 (49%) of 33 patients receiving FOLFIRINOX plus PF-04136309 who had undergone repeat imaging achieved an objective tumour response, with local tumour control achieved in 32 (97%) patients. In the FOLFIRINOX alone group, none of the five patients with repeat imaging achieved an objective response, although four (80%) of those patients achieved stable disease.

INTERPRETATION

CCR2-targeted therapy with PF-04136309 in combination with FOLFIRINOX is safe and tolerable.

FUNDING

Washington University-Pfizer Biomedical Collaborative.

Interaction of Postoperative Morbidity and Receipt of Adjuvant Therapy on Long-Term Survival After Resection for Gastric Adenocarcinoma: Results From the U.S. Gastric Cancer Collaborative

BACKGROUND

Postoperative complications (POCs) can negatively impact survival after oncologic resection. POCs may also decrease the rate of adjuvant therapy completion. We evaluated the impact of complications on gastric cancer survival and analyzed the combined effect of complications and adjuvant therapy on survival.

METHODS

We analyzed 824 patients from 7 institutions of the U.S. Gastric Cancer Collaborative who underwent curative resection for gastric adenocarcinoma between 2000 and 2012. POC were graded using the modified Clavien-Dindo system. Survival probabilities were estimated using the method of Kaplan and Meier and analyzed using multivariate Cox regression.

RESULTS

Median follow-up was 35 months. The overall complication rate was 41 %. The 5-year overall survival (OS) and recurrence-free survival (RFS) of patients who experienced complications were 27 and 23 %, respectively, compared with 43 and 40 % in patients who did not have complications (p < 0.0001 for OS and RFS). On multivariate analysis, POC remained an independent predictor for decreased OS and RFS (HR 1.3, 95 % CI 1.1-1.6, p = 0.03 for OS; HR 1.3, 95 % CI 1.01-1.6, p = 0.03 for RFS). Patients who experienced POC were less likely to receive adjuvant therapy (OR 0.5, 95 % CI 0.3-0.7, p < 0.001). The interaction of complications and failure to receive adjuvant therapy significantly increased the hazard of death compared with patients who had neither complications nor adjuvant therapy (HR 2.3, 95 % CI 1.6-3.2, p < 0.001).

CONCLUSIONS

Postoperative complications adversely affect long-term outcomes after gastrectomy for gastric cancer. Not receiving adjuvant therapy in the face of POC portends an especially poor prognosis following gastrectomy for gastric cancer.

Utility of a multidisciplinary tumor board in the management of pancreatic diseases

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Background: Multidisciplinary Tumor Boards (MTBs) are a requirement for comprehensive cancer centers and are routinely used to coordinate multidisciplinary care in oncology. Despite their widespread use, the impact of MTBs is not well characterized. We studied the outcomes of all patients presented at our pancreas MTB, with the goal of evaluating our current practices and resource utilization. Methods: Data were prospectively collected for all patients presented at a weekly pancreas-specific MTB over the 12-month period at a single-institution NCI-designated cancer center. The conference is attended by surgical, medical, and radiation oncologists, interventional gastroenterologists, pathologists, and radiologists (diagnostic and interventional). Retrospective chart review was performed at the end of the 12-month period under an IRB-approved protocol. Results: A total of 470 patient presentations were made over a 12-month period. Average age at time of presentation was 61.5 years (range 17 – 89) with 51% males. 61.7% of cases were presented by surgical oncologists and 26% by medical oncologists. 174 cases were the result of new diagnoses or referrals. 78 patients were presented more than once (average of 2.3 times). Pancreatic adenocarcinoma was the most common diagnosis (37%), followed by uncharacterized pancreatic mass (16%), and pancreatic cyst (7%). The treatment plan proposed by the presenting clinician was known or could be evaluated prior to conference in 402 cases. Presentation of a case at MTB changed the plan of management 25% (n = 100) of the time, including MTB recommendation against a planned resection in 46 cases. When the initial plan changed as a result of MTB discussion, the most common new plan was to obtain further diagnostic testing such as biopsy and/or endoscopy (n = 24). Conclusions: MTBs are required and resource-intensive but offer the opportunity to discuss a wide array of pathologies and influence management decisions in a sizable proportion of cases. Additional investigations evaluating adherence rates to MTB decisions and to published guidelines (i.e. National Comprehensive Cancer Network) will further enhance the assessment and utility of MTBs.

The impact of recent hospitalization on surgical site infection after a pancreatectomy

BACKGROUND

Surgical site infections (SSI) are a major cause of increased morbidity and cost after a pancreatectomy. Patients undergoing a pancreatectomy frequently have had recent inpatient hospital admissions prior to their surgical admission (recent pre-surgical admission, RPSA), which could increase the risk of SSI.

METHODS

The 2009-2011 Healthcare Cost Utilization Project California State Inpatient Database was used. Chi-square tests, Student's t-tests and multivariable logistic regression were used.

RESULTS

Three thousand three hundred and seventy-six patients underwent a pancreatectomy, and 444 (13.2%) had RPSA. One hundred and eighty (40.5%) RPSAs were to different hospitals other than where patients' pancreatectomy took place. In univariate analysis, patients with RPSA had a significantly higher rate of post-operative SSIs, and this was associated with a longer length of post-operative stay, higher post-operative hospital costs and increased postoperative 30-day readmission rates (Table 1). In Multivariate analysis, RPSA was an independent predictor of post-operative SSI [odds ratio (OR) = 1.68, P = 0.013], and the risk of SSI increased with increasing RPSA length of stay (OR = 1.07 per day, P = 0.001).

CONCLUSIONS

Recent pre-surgical admission is an important risk factor for SSI after a pancreatectomy. Many patients with RPSA are not admitted pre-operatively to the same hospital where the pancreatectomy occurs; in such circumstances, SSI rates may not be a sole reflection of the care provided by operating hospitals.

Abstract B60: Role of inflammatory monocyte mobilization in metastatic pancreatic cancer

Introduction: More than half of patients with Pancreatic Cancer (PC) present with metastasis. Our group and others have shown that PC induces cellular changes in the liver long before metastatic spread. These pre-metastatic changes include a significant recruitment of inflammatory monocytes (IM) by the chemokine CCL2 (produced by pre-metastatic liver) and its receptor CCR2 (expressed on IM). Based on our preliminary data, we hypothesized that IM mobilization to the liver is essential for growth of metastatic PC. We therefore optimized our model of metastatic PC to study the role of CCR2 inhibition on growth of metastatic PC.

Methods: We implanted a spontaneously derived murine PC cell line (KCKO) orthotopically in the tail of the pancreas of C57BL/6 (WT) mice. We removed the primary tumor on day 10 and divided the spleen into two hemi-spleens. At this time, mice were injected with luciferase expressing tumor cells in the inferior pole of the spleen which was removed after injection and liver metastases were detected by bioluminescence (BLI).

Results: Mice with established liver metastasis were randomized to treatment with CCR2 antagonist (CCR2i), FOLFIRINOX, CCR2i and FOLFIRINOX combination (CCR2i+FOLFIRINOX), or vehicle. Mice were treated for three weeks and were imaged biweekly in order to quantify tumor burden in the liver. Mice were sacrificed after 3 weeks and gene expression and flow cytometry studies were performed on peripheral blood, bone marrow, and liver. Liver metastases were detected by BLI in 70% of mice after 10 days and 100% of mice after 15 days following splenic injection with luciferase expressing tumor cells. Peripheral blood and liver inflammatory monocytes/macrophages were significantly increased in mice bearing liver metastasis. However, CCR2i efficiently blocked the recruitment of inflammatory monocyte/macrophage populations in the liver (p&lt;0.01). Additionally mice treated with CCR2i alone and CCR2i and FOLFIRINOX combination exhibited a shift in the immune gene profile in metastatic liver from a pro-tumor (Type 2) to an anti-tumor (Type 1) immune response. Consequently, metastatic tumor burden was significantly decreased after treatment with CCR2i and FOLFIRINOX. Interestingly, the lowest tumor burden was found in livers of mice treated with combination of CCR2 inhibitor and FOLFIRINOX. This suggests that targeting CCR2 can decrease the growth of liver metastasis in PC.

Conclusion: Our murine model of PC metastasis formation recapitulates the human form of the disease. We demonstrate that inflammatory monocyte recruitment to the liver is important in promoting the development of metastasis in liver. CCR2 blockade in combination with FOLFIRINOX decreases macrophages in the liver and impairs growth of liver metastasis.

Citation Format: Roheena Z. Panni, Dominic E. Sanford, Brian A. Belt, Timothy M. Nywening, Peter Goedegebuure, David C. Linehan. Role of inflammatory monocyte mobilization in metastatic pancreatic cancer. [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 B60.

Proposal for Standardized Tabular Reporting of Observational Surgical Studies Illustrated in a Study on Primary Repair of Bile Duct Injuries

BACKGROUND

A standard format for reporting observational surgical studies does not exist. This creates difficulties in comparing studies and in performing synthesis through systematic reviews and meta-analyses. This article proposes a method called "standard tabular reporting" and illustrates its use in a case series of bile duct reconstructions for biliary injuries occurring during cholecystectomy.

STUDY DESIGN

A database dealing with biliary injuries was constructed in sections. Each section was designed to be turned into a table covering one element of the subject. Whenever possible, American College of Surgeons NSQIP "Classic Variables and Definitions" were used for forming sections and tables. However, most tables are original and specific to biliary injury. The database was populated from clinical records of patients who sustained a biliary injury during cholecystectomy.

RESULTS

Tables were created dealing with the following subjects: demographics, index operation, presentation, classification of injury, preoperative risk assessment, preoperative laboratory values, operative repair technique, postoperative complications, and long-term outcomes. Between 1997 and 2013, 122 primary bile duct reconstructions were performed, with 1 mortality and 47 complications. Good long-term results were obtained in 113 (92.6%) patients. No secondary surgical reconstructions have been needed.

CONCLUSIONS

Presentation of data in a standard format would facilitate comparison and synthesis of observational studies on the same subject. The biliary reconstructive methods used resulted in very satisfactory outcomes.

Improved peri-operative outcomes with epidural analgesia in patients undergoing a pancreatectomy: a nationwide analysis

BACKGROUND

In spite of limited evidence demonstrating a benefit, epidural analgesia (EA) is often used for patients undergoing a pancreatectomy. In the present study, the impact of epidural analgesia on post-operative outcomes after a pancreatectomy is examined.

METHODS

Utilizing the Nationwide Inpatient Sample, the effect of EA on peri-operative outcomes after a pancreatectomy was examined. Multivariable logistic and linear regression with propensity score matching were utilized for risk adjustment.

RESULTS

From 2008-2011, 12,440 patients underwent a pancreatectomy. Of these, 1130 (9.1%) patients received epidural analgesia. Using univariate comparison, patients receiving EA had a significantly decreased length of stay (LOS), hospital charges and post-operative inpatient mortality. In multivariate analyses, EA was independently associated with a decreased post-operative LOS (adjusted mean difference = -1.19 days, P < 0.001), decreased hospital charges (adjusted mean difference = -$16,814, P = 0.002) and decreased post-operative inpatient mortality [adjusted odds ratio (OR) = 0.42, P < 0.001]. Using 1:1 propensity score matching, patients who received an EA (n = 1070) had significantly decreased post-operative LOS (11.0 versus 12.1 days, P = 0.011), lower hospital charges ($112,086 versus $128,939, P = 0.001) and decreased post-operative inpatient mortality (1.5% versus 3.6%, P = 0.002) compared with matched controls without EA (n = 1070).

CONCLUSION

Analysis of a large hospital database reveals that EA is associated with improved peri-operative outcomes after a pancreatectomy. Additional studies are required to understand fully if this relationship is causal.

Role of inflammatory monocyte mobilization in growth of liver metastasis in a murine model of metastatic pancreatic cancer

299

Background: Pancreatic cancer (PC) is currently the fourth leading cause of death and the mortality rate approaches 100% due to early metastatic spread. Liver is the most common site of metastasis in PC. Our group and others have shown that PC induces cellular changes in the liver which include increase in inflammatory monocyte and macrophage population, long before development of metastasis. Based on our preliminary data, we developed a murine model of metastatic PC to study the role of chemotherapy in addition to novel IM blocking agents in established PC metastasis. Methods: We implanted spontaneously derived murine PC cell line (KCKO) orthotopically in the tail of pancreas of WT mice. 10 days after tumor implantation, there was an increase in infiltrating IM and macrophages in the liver by flow-cytometry and IHC. There was also an upregulation of genes associated with development of metastasis and recruitment of myeloid cells i.e. CCL2, CSF1, s100a4, s100a8, CXCL12, LOX, VEGF-A (P<0.01) by RT-PCR. However, there was no evidence of tumor metastasis at this stage in the liver. We removed the primary tumor on day 10. At this time, mice were injected with βluc-KCKO in the inferior pole of the spleen which was removed. Liver metastases were detectable by bioluminescence in 100% mice after 15 days of splenic injection. Results: Mice with established liver metastasis were randomized to treatment with CCR2i, FOLFIRINOX, CCR2i and CCR2i+FOLFIRINOX or vehicle. Mice were treated for 4 weeks and were imaged biweekly in-order to quantify tumor burden in the liver. Mice were sacrificed after 4 weeks and flow-cytometry studies were performed on peripheral blood, bone marrow and liver. The peripheral blood IM were significantly increased in mice bearing liver metastasis. However, CCR2i efficiently blocked the recruitment of IM and macrophages in liver (p<0.01). The burden of liver metastasis was significantly decreased after four weeks of treatment. Interestingly, the lowest tumor burden was found in livers of mice treated with combination of CCR2i and FOLFIRINOX. Conclusions: We demonstrate that CCR2i in combination with FOLFIRINOX decreases macrophages in the liver and impairs growth of liver metastasis.

Effect of targeting tumor-infiltrating myeloid cells on tumor progression in pancreatic adenocarcinoma

298

Background: Human pancreas cancer (PC) is associated with a heavy desmoplastic reaction and influx of bone marrow derived myeloid cells. Recruitment of these cells by the tumor allows for PC to create a favorable microenvironment that is immunosuppressive. Our work demonstrates that the most abundant type of myeloid cell in PC is granulocytes, which are positive for the chemokine receptor CXCR2. This receptor is vital for the trafficking of granulocytes from the peripheral blood to the tumor, therefore selective targeting of these cells via CXCR2 blockade may lead to potential clinical benefit in patients with PC. Methods: Human samples were obtained under IRB approved protocol at Washington University.C57BL/6 mice were injected subcutaneously or orthotopically with syngeneic PC (KCKO) cells and treated with vehicle or inhibitor daily. Tumor size was determined by caliper measurements and weight. Flow cytometry was performed and samples analyzed for myeloid markers. Results: Human PC patients have elevated levels of CXCR2+ granulocytes in the peripheral blood (p=0.02) and tumor microenvironment (p=0.002) compared to controls. In a murine model, CXCR2 inhibition reduces tumor infiltrating granulocytes (p=0.02) which was associated with a reduction in tumor growth in both a subcutaneous and orthotopic model (p=0.03). Our group has previously demonstrated that targeting the monocytic subset of myeloid cells in PC is an effective treatment strategy (p=0.02). Surprisingly, neither antagonist alone was effective at significantly decreasing the total tumor myeloid infiltrate and treatment with CCR2 inhibitor alone increased tumor infiltrating granulocytes (p=0.03). However, both therapies in combination resulted in a significant reduction in total tumor myeloid infiltrate (p<0.05) and was synergistic in regards to tumor reduction compared to either therapy alone (p<0.05). Conclusions: Human PC has an abundant CXCR2+ granulocytic infiltrate and blockade of CXCR2 may translate to potential clinically useful therapies.

Phase IB study of FOLFIRINOX plus PF-04136309 in patients with borderline resectable and locally advanced pancreatic adenocarcinoma (PC)

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Background: PF-04136309 (a novel CCR2 inhibitor) has shown anti-tumor activity in the preclinical setting in PC by depleting inflammatory monocytes and tumor associated macrophages (TAM) that contribute to an immunosuppressive tumor microenvironment. We hypothesized that combining PF-04136309 with FOLFIRINOX may improve clinical outcomes in PC. Methods: This is a phase Ib study with a dose de-escalation schema given the minimal toxicity of PF-04136309. The study includes Arm A (FOLFIRINOX only), Arm B (FOLFIRINOX plus PF-04136309) and an expansion cohort at the rapid phase II dose (RP2D). FOLFIRINOX (oxaliplatin 85 mg/m2, irinotecan 180 mg/m2, LV 400 mg/m2, 5FU bolus 400 mg/m2 and 2,400 mg/m2over 46 hours) was administered every two weeks. PF-04136309 at 500 mg twice daily via oral route was the starting dose level for Arm B. Treatment response was assessed after 6 cycles of treatment. Bone marrow biopsy and EUS/FNA at baseline and post 2 cycles were performed to assess the impact of treatment on the prevalence and function of inflammatory monocytes in the blood, bone marrow and tumor. Results: A total of 41 patients have been enrolled in the study to date (6 in Arm A, 8 in Arm B and 27 in the expansion cohort). The mean age of patients was 61.1 (range 45-75 yrs), male/female: 21/20, Caucasian/others: 32/9, borderline/locally advanced: 7/34. PF-04136309 at the starting dose did not result in additional toxicities when combined with FOLFIRINOX and it is the RP2D. Out of 35 patients treated with FOLFIRINOX plus PF-04136309, 6 are still in treatment, 6 are non-evaluable (withdrew consent or had poor tolerance). Of the 23 evaluable patients, 21 (91.3%) completed all 6 cycles; 12 (52.2%) had PR by RECIST and 11 (47.8%) had SD. Curative resections were achieved in 4 out of 5 with borderline resectable and 2 with locally advanced PC. Moreover, blockade of TAM mobilization was demonstrated by FACS and qPCR analysis of baseline and post-treatment FNA biopsies. Conclusions: Combing PF-04136309 with FOLFIRINOX is safe and tolerable. The regimen resulted in impressive treatment response and it further validated CCR2 inhibition in PC. Survival data and more correlative science will be forthcoming. Clinical trial information: 01413022.

Severe nutritional risk predicts decreased long-term survival in geriatric patients undergoing pancreaticoduodenectomy for benign disease

BACKGROUND

Weight loss and malnutrition are poorly tolerated by geriatric patients, and pancreaticoduodenectomy (PD) can result in chronic malabsorption and weight loss. We sought to determine how preoperative severe nutritional risk (SNR), as defined by the American College of Surgeons National Surgical Quality Improvement Program/American Geriatric Society Best Practice Guidelines, affects long-term survival after PD for benign disease among geriatric and nongeriatric patients.

STUDY DESIGN

All patients undergoing PD for nonmalignant conditions at a single center between 1995 and 2013 were followed for survival, excluding patients who died within 90 days of surgery. Survival of geriatric (age ≥65 years) and nongeriatric (age <65 years) patients with and without SNR was compared using Kaplan Meier methods. Cox regression was performed.

RESULTS

There were 320 patients who underwent PD for benign disease. Over the course of the study, the proportion of geriatric patients undergoing PD for benign conditions increased from 25% to 46%. In addition to being older, geriatric patients undergoing PD for benign disease were significantly more likely to have coronary artery disease (CAD) and hypertension. Geriatric patients with preoperative SNR had significantly decreased long-term survival after PD for benign disease (p < 0.001), with roughly 1 in 3 patients dead at 5 years compared with 1 in 14 patients without SNR. Survival was not significantly different among nongeriatric patients with and without SNR. In geriatric patients, age, CAD, and SNR were significantly associated with decreased survival on both univariate and multivariate analysis.

CONCLUSIONS

Severe nutritional risk can be a useful predictor of long-term survival in geriatric patients undergoing PD, and could improve patient risk stratification preoperatively. Nonoperative management should be strongly considered in geriatric patients with SNR, when malignancy is not suspected.

Association of discharge home with home health care and 30-day readmission after pancreatectomy

BACKGROUND

We sought to determine if discharge home with home health care (HHC) is an independent predictor of increased readmission after pancreatectomy.

STUDY DESIGN

We examined 30-day readmissions in patients undergoing pancreatectomy using the Healthcare Cost and Utilization Project State Inpatient Database for California from 2009 to 2011. Readmissions were categorized as severe or nonsevere using the Modified Accordion Severity Grading System. Multivariable logistic regression models were used to examine the association of discharge home with HHC and 30-day readmission using discharge home without HHC as the reference group. Propensity score matching was used as an additional analysis to compare the rate of 30-day readmission between patients discharged home with HHC with patients discharged home without HHC.

RESULTS

Of 3,573 patients who underwent pancreatectomy, 752 (21.0%) were readmitted within 30 days of discharge. In a multivariable logistic regression model, discharge home with HHC was an independent predictor of increased 30-day readmission (odds ratio = 1.37; 95% CI, 1.11-1.69; p = 0.004). Using propensity score matching, patients who received HHC had a significantly increased rate of 30-day readmission compared with patients discharged home without HHC (24.3% vs 19.8%; p < 0.001). Patients discharged home with HHC had a significantly increased rate of nonsevere readmission compared with those discharged home without HHC, by univariate comparison (19.2% vs 13.9%; p < 0.001), but not severe readmission (6.4% vs 4.7%; p = 0.08). In multivariable logistic regression models, excluding patients discharged to facilities, discharge home with HHC was an independent predictor of increased nonsevere readmissions (odds ratio = 1.41; 95% CI, 1.11-1.79; p = 0.005), but not severe readmissions (odds ratio = 1.31; 95% CI, 0.88-1.93; p = 0.18).

CONCLUSIONS

Discharge home with HHC after pancreatectomy is an independent predictor of increased 30-day readmission; specifically, these services are associated with increased nonsevere readmissions, but not severe readmissions.

Variations in definition and method of retrieval of complications influence outcomes statistics after pancreatoduodenectomy: comparison of NSQIP with non-NSQIP methods

BACKGROUND

NSQIP and the Accordion Severity Grading System have recently been used to develop quantitative methods for measuring the burden of postoperative complications. However, other audit methods such as chart reviews and prospective institutional databases are commonly used to gather postoperative complications. The purpose of this study was to evaluate discordance between different audit methods in pancreatoduodenectomy--a common major surgical procedure. The chief aim was to determine how these different methods could affect quantitative evaluations of postoperative complications.

STUDY DESIGN

Three common audit methods were compared with NSQIP in 84 patients who underwent pancreatoduodenectomy. The methods were use of a prospective database, a chart review based on discharge summaries only, and a detailed retrospective chart review. The methods were evaluated for discordance with NSQIP and among themselves. Severity grading was performed using the Modified Accordion System.

RESULTS

Fifty-three complications were listed by NSQIP and 31 complications were identified that were not listed by NSQIP. There was poor agreement for NSQIP-type complications between NSQIP and the other audit methods for mild and moderate complications (kappa 0.381 to 0.744), but excellent agreement for severe complications (kappa 0.953 to 1.00). Discordance was usually due to variations in definition of the complications in non-NSQIP methods. There was good agreement among non-NSQIP methods for non-NSQIP complications for moderate and severe complications, but not for mild complications.

CONCLUSIONS

There are important differences in perceived surgical outcomes based on the method of complication retrieval. The non-NSQIP methods used in this study could not be substituted for NSQIP in a quantitative analysis unless that analysis was limited to severe complications.

A simple effective method for generation of a permanent record of the Critical View of Safety during laparoscopic cholecystectomy by intraoperative "doublet" photography

BACKGROUND

The Critical View of Safety (CVS) is an established method for identifying the cystic duct during laparoscopic cholecystectomy. Its goal is to prevent misidentification of the bile ducts and avoid biliary injury. However, a visual record of CVS is not usually made. Intraoperative photography has the potential to record CVS and increase the safety of laparoscopic cholecystectomy. The objective of this study was to develop a simple and effective technique for recording CVS during laparoscopic cholecystectomy.

STUDY DESIGN

Techniques for photographing and rating photographs of CVS were developed. Surgeons were trained in methods of photographing both anterior and posterior views of CVS during laparoscopic cholecystectomy. Independent observers scored these views individually and together. The term doublet view was used when both anterior and posterior views of CVS were used for rating. Three criteria for CVS were used for scoring photographs. A total score of ≥ 5 of 6 points was considered satisfactory, and a total score <5 of 6 points was considered unsatisfactory.

RESULTS

Photographs of 28 patients were obtained. Critical View of Safety photographs were satisfactory in either anterior or posterior single images in 43 of 56 (76.8%) instances, and doublet photographs were satisfactory in 27 of 28 (96.4%) instances (p = 0.02). Body mass index >40 predicted a higher likelihood of unsatisfactory individual CVS photos (p = 0.02); however, there was no correlation between patient or pathologic factors and the scores of doublet views.

CONCLUSIONS

With training and adherence to straightforward photographic techniques, intraoperative doublet photography can record CVS accurately. This method is performed easily, and could be used for recording of CVS in the medical record.

Down-regulation of PLCγ2-β-catenin pathway promotes activation and expansion of myeloid-derived suppressor cells in cancer

Myeloid-derived suppressor cells (MDSCs) favor tumor promotion, mainly by suppressing antitumor T cell responses in many cancers. Although the mechanism of T cell inhibition is established, the pathways leading to MDSC accumulation in bone marrow and secondary lymphoid organs of tumor-bearing hosts remain unclear. We demonstrate that down-regulation of PLCγ2 signaling in MDSCs is responsible for their aberrant expansion during tumor progression. PLCγ2(-/-) MDSCs show stronger immune-suppressive activity against CD8(+) T cells than WT MDSCs and potently promote tumor growth when adoptively transferred into WT mice. Mechanistically, PLCγ2(-/-) MDSCs display reduced β-catenin levels, and restoration of β-catenin expression decreases their expansion and tumor growth. Consistent with a negative role for β-catenin in MDSCs, its deletion in the myeloid population leads to MDSC accumulation and supports tumor progression, whereas expression of β-catenin constitutively active reduces MDSC numbers and protects from tumor growth. Further emphasizing the clinical relevance of these findings, MDSCs isolated from pancreatic cancer patients show reduced p-PLCγ2 and β-catenin levels compared with healthy controls, similar to tumor-bearing mice. Thus, for the first time, we demonstrate that down-regulation of PLCγ2-β-catenin pathway occurs in mice and humans and leads to MDSC-mediated tumor expansion, raising concerns about the efficacy of systemic β-catenin blockade as anti-cancer therapy.

Inflammatory monocyte mobilization decreases patient survival in pancreatic cancer: a role for targeting the CCL2/CCR2 axis

PURPOSE

To determine the role of the CCL2/CCR2 axis and inflammatory monocytes (CCR2(+)/CD14(+)) as immunotherapeutic targets in the treatment of pancreatic cancer.

EXPERIMENTAL DESIGN

Survival analysis was conducted to determine if the prevalence of preoperative blood monocytes correlates with survival in patients with pancreatic cancer following tumor resection. Inflammatory monocyte prevalence in the blood and bone marrow of patients with pancreatic cancer and controls was compared. The immunosuppressive properties of inflammatory monocytes and macrophages in the blood and tumors, respectively, of patients with pancreatic cancer were assessed. CCL2 expression by human pancreatic cancer tumors was compared with normal pancreas. A novel CCR2 inhibitor (PF-04136309) was tested in an orthotopic model of murine pancreatic cancer.

RESULTS

Monocyte prevalence in the peripheral blood correlates inversely with survival, and low monocyte prevalence is an independent predictor of increased survival in patients with pancreatic cancer with resected tumors. Inflammatory monocytes are increased in the blood and decreased in the bone marrow of patients with pancreatic cancer compared with controls. An increased ratio of inflammatory monocytes in the blood versus the bone marrow is a novel predictor of decreased patient survival following tumor resection. Human pancreatic cancer produces CCL2, and immunosuppressive CCR2(+) macrophages infiltrate these tumors. Patients with tumors that exhibit high CCL2 expression/low CD8 T-cell infiltrate have significantly decreased survival. In mice, CCR2 blockade depletes inflammatory monocytes and macrophages from the primary tumor and premetastatic liver resulting in enhanced antitumor immunity, decreased tumor growth, and reduced metastasis.

CONCLUSIONS

Inflammatory monocyte recruitment is critical to pancreatic cancer progression, and targeting CCR2 may be an effective immunotherapeutic strategy in this disease.

Are readmission rates on a neurosurgical service indicators of quality of care?

OBJECT

The goal of this study was to examine the reasons for early readmissions within 30 days of discharge to a major academic neurosurgical service.

METHODS

A database of readmissions within 30 days of discharge between April 2009 and September 2010 was retrospectively reviewed. Clinical and administrative variables associated with readmission were examined, including age, sex, race, days between discharge and readmission, and insurance type. The readmissions were then assigned independently by 2 neurosurgeons into 1 of 3 categories: scheduled, adverse event, and unrelated. The adverse event readmissions were further subcategorized into patients readmitted although best practices were followed, those readmitted due to progression of their underlying disease, and those readmitted for preventable causes. These variables were compared descriptively.

RESULTS

A total of 348 patients with 407 readmissions were identified, comprising 11.5% of the total 3552 admissions. The median age of readmitted patients was 55 years (range 16-96 years) and patients older than 65 years totaled 31%. There were 216 readmissions (53% of 407) for management of an adverse event that was classified as either preventable (149 patients; 37%) or unpreventable (67 patients; 16%). There were 113 patients (28%) who met readmission criteria but who were having an electively scheduled neurosurgical procedure. Progression of disease (48 patients; 12%) and treatment unrelated to primary admission (30 patients; 7%) were additional causes for readmission. There was no significant difference in the proportion of early readmissions by payer status when comparing privately insured patients and those with public or no insurance (p = 0.09).

CONCLUSIONS

The majority of early readmissions within 30 days of discharge to the neurosurgical service were not preventable. Many of these readmissions were for adverse events that occurred even though best practices were followed, or for progression of the natural history of the neurosurgical disease requiring expected but unpredictably timed subsequent treatment. Judicious care often requires readmission to prevent further morbidity or death in neurosurgical patients, and penalties for readmission will not change these patient care obligations.

Demonstration of subpopulations with differing cancer stem cell phenotypes in xenograft and in vitro models of colorectal liver metastases

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Background: Tumors are composed of heterogeneous cell populations, some of which demonstrate enhanced tumor-forming capabilities (so-called tumor initiating cells [TIC] or cancer stem cells). In colorectal cancer (CRC), CD133, 44, and 24 are cell surface markers that identify TIC. Therefore, we sought to determine if CRC liver metastases (CRC-LM) form xenografts (in vivo) and cell cultures (in vitro) with TIC markers. Methods: CRC-LM were grafted in NOD/SCID mice and passaged serially. Xenografts were mechanically dissociated and cultured under sphere forming conditions. Flow cytometry was performed for TIC phenotype. Results: 16 of 18 (89%) CRC-LM specimens formed tumors in mice. Xenografts formed EpCAM+ tumors and spheres. The frequency of CD133+, CD44+, and CD133+/CD44+ tumor cells were 55%, 33%, and 23%, respectively. There was a subpopulation of CD133+/CD44+ cells with elevated CD44 expression(CD44hi). This CD133+/CD44hi population was also CD24+; representing 5% of cells. Eight of eleven (73%) xenografts formed spheres in vitro. The frequency of CD133+, CD44+, and CD133+/CD44+ cells were 63%, 47%, and 26%, respectively. CD133+/CD44+/CD24+ cells made up 8% of sphere-forming cells. There was a non-significant trend towards increased frequency of CD133+, CD44+, and CD133/CD44 positive cells in the spheres compared to the xenografts. However, the percentage of CD133+/CD44+/CD24+ cells was significantly increased in spheres relative to xenografts (8% vs. 5%, respectively; p<0.05) (see Table). Conclusions: CRC-LM derived xenografts and spheres are composed of distinct cell populations with differing levels of TIC/cancer stem cells. Sphere cultures may enhance for the most enriched TIC population. Thus, xenografts and sphere cultures are important model systems to further study the importance of cancer stem cells in CRC progression and metastases. [Table: see text]

Abstract A64: Peripheral blood monocytes predict survival in pancreatic cancer

Background: Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy with a 5-year survival of &lt; 5%, and a mortality rate nearly equal to its incidence. Characteristic of this tumor is a microenvironment in which monocytes/macrophages are abundant. Human monocytes are divided into two major subsets: inflammatory (IM) and resident (RM) monocytes. IM make up 85%-90% of human peripheral blood monocytes, and are identified by the expression of CD14 and CCR2. The CCL2-CCR2 chemokine axis is a crucial signaling pathway in physiologic IM recruitment from the bone marrow under inflammatory conditions. Within the tumor microenvironment, IM can differentiate into tumor associated-macrophages (TAM) which are immunosuppressive, and directly promote tumor progression by enhancing angiogenesis, growth, and invasion. We present evidence that IM are recruited from the bone marrow to the peripheral blood and tumors of PDAC patients. Furthermore, we hypothesize that that peripheral blood monocyte count is predictive of patient survival in PDAC.

Methods: PDAC tumor specimens (n=11) and normal pancreas (n=10) were subjected to flow cytometry and RT-PCR. Flow cytometry was performed on the peripheral blood mononuclear cells (PBMC) and bone marrow mononuclear cells (BMMC) of PDAC patients (n=13) and compared to healthy controls (n=11). For the survival analysis, 483 patients with PDAC underwent pancreaticoduodenectomy between 1997 and 2011 at a single institution. We excluded 110 patients with pre-operative leukocytosis (WBC&gt;11,000 cell/ul) or who died within 30 days of surgery. We stratified the remaining 373 patients into 3 groups based on the prevalence of monocytes in peripheral blood leukocytes using their pre-operative CBC: low(&lt;6%)[n=47], mid(≥6% to &lt;11%)[n=271], and high(≥11%)[n=55] %monocyte groups. We used standard Kaplan-Meier survival statistics to compare overall survival between the three groups.

Results: PDAC tumors are infiltrated by CCR2+ cells of monocyte lineage (CD45+, CD11b+, HLA-DR+, CD115+, CD14+) [37.9% ±1.6% of CD45+ cells], and these tumors expressed significantly more CCL2 relative to normal pancreas[p&lt;0.01]. IM (CD45+, CD11b+, HLA-DR+, CD14+, CCR2+, CD16-, CX3CR1 low) were significantly more prevalent in the PBMC of PDAC patients compared to controls [10.8%±1.1% vs 5.7%±1.1% of CD45+ cells; p&lt;0.005]; whereas, resident monocytes (CD45+, CD11b+, HLA-DR+, CD16+, CX3CR1 high, CD14 low, CCR2-) were not significantly different [0.67% ±0.1% vs 0.72% ±0.1%; p=0.76]. However, IM were significantly decreased in the bone marrow of PDAC patients compared to healthy controls [10.4% ±1.1 vs 14.9 ±1.2%; p&lt;0.01]. This suggests that the mechanism of increased IM in the peripheral blood of PDAC patients is mobilization from the bone marrow. Survival analysis of PDAC patients revealed that patients in the low %monocyte group survived significantly longer than patients in the high %monocyte group (27.8 months vs 18.2 months; p=0.02 on log-rank test). Also, there was a statistically significant incremental decrease in survival from the low to mid to high %monocyte groups (p=0.01 on log-rank test for trend).

Conclusion: IM are recruited from the bone marrow to the tumor microenvironment in PDAC through the CCL2/CCR2 chemokine axis, and the prevalence of peripheral blood monocytes correlates with decreased patient survival. Developing effective intervention strategies to thwart monocyte recruitment may hold significant promise in this disease.

Citation Format: Dominic E. Sanford, Brian A. Belt, Roheena Z. Panni, Jonathan B. Mitchem, David G. Denardo, S. Peter Goedegebuure, David C. Linehan. Peripheral blood monocytes predict survival in pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A64.