Hepatopancreaticobiliary Resection Arginine Immunomodulation (PRIMe) trial: protocol for a randomised phase II trial of the impact of perioperative immunomodulation on immune function following resection for hepatopancreaticobiliary malignancy

INTRODUCTION

Surgical stress results in immune dysfunction, predisposing patients to infections in the postoperative period and potentially increasing the risk of cancer recurrence. Perioperative immunonutrition with arginine-enhanced diets has been found to potentially improve short-term and cancer outcomes. This study seeks to measure the impact of perioperative immunomodulation on biomarkers of the immune response and perioperative outcomes following hepatopancreaticobiliary surgery.

METHODS AND ANALYSIS

This is a 1:1:1 randomised, controlled and blinded superiority trial of 45 patients. Baseline and perioperative variables were collected to evaluate immune function, clinical outcomes and feasibility outcomes. The primary outcome is a reduction in natural killer cell killing as measured on postoperative day 1 compared with baseline between the control and experimental cohorts.

ETHICS AND DISSEMINATION

This trial has been approved by the research ethics boards at participating sites and Health Canada (parent control number: 223646). Results will be distributed widely through local and international meetings, presentation, publication and ClinicalTrials.gov (identifier: NCT04549662). Any modifications to the protocol will be communicated via publications and ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT04549662.

Minimally Invasive Compared to Open Colorectal Cancer Resection for Older Adults: A Population-based Analysis of Long-term Functional Outcomes

OBJECTIVE

We sought to compare long-term healthcare dependency and time-at-home between older adults undergoing minimally invasive surgery (MIS) for colorectal cancer (CRC) and those undergoing open resection.

BACKGROUND

Although the benefits of MIS for CRC resection are established, data specific to older adults are lacking. Long-term functional outcomes, central to decision-making in the care for older adults, are unknown.

METHODS

We performed a population-based analysis of patients ≥70years old undergoing CRC resection between 2007 to 2017 using administrative datasets. Outcomes were receipt of homecare and "high" time-at-home, which we defined as years with ≤14 institution-days, in the 5years after surgery. Homecare was analyzed using time-to-event analyses as a recurrent dichotomous outcome with Andersen-Gill multivariable models. High timeat-home was assessed using Cox multivariable models.

RESULTS

Of 16,479 included patients with median follow-up of 4.3 (interquartile range 2.1-7.1) years, 7822 had MIS (47.5%). The MIS group had lower homecare use than the open group with 22.3% versus 31.6% at 6 months and 14.8% versus 19.4% at 1 year [hazard ratio 0.87,95% confidence interval (CI) 0.83-0.92]. The MIS group had higher probability ofhigh time-at-home than open surgery with 54.9% (95% CI 53.6%-56.1%) versus 41.2% (95% CI 40.1%-42.3%) at 5years (hazard ratio 0.71, 95% CI 0.68-0.75).

CONCLUSIONS

Compared to open surgery, MIS for CRC resection was associated with lower homecare needs and higher probability of high time-at-home in the 5 years after surgery, indicating reduced long-term functional dependence. These are important patient-centered endpoints reflecting the overall long-term treatment burden to be taken into consideration in decision-making.

PATCH-DP: a single-arm phase II trial of intra-operative application of HEMOPATCH™ to the pancreatic stump to prevent post-operative pancreatic fistula following distal pancreatectomy

BACKGROUND

Post-operative pancreatic fistula (POPF) is the most significant cause of morbidity following distal pancreatectomy. Hemopatch™ is a thin, bovine collagen-based hemostatic sealant. We hypothesized that application of Hemopatch™ to the pancreatic stump following distal pancreatectomy would decrease the incidence of clinically-significant POPF.

METHODS

We conducted a prospective, single-arm, multicentre phase II study of application of Hemopatch™ to the pancreatic stump following distal pancreatectomy. The primary outcome was clinically-significant POPF within 90 days of surgery. A sample size of 52 patients was required to demonstrate a 50% relative reduction in Grade B/C POPF from a baseline incidence of 20%, with a type I error of 0.2 and power of 0.75. Secondary outcomes included incidence of POPF (all grades), 90-day mortality, 90-day morbidity, re-interventions, and length of stay.

RESULTS

Adequate fixation Hemopatch™ to the pancreatic stump was successful in all cases. The rate of grade B/C POPF was 25% (95%CI: 14.0-39.0%). There was no significant difference in the incidence of grade B/C POPF compared to the historical baseline (p = 0.46). The 90-day incidence of Clavien-Dindo grade ≥3 complications was 26.9% (95%CI: 15.6-41.0%).

CONCLUSION

The use of Hemopatch™ was not associated with a decreased incidence of clinically-significant POPF compared to historical rates. (NCT03410914).

Early operative management in patients with adhesive small bowel obstruction: population-based cost analysis

Background

Adhesive small bowel obstruction (aSBO) is a potentially recurrent disease. Although non‐operative management is often successful, it is associated with greater risk of recurrence than operative intervention, and may have greater downstream morbidity and costs. This study aimed to compare the current standard of care, trial of non‐operative management (TNOM), and early operative management (EOM) for aSBO.

Methods

Patients admitted to hospital between 2005 and 2014 in Ontario, Canada, with their first episode of aSBO were identified and propensity‐matched on their likelihood to receive EOM for a cost–utility analysis using population‐based administrative data. Patients were followed for 5 years to determine survival, recurrences, adverse events and inpatient costs to the healthcare system. Utility scores were attributed to aSBO‐related events. Cost–utility was presented as the incremental cost‐effectiveness ratio (ICER), expressed as Canadian dollars per quality‐adjusted life‐year (QALY).

Results

Some 25 150 patients were admitted for aSBO and 3174 (12·6 per cent) were managed by EOM. Patients managed by TNOM were more likely to experience recurrence of aSBO (20·9 per cent versus 13·2 per cent for EOM; P < 0·001). The lower recurrence rate associated with EOM contributed to an overall net effectiveness in terms of QALYs. The mean accumulated costs for patients managed with EOM exceeded those of TNOM ($17 951 versus $11 594 (€12 288 versus €7936) respectively; P < 0·001), but the ICER for EOM versus TNOM was $29 881 (€20 454) per QALY, suggesting cost‐effectiveness.

Conclusion

This retrospective study, based on administrative data, documented that EOM may be a cost‐effective approach for patients with aSBO in terms of QALYs. Future guidelines on the management of aSBO may also consider the long‐term outcomes and costs.

Longer Trials of Non-operative Management for Adhesive Small Bowel Obstruction Are Associated with Increased Complications

BACKGROUND

Current guidelines for the management of adhesive small bowel obstruction suggest a limited trial of non-operative management, often of 3-5 days. A longer delay to operation may worsen post-operative outcomes in patients who ultimately require operation. Our objective was to evaluate the impact of time to operation on post-operative outcomes in patients who undergo operation following a trial of non-operative management for adhesive small bowel obstruction.

METHODS

We used health administrative data to identify patients with adhesive small bowel obstruction who underwent operative management following a trial of non-operative management from 2005 to 2014 in the province of Ontario, Canada. We used multivariable logistic regression to examine the relationship between the time from admission to operation with rates of 30-day mortality, serious complication, and bowel resection.

RESULTS

Three thousand five hundred sixty-three patients underwent operation after a trial of non-operative management for adhesive small bowel obstruction. Older patients, patients with a high comorbidity burden, and patients with a lower socioeconomic status were more likely to experience a longer pre-operative period. After adjusting for covariates, each additional day from admission to operation increased odds of serious complication (OR = 1.07, 95% CI = 1.03-1.11) and bowel resection (OR = 1.06, 95% CI = 1.03-1.98). Longer times to operation were not associated with greater adjusted odds of 30-day mortality.

CONCLUSION

Each additional day from admission to operation is associated with greater odds of adverse outcomes. Clinical practice guidelines should emphasize strategies that identify patients who will ultimately require operation.

Association of Surgical Intervention for Adhesive Small-Bowel Obstruction With the Risk of Recurrence

Importance

Adhesive small-bowel obstruction (aSBO) is a potentially chronic, recurring surgical illness. Although guidelines suggest trials of nonoperative management, the long-term association of this approach with recurrence is poorly understood.

Objective

To compare the incidence of recurrence of aSBO in patients undergoing operative management at their first admission compared with nonoperative management.

Design, Setting, and Participants

This longitudinal, propensity-matched, retrospective cohort study used health administrative data for the province of Ontario, Canada, for patients treated from April 1, 2005, through March 31, 2014. The study population included adults aged 18 to 80 years who were admitted for their first episode of aSBO. Patients with nonadhesive causes of SBO were excluded. A total of 27 904 patients were included and matched 1:1 by their propensity to undergo surgery. Factors used to calculate propensity included patient age, sex, comorbidity burden, socioeconomic status, and rurality of home residence. Data were analyzed from September 10, 2017, through October 4, 2018.

Exposures

Operative vs nonoperative management for aSBO.

Main Outcomes and Measures

The primary outcome was the rate of recurrence of aSBO among those with operative vs nonoperative management. Time-to-event analyses were used to estimate hazard ratios of recurrence while accounting for the competing risk of death.

Results

Of 27 904 patients admitted with their first episode of aSBO, 6186 (22.2%) underwent operative management. Mean (SD) patient age was 61.2 (13.6) years, and 51.1% (14 228 of 27 904) were female. Patients undergoing operative management were younger (mean [SD] age, 60.2 [14.3] vs 61.5 [13.4] years) with fewer comorbidities (low burden, 382 [6.2%] vs 912 [4.2%]). After matching, those with operative management had a lower risk of recurrence (13.0% vs 21.3%; hazard ratio, 0.62; 95% CI, 0.56-0.68; P < .001). The 5-year probability of experiencing another recurrence increased with each episode until surgical intervention, at which point the risk of subsequent recurrence decreased by approximately 50%.

Conclusions and Relevance

According to this study, operative management of the first episode of aSBO is associated with significantly reduced risk of recurrence. Guidelines advocating trials of nonoperative management for aSBO may assume that surgery increases the risk of recurrence putatively through the formation of additional adhesions. The long-term risk of recurrence of aSBO should be considered in the management of this patient population.

Predictors of Post-operative Pain and Opioid Consumption in Patients Undergoing Liver Surgery

BACKGROUND

Post-operative pain management is a critical component of perioperative care. Patients at risk of poorly controlled post-operative pain may benefit from early measures to optimize pain management. We sought to identify risk factors for post-operative pain and opioid consumption in patients undergoing liver resection.

METHODS

This is a multi-institutional prospective nested cohort study of patients undergoing open liver resection. Opioid consumption and pain scores were collected following surgery. To estimate the effects of patient factors on opioid consumption (oral morphine equivalents-OME) and on pain scores (NRS-11), we used generalized linear models and multivariable linear regression model, respectively.

RESULTS

One hundred and fifty-three patients who underwent open liver resection between 2013 and 2016 were included in the study. The mean patient age was 62.2 years, and 43.3% were female. Younger patients were significantly more likely to use more opioids in the early post-operative period (16.7 OME/10 years, p < 0.001). Patient factors that were significantly associated with increased NRS-11 pain scores also included younger patient age (difference in pain score of 0.3/10 years with cough and 0.2/10 years at rest, p < 0.01 for both) as well as a history of analgesic use (difference in pain score of 0.9 with cough and 0.6 at rest, p < 0.01 and p = 0.07, respectively).

CONCLUSION

Younger patients and those with a history of analgesic use are more likely to report higher post-operative pain and require higher doses of opioids. Early identification of these patients, and measures to better manage their pain, may contribute to optimal perioperative care.

Population-based study of the impact of small bowel obstruction due to adhesions on short- and medium-term mortality

BACKGROUND

Small bowel obstruction due to adhesions (aSBO) is a common indication for admission to a surgical unit. Despite the prevalence of this condition, the short- and medium-term survival of this patient population has not been well described. The purpose of this study was to measure the short- and medium-term survival of patients admitted to hospital with aSBO.

METHODS

Linked administrative data were used to identify patients admitted to hospital in Ontario, Canada, for aSBO between 2005 and 2011. Patients were divided into two groups: those aged less than 65 years (younger group) and those aged 65 years and older (older group). Thirty-day, 90-day and 1-year mortality rates were estimated. One-year mortality was compared with that in the general population, adjusting for age and sex. The timing of deaths in relation to admission was assessed, as well as the proportion of patients discharged before experiencing short-term mortality.

RESULTS

There were 22 197 patients admitted to hospital for aSBO for the first time in the study interval. Mean age was 64·5 years and 52·2 per cent of the patients were women. Overall, the 30-day, 90-day and 1-year mortality rates for the cohort were 5·7 (95 per cent c.i. 5·4 to 6·0), 8·7 (8·3 to 9·0) and 13·9 (13·4 to 14·3) per cent respectively. For both groups, the 1-year risk of death was significantly greater than that of the age-matched general population. The majority of deaths (62·5 per cent) occurred within 90 days of admission, with 36·4 per cent occurring after discharge from the aSBO admission.

CONCLUSION

Patients admitted with aSBO have a high short-term mortality rate. Increased monitoring of patients in the early period after admission is advisable.

Conditional disease-free survival after surgical resection of gastrointestinal stromal tumors: a multi-institutional analysis of 502 patients

IMPORTANCE

Gastrointestinal stromal tumors (GISTs) are the most commonly diagnosed mesenchymal tumors of the gastrointestinal tract. The risk of recurrence following surgical resection of GISTs is typically reported from the date of surgery. However, disease-free survival (DFS) over time is dynamic and changes based on disease-free time already accumulated following surgery.

OBJECTIVES

To assess the comparative performance of established GIST recurrence risk prognostic scoring systems and to characterize conditional DFS following surgical resection of GISTs.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study of 502 patients who underwent surgery for a primary, nonmetastatic GIST between January 1, 1998, and December 31, 2012, at 7 major academic cancer centers in the United States and Canada.

MAIN OUTCOMES AND MEASURES

Disease-free survival of the patients was classified according to 5 prognostic scoring systems, including the National Institutes of Health criteria, modified National Institutes of Health criteria, Memorial Sloan Kettering Cancer Center GIST nomogram, and American Joint Committee on Cancer gastric and nongastric categories. The concordance index (also known as the C statistic or the area under the receiver operating curve) of established GIST recurrence risk prognostic scoring systems. Conditional DFS estimates were calculated.

RESULTS

Overall 1-year, 3-year, and 5-year DFS following resection of GISTs was 95%, 83%, and 74%, respectively. All the prognostic scoring systems had fair prognostic ability. For all tumor sites, the American Joint Committee on Cancer gastric category demonstrated the best discrimination (C = 0.79). Using conditional DFS, the probability of remaining disease free for an additional 3 years given that a patient was disease free at 1 year, 3 years, and 5 years was 82%, 89%, and 92%, respectively. Patients with the highest initial recurrence risk demonstrated the greatest increase in conditional survival as time elapsed.

CONCLUSIONS AND RELEVANCE

Conditional DFS improves over time following resection of GISTs. This is valuable information about long-term prognosis to communicate to patients who are disease free after a period following surgery.

Adherence to Guidelines for Adjuvant Imatinib Therapy for GIST: A Multi-institutional Analysis

BACKGROUND

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. Adjuvant imatinib therapy improves recurrence-free and overall survival following surgery for patients with high-risk GIST; however, the factors associated with use of adjuvant imatinib therapy are unclear, and adherence to adjuvant imatinib has not been investigated. We sought to determine the clinicopathologic predictors of therapy with adjuvant imatinib following surgical resection for GIST and to determine the utilization of adjuvant imatinib in patients who underwent surgical resection of primary GIST in 2009 or later as recommended by National Comprehensive Cancer network (NCCN) guidelines.

METHODS

A multi-institutional cohort including 171 patients who underwent surgery for primary GIST at seven high-volume cancer centers in the USA and Canada between January 2009-December 2012 was used in this study. Receipt of adjuvant imatinib therapy was ascertained, and factors associated with imatinib therapy were analyzed.

RESULTS

Following surgery for primary GIST, tumor size (<5.0 cm: ref; 5.0-9.9 cm: odds ratio (OR) 2.36, 95 % confidence interval (CI) 0.74-7.55; >10.0 cm: OR 9.15, 95 % CI 2.28-36.75; p = 0.007), mitotic rate (≤5/50 mitoses per 50 high powered field [HPF]: ref; 6-10/50 HPF: OR 24.91, 95 % CI 3.64-170.35; >10/50 HPF: OR 5.80, 95 % CI 3.64-170.35; p < 0.001), and neoadjuvant therapy (OR 9.52; 95 % CI 2.51-36.14; p = 0.001) were associated with receipt of adjuvant imatinib therapy. Overall, 75 % of patients received appropriate treatment, 23 % of patients were undertreated, and 2 % of patients were overtreated as compared to NCCN guidelines. Adjuvant imatinib therapy was administered in only 53 % of patients for which the NCCN guidelines recommended adjuvant therapy.

CONCLUSION

The clinicopathologic factors associated with use of adjuvant imatinib therapy in patients following resection of primary GIST are consistent with established risk factors for recurrence. Adjuvant imatinib therapy remains underutilized in patients with intermediate and high-risk GIST and in patients who receive neoadjuvant therapy. Barriers to adjuvant imatinib therapy in this group of patients needs to be further explored.

Surgical management of advanced gastrointestinal stromal tumors: an international multi-institutional analysis of 158 patients

BACKGROUND

Patients with advanced gastrointestinal stromal tumors (GIST) are at high risk for recurrence after surgery. The aim of this study was to characterize outcomes of advanced GIST treated with surgery from a large multi-institutional database in the tyrosine kinase inhibitor (TKI) era.

STUDY DESIGN

Patients who underwent surgery for an advanced GIST from 1998 through 2012 were identified. Demographic, clinicopathologic, perioperative, and survival data were collected and analyzed.

RESULTS

There were 87 patients with locally advanced GIST and 71 patients with recurrent/metastatic GIST. The vast majority (95%) of patients with locally advanced GIST required a multivisceral resection; most patients (87%) underwent a microscopically complete (R0) resection. Although 82% of patients had high-risk tumors according to modified NIH criteria or had recurrent/metastatic disease, only 56% of patients received adjuvant TKI therapy. Among patients with locally advanced GIST, 3-year recurrence-free survival and overall survival rates were 65% and 87%, respectively. In contrast, 3-year recurrence-free survival and overall survival rates among patients with recurrent/metastatic GIST were 49% and 82%, respectively. On multivariate analysis, predictors of worse outcomes included high mitotic rate and male sex for patients with locally advanced GIST, and age and lack of adjuvant TKI therapy were associated with adverse outcomes among patients with recurrent/metastatic GIST (all p < 0.05).

CONCLUSIONS

Resection of advanced GIST can be safely accomplished with high rates of R0 resection. Among patients with advanced GIST, TKI therapy was underused. Barriers to the use of TKI therapy in this population should be explored.