The Role of Circulating Tumor DNA for Management of Patients With Rectal Cancer: Challenges and Opportunities.

ABSTRACT: Recently, organ preservation with total neoadjuvant therapy resulted in substantial progress in the management of locally advanced rectal cancer (LARC). The PROSPECT trial showed noninferiority of de-escalation of radiotherapy for patients with low-risk LARC who do not need abdominoperineal resection. Although these escalation and de-escalation approaches offer more personalized therapeutic approaches, the current state of care for patients with rectal cancer is far from individualized management. Circulating tumor DNA (ctDNA) is known to be one of the most powerful prognostic factors for early relapse and has been investigated in several interventional clinical trials to offer more precise treatment algorithms. In this review article, we discuss recent updates from studies examining the role of ctDNA for the prediction of treatment response and recurrence for patients with rectal cancer. We also elaborate on the future potential use of ctDNA in treatment escalation and de-escalation approaches for more personalized therapeutic interventions.

Comparison of outcomes of abdominoperineal resection vs low anterior resection in very-low rectal cancer.

BACKGROUND: The management of very-low rectal cancer is one of the most challenging issues faced by general and colorectal surgeons. Many feel compelled to pursue abdominoperineal resection (APR) over low anterior resection (LAR) to optimize oncologic outcomes. This study aimed to determine differences in long-term oncologic outcomes between patients undergoing APR or LAR for very-low rectal cancer. METHODS: The United States Rectal Cancer Consortium (2010-2016) was queried for adults who underwent either APR or LAR for stage I-III rectal cancers < 5 cm from anorectal junction and met inclusion criteria. The primary outcome was disease-free survival. Secondary outcomes included overall survival, length of stay, complications, recurrence location, and perioperative factors. RESULTS: A total of 431 patients with very-low rectal cancer who underwent APR or LAR were identified; 154 (35.7%) underwent APR. The overall recurrence rate was 19.6%. The median follow-up was 42.5 months. An analysis adjusted for demographics and pathologic stage observed no difference in disease-free survival between operative types (APR-hazard ratio [HR] = 0.90, 95% CI: 0.53-1.52, P = .70). Secondary outcomes demonstrated no significant difference between operation types, including overall survival (HR = 1.29, 95% CI: 0.71-2.32, P = .39), complications (OR = 1.53, 95% CI: 0.94-2.50, P = .12), or length of stay (estimate: 0.04, SE = 0.25, P = .54). CONCLUSION: We observed no significant difference in disease-free survival or overall survival between patients undergoing APR or LAR for very-low rectal cancer. This analysis supports the treatment of very-low rectal cancer, without sphincter involvement, by either APR or LAR.

Deprivation and Rurality Mediate Income Inequality's Association with Colorectal Cancer Outcomes.

INTRODUCTION: Income inequality is associated with poor health outcomes, but its association with colorectal cancer is not well-studied. The authors aimed to determine the association between income inequality and colorectal cancer incidence/mortality in U.S. counties, and hypothesized that this association was mediated by deprivation. METHODS: The authors performed a cross-sectional study of U.S. counties from 2015-2019 using statewide cancer registries and the Centers for Disease Control and Prevention WONDER database. Generalized linear negative binomial regression was performed in 2024 to estimate the association between Gini coefficient (income inequality) and colorectal cancer incidence/mortality using incidence rate ratios (IRRs) for the entire cohort and stratified by rurality. RESULTS: A total of 697,981 colorectal cancer cases were diagnosed in the 5-year study period. On adjusted regression, for every 0.1 higher Gini coefficient, there was an 11% higher risk of both colorectal cancer incidence and mortality (IRR 1.11, 95%CI 1.03,1.19 and IRR 1.11, 95%CI 1.05, 1.18 respectively). The association between income inequality and incidence/mortality peaked in more rural counties, however there was not an overall dose-dependent relationship between rurality and these associations. Deprivation mediated the association between income inequality and colorectal cancer incidence (indirect effect B coefficient 0.088, p<0.001) and mortality (B coefficient 0.088, p<0.001). The magnitude and direction of the direct, indirect, and total effects differed in each rurality strata. CONCLUSIONS: Much of income inequality's association with colorectal cancer outcomes operates through deprivation. Rural counties have a stronger association between higher income inequality and higher mortality, which works in tandem with deprivation.

Variables impacting prolonged post-anesthesia care unit length of stay in gynecologic cancer patients in the era of same day minimally invasive hysterectomy.

OBJECTIVES: Minimally invasive surgery for treatment of gynecologic malignancies is associated with decreased pain, fewer complications, earlier return to activity, lower cost, and shorter hospital stays. Patients are often discharged the day of surgery, but occasionally stay overnight due to prolonged post-anesthesia care unit (PACU) stays. The objective of this study was to identify risk factors for prolonged PACU length of stay (LOS). METHODS: This is a single institution retrospective review of patients who underwent minimally invasive hysterectomy for gynecologic cancer from 2019 to 2022 and had a hospital stay <24-h. The primary outcome was PACU LOS. Demographics, pre-operative diagnoses, and surgical characteristics were recorded. After Box-Cox transformation, linear regression was used to determine significant predictors of PACU LOS. RESULTS: For the 661 patients identified, median PACU LOS was 5.04 h (range 2.16-23.76 h). On univariate analysis, longer PACU LOS was associated with increased age (ρ = 0.106, p = 0.006), non-partnered status [mean difference (MD) = 0.019, p = 0.099], increased alcohol use (MD = 0.018, p = 0.102), increased Charlson Comorbidity Index (CCI) score (ρ = 0.065, p = 0.097), and ASA class ≥3 (MD = 0.033, p = 0.002). Using multivariate linear regression, increased age (R2 = 0.0011, p = 0.043), non-partnered status (R2 = 0.0389, p < 0.001), and ASA class ≥3 (R2 = 0.0250, p = 0.023) were associated with increased PACU LOS. CONCLUSIONS: Identifying patients at risk for prolonged PACU LOS, including patients who are older, non-partnered, and have an ASA class ≥3, may allow for interventions to improve patient experience, better utilize hospital resources, decrease PACU overcrowding, and limit postoperative admissions and complications. The relationship between non-partnered status and PACU LOS is the most novel relationship identified in this study.

Association of Surgical Approaches and Outcomes in Total Mesorectal Excision and Margin Status for Rectal Cancer.

INTRODUCTION: Despite being a key metric with a significant correlation with the outcomes of patients with rectal cancer, the optimal surgical approach for total mesorectal excision (TME) has not yet been identified. The aim of this study was to assess the association of the surgical approach on the quality of TME and surgical margins and to characterize the surgical and long-term oncologic outcomes in patients undergoing robotic, laparoscopic, and open TME for rectal cancer. METHODS: Patients with primary, nonmetastatic rectal adenocarcinoma who underwent either lower anterior resection or abdominoperineal resection via robotic (Rob), laparoscopic (Lap), or open approaches were selected from the US Rectal Cancer Consortium database (2007-2017). Quasi-Poisson regression analysis with backward selection was used to investigate the relationship between the surgical approach and outcomes of interest. RESULTS: Among the 664 patients included in the study, the distribution of surgical approaches was as follows: 351 (52.9%) underwent TME via the open approach, 159 (23.9%) via the robotic approach, and 154 (23.2%) via the laparoscopic approach. There were no significant differences in baseline demographics among the three cohorts. The laparoscopic cohort had fewer patients with low rectal cancer (<6 cm from the anal verge) than the robotic and open cohorts (Lap 28.6% versus Rob 59.1% versus Open 45.6%, P = 0.015). Patients who underwent Rob and Lap TME had lower intraoperative blood loss compared with the Open approach (Rob 200 mL [Q1, Q3: 100.0, 300.0] versus Lap 150 mL [Q1, Q3: 75.0, 250.0] versus Open 300 mL [Q1, Q3: 150.0, 600.0], P < 0.001). There was no difference in the operative time (Rob 243 min [Q1, Q3: 203.8, 300.2] versus Lap 241 min [Q1, Q3: 186, 336] versus Open 226 min [Q1, Q3: 178, 315.8], P = 0.309) between the three approaches. Postoperative length of stay was shorter with robotic and laparoscopic approach compared to open approach (Rob 5.0 d [Q1, Q3: 4, 8.2] versus Lap 5 d [Q1, Q3: 4, 8] versus Open 7.0 d [Q1, Q3: 5, 9], P < 0.001). There was no statistically significant difference in the quality of TME between the robotic, laparoscopic, and open approaches (79.2%, 64.9%, and 64.7%, respectively; P = 0.46). The margin positivity rate, a composite of circumferential margin and distal margin, was higher with the robotic and open approaches than with the laparoscopic approach (Rob 8.2% versus Open 6.6% versus Lap 1.9%, P = 0.17), Rob versus Lap (odds ratio 0.21; 95% confidence interval 0.05, 0.83) and Rob versus Open (odds ratio 0.5; 95% confidence interval 0.22, 1.12). There was no difference in long-term survival, including overall survival and recurrence-free survival, between patients who underwent robotic, laparoscopic, or open TME (Figure 1). CONCLUSIONS: In patients undergoing surgery with curative intent for rectal cancer, we did not observe a difference in the quality of TME between the robotic, laparoscopic, or open approaches. Robotic and open TME compared to laparoscopic TME were associated with higher margin positivity rates in our study. This was likely due to the higher percentage of low rectal cancers in the robotic and open cohorts. We also reported no significant differences in overall survival and recurrence-free survival between the aforementioned surgical techniques.

A Novel Digital Health Platform With Health Coaches to Optimize Surgical Patients: Feasibility Study at a Large Academic Health System.

BACKGROUND: Pip is a novel digital health platform (DHP) that combines human health coaches (HCs) and technology with patient-facing content. This combination has not been studied in perioperative surgical optimization. OBJECTIVE: This study's aim was to test the feasibility of the Pip platform for deploying perioperative, digital, patient-facing optimization guidelines to elective surgical patients, assisted by an HC, at predefined intervals in the perioperative journey. METHODS: We conducted an institutional review board-approved, descriptive, prospective feasibility study of patients scheduled for elective surgery and invited to enroll in Pip from 2.5 to 4 weeks preoperatively through 4 weeks postoperatively at an academic medical center between November 22, 2022, and March 27, 2023. Descriptive primary end points were patient-reported outcomes, including patient satisfaction and engagement, and Pip HC evaluations. Secondary end points included mean or median length of stay (LOS), readmission at 7 and 30 days, and emergency department use within 30 days. Secondary end points were compared between patients who received Pip versus patients who did not receive Pip using stabilized inverse probability of treatment weighting. RESULTS: A total of 283 patients were invited, of whom 172 (60.8%) enrolled in Pip. Of these, 80.2% (138/172) patients had ≥1 HC session and proceeded to surgery, and 70.3% (97/138) of the enrolled patients engaged with Pip postoperatively. The mean engagement began 27 days before surgery. Pip demonstrated an 82% weekly engagement rate with HCs. Patients attended an average of 6.7 HC sessions. Of those patients that completed surveys (95/138, 68.8%), high satisfaction scores were recorded (mean 4.8/5; n=95). Patients strongly agreed that HCs helped them throughout the perioperative process (mean 4.97/5; n=33). The average net promoter score was 9.7 out of 10. A total of 268 patients in the non-Pip group and 128 patients in the Pip group had appropriate overlapping distributions of stabilized inverse probability of treatment weighting for the analytic sample. The Pip cohort was associated with LOS reduction when compared to the non-Pip cohort (mean 2.4 vs 3.1 days; median 1.9, IQR 1.0-3.1 vs median 3.0, IQR 1.1-3.9 days; mean ratio 0.76; 95% CI 0.62-0.93; P=.009). The Pip cohort experienced a 49% lower risk of 7-day readmission (relative risk [RR] 0.51, 95% CI 0.11-2.31; P=.38) and a 17% lower risk of 30-day readmission (RR 0.83, 95% CI 0.30-2.31; P=.73), though these did not reach statistical significance. Both cohorts had similar 30-day emergency department returns (RR 1.06, 95% CI 0.56-2.01, P=.85). CONCLUSIONS: Pip is a novel mobile DHP combining human HCs and perioperative optimization content that is feasible to engage patients in their perioperative journey and is associated with reduced hospital LOS. Further studies assessing the impact on clinical and patient-reported outcomes from the use of Pip or similar DHPs HC combinations during the perioperative journey are required.

Predictors of recurrence and long-term patient reported outcomes following surgical repair of anal fistula, a retrospective analysis.

PURPOSE: Surgery for anal fistulas can result in devastating complications, including reoperations and fecal incontinence. There is limited contemporary evidence comparing outcomes since the adoption of the ligation of intersphincteric fistula tract procedure into mainstream practice. The purpose of this study is to compare recurrence rates and long-term outcomes of anal fistula following repair. METHODS: Data was collected from the electronic medical records or patient reported outcomes from patients aged 18 or older with a primary or recurrent cryptoglandular anal fistula. Primary outcome was recurrence defined as the identification of at least one fistula os or a high clinical suspicion of anal fistula. Secondary outcomes included fecal incontinence and postoperative quality of life. RESULTS: A total of 171 patients underwent definitive surgical repairs for their anal fistula. So 66.5% had a simple fistula, and 33.5% had a complex fistula. Of the 171 patients, 12.5% had a recurrence. The recurrence rates were 5.9% for simple fistula and 25.4% for complex fistula. Predictors of recurrence included diabetes mellitus, history of anorectal abscess, complex fistula, and sphincter sparing surgery. LIFT or plug/biologic procedures were both associated with a 50% or greater recurrence rate. No significant differences were found in fecal incontinence or associated quality of life between sphincter sparing or non-sphincter sparing surgical resections. CONCLUSION: The study provides insights into the long-term outcomes of surgical repair for anal fistula. We demonstrate that sphincter sparing operations are associated with increased recurrence, meanwhile, non-sphincter sparing surgeries did not increase the risk of fecal incontinence or worsen quality of life.

Prophylactic defunctioning stomas improve clinical outcomes of anastomotic leak following rectal cancer resections: An analysis of the US Rectal Cancer Consortium.

PURPOSE: Anastomotic leak (AL) is a complication of low anterior resection (LAR) that results in substantial morbidity. There is immense interest in evaluating immediate postoperative and long-term oncologic outcomes in patients who undergo diverting loop ileostomies (DLI). The purpose of this study is to understand the relationship between fecal diversion, AL, and oncologic outcomes. METHODS: This is a retrospective multicenter cohort study using patient data obtained from the US Rectal Cancer Consortium database compiled from six academic institutions. The study population included patients with rectal adenocarcinoma undergoing LAR. The primary outcome was the incidence of AL among patients who did or did not receive DLI during LAR. Secondary outcomes included risk factors for AL, receipt of adjuvant therapy, 3-year overall survival, and 3-year recurrence. RESULTS: Of 815 patients, 38 (4.7%) suffered AL after LAR. Patients with AL were more likely to be male, have unintentional preoperative weight loss, and are less likely to undergo DLI. On multivariable analysis, DLI remained protective against AL (p < 0.001). Diverted patients were less likely to undergo future surgical procedures including additional ostomy creation, completion proctectomy, or pelvic washout for AL. Subgroup analysis of 456 patients with locally advanced disease showed that DLI was correlated with increased receipt of adjuvant therapy for patients with and without AL on univariate analysis (SHR:1.59; [95% CI 1.19-2.14]; p = 0.002), but significance was not met in multivariate models. CONCLUSION: Lack of DLI and preoperative weight loss was associated with anastomotic leak. Fecal diversion may improve the timely initiation of adjuvant oncologic therapy. The long-term outcomes following routine diverting stomas warrant further study.

Association of omental pedicled flap with anastomotic leak following low anterior resection for rectal cancer.

BACKGROUND AND OBJECTIVES: Anastomotic leak following colorectal anastomosis adversely impacts short-term, oncologic, and quality-of-life outcomes. This study aimed to assess the impact of omental pedicled flap (OPF) on anastomotic leak among patients undergoing low anastomotic resection (LAR) for rectal cancer using a multi-institutional database. METHODS: Adult rectal cancer patients in the US Rectal Cancer Consortium, who underwent a LAR for stage I-III rectal cancer with or without an OPF were included. Patients with missing data for surgery type and OPF use were excluded from the analysis. The primary outcome was the development of anastomotic leaks. Multivariable logistic regression was used to determine the association. RESULTS: A total of 853 patients met the inclusion criteria and OPF was used in 106 (12.4%) patients. There was no difference in age, sex, or tumor stage of patients who underwent OPF versus those who did not. OPF use was not associated with an anastomotic leak (p = 0.82), or operative blood loss (p = 0.54) but was associated with an increase in the operative duration [ß = 21.42 (95% confidence interval = 1.16, 41.67) p = 0.04]. CONCLUSIONS: Among patients undergoing LAR for rectal cancer, OPF use was associated with an increase in operative duration without any impact on the rate of anastomotic leak.

Short-course radiation with consolidation chemotherapy does not increase operative morbidity compared to long-course chemoradiation: A retrospective study of the US rectal cancer consortium.

BACKGROUND AND OBJECTIVES: Neoadjuvant short-course radiation and consolidation chemotherapy (SC TNT) remains less widely used for rectal cancer in the United States than long-course chemoradiation (LCRT). SC TNT may improve compliance and downstaging; however, a longer radiation-to-surgery interval may worsen pelvic fibrosis and morbidity with total mesorectal excision (TME). A single, US-center retrospective analysis has shown comparable risk of morbidity after neoadjuvant short-course radiation with consolidation chemotherapy (SC TNT) and long-course chemoradiation (LCRT). Validation by a multi-institutional study is needed. METHODS: The US Rectal Cancer Consortium database (2010-2018) was retrospectively reviewed for patients with nonmetastatic, rectal adenocarcinoma treated with neoadjuvant LCRT or SC TNT before TME. The primary endpoint was severe postoperative morbidity. Cohorts were compared by univariate analysis. Multivariable logistic regression modeled the odds of severe complication. RESULTS: Of 788 included patients, 151 (19%) received SC TNT and 637 (81%) LCRT. The SC TNT group had fewer distal tumors (33.8% vs. 50.2%, p < 0.0001) and more clinical node-positive disease (74.2% vs. 47.6%, p < 0.0001). The intraoperative complication rate was similar (SC TNT 5.3% vs. 4.4%, p = 0.65). There was no difference in overall postoperative morbidity (38.4% vs. 46.3%, p = 0.08). Severe morbidity was similar with low anterior resection (9.1% vs. 15.3%, p = 0.10) and abdominoperineal resection (24.4% vs. 29.7%, p = 0.49). SC TNT did not increase the odds of severe morbidity relative to LCRT on multivariable analysis (OR 0.64, 95% CI 0.37-1.10). CONCLUSIONS: SC TNT does not increase morbidity after TME for rectal cancer relative to LCRT. Concern for surgical complications should not discourage the use of SC TNT when aiming to increase the likelihood of complete clinical response.

Use of Perioperative Intravenous Lidocaine as Part of an Abdominal Surgery Enhanced Recovery Pathway Does Not Significantly Impact Postoperative Pain.

BACKGROUND: The utility of perioperative intravenous lidocaine in improving postoperative pain control remains unclear. We aimed to compare postoperative pain outcomes in ERP abdominal surgery patients who did vs did not receive intravenous lidocaine. We hypothesized that patients receiving lidocaine would have lower postoperative pain scores and consume fewer opioids. METHODS: We performed a retrospective cohort study of patients undergoing elective abdominal surgery at a single institution via an ERP from 2017 to 2018. Patients who received lidocaine in the 6 months prior to a lidocaine shortage were compared to those who did not receive lidocaine for 6 months following the shortage. The primary outcome measures were pain scores as measured on the visual analogue scale and opioid consumption as measured by oral morphine equivalents (OME). RESULTS: We identified 1227 consecutive ERP abdominal surgery patients for inclusion (519 patients receiving lidocaine and 708 patients not receiving lidocaine). Demographics between the two cohorts were similar, with the following exceptions: more females, and more patients with a history of psychiatric diagnoses in the group that did not receive lidocaine. Adjusted, mixed linear models for both OME (P = .23) and pain scores (P = .51) found no difference between the lidocaine and no lidocaine groups. DISCUSSION: In our study of ERP abdominal surgery patients, perioperative intravenous lidocaine did not offer improvement in postoperative pain scores or OME consumed. We therefore do not recommend the use of intravenous lidocaine as part of an ERP multimodal pain management strategy in abdominal surgery patients.

REMAP Periop: a randomised, embedded, multifactorial adaptive platform trial protocol for perioperative medicine to determine the optimal enhanced recovery pathway components in complex abdominal surgery patients within a US healthcare system.

INTRODUCTION: Implementation of enhanced recovery pathways (ERPs) has resulted in improved patient-centred outcomes and decreased costs. However, there is a lack of high-level evidence for many ERP elements. We have designed a randomised, embedded, multifactorial, adaptive platform perioperative medicine (REMAP Periop) trial to evaluate the effectiveness of several perioperative therapies for patients undergoing complex abdominal surgery as part of an ERP. This trial will begin with two domains: postoperative nausea/vomiting (PONV) prophylaxis and regional/neuraxial analgesia. Patients enrolled in the trial will be randomised to arms within both domains, with the possibility of adding additional domains in the future. METHODS AND ANALYSIS: In the PONV domain, patients are randomised to optimal versus supraoptimal prophylactic regimens. In the regional/neuraxial domain, patients are randomised to one of five different single-injection techniques/combination of techniques. The primary study endpoint is hospital-free days at 30 days, with additional domain-specific secondary endpoints of PONV incidence and postoperative opioid consumption. The efficacy of an intervention arm within a given domain will be evaluated at regular interim analyses using Bayesian statistical analysis. At the beginning of the trial, participants will have an equal probability of being allocated to any given intervention within a domain (ie, simple 1:1 randomisation), with response adaptive randomisation guiding changes to allocation ratios after interim analyses when applicable based on prespecified statistical triggers. Triggers met at interim analysis may also result in intervention dropping. ETHICS AND DISSEMINATION: The core protocol and domain-specific appendices were approved by the University of Pittsburgh Institutional Review Board. A waiver of informed consent was obtained for this trial. Trial results will be announced to the public and healthcare providers once prespecified statistical triggers of interest are reached as described in the core protocol, and the most favourable interventions will then be implemented as a standardised institutional protocol. TRIAL REGISTRATION NUMBER: NCT04606264.

Implementing a Serious Illness Risk Prediction Model: Impact on Goals of Care Documentation.

CONTEXT: Goals of care conversations can promote high value care for patients with serious illness, yet documented discussions infrequently occur in hospital settings. OBJECTIVES: We sought to develop a quality improvement initiative to improve goals of care documentation for hospitalized patients. METHODS: Implementation occurred at an academic medical center in Pittsburgh, Pennsylvania. Intervention included integration of a 90-day mortality prediction model grouping patients into low, intermediate, and high risk; a centralized goals of care note; and automated notifications and targeted palliative consults. We compared documented goals of care discussions by risk score before and after implementation. RESULTS: Of the 12,571 patients hospitalized preimplementation and 10,761 postimplementation, 1% were designated high risk and 11% intermediate risk of mortality. Postimplementation, goals of care documentation increased for high (17.6%-70.8%, P< 0.0001) and intermediate risk patients (9.6%-28.0%, P < 0.0001). For intermediate risk patients, the percentage of goals of care documentation performed by palliative medicine specialists increased from pre- to postimplementation (52.3%-71.2%, P = 0.0002). For high-risk patients, the percentage of goals of care documentation completed by the primary service increased from pre-to postimplementation (36.8%-47.1%, P = 0.5898, with documentation performed by palliative medicine specialists slightly decreasing from pre- to postimplementation (63.2%-52.9%, P = 0.5898). CONCLUSIONS: Implementation of a goals of care initiative using a mortality prediction model significantly increased goals of care documentation especially among high-risk patients. Further study to assess strategies to increase goals of care documentation for intermediate risk patients is needed especially by nonspecialty palliative care.

Neoadjuvant Immunotherapy for Patients with dMMR/MSI-High Gastrointestinal Cancers: A Changing Paradigm.

Immune checkpoint inhibitors have revolutionized the management of mismatch repair-deficient (MMR-D)/microsatellite instability-high (MSI-H) gastrointestinal cancers, particularly colorectal cancer. Cancers with the MMR-D/MSI-H genotype often carry a higher tumor mutation burden with frameshift alterations, leading to increased mutation-associated neoantigen (MANA) generation. The dramatic response seen with immune checkpoint inhibitors (ICIs), which are orchestrated by MANA-primed effector T cells, resulted in the rapid development of these novel therapeutics within the landscape of MSI-H gastrointestinal cancers. Recently, several clinical trials have utilized ICIs as potential neoadjuvant therapies for MSI-H gastrointestinal cancers and demonstrated deep clinical and pathological responses, creating opportunities for organ preservation. However, there are potential challenges to the neoadjuvant use of ICIs for certain disease types due to the clinical risk of overtreatment for a disease that can be cured through a surgery-only approach. In this review article, we discuss neoadjuvant management approaches with ICI therapy for patients with MSI-H gastrointestinal cancers, including those with oligometastatic disease. We also elaborate on potential challenges and opportunities for the neoadjuvant utilization of ICIs and provide further insight into the changing treatment paradigm of MMR-D/MSI-H gastrointestinal cancers.

Development and Validation of a Machine Learning Model to Identify Patients Before Surgery at High Risk for Postoperative Adverse Events.

Importance: Identifying patients at high risk of adverse outcomes prior to surgery may allow for interventions associated with improved postoperative outcomes; however, few tools exist for automated prediction. Objective: To evaluate the accuracy of an automated machine-learning model in the identification of patients at high risk of adverse outcomes from surgery using only data in the electronic health record. Design, Setting, and Participants: This prognostic study was conducted among 1 477 561 patients undergoing surgery at 20 community and tertiary care hospitals in the University of Pittsburgh Medical Center (UPMC) health network. The study included 3 phases: (1) building and validating a model on a retrospective population, (2) testing model accuracy on a retrospective population, and (3) validating the model prospectively in clinical care. A gradient-boosted decision tree machine learning method was used for developing a preoperative surgical risk prediction tool. The Shapley additive explanations method was used for model interpretability and further validation. Accuracy was compared between the UPMC model and National Surgical Quality Improvement Program (NSQIP) surgical risk calculator for predicting mortality. Data were analyzed from September through December 2021. Exposure: Undergoing any type of surgical procedure. Main Outcomes and Measures: Postoperative mortality and major adverse cardiac and cerebrovascular events (MACCEs) at 30 days were evaluated. Results: Among 1 477 561 patients included in model development (806 148 females [54.5%; mean [SD] age, 56.8 [17.9] years), 1 016 966 patient encounters were used for training and 254 242 separate encounters were used for testing the model. After deployment in clinical use, another 206 353 patients were prospectively evaluated; an additional 902 patients were selected for comparing the accuracy of the UPMC model and NSQIP tool for predicting mortality. The area under the receiver operating characteristic curve (AUROC) for mortality was 0.972 (95% CI, 0.971-0.973) for the training set and 0.946 (95% CI, 0.943-0.948) for the test set. The AUROC for MACCE and mortality was 0.923 (95% CI, 0.922-0.924) on the training and 0.899 (95% CI, 0.896-0.902) on the test set. In prospective evaluation, the AUROC for mortality was 0.956 (95% CI, 0.953-0.959), sensitivity was 2148 of 2517 patients (85.3%), specificity was 186 286 of 203 836 patients (91.4%), and negative predictive value was 186 286 of 186 655 patients (99.8%). The model outperformed the NSQIP tool as measured by AUROC (0.945 [95% CI, 0.914-0.977] vs 0.897 [95% CI, 0.854-0.941], for a difference of 0.048), specificity (0.87 [95% CI, 0.83-0.89] vs 0.68 [95% CI, 0.65-0.69]), and accuracy (0.85 [95% CI, 0.82-0.87] vs 0.69 [95% CI, 0.66, 0.72]). Conclusions and Relevance: This study found that an automated machine learning model was accurate in identifying patients undergoing surgery who were at high risk of adverse outcomes using only preoperative variables within the electronic health record, with superior performance compared with the NSQIP calculator. These findings suggest that using this model to identify patients at increased risk of adverse outcomes prior to surgery may allow for individualized perioperative care, which may be associated with improved outcomes.

Enhanced Recovery Protocols Reduce Mortality Across Eight Surgical Specialties at Academic and University-affiliated Community Hospitals.

OBJECTIVE: To determine if implementation of a simplified ERP across multiple surgical specialties in different hospitals is associated with improved short and long-term mortality. Secondary aims were to examine ERP effect on length of stay, 30-day readmission, discharge disposition, and complications. SUMMARY BACKGROUND DATA: Enhanced recovery after surgery and various derivative ERPs have been successfully implemented. These protocols typically include elaborate sets of multimodal and multidisciplinary approaches, which can make implementation challenging or are variable across different specialties. Few studies have shown if a simplified version of ERP implemented across multiple surgical specialties can improve clinical outcomes. METHODS: A simplified ERP with 7 key domains (minimally invasive surgical approach when feasible, pre-/intra-operative multimodal analgesia, postoperative multimodal analgesia, postoperative nausea and vomiting prophylaxis, early diet advancement, early ambulation, and early removal of urinary catheter) was implemented in 5 academic and community hospitals within a single health system. Patients who underwent nonemergent, major orthopedic or abdominal surgery including hip/knee replacement, hepatobiliary, colorectal, gynecology oncology, bariatric, general, and urological surgery were included. Propensity-matched, retrospective case-control analysis was performed on all eligible surgical patients between 2014 and 2017 after ERP implementation or in the 12 months preceding ERP implementation (control population). RESULTS: A total of 9492 patients (5185 ERP and 4307 controls) underwent ERP eligible surgery during the study period. Three thousand three hundred sixty-seven ERP patients were matched by surgical specialty and hospital site to control non-ERP patients. Short and long-term mortality was improved in ERP patients: 30 day: ERP 0.2% versus control 0.6% ( P = 0.002); 1-year: ERP 3.9% versus control 5.1% ( P < 0.0001); 2-year: ERP 6.2% versus control 9.0% ( P < 0.0001). Length of stay was significantly lower in ERP patients (ERP: 3.9 ± 3.8 days; control: 4.8 ± 5.0 days, P < 0.0001). ERP patients were also less likely to be discharged to a facility (ERP: 11.3%; control: 14.8%, P < 0.0001). There was no significant difference for 30-day readmission. All complications except venous thromboembolism were significantly reduced in the ERP population (P < 0.02). CONCLUSIONS: A simplified ERP can uniformly be implemented across multiple surgical specialties and hospital types. ERPs improve short and long-term mortality, clinical outcomes, length of stay, and discharge disposition to home.

Drainage of anorectal abscesses in the operating room is associated with a decreased risk of abscess recurrence and fistula formation.

BACKGROUND: Timely incision and drainage (I&D) is first line management for anorectal abscesses. We aimed to define current practices in anorectal abscess management and identify factors associated with abscess recurrence and fistula formation. METHODS: Index episodes of anorectal abscesses treated with I&D in 2014-2018 at a multi-hospital healthcare system were included. Association with one-year abscess recurrence or fistula formation was evaluated using Cox proportional hazard regression. Fistulae were captured only among patients without fistulae at the index operation. RESULTS: A total of 458 patients met study criteria. One-year rate of abscess recurrence or fistula formation was 20.3%. When compared to bedside procedures, drainage in the operating room was associated with a reduced risk of either recurrence or fistula formation (aHR 0.20 [95%CI 0.114-0.367]). CONCLUSIONS: Improved exposure and patient comfort in the operating room may allow more complete drainage contributing to decreased rates of abscess recurrence or fistula formation.

Is There a Role for Adjuvant Chemotherapy in Pathologic Node-Negative Locally Advanced Rectal Cancer After Neoadjuvant Chemoradiation Therapy?

BACKGROUND: Neoadjuvant chemoradiation therapy (NCRT, 5-fluorouracil and radiation) followed by resection and adjuvant chemotherapy (AC) is one of the standard treatment paradigms for locally advanced rectal adenocarcinoma. However, the utility of AC in patients with pathologic lymph node (pLN)-negative disease is unclear. Our aim is to assess the value of AC stratified by pLN status. METHODS: The US Rectal Cancer Consortium database (2007-2017) was retrospectively reviewed for patients with clinical stage II and III rectal adenocarcinoma who received neoadjuvant chemoradiation (NACR) and curative-intent resection. Those who received neoadjuvant systemic chemotherapy or underwent local resection were excluded. Patients were categorized by pLN status. Primary outcome was overall survival (OS). RESULTS: Of 213 patients, 70% had pLN-negative disease and 30% pLN-positive disease. Median age was 57 years, 65% were male, and median follow-up was 31 months. Among patients with pLN-negative disease, 74% received AC. Receipt of AC was not associated with improved 5-year OS (82% versus 74%, respectively; p = 0.16). This finding persisted on multivariable analysis. Of patients with pLN-positive disease, 83% received AC. Patients with pLN-positive disease demonstrated improved 5-year OS with receipt of AC (72% compared with 0% with no adjuvant chemotherapy, p = 0.04). CONCLUSION: After receiving neoadjuvant chemoradiation, adjuvant chemotherapy for patients with pLN-negative disease does not appear to be associated with improved survival. Further validation and prospective studies are needed to evaluate the utility of adjuvant chemotherapy in this setting.