Society: SSAT

Background:
Socioeconomic status (SES) has proven significant impact on colorectal cancer (CRC) outcomes. Lower SES has correlated with increased comorbidities, risk of postoperative complications, and inadequate adherence to treatment guidelines. Previous studies were limited in defining SES because of databases lacking sufficient socioeconomic variables. We utilized the CDC’s Social Vulnerability Index (SVI) which contains additional information that more accurately determines SES. We hypothesize that higher SVI associates with worse clinical outcomes in CRC patients undergoing surgery at a high-volume tertiary care center.

Methods:
This is a single institution retrospective study of National Surgical Quality Improvement Program (NSQIP) data for patients aged 18 and older who underwent CRC surgery from 2013-2020. Patient zip codes were used to determine SES via the SVI database. Patients were divided into quartiles from low to high SVI (Q1-Q4). Outcomes measured included NSQIP defined morbidity, surgical site infection (SSI), extended length of stay (LOS>7), 30-day readmission. Bivariate and multivariate analysis were completed.

Results:
1,242 patients underwent CRC surgery during the study period. Morbidity, LOS>7, and SSI trended higher in the third and fourth quartiles but were not statistically significant. Bivariate analysis revealed a significantly increased risk of morbidity, SSI, and readmission in the third quartile, and a significantly increased LOS>7 in the fourth quartile. Continuous bivariate analysis showed that every 10 unit increase in SVI significantly increased risk for morbidity, LOS>7, and SSI. There was also a significant risk to morbidity and LOS>7 per 10 unit increase in social vulnerability on continuous multivariate analysis.

Conclusion:
This study represents a novel application of the SVI to investigate clinical outcomes using NSQIP data. Both bivariate and multivariate analysis revealed a significantly increased risk of poor clinical outcomes with higher SVI. Future application of the SVI may reveal possible interventions to improve colorectal and other surgical outcomes.

Introduction:
Multiple randomized control trials have evaluated laparoscopic (LP) and open proctectomy (OP) for rectal cancer, with mixed results. COREAN, CLASICC and COLOR II supported the use of LP, while ALaCaRT and Z6051 did not. Additionally, there is limited data on long-term oncologic outcomes for robotic proctectomy (RP). The aim of this study is to examine the effect of surgical approach on oncologic factors and survival for patients undergoing open, laparoscopic and robotic proctectomies.

Methods:
Patients in the National Cancer Database with locally advanced rectal cancer were stratified based on surgical approach from 2010-2018. Patient demographics and tumor characteristics were compared with univariate analysis. Intent to treat multivariable analysis and survival analysis with Cox proportional hazard ratios and Kaplan-Meier method were performed. Data analysis was performed using STATA v.17 and R v.4.0.2.

8,293 patients were identified. 3,991 (48.1%) underwent OP, 2,101 (25.3%) underwent LP, 1,666 (20.1%) underwent RP. Conversion rates were 7% for RP and 20% for LP. No clinically significant difference in age or sex was noted between groups. Differences in distribution of race were noted, with those who were Black more likely to have open compared to LP or RP (p-value < 0.001). MIS approaches appear to be more common at academic and comprehensive cancer centers (p-value<0.001). And patients with private insurance are more likely to undergo LP or RP (p-value<0.001). On multivariable analysis, patients who underwent LP (OR 0.760; 95% CI 0.611-0.946; p-value=0.014) or RP (OR 0.660; 95% CI 0.511-0.853; p-value=0.002) were less likely to have positive margins compared to OP. Patients who underwent LP (OR 0.842; 95% CI 0.738-0.961; p-value=0.011) and RP (OR 0.712; 95% CI 0.615-0.825; p-value<0.001) were less likely to have positive lymph nodes compared to those who underwent OP. No difference in 30-day or 90-day mortality was noted. On adjusted survival analysis a reduction in overall survival (OS) for OP compared to LP (HR 0.811; 95% CI:0.725-0.907; p-value<0.01) and RP (HR 0.78; 95% CI:0.67-0.905; p-value=0.01) was demonstrated. There was no difference in OS between LP and RP (HR 0.96; 95% CI: 0.820-1.13; p-value=0.654).

Conclusion:
MIS proctectomy is associated with improved survival compared to open technique. Importantly, there was no difference in survival between a robotic and laparoscopic approach. This suggests that robotic assisted proctectomies are a safe option.

Background: Extremity deep venous thromboses (DVTs) and portomesenteric venous thromboses (PMVTs) differ in their etiology, potential sequelae, and the efficacy of pharmacologic prophylaxis in preventing their occurrence. However, the National Surgical Quality Improvement Program (NSQIP) tracks the occurrence of both extremity DVTs and PMVTs within 30 days of surgery together under its “vein thrombosis requiring therapy” variable without distinguishing the two. We therefore aimed to determine the incidence of extremity DVTs and PMVTs in patients undergoing surgery for colorectal, pancreatic, and splenic malignancies to clarify the specific complications captured under the “vein thrombosis requiring therapy” variable in NSQIP and whether further division of this variable is warranted.

Methods: Patients undergoing operations for colorectal, pancreatic, and splenic malignancies at a single institution between January 1, 2006 and March 1, 2021 were identified. Patients who experienced a new onset upper or lower extremity DVT or a PMVT within 30 days of surgery were considered cases for the study (NSQIP DVT). Patients were then stratified by cancer type, and the anatomic location of each patient’s DVT (extremity or portomesenteric) was recorded. Univariate comparisons between cancer types and venous thromboembolism types were performed.

Results: A total of 8,491 operations for colorectal (n=6,003), pancreatic (n=1,496), or splenic malignancies (n=992). The overall incidence of NSQIP DVTs was 1.7%; 52% of NSQIP DVTs were PMVTs. The overall NSQIP DVT rate was highest in operations for a splenic malignancy (3.3%), followed by operations for pancreatic (2.7%) and colorectal (1.1%) malignancies (p < 0.01). After operations for pancreatic and splenic malignancies, the majority of NSQIP DVTs were either PMVTs alone or combined PMVTs plus extremity DVTs (pancreatic: 70%, splenic: 58%), while PMVTs comprised over a third of the NSQIP DVTs after surgery for colorectal malignancies (38%) (FIGURE). Of patients with an extremity DVT, 17% were also diagnosed with a pulmonary embolism (PE), compared to patients with a PMVT where a pulmonary embolism was diagnosed in only 4% of patients (p = 0.01). Lastly, PMVTs were diagnosed at a later postoperative day (median, [interquartile range]) than extremity DVTs for colorectal (19, [10-28] vs 15, [8-22]; p = 0.23) and pancreatic (21, [12-27] vs 15.5, [7-20]; p = 0.07) malignancies, but not for splenic malignancies (15 [9-22] vs 18 [12-28]); p = 0.16)

Conclusion: The current NSQIP DVT variable does not represent the full clinical picture of venous thromboembolic events after operations for colorectal, pancreatic, and splenic malignancies. The variable should be redesigned into separate “extremity DVT” and “PMVT” variables to better reflect postoperative outcomes and strengthen future research utilizing NSQIP datasets.

Incidence and Distribution of "NSQIP DVTs" Overall and by Tumor Location

Background
Colorectal cancer is the 4th most commonly diagnosed malignancy and the 3rd leading cause of mortality worldwide. A positive resection margin following surgery for colon cancer is linked with higher rates of recurrence and worse survival. The aim of this study was to use a developed diffuse reflectance spectroscopy (DRS) probe and tracking system to distinguish cancer and non-cancer colorectal tissue live on-screen intraoperatively in order to aid margin assessment.

Methods

Patients undergoing elective colorectal cancer resection surgery at a tertiary hospital in London were prospectively recruited between April 2021 and July 2022. A hand-held DRS probe was used on the surface of freshly resected ex-vivo colorectal tissue. Spectral data was acquired for normal and cancerous tissue. Binary classification was achieved using supervised machine learning classifiers, which were evaluated in terms of sensitivity, specificity, accuracy and the area under the curve.

Results

A total of 2702 mean spectra were obtained for normal and cancerous colorectal tissue. The Light Gradient Boosting Model was the best performing machine learning algorithm for differentiating normal and cancerous colorectal tissue, with an overall diagnostic accuracy of 90.7% and area under the curve of 96.7%. Live on-screen classification of tissue type was achieved using a graduated colourmap.

Conclusion

Real-time classification of tissue type was achieved using a DRS system, with high diagnostic accuracy, allowing differentiation of cancerous and normal colorectal tissue. This is a promising step towards an in-vivo classification system that is able to aid surgeons with accurate resection margin assessment for colorectal cancer intra-operatively.

Introduction
Recently, the use of minimally invasive surgery has been identified as a surrogate for quality of surgical care, while rates of emergent surgery are a surrogate for access to care. It has been demonstrated that health care outcomes may be more dependent on socioeconomic status and access to care than biologic factors. While significant advancements have been made in the management of patients with inflammatory bowel disease (IBD), it seems that the presence of disparate outcomes between black and white patients has not changed. We utilized the American College of Surgeons National Surgery Quality Improvement Program (NSQIP) database to evaluate trends in the rates of emergent operations, use of laparoscopic surgery and surgical outcomes comparing black and white patients.
Materials and Methods
The NSQIP database from the year 2012 to 2020 was used to evaluate trends in emergency surgery, laparoscopy and outcomes in IBD patients undergoing colectomy. IBD patients were identified using ICD codes for Crohn’s disease (ICD9: 555.x; ICD10 K50.x) and ulcerative colitis (ICD9: 556.x; ICD10 K51.x). The primary outcomes were rates of emergent and laparoscopic surgery over time. Secondary outcomes were length of stay and complication rates. Categorical variables were analyzed using Chi-square test, continuous variables using the Student’s t-test or Wilcoxon rank sums test, and proportions of laparoscopic and emergent surgeries using logistic regression modeling.
Results
There were 18,979 patients with IBD with race of either white (17,220) or black (1759) in the study period. The utilization of laparoscopic surgery is increasing at a greater rate in white patients compared to black patients (Figure 1), while emergent surgeries are remaining similar (Figure 2). The rates of any complication (25.7% vs 21.1%, p <0.0001) and major complication (23.2% vs 17.9%, p <0.0001) were higher in black patients. In subgroup analysis of patients undergoing laparoscopic surgery, rates of any complication were similar (17.9% vs 15.7%, p = 0.07), while major complications were more frequent in black patients (16.1% vs 13.2%, p = 0.01). Median post-operative length of stay was higher in black patients (6 days vs 5, p <0.0001).
Conclusion
There was an overall increase in the rate of laparoscopic surgery between 2012 and 2020 in IBD patients undergoing colectomy, however this disproportionately represented white patients. Additionally, black patients experienced greater post operative length of stay and increased complications compared to white patients, a disparity which is attenuated in the laparoscopic surgery group. These results raise concerns that while access to care is improving based on the declining rate of emergent surgeries, quality of surgical care is not improving. Further research is required to explore the underlying factors contributing to this disparity.

Introduction: Patients with fulminant Clostridioides difficile infection (CDI) may require surgical intervention. If surgery is required, total abdominal colectomy (TAC) is the most common approach. Diverting loop ileostomy (DLI) with antegrade colonic lavage has been introduced as a colon-sparing surgical approach to fulminant CDI. Prior analyses of National Inpatient Sample (NIS) data suggested equivalent postoperative outcomes between groups but did not evaluate healthcare resource utilization. As such, we aimed to analyze a more recent NIS cohort to compare these two approaches in terms of both postoperative outcomes and healthcare resource utilization.

Methods: A retrospective analysis of the NIS from 2016 to 2019 was conducted. Adult patients who underwent either a TAC or DLI with antegrade colonic lavage for fulminant CDI were identified using the relevant International Classification of Diseases, 10^th revision codes. The primary outcome was postoperative in-hospital morbidity. Secondary outcomes included postoperative in-hospital mortality, specific postoperative complications, total admission healthcare cost, and length of stay (LOS). Univariable and multivariable regressions were utilized to compare the two operative approaches. Subgroup analyses were performed for patients undergoing early intervention (i.e., intervention within three days of admission).

Results: In total, 886 patients underwent TAC and 409 patients underwent DLI with antegrade colonic lavage. Adjusted analyses demonstrated no difference between groups in terms of postoperative in-hospital morbidity (aOR 0.96, 95%CI 0.64-1.44, p=0.85) or postoperative in-hospital mortality (aOR 1.15, 95%CI 0.81-1.64, p=0.436). On adjusted analyses, patients undergoing TAC experienced significantly decreased total admission healthcare cost (MD 79,715.34, 95%CI 133,841-25,588, p=0.004) and shorter postoperative LOS (MD 4.06, 95%CI 6.96-1.15, p=0.006). Findings were similar in the subgroup of patients undergoing early intervention. Younger patients (aOR 0.98, 95%CI 0.97-0.99, p=0.003) and patients being managed at teaching hospitals (aOR 3.38, 95%CI 1.15-9.97, p=0.027) were significantly more likely to undergo DLI with antegrade colonic lavage.

Conclusions: There are minimal differences between TAC and DLI with antegrade colonic lavage for fulminant CDI in terms of postoperative morbidity and mortality. Healthcare resource utilization, however, is significantly improved when patients undergo TAC as evidenced by clinically important decreases in total admission healthcare cost and postoperative LOS. Future prospective comparative studies reporting long-term outcomes are required to determine whether one approach is more favourable in this setting.

Introduction:
The incidence of diverticulitis has a well-documented cyclic variation, with the highest incidence in the summer months (quarter 3: July- September). Previous studies have not evaluated the severity of the disease by season. We hypothesize that there may be differences in severity based on the time of year; that perhaps patients presenting in the “off-season” may have more severe disease. The aim of this study was to identify differences in severity of diverticulitis based on the time of year.

Methods: A retrospective cohort study of patients admitted with CT-confirmation of diverticulitis in one health system (2006-2021) was performed. Outcomes reflecting disease severity, including operation within 24 hours of admission, operation during index admission (>24hrs), length of stay, and 30-day readmission were obtained. Univariate and multivariate analyses were performed to compare outcomes based on the admission months according to quarter of the year: Q1 (Jan 1-March 31), Q2 (April 1-June 30), Q3 (July 1-Sept 30), Q4 (Oct 1-Dec 31). A secondary analysis was performed using just admissions in the summer months (May-Aug) vs winter months (Nov-Feb).

Results:
A total of 8,622 patients were included; 55.4% female (n=4,777), 20.5% smokers (1,768), and 92.2% with uncomplicated disease (7,950), with a mean age of 60.6 years (SD15.4). Rates of admission were highest in Q3 (2497, 29.0%), followed by Q2 (2226, 25.8%), Q4 (2077, 24.1%) and Q1 (1822, 21.1%). Although not significant, admissions for complicated diverticulitis were highest in Q1 (165, 9.1%) and lowest in Q3 (171, 6.9 %; p=0.07), rates of emergent operation were highest in Q1 (180, 2.1%) and lowest in Q3 (42, 1.7%), rates of operative intervention during index admission were highest in Q1 (n=30, 1.7) and lowest in Q3 (n=28, 1.1%; p=0.48), and readmission rates were highest in Q1 (n=220, 12.1%) and lowest in Q3 (n=249, 10.0%; p=0.18). On multivariate regression, patients in Q3 had a significantly decreased odds of presenting with complicated disease (OR 0.73, 95%CI0.59-0.92) compared to Q1, a significantly lower risk of emergent operation (OR0.65; 95%CI 0.42-0.98), and a significantly lower rate of 30 day readmission (OR 0.81, 95%CI 0.67-0.98). When just comparing summer to winter, patients in the winter were significantly more likely to require an emergent operation (OR 1.48, 95%CI 1.03-2.14).

Conclusion:
While diverticulitis admissions have a slightly higher incidence in the summer months, the severity of disease is significantly worse in the winter months with regard to complicated disease, needing an emergent operation, or being readmitted within 30 days. This suggests that disease severity overall might be worse for patients presenting in the “off-season,” allowing clinicians to better manage expectations and anticipate possible hospital resource utilization.

Table 1: Comparision of Patient Population and Outcomes in the Winter versus Summer Months

Table 1: Comparision of Patient Population and Outcomes in the Winter versus Summer Months

Graph 1: Incidence of Disease-Severity Measures by Season

Graph 1: Incidence of Disease-Severity Measures by Season

Introduction: Rectal cancer is a leading cancer diagnosis in the US, and the number of older patients diagnosed with this disease is expected to rise. Locally advanced rectal cancer (LARC) is commonly treated with consolidation neoadjuvant chemoradiation with the goal of organ preservation. However, frailty is not often recognized or considered in the treatment algorithm for rectal cancer. The prevalence of frailty in Medicare beneficiaries with cancer has been reported to approach 50% and the treatment of frail older cancer patients is complex and challenging. In the current study, we assessed the impact of frailty on the early postoperative outcomes of frailty among rectal cancer patients.

Methods
This retrospective, propensity score-matched study was conducted by extracting patients from the institutional’s rectal cancer database and merging with the institutional’s NSQIP registry. Patient characteristics included demographics, neoadjuvant therapy, time on neoadjuvant therapy, time to surgery, surgical approach, and oncological staging. Frailty was assessed using the Modified Frailty Index (mFI). Outcomes include loss of independence (LOI) or need for increased support outside the home, length of stay, and major complications (Clavien-Dindo II-IV). For analysis, patients were matched for frailty status, contingent on sex, race, chemoradiation, and procedure approach.

Results
129 patients operated on due to LARC from 2010 to 2021 were identified and in this group, 27 (21%) were frail. Neoadjuvant chemoradiotherapy was given at a similar rate in frail and non-frail patients (70% vs. 70.6%). No significant differences were observed in the surgical approach (Robotic 22% vs. 35%, p=0.25), the R0 resection rate (85% vs. 92%, p=0.29), and complete pathologic response rate (22% vs. 27%, p=0.81) in frail and non-frail patients, respectively. On propensity matched analysis, rectal cancer treatment outcomes in frail patients were associated with longer hospitalization time (OR=1.67; 95%CI 1.5-1.9; p<0.001) and a higher rate of major complications (OR=3.21; 95%CI 1.4-7.5, p=0.007). Frail patients had a significant increase in LOI (OR=2.14; 95%CI 1.4-3.2; p<0.001)

Conclusions
Frail patients undergo similar multimodal treatment for rectal cancer as non-frail patients and have poor postoperative outcomes. Further studies are necessary to examine the effect of this treatment paradigm on long-term cancer specific outcomes in the frail older patient so that properly balanced treatment strategies can be established.

Background
In a previous study, we demonstrated that the frequency of mismatch repair genes defect was similar in metachronous and sporadic colorectal cancer while an altered immune microenvironment may be a crucial factor for the occurrence of metachronous ones. The density of tumor-infiltrating lymphocytes (TIL) is an independent predictor of outcome in patients with colorectal cancer, and our hypothesis is that they can be involved in the onset of metachronous rectal cancer. The aim of this study was to analyze the tumor microenvironment in sporadic and metachronous rectal cancer.
Methods
This study is a sub-analysis of data from the IMMUNOREACT 1 and 2 (NCT04915326 and NCT04917263) including all the patients whose records had information about the past medical history. We defined as metachronous cancer a rectal cancer arising after a previous colorectal cancer at least 6 months after the first surgery. In this multicentric study, we collected healthy mucosa surrounding the rectal cancer. A panel of immune markers was retrospectively investigated at immunohistochemistry: CD3, CD4, CD8, CD8beta, Tbet, FoxP3, PD-L1, MSH6, and PMS2 and CD80. Immune markers within the healthy rectal mucosa were compared between patients with metachronous rectal cancer and those with a sporadic one. Sporadic rectal cancer and metachronous rectal cancer were compared. Nonparametric tests were used for small sample size comparison.
Results
A total of 412 patients with rectal cancer included in the retrospective cohort of IMMUNOREACT 1 and 2 cohorts were analyzed and 18 of them had a metachronous rectal cancer. Previously, only 4 of them had a right colon cancer while the other 14 had a previous left or sigmoid colon cancer. No mismatch repair gene deficiencies were observed in the two cohorts. In therapy-naïve patients with metachronous cancer, CD8+ T-cells infiltration was lower than that in patients with sporadic cancer (p=0.021). Moreover, in the whole cohort of patients, metachronous cancer had less frequently aa high level of CD8+ T cell infiltration than sporadic cancers (p=0.047).
Conclusion
Our study showed that, metachronous rectal cancer occurs frequently in the same site of the primitive ones suggesting a role for the cancerization field. Moreover, our data suggest that a constitutive weak cytotoxic T-cell activity may be a crucial factor, permitting the occurrence of metachronous CRC.

Background: Although the incidence of rectal cancer is increasing in younger patients, the majority of those diagnosed with it are older. However, patients over 80 years of age are typically excluded from clinical trials. Due to comorbidities and frailty, providers may recommend adjustments to National Comprehensive Cancer Network (NCCN) guidelines in these patients. We aimed to characterize the demographics and outcomes of elderly patients (80+ years) with T2 N0 rectal adenocarcinoma treated with preferred transabdominal resections versus those treated with less aggressive localized excision.

Methods: We conducted a retrospective review of the National Cancer Database (NCDB) for patients 80 years of age and older with clinical T2 N0 (stage I) rectal adenocarcinoma from 2004 to 2017. Patients were divided into two cohorts based on whether they underwent local excision versus definitive abdominal resection. Multivariable logistic regression was used to examine the adjusted association between the type of procedure and mortality and readmission rates.

Results: A total of 2,076 patients aged 80 and older with clinical T2 N0 rectal adenocarcinoma met inclusion criteria for the study. Of these, 765 (37%) underwent local excision while 1,311 (63%) had transabdominal resections. On univariate analysis, younger age (median age 83 versus 84 years, p<0.001) and male sex (52.9% versus 45.8%, p<0.002) were significantly associated with transabdominal resection. Race, ethnicity, facility type and region, insurance status, education level, geographic location, distance from facility, Charles-Deyo score, tumor grade, and radiation treatment were not significantly different between the two groups. In terms of post-operative mortality, 30 day mortality (0.9% in local excision versus 3.2% in formal resection, p<0.001) and 90 day mortality (3.9% in local excision versus 6.2% in formal resection, p<0.024) were significantly lower in the local excision group. However, months between diagnosis and last contact/death (a marker for longer term survival) was significantly higher in the abdominal resection group (49.6 months versus 41.9 months, p<0.001). Unplanned readmission within 30 days was not significantly different between the two groups. On multivariable logistic regression, only 30 day mortality maintained significance (OR 3.34, 95% CI 1.51-7.81, p<0.003).

Conclusions: On multivariable analysis, 30 day mortality was the only improved outcome in the local excision group. For the frail, elderly rectal cancer patient with T2 N0 disease, local excision with or without radiation therapy may be a reasonable alternative with only mildly diminished survival benefit but much improved perioperative risk profile. Future research should address rates of morbidity, recurrence, and long term mortality, as well as combinations of radiation and chemotherapy.

Background: Patients with inflammatory bowel diseases (IBD) are at increased risk for colorectal cancer (CRC). Total proctocolectomy with ileal pouch anal anastomosis (IPAA) is the treatment of choice in patients with IBD-associated dysplasia or CRC; however, CRC may also be discovered incidentally in a small percentage of cases of IPAA performed for other IBD-related indications. The aim of our study was to determine whether incidentally found CRC in the proctocolectomy specimen was associated with worse oncological and pouch-related outcomes compared to preoperatively diagnosed CRC.
Methods: Our prospectively maintained institutional pelvic pouch registry (1983 – 2021) was retrospectively reviewed. Patients with finding of colorectal adenocarcinoma at final pathology after proctocolectomy were included. Patients were divided into two groups: preoperative diagnosis (PreD) group if they had a preoperative biopsy positive for either dysplasia or adenocarcinoma, and incidental diagnosis (InD) group, if all their preoperative biopsies were negative for both dysplasia and adenocarcinoma and indication for IPAA was not related to dysplasia or cancer. The long term outcomes of the two groups were compared.
Results: A total of 164 patients were included: 53 (32%) in the InD group and 111 (68%) in the PreD. Patients in the InD group were younger than in the PreD group (median 44 years vs 49, p=0.05). Other demographic characteristics were similar between the two groups (Table 1). In the PreD group, 5% patients had low grade dysplasia at preoperative biopsy, 40% high grade dysplasia, 55% cancer (of which 9% in situ), 5% indeterminate. In the PreD group, 6 (6%) patients underwent neoadjuvant treatment. There were no differences in cancer staging, differentiation, and location between the groups. Nine (17%) patients in the InD and 25 (23%) in the PreD group underwent adjuvant chemotherapy (p = 0.446). After a median follow up of 11 (IQR 3 – 25) years for InD and 9 (IQR 3 – 20) years for PreD group, deaths were 14 (26%) in the InD and 18 (16%) in the PreD group, of which 3 (6%) and 7 (6%) cancer-related. Recurrences were 2 (4%) in the InD and 12 (11%) in the PreD group. Pouch failures were 5 (9%) in the InD and 9 (8%) in the PreD groups, of which 2 (5%) and 4 (4%) cancer-related. Ten-year overall survival (Figure 1a) was 94% for InD and 89% for PreD (p=0.41), cancer-specific survival was 96% for InD and 94% for PreD, disease-free survival 95% for InD and 88% for PreD (p=0.15), pouch survival (Figure 1b) 89% for InD and 97% for PreD (p=0.80).
Conclusion: IBD patients with an incidental finding of colorectal cancr during total proctocolectomy with IPAA appear to have similarly excellent oncological and pouch outcomes as patients with a preoperative cancer diagnosis.

Table 1. Characteristics of the two cohorts

Table 1. Characteristics of the two cohorts

Figure 1. Kaplan Meier curve for a) Overall survival; b) Pouch survival

Figure 1. Kaplan Meier curve for a) Overall survival; b) Pouch survival

Background: Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal cancer. In cases of invisible or non-endoscopically resectable dysplasia found at colonoscopy, total proctocolectomy with ileal pouch anal anastomosis can be offered with good long-term oncological outcomes and pouch survival, however, little is known regarding cancer-related outcomes when dysplasia is found incidentally after surgery. We hypothesized incidental colorectal dysplasia is associated with worse oncologic outcomes compared to dysplasia diagnosed preoperatively.
Methods: Using our prospectively collected pouch registry, we identified patients who had a) preoperative dysplasia or b) dysplasia found only after colectomy. Patients with cancer preoperatively or after colectomy were excluded. Included patients were divided into three groups: ONLYPRE (+preoperative biopsy, negative final pathology), PREFINAL (+preoperative biopsy and final pathology), and ONLYFINAL (negative preoperative biopsy, +final pathology. Long-term pouch survival in the three groups was assessed with survival analysis.
Results: In total, 517 patients were included: ONLYPRE = 125, PREFINAL = 254, ONLYFINAL = 137. No demographic differences were observed between groups. The preoperative diagnosis was ulcerative colitis in the majority of cases. In patients with a positive preoperative biopsy, the concordance between preoperative biopsy and final pathology was 49% (Figure 1a). After a median follow-up of 12 years (IQR 3 – 21), there were no differences in overall, disease-free or pouch survival between groups (Figure 1b, c, d). Cancer/dysplasia developed in 11 patients: 3 (2%) in the ONLYPRE, 5 (2%) in the PREPOST, and 3 (2%) in the ONLYPOST group (Table 1). Oncologically, one required redo pouch (ONLYPRE group), while 4 required pouch excision: 1 (1%) In ONLYPRE, 1 (0.5%) in the PREPOST, and 2 (2%) in the ONLYPOST group (p = 0.24). Only one cancer-related death occurred in the entire cohort (ONLYPRE group). Disease-free survival at 10 years was 98% for ONLYPRE, 98% for PREPOST, and 98% for ONLYPOST (p = 0.968). Pouch survival at 10 years was 96% for ONLYPRE, 99% for PREPOST, and 97% for ONLYPOST (p = 0.236).
Conclusion: An ileoanal pouch in the setting of IBD-associated dysplasia, regardless of when it is diagnosed, confers exceptionally good long-term outcomes. The incidental finding of dysplasia during proctocolectomy does not seem to be associated with worsened outcomes compared to preoperatively diagnosed dysplasia.

Table 1. Diagnosis and management of patients with cancer/dysplasia development after pelvic pouch

Table 1. Diagnosis and management of patients with cancer/dysplasia development after pelvic pouch

Figure 1. Pathology and long-term outcomes after pelvic pouch for dysplasia. a) Concordance between preoperative biopsy and final pathology; b) Overall survival; c) Disease free survival; d) Pouch survival

Figure 1. Pathology and long-term outcomes after pelvic pouch for dysplasia. a) Concordance between preoperative biopsy and final pathology; b) Overall survival; c) Disease free survival; d) Pouch survival

BACKGROUND: Adherence to current recommendations for the optimal time from diagnosis to treatment for patients with colorectal cancer (CRC) may have been disrupted by the COVID-19 pandemic. This study aimed to evaluate the impact of the pandemic on time to surgery or systemic therapy for patients diagnosed with colorectal cancer and delineate factors predictive of delayed treatment.

METHODS: Using the National Cancer Database, patients diagnosed with CRC were categorized based on year of diagnosis as COVID (2020) versus Pre-COVID (2018-2019). Sub-analyses were performed for patients who were tested for COVID-19 as well as those who had a positive COVID-19 result in 2020. Categorical variables were compared by chi-square analysis. Multivariate regression was used to control for confounding and assess odds ratios for delayed time to initial treatment (defined as greater than 60 days) for surgery or systemic treatment with chemotherapy or immunotherapy. Further subgroup analysis was performed to assess odds ratios for delayed treatment for patients who were tested for COVID or had a COVID-positive result.

RESULTS: 57,676 patients were diagnosed with CRC pre-COVID compared to 24,149 during COVID; 11,426 (47.3%) received COVID-19 testing and 803 (7.0%) had a positive COVID result. A larger proportion of patients diagnosed during COVID were Asian or other non-white/Black race; Hispanic; resided in the South or West; were uninsured, on Medicaid or Government insurance; and had higher stage at diagnosis. Proportions of delay to surgery (> 60 days) were comparable for patients diagnosed in 2020 (12.7%) compared to pre-COVID (13.2%), but higher for patients who were tested for COVID (15.6%) or COVID-positive in 2020 (17.8%). In a multivariate analysis controlling for patient demographics and year of diagnosis, diagnosis during COVID was not associated with delay to surgery, but COVID testing and positivity were. Delay to surgery was also associated with male sex, Black race, residence in the West or South, uninsured/Medicaid/Government insurance, or Stage 0-3 at diagnosis. Diagnosis during COVID did not increase delays to systemic therapy, regardless of COVID testing or positivity. However, the following characteristics were associated with delay to systemic therapy: any non-white race, Hispanic ethnicity, residence in the West or South, uninsured/Medicaid/Government insurance status, and stage 0-3.

DISCUSSION: While the COVID-19 pandemic did not delay treatment for CRC overall, COVID tested or COVID positive patients had increased delays to surgery compared to pre-COVID. Vulnerable and underserved populations were disproportionately affected by delays to surgery and systemic therapy. The difference in population colorectal disease outcomes mediated by these delays in treatment are yet to be realized.

Risk Associations for Delay to Surgery in the COVID versus non-COVID era using multivariate logistic regression. *Stages 0-1 combined due to low numbers.

Risk Associations for Delay to Surgery in the COVID versus non-COVID era using multivariate logistic regression. *Stages 0-1 combined due to low numbers.

Risk Associations for Delay to Systemic Treatment in the COVID versus non-COVID era using multivariate logistic regression. *Stages 0-1 combined due to low numbers.

Risk Associations for Delay to Systemic Treatment in the COVID versus non-COVID era using multivariate logistic regression. *Stages 0-1 combined due to low numbers.

Introduction: The COVID-19 pandemic has led to both direct and indirect delays in care, resulting in the disruption of many health screening services. Recent studies have demonstrated diminished screening rates for colorectal cancer. The exact impact this has had on incidence rates for colorectal cancer and possible missed diagnoses are yet unknown.

Methods: Using the National Cancer Database (NCDB), patients diagnosed with colorectal cancer from 2010-2020 were standardized to population level data, given that the NCDB represents 71.0% of colon and 75.9% of rectosigmoid cancers in the United States. This was done by utilizing the United States (US) population estimates per year per the census bureau data to calculate the annual incidence rate per 100,000. A 2010-2019 linear regression model of incidence rates (designated as pre-COVID) was used to calculate a predicted 2020 incidence rate and compare this to the actual incidence rate in 2020 (COVID). Sub-analyses were performed for patients based on age, sex, race, and geographic region.

Results: 817,652 patients were identified for analysis. After standardizing NCDB cases to US population data, the actual 2020 incidence (cases per 100,000) was 28.209 compared to the predicted 2020 incidence of 34.435, resulting in an actual incidence of 18.1% less than predicted. This effect was further amplified for patients that were male (18.6% less), black (18.8% less), and Hispanic (18.7% less), although these did not achieve significance. Patients less than 65 years old, of race other than black or white (Asian, Native Hawaiian, other Pacific Islander, American Indian), and those treated in the Western geographic region of the US had significantly lower rates of diagnosis than years prior (19.4% less, 22.1% less, and 21.9% less respectively).

Conclusion: The reported incidence of colorectal cancer significantly decreased during the COVID-19 pandemic in 2020, suggesting many patients harboring undiagnosed cancers. While the true clinical effect of COVID-19 on colorectal cancer diagnosis has yet to be seen, our data suggests missed diagnoses may drive subsequent increased incidences and higher stage at diagnosis in the coming years. In addition to the human toll, this may further burden the healthcare system and increase healthcare costs. It is imperative that providers strongly encourage patients to schedule colorectal cancer screening to flatten this pending cancer wave.

Background: Ileocolic anastomoses have a lower risk of anastomotic leak (AL) than other more distal anastomoses resulting in lower utilization of diversion. However, some patients perceived to be at high risk of AL are still diverted and exposed to the negative sequelae of an ileostomy. It is challenging in practice to identify patients at high enough risk of AL after a right-sided resection to justify diversion secondary to the low overall rate and the many proposed risk factors. Therefore, we used a multicenter database to develop and validate an anastomotic leak risk calculator that can assist surgical decision-making on when, if ever, diversion should be used for ileocolic resections.

Methods: The American College of Surgeons National Surgical Quality Improvement Program Colectomy Targeted PUF was queried from 2012-2020 for patients undergoing elective right-sided colectomy for cancer, benign neoplasm, or Crohn’s disease. Multivariable logistic regression identified independent predictors of AL in patients who were not diverted. Point values were assigned to these variables based on their maximum likelihood estimates to develop a risk score. Boot-strap analysis (200 replications) was performed for internal validation. Visual correspondence between predicted anastomotic leak rate and actual anastomotic leak rate and 95% confidence interval (CI) was assessed within each risk score decile. Lastly, risk scores were calculated for patients who were diverted at the time of elective right-sided colectomy.

Results: A total of 42,176 patients (53% female) with a median age of 66 years (range, 18-90) underwent right-sided resection without diversion. 2.4% of patients experienced an anastomotic leak, and independent risk factors for AL included male sex, tobacco use, immunosuppressant use, bowel preparation other than combination mechanical and antibiotic, an open approach, and a wound class of III or IV (TABLE). A risk calculator incorporating these variables showed excellent calibration and fair discrimination (raw c-index 0.64, boot-strap validated c-index 0.64) for prediction of anastomotic leak. There was strong visual correspondence with the predicted risk within the 95% CI of actual AL rate for nine of the ten deciles (FIGURE). An additional 1,013 patients underwent elective right-sided colectomy and were diverted, but 85% of these patients would have been in risk decile 8 or less indicating a predicted AL rate of less than 6%.

Conclusion: An internally valid AL risk score was developed for elective ileocolic resection. Applying the scores to diverted patients revealed that the majority of them were likely not at high enough risk to justify an ileostomy. Diversion after elective right-sided resections should be reserved for extreme circumstances in patients with potentially modifiable risk factors.

Points Assigned Per Variable in Final Risk Score

Points Assigned Per Variable in Final Risk Score

Predicted Versus Actual Anastomotic Leak Rate by Decile

Predicted Versus Actual Anastomotic Leak Rate by Decile

Purpose: Rectal procidentia, or prolapse, is a benign, but debilitating condition that disproportionately affects women (9:1) commonly in their seventh decade of life.<font size="1"> </font>There are countless operations and combinations described, however there is no standard approach. Successful outcomes in rectal prolapse surgery include prevention of recurrence and improvement in functional outcomes. Although associated with higher recurrence, perineal approaches are preferred in elderly and high-risk patients. Perineal rectosigmoidectomy (Altemeier) is one of the most common, well-tolerated perineal approach. However, its recurrence rates are up to 58%. Anal encirclement (Thiersch) is an alternative approach to mechanically restrict the lumen, but its recurrence rates are also up to 50%. We hypothesize that combining these approaches would reduce the recurrence of rectal prolapse.

Methods: This was a single institution (Royal University Hospital, SK), retrospective analysis from July 2017-October 2022. Patients >18 years of age with a rectal prolapse who underwent an operation with either an Altemeier or Altemeier +Thiersch where included. Rectal prolapse was defined as circumferential, full-thickness protrusion of the rectal wall through the anal verge. Variables were analyzed using Pearson’s Chi-squared Test or Man Whitney-U Test as appropriate. Repeated measurement ANOVA was used to compare changes. A p-value of <0.05 was considered significant. All data was analyzed using SPSS v.28 (IBM Corp, Armonk, NY). Recurrence was the primary outcome measured. Secondary outcomes were operative time, length of hospital stay, and complications.

Results: Twenty-three patients underwent an Altemeier, and twenty-one patients underwent Altemeier + Thiersch. The two groups had similar demographics, including average age, BMI, gender, ASA, and length of prolapse (Table 1). Patients who received the combined procedure had a lower rate (9.5%) of recurrent rectal prolapse, despite a higher proportion of them having had a previous prolapse procedure, than the Altemeier group alone (34.8%). This reduction in the incidence of recurrence was statistically significantly, p 0.023 (Table 1). There was no statistical difference in the average OR time between the two groups. The average hospital stay for patients who underwent the combined procedure was 2.3 days less (p 0.031). There were 5 complications in the Altemeier group compared to the combined group, however this difference was not statistically significant (Table 2).

Conclusion: The combination of an Altemeier + Thiersch reduces the risk of rectal prolapse recurrence than an Altemeier alone. It is safe and is effective in patients with a history of previous failed prolapse procedures.

Table 2: Outcomes

Table 1: Demographics

Introduction
Universal screening of all colorectal and endometrial cancer patients is used to identify patients with Lynch syndrome. Identification of patients with Lynch syndrome has treatment and surveillance implications for patients and their families. An assessment of National Cancer Institute designated comprehensive cancer programs showed that only 71% are performing universal screening, with cost being one of the major obstacles. Net Present Value (NPV) is a financial tool designed to identify difference between present value of cash inflows and the outflows over time and is used to calculate whenever investment in the new project if financially sound (positive NPV) or not (negative NPV). We hypothesize that investment into universal tumor screening on all newly diagnosed colorectal cancers will generate profit over time.
Methods
A financial model was created based on number of newly diagnosed colorectal cancer patients. We presumed that 1/25 individuals with colorectal cancer have Lynch syndrome. NCCN guidelines were used to identify required surveillance intervals. Cost of testing was presumed to be absorbed by the hospital. Index operations were omitted and only surveillance going forward was used. Charges and discount rates from Northwestern Medcine were used in the calculation
Results
Two hundred new cases of colorectal cancer are expected to be identified at our institution annually. Immunohistochemistry for all four mismatch repair proteins will cost $209 per patient ($52.25 per stain per protein) and $5,000 on pathology technician time per year. In our cohort, 8 new patients (equal number of males and females was presumed) is expected to be identified as having Lynch syndrome. These newly diagnosed individuals will require flexible sigmoidoscopy (presuming recommended resection was performed), EGD, pelvic exam and endometrial ultrasound for female patients and a dermatology visit. Based on current charges, 5-year NPV is positive at $110,000 and 10 year NPV is positive at $199.663. Presuming average size of American family and 50% of siblings and children having the mutation, additional 8 individuals will be identified leading to genetic testing, recurrent colonoscopy, EGD, dermatology appointments and pelvic exams and ultrasounds in females leading to additional 10-year positive NPV of $253,018. NPV remains positive even for institution that sees 25 new colorectal cancers per year.
Conclusion
Financial investment in universal screening on all new cases of colorectal cancer results in a positive NPV and significant profit for the hospital over time. Upfront investment in screening is still profitable even in low volume hospitals. This will also improve quality of care of those patients and allows for personalized care as well especially in the era of immunotherapy.

Introduction: Appendiceal tumors are rare, comprised of a range of histologies which vary in cellular behavior. National guidelines for the role of completion colectomy have evolved over time. We hypothesized that the national frequency of colectomies for appendiceal tumors based on histology has changed over time and affected clinical outcomes.

Method(s): Patients with appendiceal tumors diagnosed between 2004 and 2017 were identified in the National Cancer Database. Goblet cell adenocarcinoma (GCA), mucinous neoplasm, neuroendocrine neoplasm (NEN), and non-mucinous neoplasm histologies were studied. Characteristics of patients receiving appendectomy versus right hemicolectomy (RHC) were described and compared. Predictors of RHC were identified. Survival by extent of surgery for each histologic subtype was compared using Cox proportional hazards regression.

Results: Of 18216 study cases, 1970 (11%) were GCAs, 6219 (34%) mucinous neoplasms, 5603 (31%) NENs, and 4424 (24%) non-mucinous neoplasms. While RHC was performed for the majority of GCAs (69%), mucinous neoplasms (65%), and non-mucinous neoplasms (68%) across the study timeframe, the overall rate of RHC for NEN dropped from 68% in 2004-2009 to 44% from 2010-2017 (p<0.001) (Figure 1). For all subtypes, stage was the strongest predictor of type of operation, with higher stage associated with greater odds of RHC (p<0.001 for all). Higher grade and lymphovascular invasion were strongly associated with RHC for mucinous neoplasms (p<0.001). Lymphovascular invasion was a predictor of RHC for non-mucinous neoplasms (p=0.047). RHC was associated with higher rate of unplanned readmission for the cohort as a whole (5% vs. 3%, p<0.001). On risk-adjusted analysis, RHC was associated with increased survival compared to appendectomy alone for GCA (HR: 0.74, p=0.018), mucinous neoplasms (HR: 0.85, p=0.001), and non-mucinous neoplasms (HR: 0.84, p=0.002), but not for NEN (HR: 0.99, p=0.947).

Conclusion(s): The rate of completion colectomy for appendiceal GCAs, mucinous neoplasms, and non-mucinous neoplasms remains high, while rate of completion colectomy is decreasing for NENs. Survival benefit of colectomy varies significantly based on histology. These findings suggest that surgeons should be selective in offering colectomy to patients based on histologic subtype.

Daniel Kerekes

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ROLE OF COLECTOMY FOR APPENDICEAL TUMORS

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