Initial Experience Using Laparoscopic HIPEC for Gastric Cancer with Peritoneal Metastasis: Safety and Outcomes.

BACKGROUND: Peritoneal metastases (PM) develop in approximately 20% of patients with gastric cancer (GC). For selected patients, treatment of PM with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promising results. This report aims to describe the safety and perioperative outcomes of laparoscopic HIPEC for GC/PM. METHODS: This retrospective cohort study evaluated patients who had GC and PM treated with laparoscopic HIPEC (2018-2022). The HIPEC involved cisplatin and mitomycin C (MMC) or MMC alone. The primary end point was perioperative safety. RESULTS: The 22 patients in this study underwent 27 procedures. The mean age was 58 ± 13 years. All the patients were Eastern Cooperative Oncology Group (ECOG) 0 or 1 (55 and 45%, respectively). Five patients underwent a second laparoscopic HIPEC, with a median of 126 days (interquartile range [IQR], 117-166 days) between procedures. The median peritoneal carcinomatosis index (PCI) was 4 (IQR, 2-9), and the median hospital stay was 2 days (IQR, 1-3 days). No 30-day readmissions or complications occurred. Eight patients (36%) underwent gastrectomy (CRS ± HIPEC). After an average follow-up period of 11 months, 7 (32%) of the 22 patients were alive. The median overall survival was 11 months (IQR, 195-739 days) from the initial procedure and 19.3 months (IQR, 431-1204 days) from the diagnosis. CONCLUSIONS: Laparoscopic HIPEC appears to be safe with minimal perioperative complications. Approximately one third of the patients undergoing initial laparoscopic HIPEC ultimately proceeded to cytoreduction and gastrectomy. Preliminary survival data from this highly selected cohort suggest that the addition of laparoscopic HIPEC to systemic chemotherapy does not compromise other treatment options. These initial results suggest that laparoscopic HIPEC may offer benefit to patients with GC and PM and aid in the selection of patients who may benefit from curative-intent resection.

Neighborhood-Level Socioeconomic Disadvantage Predicts Outcomes in Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Malignancy.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) improves survival in select patients with peritoneal metastases (PM), but the impact of social determinants of health on CRS/HIPEC outcomes remains unclear. PATIENTS AND METHODS: A retrospective review was conducted of a multi-institutional database of patients with PM who underwent CRS/HIPEC in the USA between 2000 and 2017. The area deprivation index (ADI) was linked to the patient's residential address. Patients were categorized as living in low (1-49) or high (50-100) ADI residences, with increasing scores indicating higher socioeconomic disadvantage. The primary outcome was overall survival (OS). Secondary outcomes included perioperative complications, hospital/intensive care unit (ICU) length of stay (LOS), and disease-free survival (DFS). RESULTS: Among 1675 patients 1061 (63.3%) resided in low ADI areas and 614 (36.7%) high ADI areas. Appendiceal tumors (n = 1102, 65.8%) and colon cancer (n = 322, 19.2%) were the most common histologies. On multivariate analysis, high ADI was not associated with increased perioperative complications, hospital/ICU LOS, or DFS. High ADI was associated with worse OS (median not reached versus 49 months; 5 year OS 61.0% versus 28.2%, P < 0.0001). On multivariate Cox-regression analysis, high ADI (HR, 2.26; 95% CI 1.13-4.50; P < 0.001), cancer recurrence (HR, 2.26; 95% CI 1.61-3.20; P < 0.0001), increases in peritoneal carcinomatosis index (HR, 1.03; 95% CI 1.01-1.05; P < 0.001), and incomplete cytoreduction (HR, 4.48; 95% CI 3.01-6.53; P < 0.0001) were associated with worse OS. CONCLUSIONS: Even after controlling for cancer-specific variables, adverse outcomes persisted in association with neighborhood-level socioeconomic disadvantage. The individual and structural-level factors leading to these cancer disparities warrant further investigation to improve outcomes for all patients with peritoneal malignancies.

Return to intended oncologic therapy after colectomy for stage III colon adenocarcinoma: Does surgical approach matter?

AIM: Return to intended oncologic treatment (RIOT) is an important paradigm for surgically resected cancers requiring multimodal treatment. Benefits of minimally invasive colectomy (MIC) may allow earlier initiation of adjuvant chemotherapy (ACT) and have associated survival benefits. We sought to determine if operative approach affects RIOT timing in resected stage III colon cancer. METHODS: NCDB identified pathological stage III colon adenocarcinoma patients who underwent resection and received ACT. Propensity score matching and kernel density estimation compared operative approaches and conversion impact on intervals to RIOT. RESULTS: A total of 15,132 open colectomies (OC) versus 14,107 MIC were included. MIC patients had two-days shorter median length of stay (LOS) (4 vs. 6 days; p < 0.001), one-week shorter median time to RIOT (6 vs. 7 weeks; p = 0.015) comparing 12,867 matched pairs. There was no difference in time interval to RIOT between the LC versus RC, converted MIC vs. OC groups. MIC was a favourable predictor of earlier RIOT (HR 1.14 [1.07-1.22]; p < 0.001). CONCLUSION: MIC in stage III colon cancer is associated with a shorter time to RIOT when compared to OC. Since timely initiation of ACT may influence cancer outcome, MIC may be oncologically preferable. Prospective studies are needed to assess RIOT and survival outcomes in stage III colon cancer.

Validation of the AJCC 8th Edition Staging System for Disseminated Appendiceal Cancer Patients Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: A Multi-institutional Analysis.

BACKGROUND: The AJCC 8th edition stratifies stage IV disseminated appendiceal cancer (dAC) patients based on grade and pathology. This study was designed to externally validate the staging system and to identify predictors of long-term survival. METHODS: A 12-institution cohort of dAC patients treated with CRS ± HIPEC was retrospectively analyzed. Overall survival (OS) and recurrence-free survival (RFS) were analyzed by using Kaplan-Meier and log-rank tests. Univariate and multivariate cox-regression was performed to assess factors associated with OS and RFS. RESULTS: Among 1009 patients, 708 had stage IVA and 301 had stage IVB disease. Median OS (120.4 mo vs. 47.2 mo) and RFS (79.3 mo vs. 19.8 mo) was significantly higher in stage IVA compared with IVB patients (p < 0.0001). RFS was greater among IVA-M1a (acellular mucin only) than IV M1b/G1 (well-differentiated cellular dissemination) patients (NR vs. 64 mo, p = 0.0004). Survival significantly differed between mucinous and nonmucinous tumors (OS 106.1 mo vs. 41.0 mo; RFS 46.7 mo vs. 21.2 mo, p < 0.05), and OS differed between well, moderate, and poorly differentiated (120.4 mo vs. 56.3 mo vs. 32.9 mo, p < 0.05). Both stage and grade were independent predictors of OS and RFS on multivariate analysis. Acellular mucin and mucinous histology were associated with better OS and RFS on univariate analysis only. CONCLUSIONS: AJCC 8th edition performed well in predicting outcomes in this large cohort of dAC patients treated with CRS ± HIPEC. Separation of stage IVA patients based on the presence of acellular mucin improved prognostication, which may inform treatment and long-term, follow-up strategies.

The impact of age and comorbidity on localized pancreatic cancer outcomes: A US retrospective cohort analysis with implications for surgical centralization.

Introduction: Age and comorbidity are independently associated with worse outcomes for pancreatic adenocarcinoma (PDAC). However, the effect of combined age and comorbidity on PDAC outcomes has rarely been studied. This study assessed the impact of age and comorbidity (CACI) and surgical center volume on PDAC 90-day and overall survival (OS). Methods: This retrospective cohort study used the National Cancer Database from 2004 to 2016 to evaluate resected stage I/II PDAC patients. The predictor variable, CACI, combined the Charlson/Deyo comorbidity score with additional points for each decade lived ≥50 years. The outcomes were 90-day mortality and OS. Results: The cohort included 29,571 patients. Ninety-day mortality ranged from 2 % for CACI 0 to 13 % for CACI 6+ patients. There was a negligible difference (1 %) in 90-day mortality between high- and low-volume hospitals for CACI 0-2 patients; however, there was greater difference for CACI 3-5 (5 % vs. 9 %) and CACI 6+ (8 % vs. 15 %). The overall survival for CACI 0-2, 3-5, and 6+ cohorts was 24.1, 19.8, and 16.2 months, respectively. Adjusted overall survival showed a 2.7 and 3.1 month survival benefit for care at high-volume vs. low-volume hospitals for CACI 0-2 and 3-5, respectively. However, there was no OS volume benefit for CACI 6+ patients. Conclusions: Combined age and comorbidity are associated with short- and long-term survival for resected PDAC patients. A protective effect of higher-volume care was more impactful for 90-day mortality for patients with a CACI above 3. A centralization policy based on volume may have greater benefit for older, sicker patients. Key message: Combined comorbidity and age are strongly associated with 90-day mortality and overall survival for resected pancreatic cancer patients. When assessing the impact of age and comorbidity on resected pancreatic adenocarcinoma outcomes, 90-day mortality was 7 % higher (8 % vs. 15 %) for older, sicker patients treated at high-volume vs. low-volume centers but only 1 % (3 % vs. 4 %) for younger, healthier patients.

Trends and Characteristics of Potentially Preventable Emergency Department Visits Among Patients With Cancer in the US.

Importance: An initial step to reducing emergency department (ED) visits among patients with cancer is to identify the characteristics of patients visiting the ED and examine which of those visits could be prevented. Objective: To explore nationwide trends and characteristics of ED visits and examine factors associated with potentially preventable ED visits and unplanned hospitalizations among patients with cancer in the US. Design, Setting, and Participants: This cross-sectional study used data on ED visits from the National Hospital Ambulatory Medical Care Survey from January 1, 2012, to December 31, 2019; US Cancer Statistics reports were used to estimate new cancer cases each year. Frequencies and trends among 35 510 014 ED visits by adult patients (aged ≥18 years) with cancer were calculated. Main Outcomes and Measures: The primary outcome was potentially preventable ED visits, and secondary outcomes were unplanned hospitalizations and the immediacy of the ED visits. Potentially preventable ED visits were identified using the Centers for Medicare & Medicaid Services definition. The Emergency Severity Index, a triage algorithm that ranks patients based on the urgency of their health care condition, was used to measure the immediacy of ED visits (immediate [most urgent], emergent, urgent, less urgent, and nonurgent), with the categories of immediate and emergent classified as high acuity. The Wilcoxon rank sum test was used to calculate trends in ED visits among patients with cancer over time. Multivariable logistic regression analyses were performed to examine the associations of patient, hospital, and temporal factors with potentially preventable ED use and ED use resulting in hospitalization. Results: Among 854 911 106 ED visits, 35 510 014 (4.2%) were made by patients with cancer (mean [SD] age, 66.2 [16.2] years); of those, 55.2% of visits were among women, 73.2% were among non-Hispanic White individuals, 89.8% were among patients living in a private residence, and 54.3% were among Medicare enrollees. A total of 18 316 373 ED visits (51.6%) were identified as potentially preventable, and 5 770 571 visits (21.3%) were classified as high acuity. From 2012 to 2019, potentially preventable ED visits increased from 1 851 692 to 3 214 276. Pain (36.9%) was the most common reason for potentially preventable ED visits. The number of patients who visited an ED because of pain increased from 1 192 197 in 2012 to 2 405 849 in 2019 (a 101.8% increase). Overall, 28.9% of ED visits resulted in unplanned hospitalizations, which did not change significantly over time (from 32.2% in 2012 to 26.6% in 2019; P = .78 for trend). Factors such as residence in a nursing home (odds ratio, 1.73; 95% CI, 1.25-2.41) were positively associated with having a potentially preventable ED visit, and factors such as the presence of more than 1 comorbidity (odds ratio, 1.82; 95% CI, 1.43-2.32) were positively associated with having an unplanned hospitalization. Conclusions and Relevance: In this study, 51.6% of ED visits among patients with cancer were identified as potentially preventable, and the absolute number of potentially preventable ED visits increased substantially between 2012 and 2019. These findings highlight the need for cancer care programs to implement evidence-based interventions to better manage cancer treatment complications, such as uncontrolled pain, in outpatient and ambulatory settings.

A Novel Nomogram for Early Identification and Intervention in Colorectal Cancer Patients at Risk for Malnutrition.

BACKGROUND: Malnutrition is under-recognized in cancer patients and can lead to poor treatment outcomes. We aim to develop an outpatient-focused score based on the Malnutrition Screening Tool (MST) to help identify colorectal cancer (CRC) profiles at high risk for malnutrition. METHODS: 506 CRC patients during initial outpatient oncology consultation at our tertiary referral outpatient oncology clinic completed the MST. Objective and subjective data were collected through chart review. Data gathered are as follows: demographics, anthropometrics, laboratory values, patient-reported symptoms, MST score, cancer history, performance status, socioeconomic status, and Charlson Comorbidity. Predictors of malnutrition were identified by logistic regression. Receiver operating curve (ROC), area under the curve (AUC), and our model's predictability were determined. RESULTS: Significant predictors of malnutrition are as follows: younger age (20-39 vs >40 years) (P = .007), normal-to-low body mass index at presentation (P = .019), Eastern Cooperative Oncology Group classification 2-3 (P = .012), metastatic disease (P = .046), albumin <3.0 g/dL (P = .033), fatigue (P < .001), and change in stool/bowel habits (P = .002). In our derived malnutrition score, risk of malnutrition increased from 11% for score 0, to 100% for scores 9-10. Receiver operating curve showed AUC .745 (95% CI, .697-.793). DISCUSSION: An outpatient clinic-derived malnutrition score obtained from objective and patient-reported variables may facilitate identification of CRC patients at highest risk for malnutrition. Rapid identification and intervention in high-risk patients may improve treatment recovery, therapy tolerance, and quality of life. Our tool requires external validation before application in clinical practice.

Hospital Surgical Volume Is Poorly Correlated With Delivery of Multimodal Treatment for Localized Pancreatic Cancer: A National Retrospective Cohort Study.

Using Donabedian's quality of care model, this study assessed process (hospital multimodal treatment) and structure (hospital surgical case volume) measures to evaluate localized pancreatic cancer outcomes. Background: Treatment at high surgical volume hospitals has been shown to improve short-term outcomes. However, multimodal treatment-surgery and chemotherapy-is the standard of care yet only received by 35% of US patients and has not been examined at the hospital level. Methods: The National Cancer Database was used to identify a cohort of clinical stage I pancreatic cancer patients eligible for multimodal treatment from 2004 to 2016. Hospital multimodal treatment was defined as the number of patients receiving surgery and chemotherapy by the number of eligible patients per hospital. Descriptive statistics and survival analyses were conducted. Results: A total of 16,771 patients met inclusion criteria, of whom 68.0% received curative-intent surgery and 35.8% received multimodal treatment. There was poor correlation between hospital surgical volume and delivery of multimodal treatment (Spearman correlation 0.214; P < 0.001). Of patients cared for at the highest surgical volume hospitals, 18.8% and 52.1% were treated at hospitals with low (0%-25%) and moderate (>25%-50%) multimodal treatment delivery, respectively. Higher hospital multimodal treatment delivery was associated with improved overall survival. Discussion: Although the volume-outcome relationship for pancreatic cancer has demonstrated improved outcomes, this work identified poor correlation between hospital surgical volume and delivery of multimodal treatment. The role of care coordination in the delivery of multimodal treatment warrants further investigation as it is associated with improved survival for patients with localized pancreatic cancer.

Safe performance of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients with HIV infection.

BACKGROUND: Patients with HIV (PHIV) are living longer with the adoption of anti-retroviral therapy. As such, more patients are presenting with advanced cancer diagnoses, including peritoneal surface malignancies. The objective of this study was to assess the safety of CRS/HIPEC in this cohort of patients. CASE: Five PHIV were identified, four of whom underwent CRS/HIPEC. Primary sites of disease were low-grade appendiceal mucinous tumors in three patients and peritoneal mesothelioma in the other. Operative time ranged from 7 to 14 h. One patient developed a Clavien grade II complication postoperatively. There was no instance of neutropenia identified. One patient died of disease 19 months after surgery; the remaining three patients are alive 11, 21, and 33 months postoperatively. CONCLUSION: This study demonstrates that CRS/HIPEC can be performed in PHIV without prohibitive complications and operative recovery approximates that of non-HIV patients. Though more study is needed, HIV should not preclude a patient from being offered CRS/HIPEC.

Management of Malignant Small Bowel Obstruction: Is Intestinal Bypass Effective Palliation?

BACKGROUND/PURPOSE: Malignant small bowel obstruction (mSBO) is a common consequence of advanced malignancies. Surgical consultation is common, however data on the outcomes following an operation are lacking. We investigated a specific operative approach-intestinal bypass-to determine the outcomes associated with this intervention. METHODS: Patients with a preoperative diagnosis of mSBO who underwent intestinal bypass between 2015 and 2021 were included. Isolated colonic obstruction was excluded as was gastric outlet obstruction. Perioperative and postoperative outcomes were measured, including complications, overall survival, return to oral intake, and return to intended oncologic therapy. Patients were additionally grouped as to whether the operation was performed as elective or as inpatient. RESULTS: Overall, 55 patients were identified, with a mean age of 61.2 ± 14 years. The most common primary malignancy was colorectal cancer (65.5%) and 80% of patients had a preoperative diagnosis of metastatic disease. Small bowel to colon was the most common bypass procedure (51%). Severe complications occurred in 25.5% of patients with three in-hospital mortalities (5.5%). Survival rates at 30, 90, and 180 days were 91%, 80%, and 62%, respectively. The majority of patients were discharged to home (85.5%) and were tolerating an oral diet (74.6%). Twenty-seven patients (49.1%) returned to some form of oncologic treatment. CONCLUSIONS: Patients with mSBO face a potentially terminal condition. In this study, approximately 75% of patients who underwent intestinal bypass were able to regain the ability to eat, and 49% returned to oncologic therapy. Although retrospective, these data suggest the approach is efficacious for palliation of this difficult sequela of advanced cancer.

Development and Validation of an Explainable Machine Learning Model for Major Complications After Cytoreductive Surgery.

Importance: Cytoreductive surgery (CRS) is one of the most complex operations in surgical oncology with significant morbidity, and improved risk prediction tools are critically needed. Machine learning models can potentially overcome the limitations of traditional multiple logistic regression (MLR) models and provide accurate risk estimates. Objective: To develop and validate an explainable machine learning model for predicting major postoperative complications in patients undergoing CRS. Design, Setting, and Participants: This prognostic study used patient data from tertiary care hospitals with expertise in CRS included in the US Hyperthermic Intraperitoneal Chemotherapy Collaborative Database between 1998 and 2018. Information from 147 variables was extracted to predict the risk of a major complication. An ensemble-based machine learning (gradient-boosting) model was optimized on 80% of the sample with subsequent validation on a 20% holdout data set. The machine learning model was compared with traditional MLR models. The artificial intelligence SHAP (Shapley additive explanations) method was used for interpretation of patient- and cohort-level risk estimates and interactions to define novel surgical risk phenotypes. Data were analyzed between November 2019 and August 2021. Exposures: Cytoreductive surgery. Main Outcomes and Measures: Area under the receiver operating characteristics (AUROC); area under the precision recall curve (AUPRC). Results: Data from a total 2372 patients were included in model development (mean age, 55 years [range, 11-95 years]; 1366 [57.6%] women). The optimized machine learning model achieved high discrimination (AUROC: mean cross-validation, 0.75 [range, 0.73-0.81]; test, 0.74) and precision (AUPRC: mean cross-validation, 0.50 [range, 0.46-0.58]; test, 0.42). Compared with the optimized machine learning model, the published MLR model performed worse (test AUROC and AUPRC: 0.54 and 0.18, respectively). Higher volume of estimated blood loss, having pelvic peritonectomy, and longer operative time were the top 3 contributors to the high likelihood of major complications. SHAP dependence plots demonstrated insightful nonlinear interactive associations between predictors and major complications. For instance, high estimated blood loss (ie, above 500 mL) was only detrimental when operative time exceeded 9 hours. Unsupervised clustering of patients based on similarity of sources of risk allowed identification of 6 distinct surgical risk phenotypes. Conclusions and Relevance: In this prognostic study using data from patients undergoing CRS, an optimized machine learning model demonstrated a superior ability to predict individual- and cohort-level risk of major complications vs traditional methods. Using the SHAP method, 6 distinct surgical phenotypes were identified based on sources of risk of major complications.

Parenchyma-Sparing Central Hepatectomy Versus Extended Resections for Liver Tumors: a Value-Based Comparative Analysis.

BACKGROUND: Parenchyma-sparing (PS) liver resection is recommended for liver tumors. The value of PS-approaches as compared to more extended resections is unknown. We sought to examine value-based differences (quality/cost) of central hepatectomy (CH) versus more extended resections. METHODS: A retrospective cohort study including consecutive patients having CH or right/extended hepatectomies (R/EH) at a high-volume cancer center was performed (2015-2019). The primary outcome was the value ratio, calculated as quality/cost. Quality was defined as the proportion of patients achieving a textbook outcome. Perioperative actual direct costs ($USD) for each patient were abstracted from institutional financial records spanning throughout the perioperative period. Value ratios were calculated and compared for each approach; sensitivity analysis was performed by modelling TO and cost thresholds. RESULTS: Among 651 hepatobiliary operations (426 liver resections), 90 patients met inclusion criteria: 19 CH and 71 R/EH. TO occurred in 68% and 69% of CH and R/EH, respectively (P = 0.96). Mean direct costs were $21,826 for CH and $28,599 for R/EH (P = 0.008). CH provided a greater value (value ratio CH = 0.33 vs. R/EH = 0.26; P = 0.004) with a shift favoring R/EH only when the TO threshold for CH was below 51% (CH = 0.23 vs. R/EH = 0.24) or that of R/EH was over 90% (CH = 0.31 vs. R/EH = 0.32). CONCLUSIONS: These findings support a PS approach for central liver tumors (central hepatectomy) as it offers higher value than more extended resections. In the context of high-volume centers with outcomes within established national benchmarks, patients with central tumors should be considered for CH over more extended non-PS approaches.

Pilot trial of remote monitoring to prevent malnutrition after hepatopancreatobiliary surgery.

BACKGROUND: Patients undergoing hepatopancreatobiliary (HPB) surgery, such patients with pancreatic, periampullary, and liver cancer, are at high risk for malnutrition. Malnutrition increases surgical complications and reduces overall survival. Despite its severity, there are limited interventions addressing malnutrition after HPB surgery. The aim of this pilot trial was to examine feasibility, acceptability, usability, and preliminary efficacy of a remote nutrition monitoring intervention after HPB surgery. METHODS: Participants received tailored nutritional counseling before and after surgery at 2 and 4 weeks after hospital discharge. Participants also recorded nutritional intake daily for 30 days, and these data were reviewed remotely by registered dietitians before nutritional counseling visits. Descriptive statistics were used to describe study outcomes. RESULTS: All 26 patients approached to participate consented to the trial before HPB surgery. Seven were excluded after consent for failing to meet eligibility criteria (e.g., did not receive surgery). Nineteen participants (52.6% female, median age = 65 years) remained eligible for remote monitoring post-surgery. Nineteen used the mobile app food diary, 79% of participants recorded food intake for greater than 80% of study days, 95% met with the dietitian for all visits, and 89% were highly satisfied with the intervention. Among participants with complete data, the average percent caloric goal obtained was 82.4% (IQR: 21.7). CONCLUSIONS: This intervention was feasible and acceptable to patients undergoing HPB surgery. Preliminary efficacy data showed most participants were able to meet calorie intake goals. Future studies should examine intervention efficacy in a larger, randomized controlled trial. TRIAL REGISTRATION: Clinicaltrials.gov. Registered 16 September 2019, https://clinicaltrials.gov/ct2/show/NCT04091165 .

The impact of socioeconomic status on survival in stage III colon cancer patients: A retrospective cohort study using the SEER census-tract dataset.

BACKGROUND: The impact of socioeconomic status (SES) has been described for screening and accessing treatment for colon cancer. However, little is known about the "downstream" effect in patients who receive guideline-concordant treatment. This study assessed the impact of SES on cancer-specific survival (CSS) and overall survival (OS) for stage III colon cancer patients. METHODS: The SEER Census Tract-Level SES Dataset from 2004 to 2015 was used to identify stage III colon adenocarcinoma patients who received curative-intent surgery and adjuvant chemotherapy. The predictor variable was census tract SES. SES was analyzed as quintiles. The outcome variables were OR and CSS. Statistical analysis included chi square tests for association, Kaplan-Meier, Cox, Fine and Gray regression for survival analysis. RESULTS: In total, 27,222 patients met inclusion criteria. Lower SES was associated with younger age, Black or Hispanic race/ethnicity, Medicaid/uninsured, higher T stage, and lower grade tumors. CSS at the 25th percentile was 54 months for the lowest SES quintile and 80 for the highest. Median OS was 113 months for the lowest SES quintile and not reached for highest. The 5-year CSS rate was 72.4% for the lowest SES quintile compared to 78.9% in the highest (p < 0.001). The 5-year OS rate was 66.5% for the lowest SES quintile and 74.6% in the highest (p < 0.001). CONCLUSION: This is the first study to evaluate CSS and OS in an incidence-based cohort of stage III colon cancer patients using a granular, standardized measure of SES. Despite receipt of guideline-based treatment, SES was associated with disparities in CSS and OS.