Introduction: Peritoneal mesothelioma (PM) is a rare cancer associated with high mortality. No studies exist using the National Cancer Database (NCDB) that have examined factors associated with long-term survival (LTS). Methods: NCDB 2006-2019 was queried for patients with PM. Primary objective was to determine the characteristics of LTS among patients with peritoneal mesothelioma. Secondary objective: identified predictors of LTS were then used to develop and internally validate a nomogram to predict the probability of LTS among patients. LTS was defined as 5 or more years of survival after diagnosis. Univariate and multivariate logistic analyses were performed. Results: The study included 3,636 patients with PM, 17.8% had LTS. The median survival time was 17.7 months. For LTS, the median survival time was ∼92 months while the median survival time of non-long-term survivors (NLTS) was 11.7 months. Following factors were common with LTS patients compared to the NLTS: female, younger, privately insured, treatment at academic/research institutions and treatment at high case volume institutions, Charlson-Deyo comorbidity score of 0, receiving radical surgery, receiving chemotherapy, greater proportion of grade 1 disease, negative lymph nodes, and lower rates of lymphovascular invasion ( P < .001). The nomogram included age, gender, and surgical margins. Conclusion: A subset of PM patients can be long-term survivors with effective patient selection and appropriate care. This study highlights critical factors that influence LTS, paving the way for personalized treatment strategies and enhanced prognostication. Further research is needed to improve patient selection and ensure patients likely to be LTS receive adequate care.

Textbook oncologic outcome (TOO) is attained when all desired short-term quality metrics are met following an oncologic operation. The objective of this study was to determine the impact of race on TOO attainment following colectomy for colon cancer. The 2004–2017 National Cancer Database was queried for patients with non-metastatic colon cancer who underwent colectomy. TOO was defined as: negative margins (R0), adequate lymphadenectomy (LAD) (n ≥ 12), no prolonged length of stay (LOS), no 30-day readmission or mortality, and initiation of systemic therapy in ≤ 12 weeks. Racial groups were defined as White, Black, or Hispanic. 508,312 patients were identified of which 34

Gastropleural fistulas are rare complications with significant mortality and morbidity. There are limited reports on the successful management of gastropleural fistulas with advanced endoscopic procedures. The following case of a 75-year-old woman with a history of recurrent pseudomyxoma peritonei secondary to ruptured low-grade appendiceal mucinous neoplasm status post cytoreductive surgery highlights the successful treatment of a gastropleural fistula with endoscopic suturing.

e15637 Background: Treatment of early stage rectal cancer requires a multi-disciplinary approach and is often treated with curative intent surgery with use of total neoadjuvant treatment (TNT) or neoadjuvant chemoradiotherapy (nCRT) in select cases pre-operatively. In this study, we determine the various clinicopathologic factors associated with the use of these different approaches (Surgery upfront vs nCRT vs TNT) and their effect on patient survival. Methods: The National Cancer Database (NCDB) was queried for patients with clinical T2N0M0 and T3N0M0 rectal cancer between 2004-2019. Results: 36,869 patients were identified, of which about half had nCRT only while < 15% had received TNT. Patients who underwent nCRT had the highest median OS compared to those who underwent surgery only (106.8 vs 126.5 months, p < 0.001). The surgery upfront cohort had the highest proportion of patients who were seen at a facility with high/very high case volume per year quartiles (surgery: 52.5%, nCRT: 47.3%, and TNT: 48.3%, p < 0.001). The highest median age was among the surgery cohort at 69 years followed by the nCRT cohort at 64 years and TNT cohort at 61 years (p < 0.001). Amongst patients with a Charlson-Deyo co-morbidity score of 2 or more, the surgery upfront cohort had the highest proportion while the TNT cohort had the lowest (p < 0.001). Low anterior resection (LAR) was the most common procedure among all three cohorts. A multivariate logistic regression model revealed that when compared to surgery only, the nCRT (Adjusted Odds Ratio (AOR) = 1.51, p < 0.001) and TNT (AOR = 1.62, p < 0.001) were both associated with an increased likelihood of 5-year long-term survival (LTS), with TNT having a stronger association. Among the various pre-operative characteristics, patients 70 years and older, patient with normal CEA and presence of LVI were less likely to have LTS with TNT as compared to surgery upfront. On the other hand, patients with clinical T3 stage who received TNT were much more likely to have improved LTS as compared to T2 stage (Relative Risk Ratio (RRR) 16.19, p < 0.001). Conclusions: Results of our study show that patients with early stage T2N0 and T3N0 rectal cancer who underwent neoadjuvant treatment had an improved median OS compared to patients who received surgery upfront. Both nCRT and TNT were associated with an increased likelihood of long-term survival, with TNT having a stronger association particularly in the T3N0 cohort.

INTRODUCTION:The objective of this study was to determine the incidence of textbook oncologic outcome (TOO) and its impact on overall survival (OS) among patients with invasive ductal carcinoma (IDC) following modified radical mastectomy (MRM) versus MRM with contralateral prophylactic mastectomy (MRM ​+ ​CPM). METHODS:The 2004-2017 National Cancer Database was queried for patients with IDC who underwent MRM and MRM ​+ ​CPM. TOO was defined as: resection with negative margins, adequate lymphadenectomy, length of stay ≤50th percentile, and no 30-day readmission or mortality. RESULTS:87,573 patients were identified, of which 14.3% underwent MRM ​+ ​CPM. Logistic regression models revealed that MRM ​+ ​CPM is independently associated with a reduced likelihood of achieving TOO (AOR ​= ​0.71; P ​< ​0.001). MRM patients who achieved TOO had a higher median OS compared to those who did not (164.6 vs.142.2 months, P ​< ​0.001). CONCLUSIONS:MRM ​+ ​CPM is associated with a lower incidence of TOO attainment compared to MRM.

Introduction Palliative interventions (PI) are offered to patients with pancreatic cancer with the aim of enhancing quality of life and improving overall survival (OS). The purpose of this study was to determine the impact of PI on survival amongst patients with unresected pancreatic cancer. Methods Patients with stage I-IV unresected pancreatic adenocarcinoma were identified using the 2010-2016 National Cancer Database. The cohort was stratified by PI received: palliative surgery (PS), radiation therapy (RT), chemotherapy (CT), pain management (PM), or a combination (COM) of the preceding. Kaplan-Meier method with log-rank test was used to compare and estimate OS based on the PI received. A multivariate proportional hazards model was utilized to identify predictors of survival. Results 25,995 patients were identified, of which 24.3% received PS, 7.7% RT, 40.8% CT, 16.6% PM, and 10.6% COM. The median OS was 4.9 months, with stage III patients having the highest and stage IV the lowest OS (7.8 vs 4.0 months). Across all stages, PM yielded the lowest median OS and CT the highest (P < .001). Despite this, the stage IV cohort was the only group in which CT (81%) accounted for the largest proportion of PI received (P < .001). Although all PI were identified as positive predictors of survival on multivariate analysis, CT had the strongest association (HR .43; 95% CI, .55-.60, P = .001). Conclusion PI offers a survival advantage to patients with pancreatic adenocarcinoma. Further studies to examine the observed limited use of CT in earlier disease stages are warranted.

e16325 Background: Peritoneal mesothelioma (PM) is a rare, fatal malignancy. The aim of the study is to determine the clinical and sociodemographic characteristics associated with long-term survival (LTS). Methods: The 2004 - 2019 National Cancer Database was queried for patients with PM. LTS was defined as having survived at least 5 years following diagnosis. Univariate and multivariate logistic analyses were performed to identify characteristics associated with LTS. A nomogram predicting the likelihood of LTS was developed. Results: 3,636 patients were identified, of which, 18% experienced LTS. The median overall survival (OS) for the entire study population was 17.7 months. The median OS for the LTS cohort was 92 months and 11.7 months for non-long-term survivors (NLTS). In univariate analysis, LTS was more likely to occur in younger (< 50 years), healthy (Charlson-Deyo = 0), female and privately insured patients that traveled farther for care, were treated at an academic or very high-volume center, had epithelial histology, underwent radical surgery and received chemotherapy (p < 0.001). Interestingly, among those who were treated non-operatively, LTS was associated with a longer time-to-chemotherapy (LTS = 50 days, NLTS = 32 days, p < 0.001). Although not statistically significant, among those who received surgery, results suggest that LTS was more likely achieved in those who received hyperthermic intraperitoneal chemotherapy (HIPEC) (p = 0.086). Patients who underwent surgery plus HIPEC experienced the longest median OS (65.9 months) when compared those who underwent surgery plus systemic therapy (38 months) or surgery alone (9.6 months) (p < 0.001). Multivariate logistic regression analysis suggests that age, female gender, and surgical margins are independent predictors of LTS. Based on our nomogram, patients with favorable characteristics resulted in a total score of at least 19 and had an approximate 50% chance of LTS. Conclusions: Age, gender and surgical margins were found to be independent predictors of LTS. Additionally, our nomogram may help predict LTS among patients with PM.

Backgrounds/Aims:Current literature presents limited data regarding outcomes following conversion at the time of minimally invasive pancreaticoduodenectomy (MI-PD).Methods:The National Cancer Database was queried for patients who underwent pancreaticoduodenectomy. Patients were stratified into three groups: MI-PD, converted to open pancreaticoduodenectomy (CO-PD), and open pancreaticoduodenectomy (O-PD). Multivariable modeling was applied to compare outcomes of MI-PD and CO-PD to those of O-PD.Results:Of 17,570 patients identified, 12.5%, 4.2%, and 83.4% underwent MI-PD, CO-PD, and O-PD, respectively. Robotic pancreaticoduodenectomy (R-PD) resulted in a higher lymph node yield (n = 23.2 ± 12.2) even when requiring conversion (n = 22.4 ± 13.2, p < 0.001). Margin positivity was higher in the CO-PD group (26.6%) than in the MI-PD group (21.3%) and the O-PD (22.6%) group (p = 0.017). Length of stay was shorter in the MI-PD group (laparoscopic pancreaticoduodenectomy 10.4 ± 8.6, R-PD 10.6 ± 8.8) and the robotic converted to open group (10.7 ± 6.4) than in the laparoscopic converted to open group (11.2 ± 9) and the O-PD group (11.5 ± 8.9) (p < 0.001). After adjusting for patient and tumor characteristics, both MI-PD (odds ratio = 1.40; p < 0.001) and CO-PD (odds ratio = 1.24; p = 0.020) were significantly associated with an increased likelihood of long-term survival.Conclusions:CO-PD does not negatively impact perioperative or oncologic outcomes.

BACKGROUND:Textbook oncologic outcome (TOO) is a composite outcome measure realized when all desired short-term quality metrics are met following an oncologic operation. This study examined whether minimally invasive gastrectomy (MIG) is associated with increased likelihood of TOO attainment.METHODS:The 2010-2016 National Cancer Database was queried for patients with gastric cancer who underwent gastrectomy. Surgical approach was described as open (OG), laparoscopic (LG), or robotic (RG). TOO was defined as having met five metrics: R0 resection, AJCC compliant lymph node evaluation (n ≥ 15), no prolonged length of stay (< 75th percentile by year), no 30-day readmission, and receipt of guideline-accordant systemic therapy.RESULTS:Of 21,015 patients identified, 5708 (27.2%) underwent MIG (LG = 21.9%, RG = 5.3%). Patients who underwent RG were more likely to have met all TOO criteria, and consequently TOO. Logistic regression models revealed that patients undergoing MIG were significantly more likely to attain TOO. MIG was associated with a higher likelihood of adequate LAD, no prolonged LOS, and concordant chemotherapy. Patients who underwent LG and achieved TOO had the highest median OS (86.7 months), while the OG non-TOO cohort experienced the lowest (34.6 months). The median OS for the RG TOO group was not estimable; however, the mortality rate (.7%) was the lowest of the six cohorts.CONCLUSION:RG resulted in a significantly increased likelihood of TOO attainment. Although TOO is associated with increased OS across all surgical approaches, attainment of TOO following MIG is associated with a statistically significantly higher median OS.

Textbook oncologic outcome (TOO) is a composite outcome measure realized when all desired short-term quality metrics are met after an oncologic operation. This study examined the incidence and impact of achieving a TOO among patients undergoing resection of gastric adenocarcinoma. The 2004–2016 National Cancer Database was queried for patients who underwent curative gastrectomy. Textbook oncologic outcome was defined as having met five metrics: R0 resection, American Joint Committee on Cancer-compliant lymph node evaluation (n ≥ 15), no prolonged hospital stay (< 75th percentile by year), no 30-day readmission, and receipt of guideline-accordant systemic therapy. Of 34,688 patients identified, 8249 (23.8

Introduction: Textbook oncologic outcome (TOO) is a composite outcome measure attained when all desired short-term quality metrics are met following an oncologic operation. The objective of this study was to determine the incidence of TOO and its impact on the overall survival (OS) among patients with invasive ductal carcinoma (IDC) following modified radical mastectomy (MRM). Methods: The 2004-2017 National Cancer Database was queried for patients with non-metastatic IDC who underwent MRM. TOO was defined as having attained five metrics: resection with negative microscopic margins, American Joint Committee on Cancer compliant lymph node evaluation (n > 10), no prolonged length of stay (50th percentile by year), no 30-d readmission, and no 30-d mortality. OS was defined as the time in months between the date of diagnosis and the date of death or last contact. Results: A total of 75,063 patients were identified, of which 40.8% achieved TOO. The TOO patients had a lower median age and were more likely to be White, privately insured, and without comorbidities. In terms of facility characteristics, patients with TOO were more likely to be seen in comprehensive community cancer programs with a high case-volume per year. The TOO group had a statistically significant higher median OS compared to the non-TOO group (165.6 versus 142.2 mo; P < 0.001). On multivariate analysis TOO was independently associated with a reduced risk of death (HR = 0.82; P < 0.001). Conclusions: TOO is achieved in approximately 41% of patients undergoing MRM for IDC. Achieving TOO is associated with improved median OS and reduced risk of death. TOO therefore merits further attention in efforts to improve surgical outcomes. Published by Elsevier Inc.

Cibulas, Megan Aileen MD; Avila, Azalia MD; Shah, Pratik P. MS; Mahendra, Ashwin M. BSE; Samuels, Shenae PhD, MPH; Gannon, Christopher J. MD, FACS; Llaguna, Omar H. MD, FACS Author Information

Background: Local recurrence (LR) rates in patients with retroperitoneal sarcoma (RPS) are high, ranging from 40% to 80%, with no definitive studies describing the best way to administer radiation. Intraoperative electron beam radiation therapy (IOERT) provides a theoretical advantage for access to the tumor bed with reduced toxicity to surrounding structures. The goal of this study was to evaluate the role of IOERT in high-risk patients.Methods: An institutional review board approved, single institution sarcoma database was queried to identify patients who received IOERT for treatment of RPS from 2/2001 to 1/2009. Data were analyzed using the Kaplan-Meier method, Cox regression, and Fisher Exact tests.Results: Eighteen patients (median age 51 y, 25-76 y) underwent tumor resection with IOERT (median dose 1250 cGy) for primary (n = 13) and recurrent (n = 5) RPS. Seventeen patients received neoadjuvant radiotherapy. Eight high-grade and 10 low-grade tumors were identified. Median tumor size was 15 cm. Four patients died and two in the peri-operative period. Median follow-up of survivors was 3.6 y. Five patients (31%) developed an LR in the irradiated field. Three patients with primary disease (25%) and two (50%) with recurrent disease developed an LR (P = 0.5). Four patients with high-grade tumors (57%) and one with a low-grade tumor (11%) developed an LR (P = 0.1). The 2- and 5-y OS rates were 100% and 72%. Two-and 5-y LR rates were 13% and 36%.Conclusions: Using a multidisciplinary approach, we have achieved low LR rates in our high-risk patient population indicating that IOERT may play an important role in managing these patients. (C) 2013 Elsevier Inc. All rights reserved.