Preoperative CA 19-9 Predicts Disease Progression in Colorectal Peritoneal Metastases Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: An Analysis from the US HIPEC Collaborative

INTRODUCTION

Patients with colorectal peritoneal metastases (CRPM) are increasingly treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). Unfortunately, data identifying preoperative risk factors for poor oncologic outcomes after this procedure are limited. We aimed to determine the prognostic value of preoperative CEA, CA 125, and CA 19-9 on disease progression after CRS/HIPEC.

METHODS

Patients with CRPM treated with curative intent CRS/HIPEC from 12 participating sites in the United States from 2000 to 2017 were identified. Progression-free survival (PFS), defined as disease progression or recurrence, was the primary outcome.

RESULTS

In 279 patients who met inclusion criteria, the rate of disease progression was 63.8%, with a median PFS of 11 months (interquartile range [IQR] 5-20). Elevated CA 19-9 was associated with dismal PFS at 2 years (8.9% elevated vs. 30% not elevated, p < 0.01). In 113 patients who underwent upfront CRS/HIPEC, CA 19-9 emerged as the sole tumor marker independently predictive of worse PFS (hazard ratio [HR] 2.88, p = 0.048). In the subgroup of patients who had received neoadjuvant therapy (NAT), no variable was independently predictive of PFS. CA 19-9 levels over 37 U/ml were highly specific for accelerated disease progression after CRS/HIPEC. Lastly, there was no association between PFS and elevated CEA or CA 125.

CONCLUSIONS

Elevated CA 19-9 is associated with decreased PFS in patients with CRPM. While traditionally CEA is the main tumor marker assessed in colon cancer, we found that CA 19-9 may better inform preoperative risk stratification for poor oncologic outcomes in patients with CRPM. However, prospective studies are required to confirm this association.

Weekend Discharge Is Not Associated With Increased Readmission After Hyperthermic Intraperitoneal Chemotherapy

INTRODUCTION

We explored the association between weekend discharge and 30- and 90-d readmission rates in patients undergoing hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) for peritoneal carcinomatosis.

METHODS

The US HIPEC Collaborative database, comprised of a longitudinal cohort of patients undergoing CRS/HIPEC for peritoneal carcinomatosis at twelve academic institutions between 2000 and 2017, was queried for date of discharge information. Patients were retrospectively divided into weekday and weekend/holiday discharge groups. Patients <18 y old, lacking day of discharge information, or who experienced intraoperative/in-hospital mortality were excluded. Comparisons were made between patients discharged on a weekday versus those discharged on a weekend or major holiday.

RESULTS

1415 patients met inclusion criteria for the study: 1108 (78%) patients with a weekday discharge and 308 (22%) with a weekend/holiday discharge. Median age at time of surgery was 55 y (Interquartile Range: 46-63); 59% (n = 841) patients were female, 25% (n = 328) of patients had high volume disease (defined as a peritoneal cancer index >20 intraoperatively), and 92% (n = 1210) of patients had a complete cytoreduction (defined as a completeness of cytoreduction score of 0 or 1). Overall, 15% (n = 218) of patients were readmitted within 30 d and 19% (n = 265) within 90 d. In a linear mixed effects model, weekend discharge was not associated with higher 30- or 90-d readmissions (P = 0.291, P = 0.743).

CONCLUSIONS

Weekend discharges are safe following CRS/HIPEC. Length of stay initiatives should focus on discharging the patient when medically ready, rather than avoiding weekend discharge out of an abundance of caution.

Recovery of Patient-reported Quality of Life After Esophagectomy

BACKGROUND

Esophagectomy is an important, but potentially morbid, operation used to treat benign and malignant conditions that may significantly impact patient quality of life (QOL). Patient-reported outcomes (PROs) are measures of QOL that come directly from patient self-report. This study characterizes patterns of change and recovery in PROs in the first year after esophagectomy.

METHODS

Longitudinal QOL scores measuring physical function, pain, and dyspnea were obtained from esophagectomy patients during all clinic visits. PRO scores were obtained using the National Institutes of Health-sponsored Patient-Reported Outcomes Measurement Information System from April 2018 to February 2021. Mean PRO scores over 100 days after surgery were compared with baseline PRO scores using mixed-effects modeling with compound symmetry correlational structure.

RESULTS

One hundred three patients with PRO results were identified. Reasons for esophagectomy were malignancy (87.4%), achalasia (5.8%), stricture (5.8%), and dysplasia (1.0%). When comparing mean PRO scores at visits ≤ 50 days after surgery with preoperative PRO scores, physical function scores declined by 27.3% (P < .001), whereas dyspnea severity and pain interference scores had increased by 24.5% (P < .001) and 17.1% (P < .001), respectively. Although recovery occurred over the course of the 100 days after surgery, mean physical function scores and dyspnea scores were still 12.7% (P = .02) and 26.4% (P = .001) worse, respectively, than mean preoperative levels.

CONCLUSIONS

Despite declines in QOL scores immediately after esophagectomy, recovery back toward baseline was observed during the first 100 days. These findings are of considerable importance when counseling patients regarding esophagectomy, tracking recovery, and implementing quality improvement initiatives. Further long-term follow-up is needed to determine recovery beyond 100 days.

Optimal perioperative therapy for incidental gallbladder cancer (OPT-IN): A randomized phase II/III trial—ECOG-ACRIN EA2197

TPS620

Background: Gallbladder carcinoma (GBC) is a rare disease with a poor prognosis, with an overall estimated 5-year survival rate of 5-13%. Approximately 70% of gallbladder cancers in the US are found incidentally on pathologic analysis after elective cholecystectomy for presumed benign disease. Current management guidelines for incidental gallbladder cancer (IGBC) recommend re-resection for T1b, T2, and T3 lesions, which entails a partial hepatectomy and lymph node dissection. Up to 75% of patients have residual locoregional disease and 20% have disseminated disease at the time of re-resection, both factors strongly associated with poor prognosis and inoperability, respectively. For those who undergo re-resection, the recurrence rate at one year can be as high as 40%. Therefore we designed a Phase II/III trial to assess the benefit of a perioperative chemotherapy approach around the re-resection procedure compared to standard of care adjuvant therapy alone. Methods: We have enrolled 18 of 186 planned patients (Phase III design) on study NCT 04559139/EA2197. Current eligibility criteria include: Incidentally diagnosed T2 / T3 gallbladder cancer with no evidence of metastatic disease or inoperable locoregional disease. At randomization, patients must be within 12 weeks of their index cholecystectomy. Patients are randomized 2:1 to receive perioperative chemotherapy with gemcitabine and cisplatin vs adjuvant therapy alone. The primary endpoint is overall survival. Secondary endpoints include resectability, presence of residual disease, and progression-free survival. Clinical trial information: 04559139 .

The Impact of Carbohydrate Antigen 19-9 on Survival in Patients with Clinical Stage I and II Pancreatic Cancer

BACKGROUND

Carbohydrate antigen (CA) 19-9 is a biomarker to monitor treatment effect. A threshold to predict prognostic significance remains undefined. We evaluated the impact of CA19-9 on overall survival (OS) in patients with early-stage pancreatic cancer (PC) utilizing the National Cancer Database (NCDB).

METHODS

The NCDB was queried from 2010 to 2014 to identify patients with clinical stage I-II PC. Patients who had undocumented pretreatment CA19-9 were excluded. Patients were stratified into two cohorts: CA19-9 < 98 U/mL and CA19-9 ≥ 98 U/mL, and further categorized into surgery versus no surgery. Twelve- and 24-month OS rates are reported.

RESULTS

Overall, 32,382 patients (stage I: 12,173; stage II: 20,209) were included. The majority of stage I (52.1%) and II (60%) patients had CA19-9 ≥ 98 U/mL. Stage I-II patients with CA19-9 < 98 U/mL had improved OS rates (stage I: 67.5%, 42.6%; stage II: 59.8%, 32.8%) compared with stage I and II patients with CA19-9 ≥ 98 U/mL (stage I: 50.7%, 26.9%; stage II: 48.1%, 22%). Among resected stage I patients, CA19-9 <98 U/mL was associated with improved OS (< 98: 80.5%, 56%; ≥ 98: 70.2%, 42.8%), and a similar trend was seen in resected stage II patients (< 98: 77.6%, 49.9%; ≥ 98: 71%, 39.2%). Unresected stage I patients with lower CA19-9 had improved OS (< 98: 42.1%, 17.5; ≥ 98: 29.9%, 10%), with similar findings in unresected stage II patients (< 98: 41.1%, 15.3%; ≥ 98: 33.4%, 10.6%).

CONCLUSIONS

Our study demonstrated the prognostic value of CA19-9 in patients with clinical stage I-II PC, with a value < 98 U/mL demonstrating improved survival. Surgery significantly improved survival at 12 and 24 months irrespective of CA19-9.

Do Lymph Node Metastases Matter in Appendiceal Cancer with Peritoneal Carcinomatosis? A US HIPEC Collaborative Study

BACKGROUND

Whether formal regional lymph node (LN) evaluation is necessary for patients with appendiceal adenocarcinoma (AA) who have peritoneal metastases is unclear. The aim of this study was to evaluate the prognostic value of LN metastases on survival in patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC).

METHODS

A retrospective analysis of the US HIPEC collaborative, a multi-institutional consortium comprising 12 high-volume centers, was performed to identify patients with AA who underwent CRS-HIPEC with adequate LN sampling (≥ 12 LNs).

RESULTS

Two hundred-fifty patients with AA who underwent CRS-HIPEC were included. Outcomes were compared between LN - and LN + disease. Baseline patient characteristics between groups were similar, with most patients undergoing complete cytoreduction (0/1: 86.0% vs. 76.8%, p = 0.08), respectively. More adverse tumor factors were found in patients with LN + disease, including poor differentiation, signet ring cells, and lymphovascular invasion. Multivariate analysis of overall survival (OS) found LN + disease was independently associated with worse OS (HR: 2.82 95%CI: 1.25-6.34, p = 0.01), even after correction for receipt of systemic therapy. On Kaplan-Meier analysis, median OS was lower in patients with LN + disease (25.9 months vs. 91.4 months, p < 0.01). LN + disease remained associated with poor OS following propensity score matching (HR: 4.98 95%CI: 1.72-14.40, p < 0.01) and in patients with PCI ≥ 20 (HR: 3.68 95%CI: 1.54-8.80, p < 0.01).

CONCLUSIONS

In this large multi-institutional study of patients with AA undergoing CRS-HIPEC, LN status remained associated with worse OS even in the setting of advanced peritoneal carcinomatosis. Formal LN evaluation should be performed for most patients with AA undergoing CRS-HIPEC.

Implementation of a Hepatocellular Carcinoma Screening Program for At-risk Patients Safety-Net Hospital: A Model for National Dissemination

OBJECTIVE

This study aimed to enhance hepatocellular carcinoma (HCC) screening to achieve earlier diagnosis of patients with hepatitis C (HCV) cirrhosis in our Safety-Net population.

BACKGROUND

Adherence to HCC screening guidelines at Safety-Net hospitals is poor. Only 23% of patients with HCC at our health system had a screening exam within 1-year of diagnosis and 46% presented with stage IV disease. HCV-induced cirrhosis remains the most common etiology of HCC (75%) in our patients.

METHODS

In the setting of an established HCV treatment clinic, an HCC screening quality improvement initiative was initiated for patients with stage 3 fibrosis or cirrhosis by transient elastography. The program consisted of semiannual imaging. Navigators scheduled imaging appointments and tracked compliance.

RESULTS

From April 2018 to April 2021, 318 patients were enrolled (mean age 61 years, 81% Black race, 38% uninsured). Adherence to screening was higher than previously reported: 94%, 75%, and 74% of patients completed their first, second, and third imaging tests. Twenty-two patients (7%) were diagnosed with HCC; 55% stage I and 14% stage IV. All patients were referred and 13 (59%) received treatment. Median time to receipt of treatment was 77 days (range, 32-282). Median overall survival for treated patients was 32 months.

CONCLUSIONS

Implementation of an HCC screening program at a safety-net hospital is feasible and facilitated earlier diagnosis in this study. Patient navigation and tracking completion of imaging tests were key components of the program's success. Next steps include expanding the program to additional at-risk populations.

Implications of leukocytosis following distal pancreatectomy splenectomy (DPS) and association with postoperative complications

BACKGROUND

Early identification of complications after distal pancreatectomy splenectomy (DPS) poses challenges, as white blood cell count (WBC) is confounded by physiologic leukocytosis. We examined WBC patterns associated with complications after DPS.

METHODS

Clinicopathologic data were collected for patients who underwent DPS in our system from 2009 to 2016. We examined WBC, temperature, platelet count (PC), and ratios of these variables as potential early indicators of patients at risk of infections or major complications (MCs).

RESULTS

348 patients met study inclusion, of whom 206 (59%) were women and the median patient age was 59 ± 15 years. Infectious and MC rates were 11% and 16%, respectively, with <1% 30-day mortality. Postoperative WBC peaks were higher in patients with infections and MCs compared with no complication (23 vs. 17, p < 0.0001). WBC peak timing occurred postoperative day (POD) 2-3 for uncomplicated cases while peaks occurred POD9 for patients with infections and MCs.

DISCUSSION

These data define patterns of leukocytosis following DPS. Although differences in infection markers were identified for patients with and without complications, no obvious thresholds were identified. Clinical suspicion for complications after DPS remains our best tool for early identification.

Abstract 4152: Development of an immune modulating and tumor inhibiting hyaluronic acid nanoparticle encapsulated with Avasimibe for the treatment of cancer patients with comorbid atherosclerosis

Cancer and cardiovascular diseases are the leading causes of death globally. Given the high percentage of cancer patients with co-existing atherosclerosis due to many shared risk factors, the development of novel cancer therapeutic agents with strong anti-tumor efficacy and therapeutic benefit on atherosclerosis can significantly improve the outcome of cancer therapy. Immune checkpoint inhibition (ICI) therapy using therapeutic antibodies has shown promises in the treatment of several types of human cancers. However, many cancer patients showed a poor response due to low delivery efficiency, lack of effector T cells, an immunosuppressive tumor microenvironment, and intrinsic resistance in solid tumors. Increasing numbers of patients developed immunotherapy related adverse effects (irAEs). It is well known that macrophages and effector T cells drive the progression of atherosclerosis. Recent clinical studies revealed that cancer patients received ICI therapy have 3-fold higher risk of atherosclerosis and 3-fold increases in plaque progression detected by PET imaging. To enhance therapeutic efficacy of tumor immunotherapy and decrease irAEs, we have developed a hyaluronic acid nanoparticle (HANP) conjugated with PD1 mimetic peptides that target and block PD-L1 function, and encapsulated with Avasimibe (PD1Y-HANP/Ava). Avasimibe is a multifunctional agent that decreases cholesterol accumulation, inhibits tumor growth, and enhances immune response by activating cytotoxic T cells. We found that systemic administrations of PD1Y-HANP/Ava led to targeted delivery into tumors and atherosclerotic plaques in a dual colon cancer and atherosclerosis mouse model, established by injecting mouse colon tumor cells into Apoe knockout mice on a high fat diet. PD1Y-HANP/Ava treatments resulted in 78% of tumor growth inhibition. Following surgical resection of residual tumors, 80% of PD1Y-HANP/Ava treated mice had disease-free survival of &gt;120 days and were protected from tumor growth after tumor cell re-challenging. Histological analysis of the major arteries revealed that the volume of atherosclerotic plaques decreased 70% in the mice treated with PD1Y-HANP/Ava compared the no-treated mice. Our results showed that PD1Y-HANP/Ava treatment increased infiltration of CD8+ T effector and dendritic cells, and activated cytotoxic T cells in mouse colon tumors. Colon tumor specific antibodies were detected in the mouse serum following PD1Y-HANP/Ava treatment. However, the levels of CD8+ T cells, dendritic cells, and macrophages were decreased in the atherosclerotic plaques, which could prevent ICI-induced cardiovascular irAEs. Results of this study should provide us with preclinical evidence for translational development of targeted immunotherapy for colon cancer patients with comorbid atherosclerosis.

Citation Format: Lei Zhu, Weiping Qian, Minglong Chen, Tongrui Liu, Charles A. Staley, Bassel El-Rayes, Hanjoong Jo, Lily Yang. Development of an immune modulating and tumor inhibiting hyaluronic acid nanoparticle encapsulated with Avasimibe for the treatment of cancer patients with comorbid atherosclerosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4152.

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.

A phase II/III study of perioperative nivolumab and ipilimumab in patients (pts) with locoregional esophageal (E) and gastroesophageal junction (GEJ) adenocarcinoma: Results of a safety run-in—A trial of the ECOG-ACRIN Cancer Research Group (EA2174)

4064

Background: E/GEJ adenocarcinoma has a high mortality rate despite curative intent therapy. The use of immune checkpoint inhibition is beneficial for treatment of this cancer in the metastatic and adjuvant settings but the role of these agents in the perioperative setting remains unclear. Here we report the results of an initial safety run-in of nivolumab when given in combination with neoadjuvant chemoradiation. Methods: Pts with a localized T1N1-3M0 or T2-3N0-2M0 E/GEJ adenocarcinoma with an ECOG PS of 0-1 and whom were deemed surgical candidates for an esophagectomy by a qualified surgeon were eligible. In step 1, pts were randomized to neoadjuvant therapy with carboplatin AUC 2 and paclitaxel 50 mg/m2 intravenously (IV) weekly x 5 along with 41.4-50.4 Gy radiation without (Arm A) or with (Arm B) nivolumab 240 mg IV during weeks 1 and 3 of treatment, followed by esophagectomy. Pts underwent a second randomization (step 2) to adjuvant nivolumab 240 mg IV every 2 weeks x 12 cycles with or without ipilimumab 1 mg/kg IV every 6 weeks during cycles 1, 4, 7 and 10. For the safety run-in, 30 pts were planned for accrual to allow for 12 evaluable pts per arm. Pts were followed for safety during neoadjuvant therapy through surgery and toxicities monitored per CTCAEv5. Pre-specified early stopping rules were defined to allow halting of the trial if deemed unsafe. Planned study accrual is 278 pts. Neoadjuvant primary endpoint is pathologic complete response rate, adjuvant primary endpoint is disease-free survival. Results: A total of 31 pts were enrolled to the safety run-in element of the study (Arm A, n = 16; Arm B n = 15). Male, 94%; White, 100%; median age, 62; esophageal adenocarcinoma, 52%; GEJ, 48%. Grade (G) 3 events occurring in more than one pt on Arm A—decreased lymphocytes (n = 5). G4 events occurring on Arm A—decreased lymphocytes (n = 1). G3 events occurring in more than one pt on Arm B—decreased lymphocytes (n = 2); anemia (n = 2); leukopenia (n = 4); hypotension (n = 2). G4 events occurring on Arm B—decreased lymphocytes (n = 3); cardiac tamponade and pericardial effusion (n = 1). Cardiac events were thought to be secondary to tumor location, not neoadjuvant treatment. On Arm B, notable G3 events seen in one pt each included colonic obstruction, wound infection and esophageal anastomotic leak. Of pts who have reached the time for surgery, 12/14 pts on Arm A and 13/13 pts on Arm B have proceeded to surgery. Of pts who have completed step 1, 7/14 pts on Arm A and 8/11 pts on Arm B have registered to step 2. Conclusions: The addition of nivolumab to carboplatin, paclitaxel and radiation in the neoadjuvant setting appears to be safe with no disproportionate level of toxicity observed between the two treatment arms. Accrual to the remainder of the trial continues with 43/278 patients accrued. Clinical trial information: NCT03604991.

Elderly Patients Benefit From Enhanced Recovery Protocols After Colorectal Surgery

BACKGROUND

Enhanced recovery protocols (ERAS) aim to decrease physiological stress response to surgery and maintain postoperative physiological function. Proponents of ERAS state these protocols decrease lengths of stay (LOS) and complication rates. Our aim was to assess whether elderly patients receive the same benefit as younger patients using ERAS protocols.

METHODS

We queried patients from 2015 to 2017 at our institution with Enhanced Recovery in Surgery (ERIN) variables from the targeted colectomy NSQIP database. The patients were divided into sextiles and analyzed for readmission, LOS, return of bowel function, tolerating diet, mobilization, and multimodal pain management comparing the youngest sextile to the oldest sextile.

RESULTS

Two hundred sixty-two patients (73% colectomies) were enrolled in ERAS. When compared with the youngest sextile (age 19-43.8), the oldest sextile (age 71.4-92.5) had similar readmission rates at 9.8% versus 9.5% (P-value = 0.87), quicker return of bowel function, average 1.9 d versus 3.7 d (P-value < 0.01), and tolerated diet quicker, average POD 2.4 d versus 5.1 d (P-value < 0.01). There was a slight decrease in the use of multimodal pain management 88% versus 100% (P-value = 0.07), but mobilization on POD1 was slightly better in the elderly at 80% versus 78% (P-value = 0.76). Elderly patients enrolled in ERAS had an average LOS of 4.9 days versus 7.8 in the younger patients (P-value = 0.08). Among elderly non-ERAS patients average LOS was 14.6 days.

CONCLUSION

Overall, elderly patients fared better or the same on the ERIN variables analyzed than the younger cohort. ERAS protocols are beneficial and applicable to elderly patients undergoing colorectal surgery.

Impact of Perioperative Blood Transfusions on Outcomes After Hyperthermic Intraperitoneal Chemotherapy: A Propensity-Matched Analysis

BACKGROUND

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is a major operation frequently necessitating red blood cell transfusion. Using multi-institutional data from the U.S. HIPEC Collaborative, this study sought to determine the association of perioperative allogenic blood transfusion (PABT) with perioperative outcomes after CRS/HIPEC.

METHODS

This retrospective cohort study analyzed patients who underwent CRS/HIPEC for peritoneal surface malignancy between 2000 and 2017. Propensity score-matching was performed to mitigate bias. Univariate analysis was used to compare demographic, preoperative, intraoperative, and postoperative variables. Factors independently associated with PABT were identified using multivariate analysis.

RESULTS

The inclusion criteria were met by 1717 patients, 510 (29.7%) of whom required PABT. The mean Peritoneal Cancer Index (PCI) of our cohort was 14.8 ± 9.3. Propensity score-matching showed an independent association between PABT and postoperative risk of pleural effusion, hemorrhage, pulmonary embolism, enteric fistula formation, Clavien-Dindo grades 3 and 4 morbidity, longer hospital stay, and reoperation (all P < 0.05 in the multivariate analysis). Compared with the patients who received 1 to 5 red blood cell (RBC) units, the patients who received more than 5 units had a greater risk of renal impairment, a longer intensive care unit (ICU) stay, and more postoperative infections. Finally, PABT was an independent predictor of worse survival for patients with appendiceal and colorectal primaries.

CONCLUSION

Even low levels of PABT for patients undergoing CRS/HIPEC are independently associated with a greater risk of infectious and non-infectious postoperative complications, and this risk is increased for patients receiving more than 5 RBC units. Worse survival was independently predicted by PABT for patients with peritoneal carcinomatosis of an appendiceal or colorectal origin.

Comparing Activity Trackers With vs. Without Alarms to Increase Postoperative Ambulation: A Randomized Control Trial

Early ambulation is a key component to postoperative recovery; however, measuring steps taken is often inconsistent and nonstandardized. This study aimed to determine whether an activity tracker with alarms would increase postoperative ambulation in patients after elective colorectal procedures. Forty-eight patients were randomly assigned to either trackers with 5 daily alarms or activity trackers alone. Over 223 total patient days, the trackers recorded a complete data set for 216 patient days (96.9%). Increasing the postoperative day significantly affected the number of steps taken, while age, sex, Risk Analysis Index score, and approach (laparoscopic versus open) did not show a significant effect. The mean steps per day in the intervention group were 1468 (median 495; interquartile range (IQR) 1345) and in the control group was 1645 (median 1014; IQR 2498). The use of trackers with alarms did not significantly affect the number of daily steps compared to trackers alone (ANOVA, P = .93). Although activity trackers with alarms did not increase postoperative ambulation compared with trackers with no alarms, we demonstrated a strategy to operationalize the use of trackers into postoperative care to provide a quantitative value for ambulation. This enables quantification of a key component in the Enhanced Recovery After Surgery protocol.

A multi-institutional analysis of Textbook Outcomes among patients undergoing cytoreductive surgery for peritoneal surface malignancies

BACKGROUND

While recent studies have introduced the composite measure of a textbook outcome (TO) for measuring postoperative outcomes, the incidence of a TO has not been characterized among patients undergoing cytoreductive surgery (CRS) for peritoneal surface malignancies (PSM).

STUDY DESIGN

All patients who underwent CRS ± hyperthermic intraperitoneal chemotherapy (HIPEC) between 1999 and 2017 from 12 institutions were included. A TO was defined as the absence of any of the following criteria: completeness of cytoreduction >1, reoperation within 90-days, readmission within 90-days, mortality within 90-days, any grade ≥2 complication, hospital stay >75th percentile, and non-home discharge.

RESULTS

Among 1904 patients who underwent CRS, only 30.9% achieved a TO while 69.1% failed to achieve a TO most commonly because of postoperative complications. On multivariable analysis, factors associated with achieving a TO were age <65 years (OR: 1.5), albumin ≥3.5 g/dl (OR: 5.7), receipt of HIPEC (OR: 4.5), PCI ≤14 (OR: 2.2), intravenous fluid volume ≤10,000 ml (OR: 2.1), blood loss ≤1000 ml (OR: 4.2) and operative time <7 h (OR: 1.9); while receipt of neoadjuvant therapy (OR: 0.7) and liver resection (OR: 0.4) were associated with not achieving a TO (all p < 0.05). TO was associated with improved overall survival (median 159 months vs 56 months, p < 0.01) even after controlling for confounders on Cox regression (hazard ratio: 2.5, p < 0.01).

CONCLUSION

Among patients undergoing CRS ± HIPEC for PSM, failure to achieve a TO is common and independently associated with worse overall survival.

CRS/HIPEC with Major Organ Resection in Peritoneal Mesothelioma Does not Impact Major Complications or Overall Survival: A Retrospective Cohort Study of the US HIPEC Collaborative

INTRODUCTION

CRS/HIPEC is thought to confer a survival advantage for patients with malignant peritoneal mesothelioma (MPM). However, the impact of nonperitoneal organ resection is not clearly defined. We evaluated the impact of major organ resection (MOR) on postoperative outcomes and overall survival (OS).

PATIENTS AND METHODS

The US HIPEC collaborative database (2000-2017) was reviewed for MPM patients who underwent CRS/HIPEC. MOR was defined as total or partial resection of diaphragm, stomach, spleen, pancreas, small bowel, colon, rectum, kidney, ureter, bladder, and/or uterus. MOR was categorized as 0, 1, or 2+ organs.

RESULTS

A total of 174 patients were identified. Median PCI was 16 (3-39). The distribution of patients with MOR-0, MOR-1, and MOR-2+ was 94, 45, and 35 patients, respectively. MOR-1 and MOR-2+ groups had a higher frequency of any complication compared with MOR-0 (57.8%, 74.3%, and 48.9%, respectively, p = 0.035), but Clavien 3/4 complications were similar. Median length of stay was slightly higher in the MOR-1 and MOR-2+ groups (10 and 11 days) compared with the MOR-0 cohort (9 days, p = 0.005). Incomplete cytoreduction, ASA class 4, and male gender were associated with increased mortality on unadjusted analysis; however, their impact on OS was attenuated on multivariable analysis. MOR was not associated with OS based on these data (MOR-1: HR 1.67, 95% CI 0.59-4.74; MOR-2+ : HR 0.77, 95% CI 0.22-2.69).

CONCLUSIONS

MOR was not associated with an increase in major complications or worse OS in patients undergoing CRS/HIPEC for MPM and should be considered, if necessary, to achieve complete cytoreduction for MPM patients.

HSP90 expression and early recurrence in gastroenteropancreatic neuroendocrine tumors: Potential for a novel therapeutic target

BACKGROUND

Heat shock protein (HSP)-90 promotes tumor growth and is overexpressed in many malignancies. HSP90 expression profile and its potential as a therapeutic target in primary and metastatic neuroendocrine tumors (NETs) are not known.

METHODS

HSP90 cytoplasmic expression and Ki-67 index were re-reviewed and scored by a pathologist blinded to all other clinicopathologic variables for patients who underwent resection of primary and metastatic gastroenteropancreatic (GEP) neuroendocrine tumors at a single institution (2000-2013). Primary outcome was recurrence-free survival (RFS).

RESULTS

Of 263 tumors reviewed, 73% (n = 191) were primary GEP NETs, and 12% (n = 31) were NET liver metastases. Of the primary GEP-NETs, mean age was 56 years, 42% were male; 53% (n = 103) were pancreatic and 23% (n = 44) were small bowel. HSP90 expression was high in 34% (n = 64) and low in 66% (n = 127). Compared to low expression, high HSP90 was associated with advanced T-stage (T3/T4) (47 vs 27%; p = 0.02). Among patients who underwent curative-intent resections for primary, non-metastatic NETs (n = 145), high HSP90 was independently associated with worse RFS (HR 5.09, 95% CI 1.65-15.74; p = 0.005), after accounting for positive margin, LN involvement, increased tumor size, site of primary tumor, and Ki-67. When assessing NET liver metastases, 13% (n = 4) had high HSP90 expression and 87% (n = 26) had low expression. Patients with liver metastases with high HSP90 tended to have worse 1- and 3-year progression-free survival (25%, 25%) compared to those with low HSP90 (69%, 49%; p = 0.059).

CONCLUSION

HSP90 exhibits differential expression in resected GEP-NETs and liver metastases. High cytoplasmic expression is associated with early disease recurrence, even after accounting for other adverse pathologic factors. HSP90 inhibition may be a potential therapeutic target for neuroendocrine tumors.

A novel preoperative risk score to optimize patient selection for performing concomitant liver resection with cytoreductive surgery/HIPEC

BACKGROUND

While parenchymal hepatic metastases were previously considered a contraindication to cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC), liver resection (LR) is increasingly performed with CRS/HIPEC.

METHODS

Patients from the US HIPEC Collaborative (2000-2017) with invasive appendiceal or colorectal adenocarcinoma undergoing primary, curative intent CRS/HIPEC with CC0-1 resection were included. LR was defined as a formal parenchymal resection. Primary endpoints were postoperative complications and overall survival (OS).

RESULTS

A total of 658 patients were included. About 83 (15%) underwent LR of colorectal (58%) or invasive appendiceal (42%) metastases. LR patients had more complications (81% vs. 60%; p = .001), greater number of complications (2.3 vs. 1.5; p < .001) per patient and required more reoperations (22% vs. 11%; p = .007) and readmissions (39% vs. 25%; p = .014) than non-LR patients. LR patients had decreased OS (2-year OS 62% vs. 79%, p < .001), even when accounting for peritoneal carcinomatosis index and histology type. Preoperative factors associated with decreased OS on multivariable analysis in LR patients included age < 60 years (HR, 3.61; 95% CI, 1.10-11.81), colorectal histology (HR, 3.84; 95% CI, 1.69-12.65), and multiple liver tumors (HR, 3.45; 95% CI, 1.21-9.85) (all p < .05). When assigning one point for each factor, there was an incremental decrease in 2-year survival as the risk score increased from 0 to 3 (0: 100%; 1: 91%; 2: 58%; 3: 0%).

CONCLUSIONS

As CRS/HIPEC + LR has become more common, we created a simple risk score to stratify patients considered for CRS/HIPEC + LR. These data aid in striking the balance between an increased perioperative complication profile with the potential for improvement in OS.

Implications of Postoperative Complications for Survival After Cytoreductive Surgery and HIPEC: A Multi-Institutional Analysis of the US HIPEC Collaborative

BACKGROUND

Postoperative complications (POCs) are associated with worse oncologic outcomes in various cancer histologies. The impact of POCs on the survival of patients with appendiceal or colorectal cancer after cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) is unknown.

METHODS

The US HIPEC Collaborative (2000-2017) was reviewed for patients who underwent CCR0/1 CRS/HIPEC for appendiceal/colorectal cancer. The analysis was stratified by noninvasive appendiceal neoplasm versus invasive appendiceal/colorectal adenocarcinoma. The POCs were grouped into infectious, cardiopulmonary, thromboembolic, and intestinal dysmotility. The primary outcomes were overall survival (OS) and recurrence-free survival (RFS).

RESULTS

Of the 1304 patients, 33% had noninvasive appendiceal neoplasm (n = 426), and 67% had invasive appendiceal/colorectal adenocarcinoma (n = 878). In the noninvasive appendiceal cohort, POCs were identified in 55% of the patients (n = 233). The 3-year OS and RFS did not differ between the patients who experienced a complication and those who did not (OS, 94% vs 94%, p = 0.26; RFS, 68% vs 60%, p = 0.15). In the invasive appendiceal/colorectal adenocarcinoma cohort, however, POCs (63%; n = 555) were associated with decreased 3-year OS (59% vs 74%; p < 0.001) and RFS (32% vs 42%; p < 0.001). Infectious POCs were the most common (35%; n = 196). In Multivariable analysis accounting for gender, peritoneal cancer index (PCI), and incomplete resection (CCR1), infectious POCs in particular were associated with decreased OS compared with no complication (hazard ratio [HR] 2.08; p < 0.01) or other types of complications (HR, 1.6; p < 0.01). Similarly, infectious POCs were independently associated with worse RFS (HR 1.61; p < 0.01).

CONCLUSION

Postoperative complications are associated with decreased OS and RFS after CRS/HIPEC for invasive histology, but not for an indolent disease such as noninvasive appendiceal neoplasm, and this association is largely driven by infectious complications. The exact mechanism is unknown, but may be immunologic. Efforts must target best practices and standardized prevention strategies to minimize infectious postoperative complications.

Comparison of open and closed hyperthermic intraperitoneal chemotherapy: Results from the United States hyperthermic intraperitoneal chemotherapy collaborative

BACKGROUND

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal carcinomatosis can be performed in two ways: Open or closed abdominal technique.

AIM

To evaluate the impact of HIPEC method on post-operative and long-term survival outcomes.

METHODS

Patients undergoing CRS with HIPEC from 2000-2017 were identified in the United States HIPEC collaborative database. Post-operative, recurrence, and overall survival outcomes were compared between those who received open vs closed HIPEC.

RESULTS

Of the 1812 patients undergoing curative-intent CRS and HIPEC, 372 (21%) patients underwent open HIPEC and 1440 (79%) underwent closed HIPEC. There was no difference in re-operation or severe complications between the two groups. Closed HIPEC had higher rates of 90-d readmission while open HIPEC had a higher rate of 90-d mortalities. On multi-variable analysis, closed HIPEC technique was not a significant predictor for overall survival (hazards ratio: 0.75, 95% confidence interval: 0.51-1.10, P = 0.14) or recurrence-free survival (hazards ratio: 1.39, 95% confidence interval: 1.00-1.93, P = 0.05) in the entire cohort. These findings remained consistent in the appendiceal and the colorectal subgroups.

CONCLUSION

In this multi-institutional analysis, the HIPEC method was not independently associated with relevant post-operative or long-term outcomes. HIPEC technique may be left to the discretion of the operating surgeon.

Institutional variation in recovery after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: An opportunity for enhanced recovery pathways

BACKGROUND

Variations in care have been demonstrated both within and among institutions in many clinical settings. By standardizing perioperative practices, Enhanced Recovery After Surgery (ERAS) pathways reduce variation in perioperative care. We sought to characterize the variation in cytoreductive surgery (CRS)/heated intraperitoneal chemotherapy (HIPEC) perioperative practices among experienced US medical centers.

METHODS

Data from the US HIPEC Collaborative represents a retrospective multi-institutional cohort study of CRS and CRS/HIPEC procedures performed from 12 major academic institutions. Patient characteristics and perioperative practices were reported and compared. Institutional variation was analyzed using hierarchical mixed-effects linear (continuous outcomes) or logistic (binary outcomes) regression models.

RESULTS

A total of 2372 operations were included. CRS/HIPEC was performed most commonly for appendiceal histologies (64.2%). The rate of complications (overall 56.3%, range: 31.8-70.9) and readmissions (overall 20.6%, range: 8.9-33.3) varied by institution (P < .001). Institution-level variation in perioperative practice patterns existed among measured ERAS pathway process/outcomes (P < .001). The percentages of variation with each process/outcome measure attributable solely to institutional practices ranged from 0.6% to 66.6%.

CONCLUSIONS

Significant variation exists in the perioperative care of patients undergoing CRS/HIPEC at major US academic institutions. These findings provide a strong rationale for the investigation of best practices in CRS/HIPEC patients.

Predictors of Non-home Discharge after Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

Using a national database of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) recipients, we sought to determine risk factors for nonhome discharge (NHD) in a cohort of patients.

METHODS

Patients undergoing CRS/HIPEC at any one of 12 participating sites between 2000 and 2017 were identified. Univariate analysis was used to compare the characteristics, operative variables, and postoperative complications of patients discharged home and patients with NHD. Multivariate logistic regression was used to identify independent risk factors of NHD.

RESULTS

The cohort included 1593 patients, of which 70 (4.4%) had an NHD. The median [range] peritoneal cancer index in our cohort was 14 [0-39]. Significant predictors of NHD identified in our regression analysis were advanced age (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.05-1.12; P < 0.001), an American Society of Anesthesiologists (ASA) score of 4 (OR, 2.87; 95% CI, 1.21-6.83; P = 0.017), appendiceal histology (OR, 3.14; 95% CI 1.57-6.28; P = 0.001), smoking history (OR, 3.22; 95% CI, 1.70-6.12; P < 0.001), postoperative total parenteral nutrition (OR, 3.14; 95% CI, 1.70-5.81; P < 0.001), respiratory complications (OR, 7.40; 95% CI, 3.36-16.31; P < 0.001), wound site infections (OR, 3.12; 95% CI, 1.58-6.17; P = 0.001), preoperative hemoglobin (OR, 0.81; 95% CI, 0.70-0.94; P = 0.006), and total number of complications (OR, 1.41; 95% CI, 1.16-1.73; P < 0.001).

CONCLUSIONS

Early identification of patients at high risk for NHD after CRS/HIPEC is key for preoperative and postoperative counseling and resource allocation, as well as minimizing hospital-acquired conditions and associated health care costs.

Gastrointestinal Stromal Tumors: A Single Institution Experience of 176 Surgical Patients

Large single-institution series of patients undergoing resection for gastrointestinal stromal tumors (GIST) are lacking. Clinicopathologic characteristics and postoperative outcomes were retrospectively collected and analyzed from patients undergoing resection for GIST from 2002 to 2011. One hundred seventy-six patients were identified; 156 underwent resection of primary nonmetastatic disease. KIT mutations were identified in 131 patients (84.0%). Of the 156 patients with primary disease, the most common site was the stomach (75.6%). Tumors were categorized as very low (24.4%), low (35.9%), intermediate (12.2%), high (24.4%), or unknown (3.2%) risk. Symptomatic patients more often had high risk (35.6 vs 9.8%; P < 0.0001) and larger tumors (7.3 vs 3.0 cm; P < 0.0001). Forty-seven patients (30.1%) underwent laparoscopic resection (LR). Compared with open surgery, LR was performed for smaller tumors (3.8 vs 6.2 cm; P = 0.002). Positive margin rates were similar (4.3% LR vs 10.2% open; P = 0.346). Median follow-up for the 156 patients with primary tumors was 32.9 months; mean overall survival was 120.9 months (median not reached). Of the 20 patients with metastatic GIST (excluded from above analysis), five patients (25.0%) died of disease with a median follow-up of 15.9 months. Most patients with resectable primary GIST have a favorable prognosis. The presence of symptoms directly related to GIST may be associated with a poor prognosis and is likely related to increased tumor size. Laparoscopic resection is well tolerated and does not appear to compromise outcomes in well-selected patients. Highly selected patients with metastatic disease may benefit from resection.

Improving Quality of Surgical Care and Outcomes: Factors Impacting Surgical Site Infection after Colorectal Resection

Surgical site infections (SSIs) result in patient morbidity and increased costs. The purpose of this study was to determine reasons underlying SSI to enable interventions addressing identified factors. Combining data from the American College of Surgeons National Surgical Quality Improvement Project with medical record extraction, we evaluated 365 patients who underwent colon resection from January 2009 to December 2012 at a single institution. Of the 365 patients, 84 (23%) developed SSI. On univariate analysis, significant risk factors included disseminated cancer, ileostomy, patient temperature less than 36°C for greater than 60 minutes, and higher glucose level. The median number of cases per surgeon was 36, and a case volume below the median was associated with a higher risk of SSI. On multivariate analysis, significant risks associated with SSI included disseminated cancer (odds ratio [OR], 4.31; P < .001); surgery performed by a surgeon with less than 36 cases (OR, 2.19; P = .008); higher glucose level (OR, 1.06; P 5.017); and transfusion of five units or more of blood (OR, 3.26; P 5.029). In this study we found both modifiable and unmodifiable factors associated with increased SSI. Identifying modifiable risk factors enables targeting specific areas to improve the quality of care and patient outcomes.

Should Signet Ring Cell Histology Alter the Treatment Approach for Clinical Stage I Gastric Cancer?

BACKGROUND

Surgery alone is standard-of-care for stage I gastric adenocarcinoma; however, clinicians can offer preoperative therapy for clinical stage I disease with signet ring cell histology, given its presumed aggressive biology. We aimed to assess the validity of this practice.

METHODS

The National Cancer Database (2004-2015) was reviewed for patients with clinical stage I signet ring cell gastric adenocarcinoma who underwent treatment with surgery alone, perioperative chemotherapy, neoadjuvant therapy, or adjuvant therapy. Analysis was stratified by preoperative clinical/pathologic stage. Primary outcome was overall survival (OS).

RESULTS

Of 1018 patients, median age was 60 years (±14); 53% received surgery alone (n = 542), 5% received perioperative chemotherapy (n = 47), 12% received neoadjuvant therapy (n = 125), and 30% received adjuvant therapy (n = 304). For clinical stage I disease, surgery alone was associated with an improved 5-year OS rate (71%) versus perioperative chemotherapy (58%), neoadjuvant therapy (38%), or adjuvant therapy (52%) [overall p < 0.01]. For pathologic stage I, surgery alone had equivalent or improved survival compared with perioperative, neoadjuvant, and adjuvant therapy (5-year OS: 78% vs. 89% [p = 0.77] vs. 64% [p = 0.04] vs. 84% [p = 0.99]). Adjuvant therapy was associated with improved 5-year OS compared with pretreatment for those patients upstaged (37%) to pathologic stage II/III (55% vs. 36% and 34% vs. 7%; all p < 0.01).

CONCLUSIONS

This stage-specific study demonstrates improved survival with surgery alone for clinical stage I signet ring cell gastric adenocarcinoma. Despite 37% of clinical stage I patients being upstaged to pathologic stage II/III, adjuvant therapy offers a favorable rescue strategy, with improved outcomes compared with those treated preoperatively. Surgery alone also affords similar or improved survival for pathologic stage I disease versus multimodality therapy. This study challenges the bias to overtreat stage I signet ring cell gastric adenocarcinoma.

A phase II/III study of perioperative nivolumab and ipilimumab in patients (pts) with locoregional esophageal (E) and gastroesophageal junction (GEJ) adenocarcinoma: A trial of the ECOG-ACRIN Cancer Research Group (EA2174)

TPS4651

Background: E/GEJ adenocarcinoma has a high mortality rate despite curative intent treatment. A pathologic complete response (pCR) is associated with better overall survival (OS) but occurs in less than 30% of pts. Immunotherapy is effective in the metastatic setting. Here we aim to evaluate the contribution of immunotherapy in the neoadjuvant and adjuvant settings in pts with locoregional E/GEJ cancer. Methods: This is a multi-center, randomized phase II/III trial. Surgical candidates with locoregional E/GEJ adenocarcinoma receive carboplatin AUC 2 IV and paclitaxel 50 mg/m2 IV, both weekly x 5 during concurrent radiation (50.4 Gy) either with or without nivolumab 240 mg IV during weeks 1 and 3, followed by surgery. Pts with no post-operative disease receive nivolumab 240 mg IV every 2 weeks for 12 cycles either with or without ipilimumab 1 mg/kg IV every 6 weeks for 4 cycles. Eligibility criteria include pts with T1-N1-3M0 or T2-3N0-2M0 disease whom are candidates for surgery, no prior chemotherapy or radiation for this disease, no prior immunotherapy, no significant autoimmune disease. Pts must be disease free for adjuvant treatment. Primary neoadjuvant endpoint is pCR rate; primary adjuvant endpoint is disease free survival (DFS). Secondary endpoints include toxicity, DFS and OS. Pre- and mid-treatment diffusion weighted imaging MRI will be conducted during the neoadjuvant portion of the study. A neoadjuvant safety run in of 30 pts is underway. Overall, 278 pts will be needed to detect an absolute improvement of 15% in pCR rate in pts receiving and not receiving neoadjuvant nivolumab and 236 pts will be needed to detect a HR of 0.65 in favor of adjuvant ipilimumab/nivolumab over nivolumab (90% power, one sided alpha of 0.10). Accrual is expected over 34 months at a rate of 8 patients per month. If favorable at interim analysis. Clinical trial information: NCT03604991 .

The Intersection of Age and Tumor Biology with Postoperative Outcomes in Patients After Cytoreductive Surgery and HIPEC

BACKGROUND

Patient age is a significant factor in preoperative selection for major abdominal surgery. The association of age, tumor biology, and postoperative outcomes in patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) remains ill-defined.

METHODS

Retrospective analysis was performed for patients who underwent a CCR0/1 CRS/HIPEC from the US HIPEC Collaborative Database (2000-2017). Age was categorized into < 65 or ≥ 65 years. Primary outcome was postoperative major complications. Secondary outcomes were non-home discharge (NHD) and readmission. Analysis was stratified by disease histology: non-invasive (appendiceal LAMN/HAMN), and invasive (appendiceal/colorectal adenocarcinoma).

RESULTS

Of 1090 patients identified, 22% were ≥ 65 (n = 240), 59% were female (n = 646), 25% had non-invasive (n = 276) and 51% had invasive (n = 555) histology. Median PCI was 13 (IQR 7-20). Patients ≥ 65 had a higher rate of major complications (37 vs 26%, p = 0.02), NHD (12 vs 5%, p < 0.01), and readmission (28 vs 22%, p = 0.05), compared to those < 65. For non-invasive histology, age ≥ 65 was not associated with major complications or NHD on multivariable analysis. For invasive histology, when accounting for PCI and CCR, age ≥ 65 was associated with major complications (OR 2.04, 95% CI 1.16-3.59, p = 0.01). When accounting for major complications, age ≥ 65 was associated with NHD (OR 2.54, 95% CI 1.08-5.98, p = 0.03). Age ≥ 65 was not predictive of readmission for any histology when accounting for major complications.

CONCLUSIONS

Age ≥ 65 years is an independent predictor for postoperative major complications and non-home discharge for invasive histology, but not non-invasive histology. These data inform preoperative counseling, risk stratification, and early discharge planning.

Repeat Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Is Not Associated with Prohibitive Complications: Results of a Multiinstitutional Retrospective Study

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is offered to select patients with peritoneal metastases. In instances of recurrence/progression, a repeat CRS/HIPEC may be considered. The perioperative morbidity and the potential oncologic benefits are not well described.

PATIENTS AND METHODS

We performed a retrospective analysis of a multiinstitutional database to assess the perioperative outcomes following repeat CRS/HIPEC (repeat). Kaplan-Meier and Cox estimates were used to assess survival.

RESULTS

In the entire cohort, 2157 patients were analyzed, with 158 (7.3%) in the repeat cohort. The rate of complete cytoreduction was 89.8% versus 83.0% in initial versus repeat groups. The overall incidence of major complications was similar (26.3% vs. 30.7%); however, reoperation was more common in the repeat group. Perioperative outcomes such as length of stay and nonhome discharge were not significantly different. For the entire cohort, 5-year overall survival (OS) was 56.0% in the initial group and 59.5% in the repeat group. In patients with only appendiceal cancer, we observed a 5-year OS of 64.0% in the initial group compared with 67.3% in the repeat cohort. For patients with appendiceal cancer who developed a recurrence/progression, median OS was 36 months in the no repeat operation group compared with 73 months for those that did. Multivariable regression demonstrated that completeness of cytoreduction and tumor grade were associated with OS, but repeat operation was not.

CONCLUSIONS

Repeat CRS/HIPEC is not associated with prohibitive risk. Survival is possibly improved, and therefore, repeat operation should be considered in selected patients with recurrent or progressive disease.

Differences in outcome for patients with cholangiocarcinoma: Racial/ethnic disparity or socioeconomic factors?

BACKGROUND

Inequities in cancer survival are well documented. Whether disparities in overall survival (OS) result from inherent racial differences in underlying disease biology or socioeconomic factors (SEF) is not known. Our aim was to define the association of race/ethnicity and SEF with OS in pts with cholangiocarcinoma (CCA).

METHODS

Patients with CCA of all sites and stages in the National Cancer Data Base (2004-13) were included. Racial/ethnic groups were defined as non-Hispanic White (NH-W), non-Hispanic Black (NH-B), Asian, and Hispanic. Income and education were based on census data for patients' zip code. Income was defined as high (≥$63,000) vs low (<$63,000). Primary outcome was OS.

RESULTS

27,151 patients were included with a mean age of 68 yrs; 51% were male. 78% were NH-W, 8% NH-B, 8% Hispanic, and 6% Asian. 56% had Medicare, 33% private insurance, 7% Medicaid, and 4% were uninsured. 67% had low income. 19% lived in an area where >20% of adults did not finish high school. NH-B and Hispanic patients had more unfavorable SEF including uninsured status, low income, and less formal education than NH-W and Asian pts (all p < 0.001). They were also younger, more likely to be female and to have metastatic disease (all p < 0.001). Despite this, NH-B race and Hispanic ethnicity were not associated with decreased OS. Male sex, older age, non-private insurance, low income, lower education, non-academic facility, location outside the Northeast, higher Charlson-Deyo score, worse grade, larger tumor size, and higher stage were all associated with decreased OS (all p < 0.001). On MV analysis, along with adverse pathologic factors, type of insurance (p = 0.003), low income (p < 0.001), and facility type and location of treatment (p < 0.001) remained associated with decreased OS; non-white race/ethnicity was not.

CONCLUSIONS

Disparities in survival exist in CCA, however they are not driven by race/ethnicity. Non-privately insured and low-income patients had decreased OS, as did patients treated at non-academic centers and outside the Northeast. This suggests that decreased ability to access and afford care results in worse outcomes, rather than biological differences amongst racial/ethnic groups.

Receipt of Adjuvant Chemotherapy in Stage II Colon Cancer and Overall Survival: A National Cancer Database Study

BACKGROUND

There are variations in the use of adjuvant chemotherapy (AC) in stage II colon cancer (CRC). We sought to determine which patients received chemotherapy, what factors were associated with receipt of AC, and how this impacted overall survival.

METHODS

Using the National Cancer Database, patients with stage II CRC who underwent surgical resection were selected; patients who received radiation or neoadjuvant chemotherapy were excluded. High-risk features (HRFs) were defined as pathological tumor stage IV, positive surgical margins, and perineural or lymphovascular invasion. Multivariable and subgroup analysis with eight subgroups stratified in the presence of HRFs, age, and the Charlson-Deyo score was performed.

RESULTS

Of 77,739 patients identified with stage II CRC, 18.3% received AC. Younger, healthier patients with HRFs had the highest chemotherapy receipt rate (46.7%), whereas patients without HRFs, ≥ 75 y, and with the Charlson-Deyo score of 2+ had the lowest rate (2.1%). Community cancer centers were more likely to initiate AC (odds ratio = 1.24 P < 0.01) especially among healthy HRF-negative patients and younger patients. No significant racial differences in AC use were observed. AC was associated with improved overall survival in subgroups with HRFs (hazard ratio [HR]: 0.81 P < 0.001; HR: 0.75 P < 0.001; HR: 0.65 P = 0.03; HR: 0.55, P < 0.001) but not in patients without HRFs.

CONCLUSIONS

AC receipt rates differed depending on patient age and type of institution delivering care. AC was associated with survival benefits only in patients with HRFs regardless of age. These findings are clinically relevant to inform appropriate use of AC in stage II CRC.

Implications of postoperative complications on survival after cytoreductive surgery and HIPEC: A multi-institutional analysis of the United States HIPEC Collaborative

40

Background: Postoperative complications (POCs) are associated with worse oncologic outcomes in various cancer histologies. The impact of POCs on the survival of patients with appendiceal or colorectal cancer after cytoreductive surgery/heated intraperitoneal chemotherapy (CRS/HIPEC) is unknown. Methods: US HIPEC Collaborative (2000-17) was reviewed for patients who underwent CCR0/1 CRS/HIPEC for appendiceal/colorectal cancer. Analysis was stratified by non-invasive appendiceal neoplasm vs invasive appendiceal/colorectal adenocarcinoma. POCs were grouped into infectious, cardiopulmonary, thromboembolic and intestinal dysmotility. Primary outcomes were 3-yr overall survival (OS) and recurrence-free survival (RFS). Results: Of 1304 pts, median age was 55 yrs, 41% were male (n = 537), 33% had non-invasive appendiceal (n = 426) and 67% had invasive appendiceal/colorectal adenocarcinoma (n = 878). In the non-invasive appendiceal cohort, POCs were identified in 55% (n = 233) and OS and RFS did not differ between patients who experienced a complication and those who did not (OS 94 vs 94% p = 0.26; RFS 68 vs 60% p = 0.15). In the invasive appendiceal/colorectal adenocarcinoma cohort, however, POCs (63%; n = 555) were associated with decreased OS (59 vs 74% p < 0.001) and RFS (32 vs 42% p < 0.001). Infectious POCs were most common (35%; n = 196). On MV analysis accounting for gender, PCI and incomplete resection (CCR1), infectious POCs in particular were associated with decreased OS compared to no complication (HR 2.08 95%CI 1.48-2.93 p < 0.01) or other types of complications (HR 1.7 95%CI 1.28-2.25 p < 0.01). This association persisted for infectious POCs and reduced RFS (HR 1.61 95%CI 1.23-2.10 p < 0.01). Conclusions: Postoperative complications are associated with decreased OS and RFS after CRS/HIPEC for invasive histology, but not for an indolent disease like non-invasive appendiceal neoplasm. Of all complication types, infectious complications are the main driver for this association. The exact mechanism is not known, but may be immunologic. Efforts must target best practices and standardized prevention strategies to minimize infectious POCs.

The intersection of age and tumor biology with postoperative outcomes in patients after cytoreductive surgery and HIPEC

184

Background: Patient age is often a significant factor in preoperative selection for major abdominal surgery. Its association with postoperative outcomes in patients undergoing cytoreductive surgery(CRS) and hyperthermic intraperitoneal chemotherapy(HIPEC) remains ill-defined. Methods: The US HIPEC Collaborative database(2000-2017) was reviewed for patients who underwent a CCR0/1 CRS/HIPEC. Age was categorized into < 65 or >65yrs. Primary outcomes were postoperative major complications, readmission, 30-day mortality, and non-home discharge(NHD). Analysis was stratified by disease histology: non-invasive(appendiceal LAMN/HAMN), and invasive(appendiceal/colorectal adenocarcinoma). Results: Of 1090pts identified, 22% were >65yrs(n = 240), 59% were female(n = 646), 25% had non-invasive(n = 276) and 51% had invasive(n = 555) histology. Median PCI was 13(IQR7-20). Patients >65yrs had a higher rate of major complications(37vs26%, p = 0.02), readmission(28vs22%,p = 0.05), 30-day mortality(3vs1%,p = 0.02), and NHD(12vs5%,p < 0.01) compared to those < 65yrs. On multivariable analysis accounting for extent of disease as measured by PCI, for non-invasive histology, age >65yrs was an independent predictor for NHD(OR:2.54,95%CI:1.08-5.99,p = 0.03), but not major complications. For invasive histology, even when accounting for PCI, age >65yrs was an independent predictor for both NHD(OR:2.54,95%CI:1.08-5.98,p = 0.03) and major complications(OR:2.04,95%CI:1.16-3.59,p = 0.05). Age was not associated with hospital readmission or 30-day mortality for any histology. Conclusions: Regardless of histology, patients >65yrs are nearly at three-fold increased risk for non-home discharge after CRS/HIPEC. For invasive histology, age >65yrs is also associated with increased major complication rates, but the procedure seems to be better tolerated when performed for indolent biology. These data inform preoperative counseling and risk stratification. Early planning for discharge disposition in this high-risk population can potentially translate to cost savings.

Should signet-ring cell histology alter the treatment approach for clinical stage I gastric cancer?

321

Background: Upfront surgery is standard of care for stage I gastric cancer. Despite this, many clinicians administer preoperative therapy for clinical stage I disease with signet ring cell histology, given its aggressive biology. We aimed to assess the validity of this practice. Methods: The National Cancer Database (2004-2015) was reviewed for pts with non-metastatic signet ring cell gastric cancer who underwent treatment with surgery alone, perioperative chemotherapy, neoadjuvant therapy, or adjuvant therapy. Analysis was stratified by preoperative clinical stage and pathologic stage. Primary outcome was overall survival (OS). Results: Of 3000 pts, median age was 61 (IQR: 51-70). 34% were clinical stage I (n = 1018) of which 53% received surgery alone (n = 542), 5% perioperative chemotherapy (n = 47), 12% neoadjuvant therapy (n = 125), and 30% adjuvant therapy (n = 304). Median follow-up was 26 mos. For clinical stage I disease, surgery alone was associated with improved median OS (108 mos) when compared to perioperative chemotherapy (80 mos), neoadjuvant therapy (41 mos), or adjuvant therapy (73 mos, all p < 0.001). For pathologic stage I, surgery alone had equivalent survival to perioperative and adjuvant therapy (5-yr OS: 81 vs 82 vs 79%, p = 0.22). Concordance between clinical and pathologic stage I was 56%, specifically, 41% of clinical stage I pts were upstaged to pathologic stage II (44%) and stage III (56%). Adjuvant therapy for these pts was associated with improved median OS compared to pretreatment (perioperative chemotherapy / neoadjuvant therapy) for those upstaged to pathologic stage II (122 vs 37mos, p < 0.001) or stage III (40 vs 18mos, p < 0.001) disease. Conclusions: Our stage-stratified study demonstrates improved survival with upfront surgery for clinical stage I signet ring cell gastric cancer. Despite 41% of clinical stage I pts being upstaged to stage II or III on final pathology, adjuvant therapy offers a favorable rescue strategy, with improved outcomes compared to those treated preoperatively. Surgery alone also affords similar survival for pathologic stage I disease compared to multimodal therapy. This study challenges the intrinsic bias to over-treat stage I signet ring cell gastric cancer.

A novel preoperative risk score to optimize patient selection for performing concomitant liver resection with cytoreductive surgery/HIPEC

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Background: While parenchymal hepatic metastases were previously considered a contraindication to cytoreductive surgery(CRS) and heated intraperitoneal chemotherapy(HIPEC), liver resection(LR) is increasingly performed concomitantly with CRS/HIPEC. As this practice continues to expand, identification of preoperative factors associated with poor outcomes is paramount. Methods: Patients from the US HIPEC Collaborative(2000-2017) with invasive appendiceal or colorectal adenocarcinoma undergoing primary, curative intent CRS/HIPEC with CC0-1 resection were included. LR was defined as a formal parenchymal resection. Primary endpoints were postoperative complications and overall survival(OS). Results: 658 patients were included. Average age was 54 years and 45% were male; 83 (15%) underwent liver resection of colorectal (58%) or invasive appendiceal (42%) metastases. Liver resection patients had more complications (81 vs 60%; p = 0.001), greater number of complications (2.3 vs 1.5; p < 0.001), and required more reoperations (22 vs 11%; p = 0.007) and readmissions (39 vs 25%; p = 0.014) than non-liver resection patients. Liver resection patients had decreased OS (2-year OS 62% vs 79%, p < 0.001), which persisted on multivariable Cox regression when accounting for PCI and histology type. Preoperative factors associated with decreased OS on multivariable analysis in patients undergoing liver resection included age < 60 years (HR:3.61), colorectal histology (HR:3.84), and multiple liver tumors (HR:3.45) (all p < 0.05). When assigning one point for each factor, there was an incremental decrease in 2-yr survival as the risk score increased from 0 to 3 (0: 100%; 1: 91%; 2: 58%; 3: 0%; p < 0.001). Conclusions: As concurrent liver resection with CRS/HIPEC has become more common, we created a simple risk score to stratify patients considered for CRS/HIPEC with liver resection. These data aid in striking the balance between an increased perioperative complication profile with the potential for improvement in overall survival.

Should We Be Doing Cytoreductive Surgery with HIPEC for Signet Ring Cell Appendiceal Adenocarcinoma? A Study from the US HIPEC Collaborative

BACKGROUND

Appendiceal adenocarcinoma with signet ring cells (SCA) is associated with worse overall survival (OS), and it is unclear whether cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) should be pursued in this patient population. We assessed the prognostic implications of signet ring cells in patients with appendiceal adenocarcinoma and peritoneal carcinomatosis undergoing CRS-HIPEC.

METHODS

The US HIPEC Collaborative, a 12-center, multi-institutional database of patients undergoing CRS-HIPEC, was reviewed for patients with SCA. Univariate and multivariate analyses were performed.

RESULTS

Of 514 patients undergoing CRS-HIPEC for appendiceal adenocarcinoma, 125 (24%) had SCA. The SCA and non-SCA groups had similar baseline characteristics. SCA had worse OS compared with non-SCA (32.0 vs 91.4 months, p < 0.001). In univariate analysis for only SCA cases, there was worse OS in patients with poorly differentiated tumors, positive lymph nodes, LVI, PCI > 20, or incomplete cytoreduction (CC-2/3). However, multivariate analysis showed only positive lymph nodes (HR 1.14 [95% CI 1.00-1.31], p = 0.04), poor differentiation (5.60 [1.29-24.39], p = 0.02), and incomplete cytoreduction (4.90 [1.11-12.70], p = 0.03) were independently associated with decreased OS for SCA.

CONCLUSION

While signet cells are a negative prognostic feature, they should not be a contraindication to CRS-HIPEC in patients with well-moderately differentiated tumors with negative lymph nodes, where complete cytoreduction can be achieved.

Phase II Study of Preoperative Chemoradiotherapy with Oxaliplatin, Infusional 5-Fluorouracil, and Cetuximab Followed by Postoperative Docetaxel and Cetuximab in Patients with Adenocarcinoma of the Esophagus: A Trial of the ECOG-ACRIN Cancer Research Group (E2205)

BACKGROUND

A standard approach to treating resectable esophageal adenocarcinoma is chemoradiotherapy (CRT) followed by surgery; however, recurrence is common. To improve this, we designed a single-arm, phase II trial that added an epidermal growth factor receptor (EGFR) inhibitor, cetuximab (C), to CRT, with the hypothesis that EGFR inhibition would improve pathologic complete response (pCR) rate.

MATERIALS AND METHODS

We aimed to increase the pCR rate from 25% to 45%. A Simon two-stage design (α and β of 0.10) required pCR/enrolled 5/18 for stage 1 and 14/40 total. CRT: oxaliplatin 85 mg/m2 days 1, 15, and 29; infusional 5-fluorouracil 180 mg/m2 /24 hours × 35 days; C 400 mg/m2 day 1 then 250 mg/m2 days 8, 15, 22, and 29 and radiation (intensity modulated radiotherapy [IMRT] allowed) 180 cGy/day × 25 fractions (Monday through Friday). Following esophagectomy, adjuvant chemotherapy (CT): weekly docetaxel 35 mg/m2 and C 250 mg/m2 5 out of 6 weeks for two cycles.

RESULTS

Of 21 eligible patients enrolled, 17 had surgery; 4 died before operation (due to pulmonary embolism 4 days after CRT, G3 diarrhea, progressive disease during CRT, sepsis/hypoxia during CRT, and acute respiratory distress syndrome [ARDS]). pCR = 7/17. Three postoperative deaths due to ARDS resulted in seven total study-related deaths. Of the 14 remaining patients, 12 started and completed adjuvant CT. Two of seven patients with pCR died, both of ARDS. Out of the 21 eligible subjects in this study, 13 have died and 8 remain alive. The use of IMRT did not correlate with ARDS.

CONCLUSION

This regimen demonstrated promising activity. Toxicity was significant, with seven study-related deaths leading to closure after stage 1. All postoperative deaths were due to ARDS. This regimen is not recommended.

IMPLICATIONS FOR PRACTICE

Esophageal cancer is a disease with a high death rate. The current treatment involves giving chemotherapy plus radiation followed by surgery, but this cures only a quarter of patients. In order to improve survival, better treatments are needed. This trial evaluated the addition of a novel drug, cetuximab, to chemotherapy plus radiation. Unfortunately, the side effects were too great and the study was stopped early.

What is the Optimal Preoperative Imaging Modality for Assessing Peritoneal Cancer Index? An Analysis From the United States HIPEC Collaborative

BACKGROUND

Radiographic prediction of peritoneal carcinomatosis index (PCI) can improve patient selection for cytoreductive surgery. We aimed to determine the correlation of computed tomography (CT)-predicted PCI (CT-PCI) and magnetic resonance imaging (MRI)-predicted PCI (MRI-PCI) with intraoperative-PCI, and if a preoperative-PCI cutoff is associated with incomplete cytoreduction.

PATIENTS AND METHODS

Patients from the US HIPEC Collaborative (2000-2017) with appendiceal, colorectal, or peritoneal mesothelioma (PM) histology who underwent cytoreductive surgery were included. Pearson correlation coefficients were used to determine correlation between preoperative and intraoperative-PCI values. Fisher r-to-z transformation was used to compare correlations.

RESULTS

A total of 488 patients were included. Of these, 34% had noninvasive appendiceal, 30% invasive appendiceal, 28% colorectal, and 8% PM histology. CT-PCI was correlated with intraoperative-PCI for patients with noninvasive and invasive appendiceal and colorectal histologies (r = 0.689, 0.554, and 0.571; all P < .001), but not PM (r = 0.188; P = .295). MRI-PCI was correlated with intraoperative-PCI for all histologies (non-invasive appendiceal: r = 0.591; P = .002; invasive appendiceal: r = 0.848; P < .001; colorectal: r = 0.729; P < .001; PM: r = 0.890; P = .007). Comparing CT and MRI, correlations were similar in noninvasive appendiceal and colorectal histologies; MRI was better for invasive appendiceal and PM (P = .005 and P = .021, respectively). Twenty-eight (6%) patients underwent an incomplete cytoreduction (cytoreduction score, 2-3). PCI greater than 15 was associated with cytoreduction score of 2 to 3 for both CT and MRI (CT-PCI: odds ratio, 3.0; P = .033; MRI-PCI: odds ratio, 7.6; P = .071).

CONCLUSIONS

In this multi-institutional cohort, CT and MRI-PCI correlate well with intraoperative-PCI. MRI appears to be superior for invasive appendiceal and peritoneal mesothelioma. External validation in a larger population is needed.

A novel preoperative risk score to predict lymph node positivity for rectal neuroendocrine tumors: An NCDB analysis to guide operative technique

BACKGROUND/OBJECTIVE

Staging and type of resection for rectal neuroendocrine tumors (R-NETS) relies on preoperative identification of lymph node (LN) involvement. Study objective was to develop a Preoperative Rectal Stratification Score (PReSS) for LN-positivity and to assess the association of PReSS with overall survival (OS).

METHODS

All patients in the National Cancer Database (2004-2014) with non-metastatic/nonfunctional R-NETS were included. Tumor size was divided into three categories (<1, 1-2, and ≥2 cm).

RESULTS

Among 383 patients, median age was 57 years, 52% were male (n = 200), median tumor size was 1.4 cm, 43% had positive LNs (n = 163). On univariate analysis, age  > 60, poorly differentiated grade, depth of invasion past submucosa, and size >1 cm were associated with LN positivity. On multivariable analysis, depth of invasion past submucosa, and increasing tumor size >1 cm remained associated with LN positivity. As these can be determined preoperatively, incidence of LN positivity was determined for each combination of tumor size and depth of invasion. Each variable was assigned a score to create a PReSS of four groups (0-3) associated with an increasing rate of LN-positivity (PReSS group 0: 11%, 1: 38%, 2: 50%, 3: 78%, P < .01). PReSS correlated with 10-year OS (PReSS 0: 90%; 1: 81%; 2: 59%; 3: 41%).

CONCLUSION

For R-NETS, depth of invasion and tumor size predict LN positivity and both can be obtained preoperatively. PReSS incorporates both variables and stratifies tumors into four risk groups of progressively increasing LN positivity and should be used to guide surgical approach.

Duodenal neuroendocrine tumors: Somewhere between the pancreas and small bowel?

BACKGROUND

While sub-2 cm pancreatic neuroendocrine tumors (NETs) are often observed, small bowel-NETs undergo resection and lymphadenectomy regardless of size. Aim was to define the natural history of duodenal (D-NETs), determine the role of resection, and define the factors associated with overall survival (OS) after resection.

METHODS

National Cancer Database (2004-2014) was queried for the patients with nonmetastatic/nonfunctional D-NETs. Local resection (LR): local excision/polypectomy/excisional biopsy. Anatomic resection (AR): radical surgery. Tumor size was divided into less than 1 cm, 1 to 2 cm, and ≥2 cm. Propensity score weighting was used to create balanced resection and no-resection cohorts. The primary endpoint was OS.

RESULTS

Among 5502 patient, the median age was 65 years. The median follow-up was 49 months. The median tumor size was 0.8 cm. Resection was performed in 72% (n = 3954; LR: 61%, AR: 39%). Lymph node (LN) resection was performed in 26% (43% had metastasis). A total of 74% had negative margins. Resection and no-resection cohorts were propensity score weighted for age/sex/race/Charlson-Deyo score/tumor grade (all independently associated with OS on multivariable analysis). Resection was associated with improved median OS compared to no resection in all sizes (<1 cm: median not reached vs 194 months; 1-2 cm: median not reached vs 56 months; >2 cm: median not reached vs 90 months; all P < .01). Subset analysis of each resection size cohort demonstrated that neither type of resection, LN retrieval, LN positivity, or margin status was associated with OS (all P > .05).

CONCLUSION

Patients with nonmetastatic and nonfunctional D-NETS should be considered for resection regardless of tumor size. Given the lack of prognostic value, the resection type and extent of LN retrieval should be tailored to each patient's clinical picture and safety profile.

Preoperative Risk Score for Predicting Incomplete Cytoreduction: A 12-Institution Study from the US HIPEC Collaborative

BACKGROUND

For patients with peritoneal carcinomatosis undergoing cytoreductive surgery with heated intraperitoneal chemotherapy (CRS/HIPEC), incomplete cytoreduction (CCR2/3) confers morbidity without survival benefit. The aim of this study is to identify preoperative factors which predict CCR2/3.

METHODS

All patients who underwent curative-intent CRS/HIPEC of low/high-grade appendiceal, colorectal, or peritoneal mesothelioma cancers in the 12-institution US HIPEC Collaborative from 2000 to 2017 were included (n = 2027). The primary aim is to create an incomplete-cytoreduction risk score (ICRS) to predict CCR2/3 CRS utilizing preoperative data. ICRS was created from a randomly selected cohort of 50% of patients (derivation cohort) and verified on the remaining patients (validation cohort).

RESULTS

Within our derivation cohort (n = 998), histology was low-grade appendiceal neoplasms in 30%, high-grade appendiceal tumor in 41%, colorectal tumor in 22%, and peritoneal mesothelioma in 8%. CCR0/1 was achieved in 816 patients and CCR 2/3 in 116 patients. On multivariable analysis, preoperative factors associated with incomplete cytoreduction were male gender [odds ratio (OR) 3.4, p = 0.007], presence of ascites (OR 2.8, p = 0.028), cancer antigen (CA)-125 ≥ 40 U/mL (OR 3.4, p = 0.012), and carcinoembryonic antigen (CEA) ≥ 4.2 ng/mL (OR 3.2, p = 0.029). Each preoperative factor was assigned a score of 0 or 1 to form an ICRS from 0 to 4. Scores were grouped as zero (0), low (1-2), or high (3-4). Incidence of CCR2/3 progressively increased by risk group from 1.6% in zero to 13% in low and 39% in high. When ICRS was applied to the validation cohort (n = 1029), this relationship was maintained.

CONCLUSION

The incomplete cytoreduction risk score incorporates preoperative factors to accurately stratify the risk of CCR2/3 resection in CRS/HIPEC. This score should not be used in isolation, however, to exclude patients from surgery.

The Prognostic Value of Lymphovascular Invasion in Truncal and Extremity Soft Tissue Sarcomas: An Analysis from the National Cancer Database

OBJECTIVE

The aim of this study was to determine the association between lymphovascular invasion (LVI) and overall survival (OS) in truncal/extremity soft tissue sarcomas (STS).

METHODS

The National Cancer Database (NCDB) was queried for all patients, ages 18-85 years, who underwent resection of primary, truncal/extremity STS between 2010 and 2012, and had LVI data. The primary endpoint was OS.

RESULTS

Among 6169 patients identified, the most common histology groups were (1) liposarcoma (LPS, 24%), (2) undifferentiated pleiomorphic sarcoma (UPS, 19%), and (3) leiomyosarcoma (LMS, 15%); 449 patients (7%) were LVI-positive. There were no differences in demographics or comorbidities between the LVI groups. Compared with LVI-negative patients, LVI-positive patients were more likely to have larger (> 5 cm: 80% vs. 66%), deep (80% vs. 68%), and high-grade tumors (82% vs. 57%). They were also more likely to have positive margins (27% vs. 17%), nodal (16% vs. 2%) and metastatic disease (21% vs. 4%), and receive chemotherapy (37% vs. 18%; all p < 0.001). LVI was associated with worse median OS (39 months vs. MNR; p < 0.001), which persisted on stratum-specific analyses for all tumor grades, size categories, and stages I-III, but not stage IV. On multivariable Cox regression, LVI was associated with worse OS (hazard ratio [HR] 1.84, 95% confidence interval [CI] 1.39-2.44), while accounting for other significant prognostic factors. Among non-metastatic, curative-intent resections (n = 5696), LVI was still associated with worse OS (HR 1.79, 95% CI 1.28-2.49).

CONCLUSIONS

LVI appears to be an important adverse pathologic factor in truncal and extremity STS. Even when taking into account other established prognostic factors, LVI was predictive of worse OS. Knowledge of LVI status may help to better risk-stratify patients and guide management strategies, and should be considered in future prognostic classification schemes and nomograms.

Abstract 3621: Targeted hyaluronic acid nanoparticles improve treatment response in pancreatic cancer

Pancreatic cancer has poor response to chemotherapy with desmoplastic stroma identified as a delivery barrier. We have developed a nanoparticle (NP) drug system using an engineered ligand of receptor binding region of urokinase plasminogen activator (ATF) and the catalytic domain of metalloprotease (MMP14) carrying SN38 (CPT-11 analog). Hyaluronic acid (HA), a naturally occurring protein was chosen as the backbone to produce a biocompatible NP. HA can also bind to CD44, highly expressed in epithelial cancers. Dual uPAR, CD44 targeting allows for targeted delivery and facilitates receptor mediated endocytosis of NP-drug complex. MMP14 activity degrades extracellular matrix to deplete the stromal barrier. SN38 was encapsulated and recombinant ATFmmp14 conjugated to surface of self-assembled hyaluronic acid spheres (200nm) to form the complete particle (HANP). Cytotoxicity assays were conducted to determine IC50 in cell lines. Patient derived xenograft (PDX) model of a drug resistant pancreatic cancer was used for efficacy studies. Orthotopically implanted tumors were treated with HANP (10mg/kg SN38 dosage) weekly for 6 weeks via tail vein and overall survival compared to conventional therapy. HANP in-vitro cytotoxicity was greater than conventional Irinotecan (&gt;80x) and liposomal irinotecan (&gt;900x) in a PDX derived cell line (Table 1). In-vivo efficacy study demonstrated a significant improvement in survival of PDX bearing mice with HANP (n=9) (median survival 50 days), compared to FOLFIRINOX (n=9) and Gemcitabine-nab-Paclitaxel (n=9) (median survival 37 days each) and no treatment (n=13) (median survival 22 days). Combination of HANP with a modified-FOLFIRINOX regimen (n=9) led to median survival &gt;72 days (p&lt;0.001). HANP alone or in combination with a modified FOLFIRINOX led to significantly improved survival in a pancreatic cancer PDX model. Further studies are underway to evaluate preclinical PD/PK for eventual translation as targeted therapy for pancreatic cancer.

In-vitro cytoxicity assay for IC50 determinationDrugIC50 (uM)HANP0.01SN-380.012Irinotecan0.8Liposomal Irinotecan9

Citation Format: Mohammad Raheel Jajja, Lei Zhu, Dazhi Wang, Charles A. Staley, Bassel El-Rayes, David A. Kooby, Lily Yang. Targeted hyaluronic acid nanoparticles improve treatment response in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3621.

Optimal Surveillance Frequency After CRS/HIPEC for Appendiceal and Colorectal Neoplasms: A Multi-institutional Analysis of the US HIPEC Collaborative

BACKGROUND

No guidelines exist for surveillance following cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) for appendiceal and colorectal cancer. The primary objective was to define the optimal surveillance frequency after CRS/HIPEC.

METHODS

The U.S. HIPEC Collaborative database (2000-2017) was reviewed for patients who underwent a CCR0/1 CRS/HIPEC for appendiceal or colorectal cancer. Radiologic surveillance frequency was divided into two categories: low-frequency surveillance (LFS) at q6-12mos or high-frequency surveillance (HFS) at q2-4mos. Primary outcome was overall survival (OS).

RESULTS

Among 975 patients, the median age was 55 year, 41% were male: 31% had non-invasive appendiceal (n = 301), 45% invasive appendiceal (n = 435), and 24% colorectal cancer (CRC; n = 239). With a median follow-up time of 25 mos, the median time to recurrence was 12 mos. Despite less surveillance, LFS patients had no decrease in median OS (non-invasive appendiceal: 106 vs. 65 mos, p < 0.01; invasive appendiceal: 120 vs. 73 mos, p = 0.02; colorectal cancer [CRC]: 35 vs. 30 mos, p = 0.8). LFS patients had lower median PCI scores compared with HFS (non-invasive appendiceal: 10 vs. 19; invasive appendiceal: 10 vs. 14; CRC: 8 vs. 11; all p < 0.01). However, on multivariable analysis, accounting for PCI score, LFS was still not associated with decreased OS for any histologic type (non-invasive appendiceal: hazard ratio [HR]: 0.28, p = 0.1; invasive appendiceal: HR: 0.73, p = 0.42; CRC: HR: 1.14, p = 0.59). When estimating annual incident cases of CRS/HIPEC at 375 for non-invasive appendiceal, 375 invasive appendiceal and 4410 colorectal, LFS compared with HFS for the initial two post-operative years would potentially save $13-19 M/year to the U.S. healthcare system.

CONCLUSIONS

Low-frequency surveillance after CRS/HIPEC for appendiceal or colorectal cancer is not associated with decreased survival, and when considering decreased costs, may optimize resource utilization.

Caution: Increased Acute Kidney Injury in Enhanced Recovery after Surgery (ERAS) Protocols

Minimizing perioperative fluid administration is a key component of enhanced recovery after surgery protocols (ERAS). Acute kidney injury (AKI) is a major cause of morbidity and mortality in hospitalized patients. Our aim was to assess the association of ERAS with the incidence and severity of AKI in patients undergoing elective colorectal surgery. In this single-study retrospective review, patients undergoing colorectal surgery from 2013 to 2017 were included. Primary endpoint was postoperative AKI. Secondary outcomes were hospital length of stay (LOS) and 30-day readmission. Baseline demographics and procedure types were similar between both groups. AKI was higher in the ERAS versus non-ERAS group (23 vs 9%; P = 0.002). Factors associated with increased risk of AKI on univariate regression included presence of preoperative cardiovascular risk factors (hazard ratio (HR) 3.5; 95% CI 1.3-9.7; P < 0.01), more complex colorectal operations (HR 5.1; 95% CI 1.6-16.1; P < 0.01), and management with an ERAS pathway (HR 2.9; 95% CI 1.5-5.8; P < 0.01). On multivariable analysis, ERAS remained a significant risk factor for developing AKI (HR 3.44; 95% CI 1.5-7.7; P < 0.01). ERAS patients had a shorter hospital LOS (3.9 vs 5.9 days, P < 00.1) compared with non-ERAS patients, with no difference in 30-day readmission rates (11.5 vs 10.7%; P = 0.98). Although the incidence of AKI is higher in patients treated with ERAS protocols, the majority represent minor elevations in baseline serum creatinine and did not affect the reduction in hospital LOS associated with ERAS. Given the potential association of AKI, however, with increased long-term morbidity and mortality, ERAS protocols should be optimized to prevent postoperative AKI.

The value of a cross-discipline team-based approach for resection of renal cell carcinoma with IVC tumor thrombus: A report of a large, contemporary, single-institution experience

INTRODUCTION

We report the evolution of the largest, contemporary, single-institution experience with this complex procedure to highlight the value of a cross-discipline, team-based approach.

METHODS

Patients from a prospectively maintained database who underwent resection of renal cell carcinoma (RCC) with inferior vena cava (IVC) tumor thrombus from 2005 to 2016 at a single-institution were included for analysis.

RESULTS

Of 140 patients, 102 (73%) had tumor thrombus below the level of the hepatic vein confluence, and 96 (69%) were performed for curative-intent, while 43 (31%) were cytoreductive procedures for clinical trial consideration. Median overall survival (OS) of the entire cohort was 43.8 months (5-year OS:43%), and 73.6 months (5-year OS:59%) for those without metastatic disease. Fifty-one patients underwent resection from 2005 to 2010 and 89 from 2011 to 2016. All procedures since 2011 were performed by the same cross-discipline dedicated team of two surgeons, composed of a surgical and urological oncologist. When comparing the two time-periods, the team-approach after 2011 had shorter operative-times (5.3 vs 6.7 hours; P = 0.009), decreased ICU-utilization (25% vs 72%; P < 0.001), and decreased ICU length-of-stay (0.4 vs 2.2 days; P = 0.001). This group also trended towards less blood loss (1.2 vs 1.8 L), shorter average hospital length-of-stay (10 vs 11 days), and decreased 90-day mortality (6% vs 10%).

CONCLUSION

Resection of RCC with IVC tumor thrombus yields long-term survival. A dedicated, cross-discipline, and team-based approach optimizes patient outcomes and may improve value of care by reducing utilization of expensive hospital resources.