Peritoneal Microenvironment Promotes Appendiceal Adenocarcinoma Growth: A Multi-omics Approach Using Patient-Derived Xenografts

Appendiceal adenocarcinoma (AA) is unique from other gastrointestinal malignancies in that it almost exclusively metastasizes to the peritoneal cavity. However, few studies have investigated the molecular interaction of the peritoneal microenvironment and AA. Here, we use a multi-omics approach with orthotopic and flank-implanted patient-derived xenografts (PDX) to study the effect of the peritoneal microenvironment on AA. AA tumors implanted in the peritoneal microenvironment tended to grow faster and displayed greater nuclear expression of Ki-67 relative to the same tumors implanted in the flank. Comparing the tumor-specific transcriptome (excluding stromal transcription), the peritoneal microenvironment relatively upregulated genes related to proliferation, including MKI67 and EXO1. Peritoneal tumors were also enriched for proliferative gene sets, including E2F and Myc Targets. Proteomic studies found a 2.5-fold increased ratio of active-to-inactive phosphoforms of the YAP oncoprotein in peritoneal tumors, indicating downregulation of Hippo signaling.

IMPLICATIONS

The peritoneal microenvironment promotes growth of appendiceal tumors and expression of proliferative pathways in PDXs.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

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.

Prediction of Early Recurrence Following CRS/HIPEC in Patients With Disseminated Appendiceal Cancer

INTRODUCTION

In patients with disseminated appendiceal cancer (dAC) who underwent cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), characterizing and predicting those who will develop early recurrence could provide a framework for personalizing follow-up. This study aims to: (1) characterize patients with dAC that are at risk for recurrence within 2 y following of CRS ± HIPEC (early recurrence; ER), (2) utilize automated machine learning (AutoML) to predict at-risk patients, and (3) identifying factors that are influential for prediction.

METHODS

A 12-institution cohort of patients with dAC treated with CRS ± HIPEC between 2000 and 2017 was used to train predictive models using H2O.ai's AutoML. Patients with early recurrence (ER) were compared to those who did not have recurrence or presented with recurrence after 2 y (control; C). However, 75% of the data was used for training and 25% for validation, and models were 5-fold cross-validated.

RESULTS

A total of 949 patients were included, with 337 ER patients (35.5%). Patients with ER had higher markers of inflammation, worse disease burden with poor response, and received greater intraoperative fluids/blood products. The highest performing AutoML model was a Stacked Ensemble (area under the curve = 0.78, area under the curve precision recall = 0.66, positive predictive value = 85%, and negative predictive value = 63%). Prediction was influenced by blood markers, operative course, and factors associated with worse disease burden.

CONCLUSIONS

In this multi-institutional cohort of dAC patients that underwent CRS ± HIPEC, AutoML performed well in predicting patients with ER. Variables suggestive of poor tumor biology were the most influential for prediction. Our work provides a framework for identifying patients with ER that might benefit from shorter interval surveillance early after surgery.

The Clinical Significance of CEA, CA19-9, and CA125 in Management of Appendiceal Adenocarcinoma

Importance

Serum tumor markers CEA, CA19-9, & CA125 have been useful in the management of gastrointestinal and gynecological cancers, however there is limited information regarding their utility in patients with appendiceal adenocarcinoma.

Objective

Assessing the association of serum tumor markers (CEA, CA19-9, and CA125) with clinical outcomes, pathologic, and molecular features in patients with appendiceal adenocarcinoma.

Design

This is a retrospective study with results reported in 2023. The median follow-up time was 43 months.

Setting

Single tertiary care comprehensive cancer center.

Participants

Under an approved Institutional Review Board protocol, the Palantir Foundry software system was used to query the MD Anderson internal patient database to identify patients with a diagnosis of appendiceal adenocarcinoma and at least one tumor marker measured at MD Anderson between 2016 and 2023.

Results

A total of 1,338 patients with appendiceal adenocarcinoma were included, with a median age of 56.5 years. The majority of the patients had metastatic disease (80.7%). CEA was elevated in more than half of the patients tested (56%), while CA19-9 and CA125 were elevated in 34% and 27%, respectively. Individually, elevation of CEA, CA19-9, or CA125 were associated with worse 5-year survival; 82% vs 95%, 84% vs 92%, and 69% vs 93% elevated vs normal for CEA, CA19-9, and CA125 respectively (all p<0.0001). Quantitative evaluation of tumor markers increased prognostic ability. Patients with highly elevated (top 10th percentile) CEA, CA19-9 or CA125 had markedly worse survival with 5-year survival rates of 59%, 64%, and 57%, respectively (HR vs. normal : 9.8, 6.0, 7.6, all p<0.0001). Although metastatic tumors had higher levels of all tumor markers, when restricting survival analysis to 1080 patients with metastatic disease elevated CEA, CA19-9 or CA125 were all still associated worse survival (HR vs. normal : 3.4, 1.8, 3.9, p<0.0001 for CEA and CA125, p=0.0019 for CA19-9). Interestingly tumor grade was not associated with CEA or CA19-9 level, while CA-125 was slightly higher in high relative to low-grade tumors (18.3 vs. 15.0, p=0.0009). Multivariable analysis identified an incremental increase in the risk of death with an increase in the number of elevated tumor markers, with a 11-fold increased risk of death in patients with all three tumor markers elevated relative to those with none elevated. Mutation in KRAS and GNAS were associated with significantly higher levels of CEA and CA19-9.

Conclusions

These findings demonstrate the utility of measuring CEA, CA19-9, and CA125 in the management of appendiceal adenocarcinoma. Given their prognostic value, all three biomarkers should be included in the initial workup of patients diagnosed with appendiceal adenocarcinoma.

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

BACKGROUND

The AJCC 8th edition stratifies stage IV disseminated appendiceal cancer (dAC) patients based on grade and pathology. This study was designed to externally validate the staging system and to identify predictors of long-term survival.

METHODS

A 12-institution cohort of dAC patients treated with CRS ± HIPEC was retrospectively analyzed. Overall survival (OS) and recurrence-free survival (RFS) were analyzed by using Kaplan-Meier and log-rank tests. Univariate and multivariate cox-regression was performed to assess factors associated with OS and RFS.

RESULTS

Among 1009 patients, 708 had stage IVA and 301 had stage IVB disease. Median OS (120.4 mo vs. 47.2 mo) and RFS (79.3 mo vs. 19.8 mo) was significantly higher in stage IVA compared with IVB patients (p < 0.0001). RFS was greater among IVA-M1a (acellular mucin only) than IV M1b/G1 (well-differentiated cellular dissemination) patients (NR vs. 64 mo, p = 0.0004). Survival significantly differed between mucinous and nonmucinous tumors (OS 106.1 mo vs. 41.0 mo; RFS 46.7 mo vs. 21.2 mo, p < 0.05), and OS differed between well, moderate, and poorly differentiated (120.4 mo vs. 56.3 mo vs. 32.9 mo, p < 0.05). Both stage and grade were independent predictors of OS and RFS on multivariate analysis. Acellular mucin and mucinous histology were associated with better OS and RFS on univariate analysis only.

CONCLUSIONS

AJCC 8th edition performed well in predicting outcomes in this large cohort of dAC patients treated with CRS ± HIPEC. Separation of stage IVA patients based on the presence of acellular mucin improved prognostication, which may inform treatment and long-term, follow-up strategies.

Efficacy of Systemic Chemotherapy in Patients With Low-grade Mucinous Appendiceal Adenocarcinoma: A Randomized Crossover Trial

Importance

Appendiceal adenocarcinoma is a rare tumor, and given the inherent difficulties in performing prospective trials in such a rare disease, there are currently minimal high-quality data to guide treatment decisions, highlighting the need for more preclinical and clinical investigation for this disease.

Objective

To prospectively evaluate the effectiveness of fluoropyrimidine-based systemic chemotherapy in patients with inoperable low-grade mucinous appendiceal adenocarcinoma.

Design, Setting, and Participants

This open-label randomized crossover trial recruited patients at a single tertiary care comprehensive cancer center from September 2013 to January 2021. The data collection cutoff was May 2022. Enrollment of up to 30 patients was planned. Eligible patients had histological evidence of a metastatic low-grade mucinous appendiceal adenocarcinoma, with radiographic imaging demonstrating the presence of mucinous peritoneal carcinomatosis and were not considered candidates for complete cytoreductive surgery. Key exclusion criteria were concurrent or recent investigational therapy, evidence of bowel obstruction, and use of total parenteral nutrition. Data were analyzed from November 2021 to May 2022.

Interventions

Patients were randomized to either 6 months observation followed by 6 months of chemotherapy, or initial chemotherapy followed by observation.

Main Outcomes and Measures

The primary end point was the percentage difference in tumor growth in treatment and observation groups. Key secondary end points included patient-reported outcomes in the chemotherapy and observation periods, objective response rate, rate of bowel complications, and differences in overall survival (OS).

Results

A total of 24 patients were enrolled, with median (range) age of 63 (38 to 82) years, and equal proportion of men and women (eg, 12 men [50%]); all patients had ECOG performance status of 0 or 1. A total of 11 patients were randomized to receive chemotherapy first, and 13 patients were randomized to receive observation first. Most patients (15 patients [63%]) were treated with either fluorouracil or capecitabine as single agent; 3 patients (13%) received doublet chemotherapy (leucovorin calcium [folinic acid], fluorouracil, and oxaliplatin or folinic acid, fluorouracil, and irinotecan hydrochloride), and bevacizumab was added to cytotoxic chemotherapy for 5 patients (21%). Fifteen patients were available to evaluate the primary end point of difference in tumor growth during treatment and observation periods. Tumor growth while receiving chemotherapy increased 8.4% (95% CI, 1.5% to 15.3%) from baseline but was not significantly different than tumor growth during observation (4.0%; 95% CI, -0.1% to 8.0%; P = .26). Of 18 patients who received any chemotherapy, none had an objective response (14 patients [77.8%] had stable disease; 4 patients [22.2%] had progressive disease). Median (range) OS was 53.2 (8.1 to 95.5) months, and there was no significant difference in OS between the observation-first group (76.0 [8.6 to 95.5] months) and the treatment-first group (53.2 [8.1 to 64.1] months; hazard ratio, 0.64; 95% CI, 0.16-2.55; P = .48). Patient-reported quality-of-life metrics identified that during treatment, patients experienced significantly worse fatigue (mean [SD] score, 18.5 [18.6] vs 28.9 [21.3]; P = .02), peripheral neuropathy (mean [SD] score, 6.67 [12.28] vs 38.89 [34.88]; P = .01), and financial difficulty (mean [SD] score, 8.9 [15.2] vs 28.9 [33.0]; P = .001) compared with during observation.

Conclusions and Relevance

In this prospective randomized crossover trial of systemic chemotherapy in patients with low-grade mucinous appendiceal adenocarcinoma, patients did not derive clinical benefit from fluorouracil-based chemotherapy, given there were no objective responses, no difference in OS when treatment was delayed 6 months, and no difference in the rate of tumor growth while receiving chemotherapy.

Trial Registration

ClinicalTrials.gov Identifier: NCT01946854.

Influence of insurance status on the postoperative outcomes of cytoreductive surgery and HIPEC

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is increasingly performed for peritoneal surface malignancies but remains associated with significant morbidity. Scant research is available regarding the impact of insurance status on postoperative outcomes.

METHODS

Patients undergoing CRS/HIPEC between 2000 and 2017 at 12 participating sites in the US HIPEC Collaborative were identified. Univariate and multivariate analyses were used to compare the baseline characteristics, operative variables, and postoperative outcomes of patients with government, private, or no insurance.

RESULTS

Among 2268 patients, 699 (30.8%) had government insurance, 1453 (64.0%) had private, and 116 (5.1%) were uninsured. Patients with government insurance were older, more likely to be non-white, and comorbid (p < 0.05). Patients with government (OR: 2.25, CI: 1.50-3.36, p < 0.001) and private (OR: 1.69, CI: 1.15-2.49, p = 0.008) insurance had an increased risk of complications on univariate analysis. There was no independent relationship on multivariate analysis. An American Society of Anesthesiologists score of 3 or 4, peritoneal carcinomatosis index score >15, completeness of cytoreduction score >1, and nonhome discharge were factors independently associated with a postoperative complication.

CONCLUSION

While there were differences in postoperative outcomes between the three insurance groups on univariate analysis, there was no independent association between insurance status and postoperative complications after CRS/HIPEC.

Conditional Survival Following Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Surface Malignancies: An Analysis from the US HIPEC Collaborative

INTRODUCTION

The long-term prognosis of patients who undergo cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal surface malignancies (PSM) varies considerably on the basis of histological and operative factors. While overall survival (OS) estimates are used to inform adjuvant therapy and surveillance strategies, conditional survival may provide more clinically relevant estimates of prognosis by accounting for disease-free time elapsed.

PATIENTS AND METHODS

All patients from 12 academic institutions who underwent CRS ± HIPEC for PSM from 2000 to 2017 were retrospectively analyzed. OS and disease-free survival (DFS) rates were calculated using the Kaplan-Meier method while conditional overall (COS) and conditional disease-free survival (CDFS) rates were calculated at 1, 2, or 3 years from surgery for different tumor histologies.

RESULTS

Overall, 1610 patients underwent CRS ± HIPEC. Among patients with benign appendiceal mucinous tumors (N = 460), 5-year OS and COS at 3 years were 92.1% and 96.3% (Δ4.2%), respectively. For patients with well-differentiated appendiceal cancers (N = 400), 5-year OS and COS at 3 years were 76.3% and 88.3% (Δ12.0%), respectively. For patients with high-grade appendiceal cancers (N = 258), 5-year OS and COS at 3 years were 43.8% and 75.4% (Δ31.6%), respectively. For patients with colorectal cancers (N = 362), 5-year OS and COS at 3 years were 31.8% and 67.3% (Δ35.5%), respectively. For patients with peritoneal mesothelioma (N = 130), 5-year OS and COS at 3 years were 67.6% and 89.7% (Δ22.1%), respectively. Similar trends were observed for DFS/CDFS.

CONCLUSION

The conditional survival of patients undergoing CRS ± HIPEC for PSM is associated with tumor histology. COS and CDFS provide a more accurate, dynamic estimate of survival than OS and DFS, especially for patients with more aggressive histologies.

Temperature management during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

In addition to attaining complete or near complete cytoreduction, the instillation of select heated chemotherapeutic agents into the abdominal cavity has offered a chance for cure or longer survival inpatients with peritoneal surface malignancies. While the heating of chemotherapeutic agents enhances cytotoxicity, the resulting systemic hyperthermia has been associated with an increased risk of severe hyperthermia and its associated complications. Factors that have been associated with an increased risk of severe hyperthermia include intraoperative blood transfusions and longer perfusion duration. However, the development of severe hyperthermia still remains largely unpredictable. Thus, at several institutions, cooling protocols are employed during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Cooling protocols for CRS-HIPEC are not standardized and may be associated with episodes of severe hyperthermia or alternatively hypothermia. In theory, excessive cooling could result in a decreased effectiveness of the intraperitoneal chemotherapeutic agents. This presumption has been supported by a recent study of 214 adults undergoing CRS-HIPEC, where failure to attain a temperature of 38° C at the end of chemo-perfusion was associated with worse survival. Although not statistically significant, failure to maintain a temperature of 38° C for at least 30 minutes was associated with worse survival. Although studies are limited in this regard, the importance of maintaining a steady state of temperature during the hyperthermic phase of intraperitoneal chemotherapy administration cannot be disregarded. The following article describes the processes and physiological mechanisms responsible for hyperthermia during CRS-HIPEC. The challenges associated with temperature management during CRS-HIPEC and methods to avoid severe hypothermia and hyperthermia are also described.

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.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Is CRS-HIPEC Still Indicated in Patients With Extraperitoneal Disease?

INTRODUCTION

The role of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with extraperitoneal disease (EPD) is controversial.

METHODS

Among patients with peritoneal metastases from appendiceal cancer (AC) and colorectal cancer (CRC) who underwent CRS-HIPEC, those with EPD (liver, lung, or retroperitoneal lymph nodes [RP LN]) were retrospectively compared to those without EPD. Overall (OS) and recurrence-free survival (RFS) analyses were performed before/after propensity score matching (PSM).

RESULTS

Among 1341 patients with AC (64%) or CRC (36%) who underwent CRS ± HIPEC, 134 (10%) had EPD whereas 1207 (90%) did not. EPD was located in the lungs (47%), RP LN (28%), liver (18%), or multiple (6%). Patients with EPD experienced worse median OS (34 versus 63 mo; P = 0.002) and RFS (12 versus 19 mo; P < 0.001). On a multivariable analysis, EPD was associated with worse RFS (P = 0.003), but not OS (P = 0.071). After PSM, the association of EPD with OS (P = 0.204) and RFS (P = 0.056) was no longer significant. In the multivariable analysis of the PSM cohort, EPD was not associated with OS (P = 0.157) or RFS (P = 0.110).

CONCLUSIONS

The findings of this large retrospective multi-institutional study suggest that EPD alone, while a negative prognostic indicator, should not be considered an absolute contraindication to CRS ± HIPEC for otherwise well-selected patients with peritoneal surface malignancies. Further research is needed to delineate whether location of EPD influences OS and RFS following CRS-HIPEC.

Prognostic Significance of Preoperative Tumor Markers in Pseudomyxoma Peritonei from Low-Grade Appendiceal Mucinous Neoplasm: a Study from the US HIPEC Collaborative

BACKGROUND

Tumor markers are commonly utilized in the diagnostic evaluation, treatment decision making, and surveillance of appendiceal tumors. In this study, we aimed to determine the prognostic significance of elevated preoperative tumor markers in patients with pseudomyxoma peritonei secondary to low-grade appendiceal mucinous neoplasm who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

METHODS

Using a multi-institutional database, eligible patients with measured preoperative tumor markers [carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9), or cancer antigen 125 (CA-125)] were identified. Univariate and multivariate Cox-proportional hazards regression analysis assessed relationships between normal and elevated serum tumor markers with progression-free and overall survival in the context of multiple clinicopathologic variables.

RESULTS

zTwo hundred and sixty-four patients met criteria. CEA was the most commonly measured tumor marker (97%). Patients who had any elevated tumor marker had a higher peritoneal carcinomatosis index (PCI) as compared to those with normal range markers. Elevated CEA and CA 19-9 levels were individually associated with longer inpatient length of stay, requirement for intraoperative transfusion, and incomplete cytoreduction. Utilization of neoadjuvant chemotherapy, increased PCI score, elevated CA 19-9 (p = 0.007), and CA-125 levels (p = 0.01) were predictive of decreased progression-free survival on univariate analysis. However, in a multivariate model, only elevated PCI was a statistically significant predictor of progression-free survival.

CONCLUSION

Elevated preoperative tumor markers indicate a higher burden of disease but are not independently associated with survival in this retrospective multi-institutional cohort. Further prospective studies are needed to clarify the utility of these markers in this patient population.

Risk of Intraoperative Hyperthermia and Outcomes in Adults Undergoing Cytoreductive Surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is commonly used to treat peritoneal surface malignancies. We aimed to identify risk factors of intraoperative patient hyperthermia and the postoperative outcome of adults undergoing HIPEC PATIENTS AND METHODS: A retrospective, IRB approved, single center cohort study was conducted. Adults treated with cytoreductive surgery and HIPEC between 2006 and 2021 were included. The primary outcome was bladder hyperthermia during perfusion, stratified by severity and duration. Secondary outcomes were postoperative complications and recurrence-free (RFS) and overall (OS) survival. Multivariable logistic regression models were fit to estimate the effects of important covariates.

RESULTS

Out of 214 patients, 114 had mild hyperthermia (≥ 38 °C) at any time, and in 73 of these it lasted for ≥ 30 min. Independent prognostic factors of mild hyperthermia ≥ 30 min were age (OR = 0.958, 95% CI 0.933-0.984), body mas index (BMI; OR = 0.959 95% CI 0.917-1.002), gender (OR = 0.199, 95% CI 0.092-0.431), and type of chemotherapy [cisplatin versus mitomycin (OR = 0.186, 95% CI 0.070-0.491; oxaliplatin versus mitomycin (OR = 0.430, 95% CI 0.163-1.139)]. Prognostic factors of moderate-to-severe hyperthermia (≥ 39 °C) at any time were perfusion duration (OR = 1.094, 95% CI 1.018-1.177) and blood transfusion (OR = 5.689, 95% CI 1.784-18.137). Intraoperative hyperthermia was not associated with increased postoperative complications but was associated with better RFS and OS.

CONCLUSIONS

Our study demonstrates age, gender, BMI, and chemotherapy type to be associated with hyperthermia ≥ 38 °C for ≥ 30 min, whereas longer perfusion time and blood transfusion were associated with hyperthermia ≥ 39 °C. Mild hyperthermia at the end of perfusion is associated with better RFS and OS.

Impact of Ketamine on Opioid Use and Persistent Pain After Cytoreductive Surgery with Hyperthermic Chemotherapy

Background

Persistent pain and opioid use can be devastating after cytoreductive surgery (CRS) and hyperthermic intraoperative chemotherapy (HIPEC).

Methods

We conducted a retrospective study to investigate the impact of ketamine use on postoperative complications and persistent and chronic pain after CRS-HIPEC.

Results

Ketamine reduced perioperative opioid use before and after implementation of recovery after surgery programs. Ketamine did not impact the formation of persistent and chronic pain formation and long-term opioid use. Postoperative complications and postoperative re-operations were independent predictors of persistent pain. Interestingly, the risk of having a complication was increased by 1% for every doubling in opioids used intraoperatively.

Conclusion

Ketamine use reduces perioperative opioid consumption in patients undergoing CRS-HIPEC, but it is not associated with improvements in long-term opioid use and chronic pain.

Clinical Efficacy of Immune Checkpoint Inhibitors in Patients With Advanced Malignant Peritoneal Mesothelioma

This cohort study examines the clinical efficacy of immune checkpoint inhibitors (ICIs) in patients with advanced malignant peritoneal mesothelioma.

Comprehensive genomic profiling of malignant peritoneal mesothelioma (MPeM) reveals key genomic alterations (GAs) distinct from malignant pleural mesothelioma (MPM)

8557

Background: MPeM is a rare and aggressive cancer with very limited treatment options. Lack of dedicated research has impeded improvements in outcomes. Defining prevalent GAs is a critical unmet need for use of targeted therapies in these patients. Although MPeM is notably distinct from MPM vis-à-vis epidemiologic and clinical attributes, the genomic underpinings of these differences have yet to be established. We aimed at describing a comprehensive genomic profile (CGP) of MPeM in comparison to MPM. Methods: We performed a retrospective comparative analysis between 89 patients with MPeM and 241 patients with MPM (N = 330) who underwent CGP using CLIA certified next-generation sequencing assays. The cohort was generated using mesothelioma patients at MD Anderson Cancer Center (N = 223) and supplemented by additional mesothelioma patients (N = 107) from a publicly available database from Memorial Sloan Kettering Cancer Center, the MSK-IMPACT database. Essential clinicopathological variables were collected. Descriptive statistics, Fisher’s exact and Mann-Whitney tests were used for comparison. Kaplan-meier method and log rank tests were used for overall survival (OS) estimates. Results: MPeM cohort (vs. MPM) had more women (54% vs. 31%, P < 0.001) and younger age at diagnosis (56 vs. 69 years, P < 0.001). Histology was epithelioid, biphasic and sarcomatoid in 86%, 7% and 7% cases, a distribution similar to MPM cohort. At least 1 GA was found in 64 (72% vs. 82% in MPM, P = 0.044) of MPeM patients with a median of 1 (range 1 – 12) (vs. a median of 2, range 1 – 24, P < 0.001) GA per patient. A significantly lower proportion of MPeM patients had ≥ 3 mutations (14% vs. 26%, OR 2.1, P = 0.028) per patient. The most frequent mutations were present in the following genes: TP53 (24%), BAP1 (16%), NF2 (15%), MET (9%) and TRAF7, KIT and PIK3CA (each 6%). MPeM patients harbored more mutations in MET (9% vs. < 1%, P < 0.001) and TRAF7 (6% vs. < 1%, P = 0.02) but fewer mutations in BAP1 (16% vs. 32%, P = 0.003) and CDKN2B (0% vs. 5%, P = 0.041). The most common copy number variations (CNVs: amplifications or deletions) were seen in BAP1, MCL1, SETD2, WT1 (each 2%) and AURKA (1%) genes. Among genes with CNVs, MPeM had a lower rate of deletions in CDKN2A (1% vs. 6%, P = 0.040). Among more common GAs, only BAP1 mutations appeared to be associated with poor OS (45.7 vs. 127.1 months, HR 2.5, 95%CI: 0.6 – 10.1, P = 0.050) in patients with MPeM. Conclusions: In this large cohort with CGP, we identified potential molecular drivers in MPeM and demonstrated key genomic differences between MPeM and MPM. MPeM is frequently driven by GAs involved in cell cycle control, a potentially targetable pathway. Despite this insight from CGP, a large subset of patients do not have actionable GAs and for these patients, further collaborative trans-“omic” research efforts are needed to advance potential therapeutic options.

Metastatic small bowel adenocarcinoma: role of metastasectomy and systemic chemotherapy

Background

Metastatic small bowel adenocarcinoma (SBA) has a poor prognosis. Due to its rarity, high-quality data are lacking to guide treatment. This retrospective analysis was conducted to help characterize the treatment options for patients with metastatic SBA while providing clinically meaningful prognostic information.

Patients and methods

In total, 437 patients who initially presented with or developed metastatic SBA between September 1977 and September 2019 were identified from the MD Anderson Tumor Registry. Clinical data were collected from review of the medical record. Overall response rates (ORR), time to progression (TTP), and overall survival (OS) were assessed across various treatments and treatment lines.

Results

The median OS from diagnosis of metastatic disease was 15.9 months [95% confidence interval (CI): 14.3-17.9]. Seventy-five patients (17.1%) underwent metastasectomy, which was associated with a median OS of 34.5 versus 17.1 months among patients who received chemotherapy alone (P < 0.001). Fluoropyrimidine plus platinum (n = 164) was the most common first-line chemotherapy, associated with an ORR of 59% and TTP of 8.1 months. Irinotecan with 5-FU (n = 101) was the most common second-line therapy associated with an ORR of 31% and TTP of 4.0 months. Twenty-two patients received immunotherapy; 5 of 6 patients with deficient mismatch repair (dMMR) responded, while 0 of 16 with proficient mismatch repair (pMMR) responded. Taxane-based chemotherapy was given to 34 patients with an ORR of 21% and a median TTP of 2.4 months. Among 11 patients who received anti-epidermal-growth-factor-receptor (EGFR) monotherapy, the best response was stable disease (SD) in 1 patient.

Conclusions

In well-selected patients with SBA, metastasectomy appears to be associated with improved OS. This improvement was seen across metastasectomy sites, including liver, lung and peritoneal. Anti-programmed cell death protein 1 (PD-1) based immunotherapy was active for dMMR SBA but not pMMR SBA. While taxane-based chemotherapy demonstrates therapeutic activity, the activity of anti-EGFR therapy was limited.

•

Metastasectomy for well-selected metastatic SBA patients was associated with improved OS.

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Anti-PD1-based immunotherapy was active for dMMR SBA but not pMMR SBA.

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Taxane-based chemotherapy demonstrated clinical activity in refractory SBA.

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Anti-EGFR therapy demonstrated minimal activity in SBA.

The Impact of Thoracic Epidural Analgesia Versus Four Quadrant Transversus Abdominis Plane Block on Quality of Recovery After Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy Surgery: A Single-Center, Noninferiority, Randomized, Controlled Trial

BACKGROUND

Recovery after CRS-HIPEC influenced by several factors, including pain and opioid consumption. We hypothesized that 4Q-TAP blocks provide not inferior quality of recovery compared with TEA after CRS-HIPEC. We conducted a randomized, controlled trial to determine whether 4-quadrant transversus abdominis plane (4Q-TAP) block analgesia was noninferior to thoracic epidural (TEA) among patients who underwent cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS HIPEC).

METHODS

Patients 18 years or older who underwent a CRS-HIPEC surgery were randomly assigned to have either TEA or 4Q-TAP blocks. The primary outcome of this study was the change in quality of recovery 2 days after surgery. Secondary outcomes included quality of recovery on Days 1, 3, 5, 7, 10, and 30 postoperatively, opioid consumption, pain intensity, length of stay, and postoperative complications. Analyses were performed on a per-protocol basis.

RESULTS

Sixty-eight patients were included in the analysis. The difference between 4Q-TAP and TEA in the mean QoR-15 change from surgery at postoperative Days 1, 2, and 3 was 0.80 (P = 0.004), -4.5 (P = 0.134), and 3.4 (P = 0.003), respectively. All differences through postoperative day 30 were significantly within the noninferiority boundary of -10 except at postoperative Day 2 (P = 0.134). Length of stay, opioid-related adverse events, and frequency and grade of complications were not significantly different between TEA and 4Q-TAP patients.

CONCLUSIONS

Despite the significantly higher use of opioids after CRS-HIPEC in patients with 4Q-TAP blocks, their short-term quality of recovery was not inferior to those treated with TEA. Patients undergoing CRS-HIPEC can be effectively managed with 4Q-TAP blocks.

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.

The impact of HIPEC vs. EPIC for the treatment of mucinous appendiceal carcinoma: a study from the US HIPEC collaborative

INTRODUCTION

Mucinous appendiceal carcinoma is a rare malignancy that commonly spreads to the peritoneum leading to peritoneal metastases. Complete cytoreduction with perioperative intraperitoneal chemotherapy (PIC) is the mainstay of treatment, administered as either hyperthermic intra peritoneal chemotherapy (HIPEC) or early post-operative intraperitoneal chemotherapy (EPIC). Our goal was to assess the perioperative and long term survival outcomes associated with these two PIC methods.

MATERIALS AND METHODS

Patients with mucinous appendiceal carcinoma were identified in the US HIPEC Collaborative database from 12 academic institutions. Patient demographics, clinical characteristics, and survival outcomes were compared among patients who underwent HIPEC vs. EPIC with inverse probability weighting (IPW) used for adjustment.

RESULTS

Among 921 patients with mucinous appendiceal carcinoma, 9% underwent EPIC while 91% underwent HIPEC. There was no difference in Grade III-V complications between the two groups (18.5% for HIPEC vs. 15.0% for EPIC, p=.43) though patients who underwent HIPEC had higher rates of readmissions (21.2% vs. 8.8%, p<.01). Additionally, PIC method was not an independent predictor for overall survival (OS) or recurrence-free survival (RFS) after adjustment on multivariable analysis.

CONCLUSIONS

Among patients with mucinous appendiceal carcinoma, both EPIC and HIPEC appear to be associated with similar perioperative and long-term outcomes.

Integrated clinico-molecular profiling of appendiceal adenocarcinoma reveals a unique grade-driven entity distinct from colorectal cancer

BACKGROUND

Appendiceal adenocarcinoma (AA) is an orphan disease with unique clinical attributes but often treated as colorectal cancer (CRC). Understanding key molecular differences between AA and CRC is critical.

METHODS

We performed retrospective analyses of AA patients (N = 266) with tumour and/or blood next-generation sequencing (NGS) (2013-2018) with in-depth clinicopathological annotation. Overall survival (OS) was examined. For comparison, CRC cohorts annotated for sidedness, consensus molecular subtypes (CMS) and mutations (N = 3283) were used.

RESULTS

Blood-NGS identified less RAS/GNAS mutations compared to tissue-NGS (4.2% vs. 60.9%, P < 0.0001) and showed poor concordance with tissue for well-/moderately differentiated tumours. RAS (56.2%), GNAS (28.1%) and TP53 (26.9%) were most frequent mutations. Well/moderately differentiated tumours harboured more RAS (69.2%/64.0% vs. 40.5%) and GNAS (48.7%/32.0% vs. 10.1%) while moderate/poorly differentiated tumours had more TP53 (26.0%/27.8% vs. 7.7%) mutations. Appendiceal adenocarcinoma (compared to CRC) harboured significantly fewer APC (9.1% vs. 55.4%) and TP53 (26.9% vs. 67.5%) and more GNAS mutations (28.1% vs. 2.0%) (P < 0.0001). Appendiceal adenocarcinoma mutation profile did not resemble either right-sided CRC or any of the four CMS in CRC. High grade, but no mutation, was independently predictive of survival.

CONCLUSION

Integrated clinico-molecular profiling of AA identified key molecular drivers distinct from CRC. Appendiceal adenocarcinoma has a predominantly grade-driven biology that trumps mutations.

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.

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.

Abstract A07: Transcriptional profiling confirms appendiceal adenocarcinoma is distinct from colorectal cancer, in vivo models needed

Background: Despite mounting data revealing that appendiceal neoplasms are quite distinct from colorectal cancers (CRC), these rare tumors are most often treated with chemotherapy designed for CRC. The rarity of appendiceal neoplasms has made it difficult to conduct prospective or randomized clinical trials to guide therapy for these tumors; this issue is confounded by the fact that much heterogeneity exists between multiple histopathologic subtypes, including noninvasive mucinous neoplasms, mucinous and nonmucinous adenocarcinomas, carcinoids, goblet cell carcinoids, and signet ring cell carcinomas, as well as between high- and low-grade tumors. Recent large-scale genomic profiling efforts have identified frequent activating mutations in GNAS, a G-protein-coupled receptor (52% of mucinous adenocarcinomas, 72% of pseudomyxoma peritoneii (PMP), with a strong enrichment in low-grade tumors (χ2 p &lt; 0.0001). Currently available preclinical models of appendiceal tumor are very rare, and to the best of our knowledge models of low-grade, GNAS mutant appendiceal adenocarcinoma are nonexistent. Given that there is no effective systemic treatment for these low-grade tumors, here we try to address this need by generating in vivo and in vitro models of appendiceal cancer and coupling them with transcriptomic analyses to identify potential therapeutic targets in this molecularly distinct tumor type.

Methods: After prospectively obtaining informed consent, tumors from surgical resection of 13 patients with appendiceal adenocarcinoma were molecularly profiled with RNAseq and full-exome DNAseq. The histology and grade of these tumor was confirmed by expert pathology review and consisted of a mix of well (n = 4), moderate (n = 4), and poorly (n = 5) differentiated tumors. For the generation of in vivo models, fresh tumors were harvested and 0.5 cm3 tumor blocks were mixed with Matrigel and planted directly into the peritoneal cavity of nude mice by means of a 1-cm transverse abdominal incision performed under aseptic conditions.

Results: Unsupervised clustering of the transcriptomic profiles of the 13 appendiceal tumors revealed that tumors of similar grade clustered together. This was as expected given that histologic grade has been shown to be the most critical prognostic feature for appendiceal adenocarcinomas. When clustered with colorectal tumors from TCGA, the appendiceal tumors demonstrated much greater similarity to each other than the colorectal tumors, consistent with previous reports of significant differences in the somatic mutation profiles of appendiceal and colorectal tumors.

Conclusions: Appendiceal adenocarcinoma is a distinct disease from colorectal adenocarcinoma. High- and low-grade appendiceal tumors display marked differences in genomic and transcriptomic profiles; the creation of additional preclinical models of each will be critical for the development of appendix cancer-specific therapy.

Citation Format: John Paul Shen, Saikat Chowdhury, Ji Wu, Keith Fournier, Scott Kopetz, Kanwal Raghav. Transcriptional profiling confirms appendiceal adenocarcinoma is distinct from colorectal cancer, in vivo models needed [abstract]. In: Proceedings of the AACR Special Conference on the Evolving Landscape of Cancer Modeling; 2020 Mar 2-5; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2020;80(11 Suppl):Abstract nr A07.

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.

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.

Readmissions After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: a US HIPEC Collaborative Study

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) results in significant morbidity and readmissions. Previous studies have been limited by single-institution design or lack of tumor details in the database used.

METHODS

The 12-institution US HIPEC Collaborative Database was queried between 1999 and 2017. Preoperative and intraoperative patient and tumor details were analyzed for associations with readmissions.

RESULTS

A total of 2017 of 2372 cases were included in the analysis. The 30-day readmission rate was 15.9% (n = 321). Common indications for readmission included failure to thrive (29.9%), infection (23.6%), and ileus/bowel obstruction (15.1%). The readmitted cohort had more complications, including intra-abdominal abscess (21.2% vs 6.2%), ileus (28.0% vs 17.2%), anastomotic leak (11.2% vs 2.2%), enteric fistula (5.6% vs 1.5%), deep venous thrombosis (6.2% vs 2.5%), and pulmonary embolism (6.9% vs 2.5%). Factors independently associated with readmission (p < 0.05) included ECOG score ≥ 3 (OR 3.4), depression (OR 2.4), total parenteral nutrition (OR 3.6), low anterior resection or partial colectomy (OR 2.0), and stoma creation (OR 2.2). Factors not associated included neoadjuvant chemotherapy, peritoneal cancer index, and completeness of cytoreduction. Readmission rate between 31 and 90 days was 3.9% (n = 78). Independent predictors (p < 0.05) included operative time (OR 1.1), low anterior resection or partial colectomy (OR 1.7), and stoma creation (OR 2.2).

CONCLUSIONS

In the largest study to date examining readmissions after CRS-HIPEC, 30-day readmission rate was 15.9%. Tumor factors failed to predict readmission, whereas preoperative functional status and depression along with individual cytoreductive procedures predicted readmission. Patients with these risk factors or postoperative complications may benefit from closer post-discharge monitoring.

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.

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.

Primary Tumor Sidedness is Predictive of Survival in Colon Cancer Patients Treated with Cytoreductive Surgery With or Without Hyperthermic Intraperitoneal Chemotherapy: A US HIPEC Collaborative Study

INTRODUCTION

The clinical relevance of primary tumor sidedness is not fully understood in colon cancer patients with peritoneal metastasis treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

This was a retrospective cohort study of a multi-institutional database of patients with peritoneal surface malignancy at 12 participating high-volume academic centers from the US HIPEC Collaborative.

RESULTS

Overall, 336 patients with colon primary tumors who underwent curative-intent CRS with or without HIPEC were identified; 179 (53.3%) patients had right-sided primary tumors and 157 (46.7%) had left-sided primary tumors. Patients with right-sided tumors were more likely to be older, male, have higher Peritoneal Cancer Index (PCI), and have a perforated primary tumor, but were less likely to have extraperitoneal disease. Patients with complete cytoreduction (CC-0/1) had a median disease-free survival (DFS) of 11.5 months (95% confidence interval [CI] 7.6-15.3) versus 13.1 months (95% CI 9.5-16.8) [p = 0.158] and median overall survival (OS) of 30 months (95% CI 23.5-36.6) versus 45.4 months (95% CI 35.9-54.8) [p = 0.028] for right- and left-sided tumors; respectively. Multivariate analysis revealed that right-sided primary tumor was an independent predictor of worse DFS (hazard ratio [HR] 1.75, 95% CI 1.19-2.56; p =0.004) and OS (HR 1.72, 95% CI 1.09-2.73; p = 0.020).

CONCLUSION

Right-sided primary tumor was an independent predictor of worse DFS and OS. Relevant clinicopathologic criteria, such as tumor sidedness and PCI, should be considered in patient selection for CRS with or without HIPEC, and guide stratification for clinical trials.

Central Lymph Node Metastasis in Gastric Cancer Is Predictive of Survival After Preoperative Therapy

BACKGROUND

It is unclear how preoperative therapy for gastric cancer affects the metastasis rate of lymph nodes (LNs) and whether the location of positive LNs affects survival after preoperative therapy. Therefore, we determined the association between positive central lymph nodes (CnLNs) and disease stage and overall survival (OS).

METHODS

We reviewed a prospectively maintained database to identify patients who had undergone resection of gastric adenocarcinoma at our institution from 2005 to 2015. CnLNs were defined as common hepatic, celiac, and proximal splenic artery LNs (stations no. 8, 9, and 11p). The frequency of CnLN metastases and risk factors affecting OS were examined.

RESULTS

We identified 356 patients. Preoperative therapy was administered to 66% of patients. D2 LN dissection was performed in 80% of patients, and the median number of LNs examined was 25 (IQR, 18-34). In 243 patients (68%), CnLNs had undergone separate pathologic examination; the CnLN-positive rate was 9.1% (22 of 243; station no. 8, 4.5%; no. 9, 2.1%; and no. 11p, 4.8%). CnLN metastasis was associated with shorter 3-year OS in patients with pN2/3 disease (33 vs. 62%; p = 0.004). Among patients who had undergone preoperative therapy, ypT3-4 stage (HR 2.44; p = 0.01) and positive CnLNs (HR 5.44; p < 0.001) were negatively associated with OS by multivariate analysis.

CONCLUSIONS

CnLN metastases are uncommon in gastric cancer and have an adverse effect on OS in patients who have undergone preoperative therapy. Larger multi-institutional studies are needed to determine whether CnLN positivity requires a separate staging category after preoperative therapy.

Preoperative Therapy for Gastric Adenocarcinoma is Protective for Poor Oncologic Outcomes in Patients with Complications After Gastrectomy

BACKGROUND

Postoperative complications (POC) are associated with poor oncologic outcomes in gastric cancer. We sought to evaluate the impact of POC on survival in patients with gastric cancer treated with upfront surgery (UpSurg) versus those treated with preoperative therapy (PreT).

METHODS

We analyzed data from a prospectively maintained database of patients who had undergone resection of their gastric cancer at our institution. Patients with T1N0 or M1 lesions, recurrent disease, and mortality within 90 days were excluded. Survival was compared between patients with and without POC in the UpSurg and PreT groups. Cox regression analyses were used to examine factors associated with overall survival (OS) and disease-free survival (DFS).

RESULTS

A total of 421 patients underwent resection of gastric cancer: 30% underwent upfront surgery, and 51% had a POC. Among patients who had POCs, 71% were infectious and 53% were Clavien-Dindo grade III or IV. UpSurg patients with a POC had shorter OS (5-year, 47 vs. 85%; p < 0.001) and DFS (5-year, 46 vs. 76%; p < 0.001) than those without a POC. In contrast, there was no difference in OS (5-year, 57 vs. 63%; p = 0.77) and DFS (5-year, 52 vs. 52%; p = 0.52) between PreT patients with and without POC. Multivariable Cox regression model demonstrated that a POC in UpSurg patients had significant impact on DFS (2.6 [95% confidence interval (CI) 1.48-4.74]), whereas it did not in PreT patients (0.9 [95% CI 0.70-1.33]).

CONCLUSIONS

The use of preoperative therapy negated the impact of POCs on OS and DFS in patients undergoing resection for gastric cancer.

Repeat staging laparoscopy for gastric cancer after preoperative therapy

BACKGROUND AND OBJECTIVES

Staging laparoscopy is recommended before preoperative therapy in patients with locoregional gastric cancer, but yield of repeated diagnostic laparoscopy at the time of resection is unknown.

METHODS

Retrospective review of a prospective database of patients with gastric adenocarcinoma (1994-2016) who had negative staging laparoscopy followed by preoperative therapy and subsequent attempted resection. Primary outcome was positive exploration (peritoneal or unresectable disease) at the time of resection. Multivariable logistic regression identified factors associated with positive exploration.

RESULTS

Of the 451 patients with attempted resection, 54 (12.0%) had positive explorations, including 48 with peritoneal disease. Patients with positive explorations were more likely to be female and have poorly differentiated tumors, linitis features, and signet-ring morphology. There was no significant difference by exploration results in age, race, clinical stage, or delayed definitive surgery. Positive explorations were independently associated with poor differentiation (OR 4.6, 95%CI 1.4-15.3; P = 0.01) and linitis (OR 4.2, 95%CI 1.9-9.2; P < 0.001). Positive explorations were seen in 14.0% of patients with poor differentiation, 36.6% of patients with linitis, and 5.8% of patients with neither linitis nor poor differentiation.

CONCLUSION

Despite negative pretreatment laparoscopy, post-treatment repeat laparoscopy may prevent non-therapeutic laparotomies. At a minimum, we recommend selective repeat laparoscopy for patients with linitis features.

Racial disparities in preoperative chemotherapy use in gastric cancer patients in the United States: Analysis of the National Cancer Data Base, 2006-2014

BACKGROUND

No studies have investigated whether race/ethnicity is associated with the recommended use of preoperative chemotherapy or subsequent outcomes in gastric cancer. To determine whether there is such an association, analyses of patients with gastric cancer in the National Cancer Data Base (NCDB) were performed.

METHODS

Patients with clinical T2-4bN0-1M0 gastric adenocarcinoma, as defined by the eighth edition of the American Joint Committee on Cancer staging manual, who underwent gastrectomy from 2006 to 2014 were identified from the NCDB. Multiple logistic regression was conducted to examine factors associated with preoperative chemotherapy use.

RESULTS

This study identified 16,945 patients who met the criteria, and 8286 of these patients (49%) underwent preoperative chemotherapy. The use of preoperative chemotherapy remarkably increased over the study period, from 34% in 2006 to 65% in 2014. Preoperative chemotherapy was more commonly used for cardia tumors than noncardia tumors (83% vs 44% in 2014). In a multivariable analysis, races and ethnicities other than non-Hispanic (NH) white race were associated with less frequent use of preoperative chemotherapy in comparison with NH whites after adjustments for social, tumor, and hospital factors. The insurance status and the education level mediated an enhanced effect of racial/ethnic disparities in preoperative chemotherapy use. The use of preoperative chemotherapy and radiation therapy was associated with reduced racial/ethnic disparities in overall survival.

CONCLUSIONS

Racial/ethnic disparities in the use of preoperative chemotherapy and in outcomes exist among patients with gastric cancer in the United States. Efforts to improve the access to high-quality cancer care in minority groups may reduce racial disparities in gastric cancer in the United States. Cancer 2018;124:998-1007. © 2018 American Cancer Society.

Preoperative therapy for gastric adenocarcinoma in relation to oncologic outcomes in patients with complications after gastrectomy

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Background: Postoperative complications (POC) are associated with poor oncologic outcomes in gastric cancer, however, it is unknown if preoperative therapy has any impact on this association. We sought to evaluate the impact of POC on survival in patients with gastric cancer treated with upfront surgery versus those treated with preoperative therapy. Methods: We analyzed data from a prospectively maintained database of patients who had undergone resection of their gastric cancer at our institution between 1995 and 2015. Patients with T1N0 or M1 lesions, recurrent disease, mortality within 90 days, and GEJ tumors were excluded. Cox regression analyses were used to examine factors associated with overall survival (OS) and disease free survival (DFS). Interaction terms between complications and preoperative therapy were used in the multivariate model to determine their impact on OS and DFS. Results: 421 patients underwent resection of gastric cancer: 30% underwent upfront surgery, and 51% had a POC. Variables associated with POCs included total gastrectomy (p = 0.02) and additional organ resection (p = 0.05). Among patients who had POCs, 71% were infectious, 41% experienced multiple complications, and 55% were classified as Clavien-Dindo grade III or IV. On multivariable analysis, the presence of a POC had the strongest association with diminished OS (HR 3.5, 95% CI 1.9-6.5). Among patients who underwent upfront surgery, patients with a POC had shorter OS (5-year, 85% vs. 47%; p < 0.001) and DFS (5-year, 76% vs. 46%; p < 0.001) than those without a POC. In contrast, there was no difference in OS (5-year, 63% vs. 57%; p = 0.77) and DFS (5-year, 52% vs. 52%; p = 0.52) between patients with and without POC who received preoperative therapy. Interaction terms between preoperative therapy and complication in the multivariable Cox regression model were significant on OS (3.53 [95%CI: 1.92-6.52]) and DFS (2.84 [95%CI: 1.59-5.08]), which indicated that the negative impact of complications were reduced if patients received preoperative therapy. Conclusions: The use of preoperative therapy negated the impact of POCs on OS and DFS in patients undergoing resection for gastric cancer.

Preoperative accuracy of gastric cancer staging in patient selection for preoperative therapy: race may affect accuracy of endoscopic ultrasonography

Background

Over the last 15 years, large randomized controlled studies have validated the benefit of preoperative therapy for patients with resectable gastric cancer. Computed tomography (CT) and endoscopic ultrasonography (EUS) are commonly used to select patients for preoperative treatment, but studies of preoperative staging accuracy that focus on patient selection for preoperative therapy are rare; therefore, whether CT or EUS can reliably identify patients eligible for preoperative therapy is still unclear. Our purpose was to determine the accuracy of EUS and CT for preoperative staging of gastric cancer and to identify factors that may affect their usefulness in selecting patients for preoperative therapy.

Methods

We reviewed the medical records of 8,260 patients with gastric or gastroesophageal adenocarcinoma treated at our institution from 1995 to 2013, identifying those who underwent gastrectomy without preoperative treatment. We compared T stage and N status from preoperative EUS and CT reports with those drawn from surgical pathology reports. Clinicopathologic and demographic variables associated with incorrect preoperative staging were investigated using univariate and multivariate analyses.

Results

We identified 187 patients who underwent preoperative staging by EUS (n=145) and/or CT (n=134) before gastrectomy. The accuracy, sensitivity, and specificity of EUS in distinguishing stage T1 from more advanced tumors were 82%, 78%, and 85%, respectively. Variables associated with underestimation of EUS T stage were lymphovascular invasion [odds ratio (OR), 7.51; 95% confidence interval (CI), 1.91-29.50; P<0.01] and white race (OR, 3.75; 95% CI, 1.31-10.75; P=0.01). The accuracies, sensitivities, and specificities for determining N status were, respectively, 65%, 49%, and 79% with CT and 66%, 29%, and 95% with EUS. Lymphovascular invasion was associated with a false negative result (OR, 3.79; 95% CI, 1.34-10.70; P=0.01), and well- or moderately differentiated histology was associated with a false positive result for CT N status (OR, 7.14; 95% CI, 2.00-25.44; P<0.01).

Conclusions

EUS is accurate in distinguishing T1 from T2-T4 lesions; both CT and EUS have low sensitivities and high specificities in determining N status. These accuracies and variables associated with inaccurate staging, including race, should be considered when selecting gastric cancer patients for preoperative therapy.

Elevated brain natriuretic peptide (BNP) is an early marker for patients at risk for complications after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS + HIPEC)

BACKGROUND

Elevated BNP is associated with adverse cardiac outcomes after noncardiac surgery. We assessed BNP values as markers of perioperative fluid status and their correlation with major/cardiopulmonary (CP) complications following CRS + HIPEC.

METHODS

Fluid balance, BNP levels, and morbidity data were collected for all patients undergoing CRS + HIPEC between 6/2014 and 2/2016.

RESULTS

One hundred and twenty-nine patients underwent CRS + HIPEC for appendiceal adenocarcinoma (n = 99), mesothelioma (n = 16), and colon cancer (n = 14). Less than 10% had CP comorbidities. The median PCI was 14 (range 4-39); 89% underwent CC0/1 resection (n = 115). Median blood loss (EBL) was 497 mL (50-2700). Major complications (Clavien III-V) occurred in 16 (12%), CP in 17 (13%), and major/CP in 24 (18%). Thirty-day mortality occurred in 2 (1.5%). Elevated BNP on POD1 correlated with increased risk of major/CP complications (OR 2.2, P = 0.052). This was most pronounced in the 25 patients receiving cisplatin: for each 100 unit increase in POD1 BNP the OR for major/CP complication was 7.4 versus 1.2 for the remaining patients, P = 0.083. Multivariate analysis identified increased EBL (OR 4.1 P = 0.011) and a trend toward increased BNP on POD1 (OR for each 100 unit increase 2.0, P = 0.10) as risk factors for major/CP complications.

CONCLUSIONS

Postoperative BNP measurement after CRS + HIPEC may guide postoperative fluid resuscitation and facilitate identification of patients at risk for major and/or cardiopulmonary complications.