Health-Related Quality of Life After Cytoreductive Surgery/HIPEC for Mucinous Appendiceal Cancer: Results of a Multicenter Randomized Trial Comparing Oxaliplatin and Mitomycin

BACKGROUND

This study evaluated health-related quality of life (HRQOL) using patient-reported outcomes in subjects with mucinous appendiceal neoplasms who underwent cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) as part of a randomized trial comparing mitomycin with oxaliplatin.

METHODS

In this prospective multicenter study, 121 mucinous appendiceal cancer patients, with evidence of peritoneal dissemination who underwent CRS, were randomized to receive mitomycin (divided 40 mg) or oxaliplatin (200 mg/m²) for HIPEC. The Functional Assessment of Cancer Therapy Neurotoxicity (FACT-G/NTX) questionnaire was utilized to assess HRQOL. The Trial Outcome Index (TOI) is a summary index responsive to changes in physical/functional outcomes. Repeated measures mixed models with an unstructured variance matrix were applied to assess changes in HRQOL longitudinally.

RESULTS

Baseline questionnaire compliance was 95.9%. Baseline physical well-being (PWB) was independently associated with overall survival (hazard ratio 0.79, 95% confidence interval 0.66-0.96; p = 0.017). The TOI was significantly lower in the mitomycin group compared with the oxaliplatin arm at 12 weeks (p = 0.044; score difference 6.35) and 24 weeks after surgery (p = 0.049; score difference 5.61). At 12 weeks after surgery, declines from baseline were significant in the TOI (p = 0.004; score decline 8.99), PWB (p < 0.001; score decline 2.83), and FWB (p < 0.001; score decline 3.42) in the mitomycin group but not the oxaliplatin group.

CONCLUSIONS

Compared with mitomycin, HIPEC perfusion with oxaliplatin results in significantly better physical and functional outcomes. With similar survival outcomes and complication rates, oxaliplatin should be considered as the chemoperfusion agent of choice in mucinous appendiceal cancer patients undergoing CRS/HIPEC.

Neutrophil Extracellular Traps Drive Mitochondrial Homeostasis in Tumors to Augment Growth

Neutrophil infiltration and neutrophil extracellular traps (NET) in solid cancers are associated with poorer prognosis, but the mechanisms are incompletely understood. We hypothesized that NETs enhance mitochondrial function in tumor cells, providing extra energy for accelerated growth. Metastatic colorectal cancer tissue showed increased intratumoral NETs and supranormal preoperative serum MPO-DNA, a NET marker. Higher MPO-DNA correlated with shorter survival. In mice, subcutaneous tumor implants and hepatic metastases grew slowly in PAD4-KO mice, genetically incapable of NETosis. In parallel experiments, human cancer cell lines grew slower in nu/nu mice treated with DNAse, which disassembles NETs. PAD4-KO tumors manifested decreased proliferation, increased apoptosis, and increased evidence of oxidative stress. PAD4-KO tumors had decreased mitochondrial density, mitochondrial DNA, a lesser degree of ATP production, along with significantly decreased mitochondrial biogenesis proteins PGC1α, TFAM, and NRF-1. In vitro, cancer cells treated with NETs upregulated mitochondrial biogenesis-associated genes, increased mitochondrial density, increased ATP production, enhanced the percentage of cancer cells with reduced mitochondrial membrane potential, and increased the oxygen consumption rate. Furthermore, NETs increased cancer cells' expression of fission and fusion-associated proteins, DRP-1 and MFN-2, and mitophagy-linked proteins, PINK1 and Parkin. All of which were decreased in PAD4-KO tumors. Mechanistically, neutrophil elastase released from NETs activated TLR4 on cancer cells, leading to PGC1α upregulation, increased mitochondrial biogenesis, and accelerated growth. Taken together, NETs can directly alter the metabolic programming of cancer cells to increase tumor growth. NETs represent a promising therapeutic target to halt cancer progression. SIGNIFICANCE: Neutrophils through the release of NETs facilitate the growth of stressed cancer cells by altering their bioenergetics, the inhibition of which induces cell death.

Fitbit step counts during inpatient recovery from cancer surgery as a predictor of readmission

Background

Postoperative ambulation is encouraged to promote timely recovery but is rarely monitored objectively or examined as a predictor of clinical outcomes, despite growing availability of wearable devices that allow passive quantification and remote real-time monitoring of the number of steps taken during recovery.

Purpose

To determine whether the number of steps taken during inpatient recovery predicts 30- and 60-day readmission risk after metastatic cancer surgery.

Methods

Patients diagnosed with metastatic peritoneal cancer and scheduled for surgical resection were enrolled in this observational cohort study at their preoperative clinic visit. Fitbits were placed on patients' wrists upon transfer from the ICU following surgery and worn for the duration of their inpatient stay. Information about hospital readmission was extracted from electronic medical records.

Results

Seventy-one patients participated in the study (mean age = 57.14, range = 31-80 years; 42% female; 51% diagnosed with appendiceal cancer). Mean steps per day were calculated for each participant over the entire inpatient recovery period (mean stay = 12.12 days, 4-37 days). Readmission within 30 and 60 days was medically indicated for 34% and 39% of patients, respectively. After statistically adjusting for age, body mass index, comorbidity, and length of postoperative stay, higher mean steps per day predicted lower 30-day and 60-day readmission risk.

Conclusions

Higher Fitbit step counts during inpatient recovery predicted lower risk of 30- and 60-day readmission after surgery for metastatic peritoneal cancer. Results suggest that passively monitoring perioperative ambulation may identify patients at risk for readmission and highlight opportunities for behavioral intervention.

Correction to: Surveillance of Low-Grade Appendiceal Mucinous Neoplasms With Peritoneal Metastases After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Are 5 Years Enough? A Multisite Experience

In the original version of the article, Margaret Hofstedt's last name was misspelled.

Surveillance of Low-Grade Appendiceal Mucinous Neoplasms With Peritoneal Metastases After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Are 5 Years Enough? A Multisite Experience

BACKGROUND

Low-grade appendiceal mucinous neoplasms (LAMNs) are tumors that often present with widespread mucin in the peritoneal cavity (pseudomyxoma peritonei [PMP]). Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are effective treatment, but no published recommendations exist regarding surveillance.

METHODS

Data from prospective databases of patients who underwent CRS-HIPEC from 2001 to 2017 at two high-volume institutions were retrospectively analyzed. Patients who underwent complete CRS-HIPEC for PMP secondary to LAMN were included in the analysis. Pathologic examination confirmed the diagnosis of LAMN. Cases of mucinous adenocarcinomas and neuroendocrine tumors (goblet cell carcinoids) were excluded.

RESULTS

The study enrolled 156 patients. The median peritoneal cancer index (PCI) was 18 (interquartile range IQR1-3, 12-23), and 125 patients (80.1%) had a CC0 cytoreduction. According to American Joint Committee on Cancer (AJCC) grading, 152 patients (97.4%) presented with acellular mucin or G1 implants, 2 patients (1.3%) presented with G2 disease, and 2 patients (1.3%) presented with G3 disease. During the follow-up period (median, 45 months; IQR1-3 23-76 months), 23 patients (14.7%) experienced recurrence. All the recurrences were peritoneal and occurred within 5 years. The 1-, 3-, and 5-year disease-free survival (DFS) rates were respectively 95.5%, 83.4%, and 78.3%. Univariate Cox regression analysis showed that higher PCI scores (p < 0.001), a CC1 cytoreduction (p = 0.005), and higher preoperative levels of carcinoembryonic antigen (CEA) (p = 0.012) and CA-125 (p = 0.032) correlated with a shorter DFS. Only higher PCI scores independently predicted earlier recurrences (p < 0.001).

CONCLUSION

Most patients had recurrence within 3 years after CRS-HIPEC, and none after 5 years. High PCI was the only independently significant variable. The study findings support intensive surveillance (every 3-6 months) with tumor markers and imaging methods during the first 3 years, and annual surveillance thereafter, with follow-up assessment after 5 years yielding limited benefit.

Abstract 2264: Synergistic combination of oncolytic virotherapy and immunotherapy for glioma

Oncolytic viral immunotherapy is a novel approach to cancer treatment. Viruses can directly kill cancer cells, provide antigens to dendritic cells to stimulate a T cell response, and make cancer cells express genes of immune-enhancing cytokines locally within the tumor microenvironment. We hypothesized that the combination of oncolytic virus with a local stimulus for activating tumor-specific T cells and an anti-immunosuppressant would improve treatment of gliomas. An oncolytic virus encoding IL15-IL15Rα (the T cell activating stimulus) and the prostaglandin synthesis inhibitor celecoxib (the anti-immunosuppressant) were combined with adoptive transfer of tumor-specific T cells. Two oncolytic poxviruses, vvDD vaccinia virus and myxoma virus, were each engineered to express the fusion protein IL15-IL15Rα and a fluorescent protein (YFP or tdTomato Red). Viral gene expression was tested in the murine glioma line GL261 in vitro and in vivo. Orthotopic GL261 tumors in immunocompetent C57BL/6 mice were treated with vvDD-IL15-Rα vaccinia virus or vMyx-IL15Rα-tdTr combined with other treatments, including vaccination with GARC-1 peptide (a neoantigen for GL261), rapamycin, celecoxib, and adoptive T cell therapy. We found that vvDD-IL15-Rα and vMyx-IL15Rα-tdTr each infected and killed GL261 cells in vitro. In vivo, NK cells and CD8+ T cells were increased in the tumor due to the expression of IL15-IL15Rα. Each component of a combination treatment contributed to prolonging survival: an oncolytic virus, the IL15-IL15Rα expressed by the virus, a source of T cells (whether by pre-vaccination or adoptive transfer), and prostaglandin inhibition all synergized to produce total elimination of gliomas in a majority of mice. vvDD-IL15-Rα occasionally caused encephalitis, but vMyx-IL15Rα-tdTr was safe and effective, causing a strong infiltration of tumor-specific T cells and eliminating gliomas in 83% of treated mice. All these facts suggest that IL15-IL15Rα-armed oncolytic poxviruses provide potent antitumor effects against brain tumors when combined with adoptive T cell therapy, rapamycin and celecoxib.

Citation Format: Bingtao Tang, Zong Sheng Guo, David L. Bartlett, David Yan, Claire P. Schane, Jia Liu, Grant McFadden, Joanna L. Shisler, Edward J. Roy. Synergistic combination of oncolytic virotherapy and immunotherapy for glioma [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 2264.

Correction to: Postoperative Complications Independently Predict Cancer-Related Survival in Peritoneal Malignancies

In the original article, the Comprehensive Complication Index (CCI) was incorrectly identified as the Comprehensive Comorbidity Index. Wherever CCI appears, it refers to the Comprehensive Complication Index.

Repeat Cytoreductive Surgery-Hyperthermic Intraperitoneal Chemoperfusion is Feasible and Offers Survival Benefit in Select Patients with Peritoneal Metastases

INTRODUCTION

We hypothesized that repeat cytoreductive surgery-hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) for peritoneal metastases (PM) may be associated with suboptimal resection, more frequent postoperative complications, and worse oncologic outcomes.

METHODS

Using a prospectively maintained database, we compared clinicopathologic, perioperative, and oncologic outcome data in patients undergoing single or repeat CRS-HIPEC procedures. The Kaplan-Meier method was used to estimate survival. Multivariate analyses identified associations with perioperative and oncologic outcomes.

RESULTS

Of the 1294 patients undergoing CRS-HIPEC procedures at our institution, only one CRS-HIPEC procedure (single HIPEC cohort) was performed in 1169 patients (90.3%), whereas 125 patients (9.7%) underwent repeat CRS-HIPEC procedures (repeat HIPEC cohort). Of the 1440 CRS-HIPEC procedures at our institution, a first CRS-HIPEC procedure was performed in 1294 patients (89.9%), whereas subsequent second, third, and fourth CRS-HIPEC procedures were performed in 125 patients (8.7%), 18 patients (1.3%), and 3 patients (0.2%), respectively. Progression-free survival (PFS) following the second CRS-HIPEC procedure was negatively impacted by shorter PFS following the first CRS-HIPEC procedure, independent of other significant variables related to the second procedure, including completeness of cytoreduction and postoperative complications. Patients undergoing multiple CRS-HIPEC procedures were not at higher risk for suboptimal resection or postoperative complications and demonstrated equivalent PFS following each successive procedure compared to the first procedure.

CONCLUSIONS

Repeat CRS-HIPEC procedures for PM were not associated with suboptimal perioperative and oncologic outcomes. Our data confirmed our ability to select patients appropriately for repeat CRS-HIPEC procedures.

A cautionary note on the selectivity of oncolytic poxviruses

Background

Oncolytic viruses selectively infect cancer cells while avoiding infection of normal cells. Usually, selectivity is demonstrated by injecting a virus into tumor-bearing mice and observing infection and lysis of tumor cells without infection of other tissues. The general view is that this selectivity is due to tropisms of the virus. However, apparent selectivity could be due to accessibility. For example, intravenously injected virus may not gain access to cells within the central nervous system (CNS) because of the blood-brain barrier.

Purpose

We tested the CNS safety of two oncolytic poxviruses that have been demonstrated to be safe for treatment of peripheral tumors (vaccinia virus vvDD-IL15-Rα and myxoma virus vMyx-IL15Rα-tdTr).

Methods

Two poxviruses were tested for selectivity in vitro and in vivo.

Results

Both viruses infected glioma cells in vitro. In vivo, both viruses infected glioma cells and did not infect neurons when injected into a tumor or into the normal striatum. However, viral gene expression was observed in ependymal cells lining the ventricles, implying that these poxviruses were not as selective as originally predicted. For vvDD-IL15-Rα, some tumor-bearing mice died soon after virus treatment. If the same titer of vvDD-IL15-Rα was injected directly into the lateral cerebral ventricle of nontumor-bearing mice, it was uniformly fatal. Infection of ependymal cells, subventricular cells, and meninges was widespread. On the other hand, vMyx-IL15Rα-tdTr only transiently infected ependymal cells and was safe even when injected directly into the lateral cerebral ventricles. The two poxviruses also differed in their infection of dendritic cells; vvDD-IL15-Rα infected dendritic cells and lysed them but vMyx-IL15Rα-tdTr did not.

Conclusion

Vaccinia virus vvDD-IL15-Rα is very promising for treating cancer types outside of the brain. However, for cancers located within the brain, myxoma virus vMyx-IL15Rα-tdTr offers a safer alternative.

Vaccinia virus-mediated cancer immunotherapy: cancer vaccines and oncolytics

Cancer vaccines and oncolytic immunotherapy are promising treatment strategies with potential to provide greater clinical benefit to patients with advanced-stage cancer. In particular, recombinant vaccinia viruses (VV) hold great promise as interventional agents. In this article, we first summarize the current understanding of virus biology and viral genes involved in host-virus interactions to further improve the utility of these agents in therapeutic applications. We then discuss recent findings from basic and clinical studies using VV as cancer vaccines and oncolytic immunotherapies. Despite encouraging results gleaned from translational studies in animal models, clinical trials implementing VV vectors alone as cancer vaccines have yielded largely disappointing results. However, the combination of VV vaccines with alternate forms of standard therapies has resulted in superior clinical efficacy. For instance, combination regimens using TG4010 (MVA-MUC1-IL2) with first-line chemotherapy in advanced-stage non-small cell lung cancer or combining PANVAC with docetaxel in the setting of metastatic breast cancer have clearly provided enhanced clinical benefits to patients. Another novel cancer vaccine approach is to stimulate anti-tumor immunity via STING activation in Batf3-dependent dendritic cells (DC) through the use of replication-attenuated VV vectors. Oncolytic VVs have now been engineered for improved safety and superior therapeutic efficacy by arming them with immune-stimulatory genes or pro-apoptotic molecules to facilitate tumor immunogenic cell death, leading to enhanced DC-mediated cross-priming of T cells recognizing tumor antigens, including neoantigens. Encouraging translational and early phase clinical results with Pexa-Vec have matured into an ongoing global phase III trial for patients with hepatocellular carcinoma. Combinatorial approaches, most notably those using immune checkpoint blockade, have produced exciting pre-clinical results and warrant the development of innovative clinical studies. Finally, we discuss major hurdles that remain in the field and offer some perspectives regarding the development of next generation VV vectors for use as cancer therapeutics.

Correction to: Evolution of a Novel Robotic Training Curriculum in a Complex General Surgical Oncology Fellowship

In the XML of the original article, L. Mark Knab's first name was tagged incorrectly.

Gasless Transaxillary Endoscopic Thyroidectomy with Robotic Assistance: A High-Volume Experience in North America

BACKGROUND

Since its introduction nine years ago, gasless transaxillary thyroidectomy with robotic assistance (RT) has achieved a relatively limited application in North America. This study aimed to assess the outcomes of RT in a recent large, diverse North American population.

METHODS

Consenting patients were selected for the RT approach from November 2010 to July 2015 based on patient preference, and their perioperative data were retrospectively reviewed.

RESULTS

Of 301 robotic thyroidectomies completed in 281 patients, 160 were total thyroidectomy and 141 were lobectomy. Women predominated (98.9%), with a mean age of 41 years (range 17-74 years) and a mean follow-up of 24 months (range 3-71 months). The mean body mass index (BMI) was 25.7 kg/m² (range 17-44 kg/m²). However, 33.3% of patients had a BMI 25-29.9 kg/m², 12.4% had a BMI 30-34.9 kg/m², 3.5% had a BMI 35-39.9 kg/m², and 0.7% had a BMI ≥40 kg/m². Excluding 20 completion lobectomy, the indications for surgery were indeterminate cytology (53%), malignant cytology (10%), growth (18%), Graves' disease (12%), and other (5%). The mean size of the largest resected nodule was 2.5 cm (range 0.7-6.4 cm). Mean operating time for robotic lobectomy and total thyroidectomy was 81 and 109 minutes, respectively. One patient was converted to standard cervicotomy for failure to progress endoscopically. Complications included temporary dysphonia (6.0%), permanent recurrent laryngeal nerve deficit (1.3%), hypocalcemia (temporary 8.2%, permanent 1.1%), seroma (0.7%), and hematoma requiring reoperation (0.3%). Complications did not differ in patients with a BMI ≥25 kg/m² compared to those with a BMI <25 kg/m² or with respect to nodules >3 cm or surgery for Graves' thyroiditis. One patient developed grade II arm lymphedema ipsilateral to the axillary incision at two years, which resolved with conservative management. No patient had a surgical site infection or brachial plexopathy. Cancer was present histologically in 133 (48%) patients. Among 91 patients with cancer of the index nodule, 48.4% had papillary, 44.0% follicular variant papillary, 2.2% minimally invasive follicular carcinoma, and 5.5% minimally invasive Hürthle cell carcinoma. One patient had sclerosing variant thyroid paraganglioma. To date, all patients are without evidence of tumor recurrence.

CONCLUSIONS

At a high-volume center, gasless transaxillary endoscopic thyroid surgery done with robotic assistance is a safe, efficient, and effective approach in a diverse North American patient population.

Preoperative next-generation sequencing of pancreatic cyst fluid is highly accurate in cyst classification and detection of advanced neoplasia

OBJECTIVE

DNA-based testing of pancreatic cyst fluid (PCF) is a useful adjunct to the evaluation of pancreatic cysts (PCs). Mutations in KRAS/GNAS are highly specific for intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs), while TP53/PIK3CA/PTEN alterations are associated with advanced neoplasia. A prospective study was performed to evaluate preoperative PCF DNA testing.

DESIGN

Over 43-months, 626 PCF specimens from 595 patients were obtained by endoscopic ultrasound (EUS)-fine needle aspiration and assessed by targeted next-generation sequencing (NGS). Molecular results were correlated with EUS findings, ancillary studies and follow-up. A separate cohort of 159 PCF specimens was also evaluated for KRAS/GNAS mutations by Sanger sequencing.

RESULTS

KRAS/GNAS mutations were identified in 308 (49%) PCs, while alterations in TP53/PIK3CA/PTEN were present in 35 (6%) cases. Based on 102 (17%) patients with surgical follow-up, KRAS/GNAS mutations were detected in 56 (100%) IPMNs and 3 (30%) MCNs, and associated with 89% sensitivity and 100% specificity for a mucinous PC. In comparison, KRAS/GNAS mutations by Sanger sequencing had a 65% sensitivity and 100% specificity. By NGS, the combination of KRAS/GNAS mutations and alterations in TP53/PIK3CA/PTEN had an 89% sensitivity and 100% specificity for advanced neoplasia. Ductal dilatation, a mural nodule and malignant cytopathology had lower sensitivities (42%, 32% and 32%, respectively) and specificities (74%, 94% and 98%, respectively).

CONCLUSIONS

In contrast to Sanger sequencing, preoperative NGS of PCF for KRAS/GNAS mutations is highly sensitive for IPMNs and specific for mucinous PCs. In addition, the combination of TP53/PIK3CA/PTEN alterations is a useful preoperative marker for advanced neoplasia.

Superagonist IL-15-Armed Oncolytic Virus Elicits Potent Antitumor Immunity and Therapy That Are Enhanced with PD-1 Blockade

Oncolytic immunotherapy is a promising novel therapeutic for cancer, and further preclinical studies may maximize its therapeutic efficacy. In this study, we construct a novel oncolytic vaccinia virus (VV) expressing a superagoinst IL-15, a fusion protein of IL-15 and IL-15Ralpha. This virus, named vvDD-IL15-Rα, possesses similar replication efficiency as the parental virus vvDD yet leads to significantly more regression of the disease and extends the survival of mice bearing MC38 colon or ID8 ovarian cancer. This novel virus elicits potent adaptive antitumor immunity as shown by ELISPOT assays for interferon-gamma-secreting CD8+ T cells and by the rejection of tumor implants upon re-challenge in the mice, which were previously cured by vvDD-IL15-Rα treatment. In vivo cell depletion assays with antibodies showed that this antitumor activity is highly dependent on CD8+ T cells but much less so on CD4+ T cells and NK cells. Finally, the combination of the oncolytic immunotherapy with anti-PD-1 antibody dramatically improves the therapeutic outcome compared to either anti-PD-1 alone or vvDD-IL15-Rα alone. These results demonstrate that the IL-15-IL-15Rα fusion protein-expressing OV elicits potent antitumor immunity, and rational combination with PD-1 blockade leads to dramatic tumor regression and prolongs the survival of mice bearing colon or ovarian cancers.

Ferroptosis-inducing agents enhance TRAIL-induced apoptosis through upregulation of death receptor 5

Ferroptosis is considered genetically and biochemically distinct from other forms of cell death. In this study, we examined whether ferroptosis shares cell death pathways with other types of cell death. When human colon cancer HCT116, CX-1, and LS174T cells were treated with ferroptotic agents such as sorafenib (SRF), erastin, and artesunate, data from immunoblot assay showed that ferroptotic agents induced endoplasmic reticulum (ER) stress and the ER stress response-mediated expression of death receptor 5 (DR5), but not death receptor 4. An increase in the level of DR5, which is activated by binding to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and initiates apoptosis, was probably responsible for synergistic apoptosis when cells were treated with ferroptotic agent in combination with TRAIL. This collateral effect was suppressed in C/EBP (CCAAT-enhancer-binding protein)-homologous protein (CHOP)-deficient mouse embryonic fibroblasts or DR5 knockdown HCT116 cells, but not in p53-deficient HCT116 cells. The results from in vitro studies suggest the involvement of the p53-independent CHOP/DR5 axis in the synergistic apoptosis during the combinatorial treatment of ferroptotic agent and TRAIL. The synergistic apoptosis and regression of tumor growth were also observed in xenograft tumors when SRF and TRAIL were administered to tumor-bearing mice.

Evolution of a Novel Robotic Training Curriculum in a Complex General Surgical Oncology Fellowship

BACKGROUND

Robotic surgery is increasingly being used for complex oncologic operations, although currently there is no standardized curriculum in place for surgical oncologists. We describe the evolution of a proficiency-based robotic training program implemented for surgical oncology fellows, and demonstrate the outcomes of the program.

METHODS

A 5-step robotic curriculum began integration in July 2013. Fellows from July 2013 to August 2017 were included. An education portfolio was created for each fellow, including pre-fellowship experience, fellowship experience with data from robotic curriculum and operative experience, and post-fellowship practice information.

RESULTS

Of 30 fellows, 20% completed a prior fellowship, 97% trained at an academic residency, 57% had prior robotic training (median 5 h), and 43% had performed robotic surgery (median 0 cases). In fellowship, on average, fellows spent 5 h on the virtual reality curriculum and performed 19 biotissue anastomoses. For total surgeries, fellows operating from the console increased over time (p = 0.005). For pancreas, the average percentage of robotic pancreaticoduodenectomy (PD) steps completed increased (p < 0.011), as did the number of PDs in which the fellow completed the entire resection (p = 0.013). Fellows were 10 times more likely to complete the entire distal than PD from the console (p < 0.01). Post-fellowship, 83% of fellows obtained an academic position, 88% utilized robotics, and 91% performed pancreatic surgery.

CONCLUSIONS

With dedicated training, fellows can safely primarily perform complex gastrointestinal robotic surgeries and, after graduation, take jobs incorporating this skill set. In this era of scrutiny on cost and outcomes, specialized training programs offer a safe integration option for complex technical skills.

PARK7 modulates autophagic proteolysis through binding to the N-terminally arginylated form of the molecular chaperone HSPA5

Macroautophagy is induced under various stresses to remove cytotoxic materials, including misfolded proteins and their aggregates. These protein cargoes are collected by specific autophagic receptors such as SQSTM1/p62 (sequestosome 1) and delivered to phagophores for lysosomal degradation. To date, little is known about how cells sense and react to diverse stresses by inducing the activity of SQSTM1. Here, we show that the peroxiredoxin-like redox sensor PARK7/DJ-1 modulates the activity of SQSTM1 and the targeting of ubiquitin (Ub)-conjugated proteins to macroautophagy under oxidative stress caused by TNFSF10/TRAIL (tumor necrosis factor [ligand] superfamily, member 10). In this mechanism, TNFSF10 induces the N-terminal arginylation (Nt-arginylation) of the endoplasmic reticulum (ER)-residing molecular chaperone HSPA5/BiP/GRP78, leading to cytosolic accumulation of Nt-arginylated HSPA5 (R-HSPA5). In parallel, TNFSF10 induces the oxidation of PARK7. Oxidized PARK7 acts as a co-chaperone-like protein that binds the ER-derived chaperone R-HSPA5, a member of the HSPA/HSP70 family. By forming a complex with PARK7 (and possibly misfolded protein cargoes), R-HSPA5 binds SQSTM1 through its Nt-Arg, facilitating self-polymerization of SQSTM1 and the targeting of SQSTM1-cargo complexes to phagophores. The 3-way interaction among PARK7, R-HSPA5, and SQSTM1 is stabilized by the Nt-Arg residue of R-HSPA5. PARK7-deficient cells are impaired in the targeting of R-HSPA5 and SQSTM1 to phagophores and the removal of Ub-conjugated cargoes. Our results suggest that PARK7 functions as a co-chaperone for R-HSPA5 to modulate autophagic removal of misfolded protein cargoes generated by oxidative stress.

Abstract 2321: Molecular crosstalk between ferroptosis and apoptosis: Emerging role of ER stress-induced p53-independent PUMA expression

Ferroptosis is a type of programmed cell death that depends on iron and is characterized by the accumulation of lipid peroxides. In the present study, we investigated the nature of the interplay between ferroptosis and other forms of cell death such as apoptosis. Human pancreatic cancer PANC-1 and BxPC-3 and human colorectal cancer HCT116 cells were treated with ferroptotic agents such as erastin and artesunate (ART) in combination with the apoptotic agent tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). We observed synergistic interaction of erastin or ART with TRAIL as determined by cell death assay, caspase activation, poly [ADP-ribose] polymerase 1 (PARP-1) cleavage, flow cytometry analysis, and lipid peroxidation assay. Moreover, erastin and ART induced endoplasmic reticulum (ER) stress and promoted p53 upregulated modulator of apoptosis (PUMA) expression via C/EBP-homologous protein (CHOP). Synergy of erastin/ART and TRAIL was abolished in PUMA-deficient HCT116 cells and CHOP-deficient mouse embryonic fibroblasts, but not in p53-deficient HCT116 cells. The results suggest the involvement of the p53-independent CHOP/PUMA axis in response to ferroptosis inducers, which may play a key role in ferroptotic agent-mediated sensitization to TRAIL-induced apoptosis.

Citation Format: Young-Sun Lee, Se Hoon Hong, Dae-Hee Lee, Min J. Jo, Yoo A. Jeong, William T. Kwon, Haroon A. Choudry, David L. Bartlett, Yong J. Lee. Molecular crosstalk between ferroptosis and apoptosis: Emerging role of ER stress-induced p53-independent PUMA expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2321.