Genomic Predictors of Recurrence Patterns After Complete Resection of Colorectal Liver Metastases and Adjuvant Hepatic Artery Infusion Chemotherapy.

BACKGROUND: Despite curative hepatectomy, most colorectal liver metastasis (CRLM) patients relapse locally within 2 years. Genomic predictors for hepatic recurrence are poorly understood. This study was designed to identify genomic signatures for recurrence in resected CRLM patients treated with adjuvant hepatic artery infusion (HAI) and/or systemic (SYS) chemotherapy. METHODS: Patients undergoing curative hepatectomy and adjuvant HAI+SYS or SYS between January 2000 and October 2017 with next-generation sequencing data were catalogued. Gene and signaling-level alterations were checked for association with time to any (AR), liver (LR), and extrahepatic recurrence (ER) by using Kaplan-Meier analysis. RESULTS: Of 172 receiving HAI+SYS, 100 patients recurred, with 69 LR and 83 ER. Five- and ten-year LR-free rates were 57% (95% confidence interval [CI] 48-65%) and 51% (95% CI 41-60%), respectively. Five- and 10-year ER-free, rates were 51% (95% CI 43-58%) and 45% (95% CI 36-54%), respectively. More ER was observed with tumors harboring altered KRAS (38% [95% CI 25-50%] vs. 63% [95% CI 53-71%], p-adj = 0.003) and RAS/RAF (36% [95% CI 25-48%] vs. 66% [95% CI 56-74%], p-adj < 0.001) than wild-type. Co-altered RAS/RAF-TP53 was associated with worse AR (26% [95% CI 14-40%] vs. 48% [95% CI 39-57%], p-unadj < 0.001), ER (30% [95% CI 17-45%] vs. 62% [95% CI 53-70%], p-unadj < 0.001), and LR rate (40% [95% CI 24-57%] vs. 70% [95% CI 60-77%], p-unadj = 0.002). On multivariable analysis, controlling for clinical risk score, ablation, margin status, and primary T-stage, co-altered RAS/RAF-TP53 was associated with increased risk for AR (HR = 2.14, 95% CI 1.38-3.31, p-unadj < 0.001), LR (HR = 1.79, 95% CI 1.06-3.02, p-unadj = 0.029), and ER (HR = 2.81, 95% CI 1.78-4.44, p-unadj < 0.001). CONCLUSIONS: Altered KRAS, RAS/RAF, and RAS/RAF-TP53 associated with earlier local and distant recurrence in resected CRLM patients receiving adjuvant HAI+SYS. Co-altered RAS/RAF-TP53 was a novel predictor of LR warranting investigation of whether genomic cooperativity is associated with this relapsing phenotype. Systemic therapies tailored to high-risk tumor biology are needed to reduce distant relapse after hepatectomy.

Recurrence of Hepatocellular Carcinoma After Complete Radiologic Response to Trans-Arterial Embolization: A Retrospective Study on Patterns, Treatments, and Prognoses.

BACKGROUND: There is limited information about the long-term outcomes and patterns of progression in patients who have unresectable, liver-confined hepatocellular carcinoma (HCC) with complete response (CR) to transarterial embolization and do not undergo resection or transplantation (LT). METHODS: A retrospective review analyzed participants in a randomized trial comparing hepatic artery embolization (HAE) and drug-eluting bead transarterial chemoembolization (DEB-TACE) with doxorubicin who had CR according to modified response evaluation criteria in solid tumors (mRECIST). The overall survival (OS), incidence and patterns of progression, and factors associated with progression were assessed. RESULTS: Of the 101 patients in the trial, 37 with CR were included in this study. This cohort had 17 patients treated with HAE (46 %), and 20 patients managed with DEB-TACE (54 %). The median age was 67 years (range, 42-82 years). Most of the cohort were male (86.5 %) and Caucasian (78 %). The median pre-treatment Model for End-Stage Liver Disease (MELD) score was 10, and 70 % of the cohort had Barcelona Clinic Liver Cancer (BCLC) stage B or C. The median follow-up period was 49 months (95 % confidence interval [CI], 9-108 months), and the median OS was 25 months (95 % CI, 18.9-30.9 months). The 3- and 5-year survival rates were respectively 31 % (95 % CI, 16.7-45.9 %) and 18 % (95 % CI, 6.8-32.1 %). The 1- and 2-year cumulative incidences of progression were respectively 76 % (95 % CI, 57.7-86.8 %) and 92 % (95 % CI, 74.5-97.6 %). The most common first site of progression was the previously treated hepatic site or local site (32 %, 12/37). The 3-year cumulative incidence of progression was 65 % (95 % CI, 46.4-78.4 %) for the local site. CONCLUSION: Patients with advanced-stage HCC and CR to embolization do not have durable responses and experience inevitable disease progression. Most patients with progression have liver-confined disease and should be evaluated for additional consolidative treatments.

Association of genomic profiles and survival in early onset and screening-age colorectal cancer patients with liver metastases resected over 15 years.

BACKGROUND: This study explores whether genomic profiles of colorectal liver metastasis (CRLM) patients with early onset (EO, < 50 years old) and screening age (SA) primary diagnosis are associated with overall survival (OS). METHODS: All patients undergoing hepatectomy between 2002 and 2017 were identified and tumor specimens with next-generation sequencing data were cataloged. Gene and signaling-level alterations were checked for association with OS from primary diagnosis accommodating for left-truncated survival. RESULTS: Of 1822 patients, 333 were sequenced-127 (38%) EO-CRLM and 206 (62%) SA-CRLM patients. More aggressive features presented in EO-CRLM patients-synchronous metastatic presentation (83% vs. 75%, p < 0.001) and primary node-positive disease (71% vs. 61%, p < 0.001). The median OS from primary diagnosis was 11.8 years (95% confidence interval = 7.94-NA). Five-year OS did not differ by age (p = 0.702). On multivariable analysis, altered APC (EO-CRLM: [hazard ratio [HR] = 0.37, p = 0.018] vs. SA-CRLM:[HR = 0.61, p = 0.260]), BRAF (EO-CRLM:[HR = 4.38, p = 0.007] vs. SA-CRLM:[HR = 4.78, p = 0.032]), and RAS-TP53 (EO-CRLM:[HR = 2.82, p = 0.011] vs. SA-CRLM:[HR = 2.35, p = 0.003]) associated with OS. CONCLUSIONS: Despite bearing more aggressive features, EO-CRLM patients had similar genomic profiles and survival as SA-CRLM patients. Better performance status in younger patients leading to increased treatment tolerance may partly explain this. As screening and treatment strategies from older patients are applied to younger patients, genomic predictors of biology identified historically in older cohorts could apply to EO patients.

Association between biopsy method and development of peritoneal metastases in perihilar cholangiocarcinoma.

BACKGROUND: In patients with perihilar cholangiocarcinoma (PHC), there is concern that transperitoneal (TP) biopsy may seed tumor in the peritoneal cavity, increasing risk of peritoneal metastases (PM). METHODS: A retrospective review of patients undergoing surgery for PHC (1991-2014) was performed. Clinicopathologic characteristics and incidence of PM at the time of index surgery, and one and two years after surgery were compared in patients who did vs. did not undergo TP biopsy. RESULTS: Among 262 patients who underwent surgery, 37 had undergone TP biopsy, and 225 had undergone intraluminal biopsy or had no biopsy. No differences in demographic or clinicopathologic characteristics were noted between groups. The incidence of PM at surgery was not significantly different between TP and non-TP biopsy patients (5.4% vs. 7.6%, p > 0.9). Among 243 patients who did not have PM at surgery, the cumulative incidence of PM in the TP and non-TP biopsy groups were not different at one year (11.4% [95%CI 3.5-24.4] vs. 10.8% [95%CI 7.0-15.5]) or two years (20.3% [95%CI 8.7-35.2] vs. 20.1% [95%CI 14.9-25.9]) (p = 0.7). DISCUSSION: Although PM commonly occurs in patients with PHC, TP biopsy was not associated with higher incidence of PM at surgery or at one or two years after surgery.

Lending a hand for laparoscopic distal pancreatectomy: the optimal approach?

BACKGROUND: Both minimally invasive surgery (MIS) and open approaches for distal pancreatectomy are acceptable. MIS options include total laparoscopic/robotic (TLR) and hand-assist laparoscopy (HAL). When considering safety profile and specimen quality, the optimal approach is unknown. METHODS: Patients who underwent distal pancreatectomy from 2010-2018 at two major academic institutions were included. Converted procedures were categorized into final approach. Ninety-day perioperative/pathologic outcomes of MIS and open were compared. Subset analyses between TLR vs HAL and HAL vs open were performed. Intent-to-treat analysis was performed. RESULTS: Among 1006 patients, resection was performed by MIS in 35% (n = 352), open in 65% (n = 654). MIS had similar patient comorbidity profile as open but had increased operative time (183 vs 162 min; p < 0.01), lower estimated-blood-loss (EBL; 131 vs 341 mL; p < 0.01), fewer intraoperative blood transfusions (1.4 vs 5%; p < 0.01), shorter LOS (5.2 vs 7.2 days; p < 0.01). Tumor size was smaller (3.2 vs 4.4 cm; p < 0.01) with lower lymph node (LN) yield (14 vs 16; p < 0.01). When comparing HAL (n = 109) to TLR (n = 243), despite increased prior abdominal operations (60 vs 43%; p = 0.008), HAL had shorter operative time (167 vs 191 min; p < 0.01), similar length-of-stay (LOS; 5.4 vs 5.1 days; p = 0.27), and readmission rate (15 vs 13%; p = 0.47). When comparing HAL to open, the advantages of TLR approach persisted including lower EBL (171 vs 342 mL; p < 0.01), and shorter LOS (5.4 vs 7.2 days; p < 0.01). Although HAL had smaller tumors, it had a similar LN yield (16 vs 16; p = 0.80), and higher R0-rate (97 vs 83%; p < 0.01). CONCLUSION: Hand-assist laparoscopy is safe and feasible for distal pancreatectomy as operative time, complication profile, lymph node yield, and R0-rates are similar to open procedures, while maintaining the associated the advantages of a total laparoscopic/robotic approach with reduced blood loss and shorter length-of-stay.

Neonatal Fc receptor for IgG (FcRn) regulates cross-presentation of IgG immune complexes by CD8-CD11b+ dendritic cells.

Cross-presentation of IgG-containing immune complexes (ICs) is an important means by which dendritic cells (DCs) activate CD8(+) T cells, yet it proceeds by an incompletely understood mechanism. We show that monocyte-derived CD8(-)CD11b(+) DCs require the neonatal Fc receptor for IgG (FcRn) to conduct cross-presentation of IgG ICs. Consequently, in the absence of FcRn, Fcγ receptor (FcγR)-mediated antigen uptake fails to initiate cross-presentation. FcRn is shown to regulate the intracellular sorting of IgG ICs to the proper destination for such cross-presentation to occur. We demonstrate that FcRn traps antigen and protects it from degradation within an acidic loading compartment in association with the rapid recruitment of key components of the phagosome-to-cytosol cross-presentation machinery. This unique mechanism thus enables cross-presentation to evolve from an atypically acidic loading compartment. FcRn-driven cross-presentation is further shown to control cross-priming of CD8(+) T-cell responses in vivo such that during chronic inflammation, FcRn deficiency results in inadequate induction of CD8(+) T cells. These studies thus demonstrate that cross-presentation in CD8(-)CD11b(+) DCs requires a two-step mechanism that involves FcγR-mediated internalization and FcRn-directed intracellular sorting of IgG ICs. Given the centrality of FcRn in controlling cross-presentation, these studies lay the foundation for a unique means to therapeutically manipulate CD8(+) T-cell responses.

Distinct clinical outcomes and biological features of specific KRAS mutants in human pancreatic cancer.

KRAS mutations in pancreatic ductal adenocarcinoma (PDAC) are suggested to vary in oncogenicity but the implications for human patients have not been explored in depth. We examined 1,360 consecutive PDAC patients undergoing surgical resection and find that KRASG12R mutations are enriched in early-stage (stage I) disease, owing not to smaller tumor size but increased node-negativity. KRASG12R tumors are associated with decreased distant recurrence and improved survival as compared to KRASG12D. To understand the biological underpinnings, we performed spatial profiling of 20 patients and bulk RNA-sequencing of 100 tumors, finding enhanced oncogenic signaling and epithelial-mesenchymal transition (EMT) in KRASG12D and increased nuclear factor κB (NF-κB) signaling in KRASG12R tumors. Orthogonal studies of mouse KrasG12R PDAC organoids show decreased migration and improved survival in orthotopic models. KRAS alterations in PDAC are thus associated with distinct presentation, clinical outcomes, and biological behavior, highlighting the prognostic value of mutational analysis and the importance of articulating mutation-specific PDAC biology.

Can general surgery interns accurately measure their own technical skills? Analysis of cognitive bias in surgical residents' self-assessments.

BACKGROUND: Accurate self-assessment of knowledge and technical skills is key to self-directed education required in surgical training. We aimed to investigate the presence and magnitude of cognitive bias in self-assessment among a cohort of surgical interns. METHODS: First-year general surgery residents self-assessed performance on a battery of technical skill tasks (knot tying, suturing, vascular anastomosis, Fundamentals of Laparoscopic Skills peg transfer and intracorporeal suturing) at the beginning of residency. Each self-assessment was compared to actual performance. Bias and deviation were defined as arithmetic and absolute difference between actual and estimated scores. Spearman correlation assessed covariation between actual and estimated scores. Improvement in participant performance was analyzed after an end-of-year assessment. RESULTS: Participants (N = 34) completed assessments from 2017 to 2019. Actual and self-assessment scores were positively correlated (0.55, P < .001). Residents generally underestimated performance (bias -4.7 + 8.1). Participants who performed above cohort average tended to assess themselves more negatively (bias -7.3 vs -2.3) and had a larger discrepancy between self and actual scores than below average performers (deviation index 9.7 + 8.2 vs 3.8 + 3.1, P < .05). End-of-year total scores improved in 31 (91.2%) participants by an average of 11 points (90 possible). Least accurate residents in initial self-assessments (deviation indices >75th percentile) improved less than more accurate residents (median 5 vs 16 points, P < .05). All residents with a deviation index >75 percentile underestimated their performance. CONCLUSION: Cognitive bias in technical surgical skills is apparent in first-year surgical residents, particularly in those who are higher performers. Inaccuracy in self-assessment may influence improvement and should be addressed in surgical training.

Genome-Derived Classification Signature for Ampullary Adenocarcinoma to Improve Clinical Cancer Care.

PURPOSE: The clinical behavior of ampullary adenocarcinoma varies widely. Targeted tumor sequencing may better define biologically distinct subtypes to improve diagnosis and management. EXPERIMENTAL DESIGN: The hidden-genome algorithm, a multilevel meta-feature regression model, was trained on a prospectively sequenced cohort of 3,411 patients (1,001 pancreatic adenocarcinoma, 165 distal bile-duct adenocarcinoma, 2,245 colorectal adenocarcinoma) and subsequently applied to targeted panel DNA-sequencing data from ampullary adenocarcinomas. Genomic classification (i.e., colorectal vs. pancreatic) was correlated with standard histologic classification [i.e., intestinal (INT) vs. pancreatobiliary (PB)] and clinical outcome. RESULTS: Colorectal genomic subtype prediction was primarily influenced by mutations in APC and PIK3CA, tumor mutational burden, and DNA mismatch repair (MMR)-deficiency signature. Pancreatic genomic-subtype prediction was dictated by KRAS gene alterations, particularly KRAS G12D, KRAS G12R, and KRAS G12V. Distal bile-duct adenocarcinoma genomic subtype was most influenced by copy-number gains in the MDM2 gene. Despite high (73%) concordance between immunomorphologic subtype and genomic category, there was significant genomic heterogeneity within both histologic subtypes. Genomic scores with higher colorectal probability were associated with greater survival compared with those with a higher pancreatic probability. CONCLUSIONS: The genomic classifier provides insight into the heterogeneity of ampullary adenocarcinoma and improves stratification, which is dictated by the proportion of colorectal and pancreatic genomic alterations. This approach is reproducible with available molecular testing and obviates subjective histologic interpretation.

Neonatal Fc receptor: from immunity to therapeutics.

The neonatal Fc receptor (FcRn), also known as the Brambell receptor and encoded by Fcgrt, is a MHC class I like molecule that functions to protect IgG and albumin from catabolism, mediates transport of IgG across epithelial cells, and is involved in antigen presentation by professional antigen presenting cells. Its function is evident in early life in the transport of IgG from mother to fetus and neonate for passive immunity and later in the development of adaptive immunity and other functions throughout life. The unique ability of this receptor to prolong the half-life of IgG and albumin has guided engineering of novel therapeutics. Here, we aim to summarize the basic understanding of FcRn biology, its functions in various organs, and the therapeutic design of antibody- and albumin-based therapeutics in light of their interactions with FcRn.

Does variability among surgical skills diminish throughout surgical internship? Analysis of a 5-task surgical simulation assessment program starting Day 1.

BACKGROUND: Simulation assessments are not yet standardized among surgical programs. We instituted a 5-task simulation program to assess surgical technical skills longitudinally during internship. METHODS: First-year residents completed 5 simulation tasks: suturing, knot-tying, vascular anastomosis, and the peg-transfer and the intracorporeal suturing of the Fundamentals of Laparoscopic Skills. Assessments occurred just before residency, mid-year, and at the completion of the intern year. RESULTS: This study involved 19 residents: 8 categorical, 4 urology, 3 interventional radiology, 2 plastics, and 2 non-designated preliminary interns. Mean completion times improved in both the Fundamentals of Laparoscopic Skills peg-transfer (145 ± 50, 111 ± 47, and 95 ± 28 seconds) and suturing (526 ± 92, 392 ± 131, and 351 ± 158 seconds; each P < .001) tasks, and decreased variability was noted in the former. Total scores trended to improve (P = .013). Interns underwent similar training; 95% completed at least 1 core rotation by mid-year. Surgical specialty was associated with total scores during the first knot-tying session, with plastics residents scoring highest; however, all scores progressed toward the group median over time. CONCLUSION: Technical skills of beginning surgery residents were assessed longitudinally with the institution of a 5-task curriculum. Periodic assessments showed improvement in each task. Furthermore, as residents were exposed to equal surgical training, the variability in resident scores showed the greatest decrease in simpler motor tasks.

Disturbances of the Perioperative Microbiome Across Multiple Body Sites in Patients Undergoing Pancreaticoduodenectomy.

OBJECTIVE: The goals of this study were to characterize bacterial communities within fecal samples, pancreatic fluid, bile, and jejunal contents from patients undergoing pancreaticoduodenectomy (PD) and to identify associations between microbiome profiles and clinical variables. METHODS: Fluid was collected from the pancreas, common bile duct, and proximal jejunum from 50 PD patients. Postoperative fecal samples were also collected. The microbial burden within samples was quantified with droplet digital polymerase chain reaction. Bacterial 16S ribosomal RNA gene sequences were amplified, sequenced, and analyzed. Data from fecal samples were compared with publicly available data obtained from volunteers. RESULTS: Droplet digital polymerase chain reaction confirmed the presence of bacteria in all sample types, including pancreatic fluid. Relative to samples from the American Gut Project, fecal samples from PD patients were enriched with Klebsiella and Bacteroides and were depleted of anaerobic taxa (eg, Roseburia and Faecalibacterium). Similar patterns were observed within PD pancreas, bile, and jejunal samples. Postoperative fecal samples from patients with a pancreatic fistula contained increased abundance of Klebsiella and decreased abundance of commensal anaerobes, for example, Ruminococcus. CONCLUSIONS: This study confirms the presence of altered bacterial populations within samples from PD patients. Future research must validate these findings and may evaluate targeted microbiome modifications to improve outcomes in PD patients.

Disruption of the microbiota across multiple body sites in critically ill children.

BACKGROUND: Despite intense interest in the links between the microbiome and human health, little has been written about dysbiosis among ICU patients. We characterized microbial diversity in samples from 37 children in a pediatric ICU (PICU). Standard measures of alpha and beta diversity were calculated, and results were compared with data from adult and pediatric reference datasets. RESULTS: Bacterial 16S rRNA gene sequences were analyzed from 71 total tongue swabs, 50 skin swabs, and 77 stool samples or rectal swabs. The mean age of the PICU patients was 2.9 years (range 1-9 years), and many were chronically ill children that had previously been hospitalized in the PICU. Relative to healthy adults and children, alpha diversity was decreased in PICU GI and tongue but not skin samples. Measures of beta diversity indicated differences in community membership at each body site between PICU, adult, and pediatric groups. Taxonomic alterations in the PICU included enrichment of gut pathogens such as Enterococcus and Staphylococcus at multiple body sites and depletion of commensals such as Faecalibacterium and Ruminococcus from GI samples. Alpha and beta diversity were unstable over time in patients followed longitudinally. We observed the frequent presence of "dominant" pathogens in PICU samples at relative abundance >50%. PICU samples were characterized by loss of site specificity, with individual taxa commonly present simultaneously at three sample sites on a single individual. Some pathogens identified by culture of tracheal aspirates were commonly observed in skin samples from the same patient. CONCLUSIONS: We conclude that the microbiota in critically ill children differs sharply from the microbiota of healthy children and adults. Acknowledgement of dysbiosis associated with critical illness could provide opportunities to modulate the microbiota with precision and thereby improve patient outcomes.

Neonatal Fc receptor and IgG-based therapeutics.

The majority of potent new biologics today are IgG-based molecules that have demonstrated tissue-targeting specificity with favorable clinical response. Several factors determine the efficacy of these products, including target specificity, serum half-life and effector functions via complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity or drug conjugates. In this review, we will focus on the interaction between therapeutic antibody and neonatal Fc receptor (FcRn), which is one of the critical factors in determining the circulating antibody half-life. Specifically, we will review the fundamental biology of FcRn, FcRn functions in various organs, Fc mutations designed to modulate binding to FcRn, IgG-based therapeutics that directly exploit FcRn functions and tools and strategies used to study FcRn-IgG interactions. Comprehensive understanding of FcRn-IgG interactions not only allows for development of effective therapeutics, but also avoidance of potential adverse effects.

N-Glycan Moieties in Neonatal Fc Receptor Determine Steady-state Membrane Distribution and Directional Transport of IgG.

The neonatal Fc receptor (FcRn) is a major histocompatibility complex class I-related molecule known to protect IgG and albumin from catabolism and transport IgG across polarized epithelial cells in a bidirectional manner. Previous studies have shown species-specific differences in ligand binding, IgG transport direction, and steady-state membrane distribution when expressed in polarized epithelial cells. We hypothesized that these differences may be due to the additional N-glycans expressed on the rat FcRn, because N-glycans have been proposed to function as apical targeting signals, and that two of the N-glycan moieties have been shown to contribute to the IgG binding of rat FcRn. A panel of mutant human FcRn variants was generated to resemble the N-glycan expression of rat FcRn in various combinations and subsequently transfected into Madin-Darby canine kidney II cells together with human beta2-microglobulin. Mutant human FcRn clones that contained additional N-glycan side-chain modifications, including that which was fully rodentized, still exhibited specificity for human IgG and failed to bind to mouse IgG. At steady state, the mutant human FcRn with additional N-glycans redistributed to the apical cell surface similar to that of rat FcRn. Furthermore, the rodentized human FcRn exhibited a reversal of IgG transport with predominant transcytosis from an apical-to-basolateral direction, which resembled that of the rat FcRn isoform. These studies show that the N-glycans in FcRn contribute significantly to the steady-state membrane distribution and direction of IgG transport in polarized epithelia.