Unique characteristics of the tumor immune microenvironment in young patients with metastatic colorectal cancer.

Introduction: Metastatic colorectal cancer (mCRC) remains a common and highly morbid disease, with a recent increase in incidence in patients younger than 50 years. There is an acute need to better understand differences in tumor biology, molecular characteristics, and other age-related differences in the tumor microenvironment (TME). Methods: 111 patients undergoing curative-intent resection of colorectal liver metastases were stratified by age into those <50 years or >65 years old, and tumors were subjected to multiplex fluorescent immunohistochemistry (mfIHC) to characterize immune infiltration and cellular engagement. Results: There was no difference in infiltration or proportion of immune cells based upon age, but the younger cohort had a higher proportion of programmed death-ligand 1 (PD-L1)+ expressing antigen presenting cells (APCs) and demonstrated decreased intercellular distance and increased cellular engagement between tumor cells (TCs) and cytotoxic T lymphocytes (CTLs), and between TCs and APCs. These trends were independent of microsatellite instability in tumors. Discussion: Age-related differences in PD-L1 expression and cellular engagement in the tumor microenvironment of patients with mCRC, findings which were unrelated to microsatellite status, suggest a more active immune microenvironment in younger patients that may offer an opportunity for therapeutic intervention with immune based therapy.

Multiplex Fluorescent Immunohistochemistry for Preservation of Tumor Microenvironment Architecture and Spatial Relationship of Cells in Tumor Tissues.

The tumor microenvironment (TME), composed of immune cells, antigens, and local soluble factors, is integral to cancer development and progression. Traditional techniques such as immunohistochemistry, immunofluorescence, or flow cytometry limit the analysis of spatial data and cellular interactions within the TME, as they are restricted to colocalization of a small number of antigens or the loss of tissue architecture. Multiplex fluorescent immunohistochemistry (mfIHC) allows for detection of multiple antigens within a single tissue sample, providing a more comprehensive description of tissue composition and spatial interactions within the TME. This technique utilizes antigen retrieval, application of primary and secondary antibodies, followed by a tyramide-based chemical reaction to covalently bind a fluorophore to an epitope of interest and, eventually, stripping of the antibodies. This allows for multiple rounds of antibody application without concern for species cross-reactivity, as well as signal amplification which abrogates the autofluorescence that frequently plagues analysis of fixed tissues. As such, mfIHC can be used to quantify multiple cellular populations and their interactions, in situ, unlocking key biologic data that was previously unavailable. This chapter provides an overview of the experimental design, staining, and imaging strategies using a manual technique in formalin-fixed paraffin-embedded tissue sections.

Analysis of Donor Pancreata Defines the Transcriptomic Signature and Microenvironment of Early Neoplastic Lesions.

The adult healthy human pancreas has been poorly studied given the lack of indication to obtain tissue from the pancreas in the absence of disease and rapid postmortem degradation. We obtained pancreata from brain dead donors, thus avoiding any warm ischemia time. The 30 donors were diverse in age and race and had no known pancreas disease. Histopathologic analysis of the samples revealed pancreatic intraepithelial neoplasia (PanIN) lesions in most individuals irrespective of age. Using a combination of multiplex IHC, single-cell RNA sequencing, and spatial transcriptomics, we provide the first-ever characterization of the unique microenvironment of the adult human pancreas and of sporadic PanIN lesions. We compared healthy pancreata to pancreatic cancer and peritumoral tissue and observed distinct transcriptomic signatures in fibroblasts and, to a lesser extent, macrophages. PanIN epithelial cells from healthy pancreata were remarkably transcriptionally similar to cancer cells, suggesting that neoplastic pathways are initiated early in tumorigenesis. SIGNIFICANCE: Precursor lesions to pancreatic cancer are poorly characterized. We analyzed donor pancreata and discovered that precursor lesions are detected at a much higher rate than the incidence of pancreatic cancer, setting the stage for efforts to elucidate the microenvironmental and cell-intrinsic factors that restrain or, conversely, promote malignant progression. See related commentary by Hoffman and Dougan, p. 1288. This article is highlighted in the In This Issue feature, p. 1275.

Analysis of donor pancreata defines the transcriptomic signature and microenvironment of early pre-neoplastic pancreatic lesions.

The adult healthy human pancreas has been poorly studied given lack of indication to obtain tissue from the pancreas in the absence of disease and rapid postmortem degradation. We obtained pancreata from brain dead donors thus avoiding any warm ischemia time. The 30 donors were diverse in age and race and had no known pancreas disease. Histopathological analysis of the samples revealed PanIN lesions in most individuals irrespective of age. Using a combination of multiplex immunohistochemistry, single cell RNA sequencing, and spatial transcriptomics, we provide the first ever characterization of the unique microenvironment of the adult human pancreas and of sporadic PanIN lesions. We compared healthy pancreata to pancreatic cancer and peritumoral tissue and observed distinct transcriptomic signatures in fibroblasts, and, to a lesser extent, macrophages. PanIN epithelial cells from healthy pancreata were remarkably transcriptionally similar to cancer cells, suggesting that neoplastic pathways are initiated early in tumorigenesis. Statement of significance: The causes underlying the onset of pancreatic cancer remain largely unknown, hampering early detection and prevention strategies. Here, we show that PanIN are abundant in healthy individuals and present at a much higher rate than the incidence of pancreatic cancer, setting the stage for efforts to elucidate the microenvironmental and cell intrinsic factors that restrain, or, conversely, promote, malignant progression.

Direct Peritoneal Resuscitation in Trauma Patients Results in Similar Rates of Intra-Abdominal Complications.

Background: Trauma patients undergoing damage control surgery (DCS) have a propensity for complicated abdominal closures and intra-abdominal complications. Studies show that management of open abdomens with direct peritoneal resuscitation (DPR) reduces intra-abdominal complications and accelerates abdominal closure. This novel study compares intra-abdominal complication rates and the effect of DPR initiation in patients who received DPR and those who did not. Patients and Methods: A retrospective chart review was performed on 120 patients who underwent DCS. Fifty patients were identified as DCS with DPR, and matched to 70 controls by gender, race, age, body mass index (BMI), past medical history, mechanism of trauma, and injury severity score. Results: The two groups of patients, those without DPR (-DPR) and those with DPR (+DPR), were similar in their characteristics. The +DPR group was more likely to have a mesh closure than the -DPR (14% and 3%; p = 0.022). The +DPR group took longer to have a final closure (3.5 ± 2.6 days vs. 2.5 ± 1.8; p = 0.020). Infection complications and mechanical failure of the closure technique were similar among the two groups. Timing of DPR initiation had no effect on closure type but did statistically increase the number of days to closure (initiation at first operation 2.8 ± 1.8 days vs. initiation at subsequent operations 6.0 ± 3.3 days; p ≤ 0.001). Conclusions: The use of DPR did not result in different outcomes in trauma patients. Therefore, traditional resuscitative measures for DCS may not be inferior to DCS with DPR. When choosing to use DPR, initiating it at the first operation could reduce the number of days to closure.

Chemoselective, Scalable Nickel-Electrocatalytic O-Arylation of Alcohols.

The formation of aryl-alkyl ether bonds through cross coupling of alcohols with aryl halides represents a useful strategic departure from classical SN 2 methods. Numerous tactics relying on Pd-, Cu-, and Ni-based catalytic systems have emerged over the past several years. Herein we disclose a Ni-catalyzed electrochemically driven protocol to achieve this useful transformation with a broad substrate scope in an operationally simple way. This electrochemical method does not require strong base, exogenous expensive transition metal catalysts (e.g., Ir, Ru), and can easily be scaled up in either a batch or flow setting. Interestingly, e-etherification exhibits an enhanced substrate scope over the mechanistically related photochemical variant as it tolerates tertiary amine functional groups in the alcohol nucleophile.

Helenalin Analogues Targeting NF-κB p65: Thiol Reactivity and Cellular Potency Studies of Varied Electrophiles.

Helenalin is a pseudoguaianolide natural product that targets Cys38 within the DNA binding domain of NF-κB transcription factor p65 (RelA). Helenalin contains two Michael acceptors that covalently modify cysteines: a α-methylene-γ-butyrolactone and a cyclopentenone. We recently reported two simplified helenalin analogues that mimic the biological activity of helenalin and contain both electrophilic moieties. To determine the individual contributions of the Michael acceptors toward NF-κB inhibition, we synthesized a small library of helenalin-based analogues containing various combinations of α-methylene-γ-butyrolactones and cyclopentenones. The kinetics of thiol addition to a subset of the analogues was measured to determine the relative thiol reactivities of the embedded electrophiles. Additionally, the cellular NF-κB inhibitory activities of the analogues were determined to elucidate the contributions of each Michael acceptor to biological potency. Our studies suggest the α-methylene-γ-butyrolactone contributes most significantly to the NF-κB inhibition of our simplified helenalin analogues.

Nickel-Catalyzed Barton Decarboxylation and Giese Reactions: A Practical Take on Classic Transforms.

Two named reactions of fundamental importance and paramount utility in organic synthesis have been reinvestigated, the Barton decarboxylation and Giese radical conjugate addition. N-hydroxyphthalimide (NHPI) based redox-active esters were found to be convenient starting materials for simple, thermal, Ni-catalyzed radical formation and subsequent trapping with either a hydrogen atom source (PhSiH3 ) or an electron-deficient olefin. These reactions feature operational simplicity, inexpensive reagents, and enhanced scope as evidenced by examples in the realm of peptide chemistry.

Nickel-Catalyzed Cross-Coupling of Redox-Active Esters with Boronic Acids.

A transformation analogous in simplicity and functional group tolerance to the venerable Suzuki cross-coupling between alkyl-carboxylic acids and boronic acids is described. This Ni-catalyzed reaction relies upon the activation of alkyl carboxylic acids as their redox-active ester derivatives, specifically N-hydroxy-tetrachlorophthalimide (TCNHPI), and proceeds in a practical and scalable fashion. The inexpensive nature of the reaction components (NiCl2 ⋅6 H2 O-$9.5 mol(-1) , Et3 N) coupled to the virtually unlimited commercial catalog of available starting materials bodes well for its rapid adoption.

Infectious complications in combined colon resection and ablation of colorectal liver metastases.

BACKGROUND: The multifactorial incidence of infectious complications carries considerable consequences for patients undergoing more extensive surgery with intent to cure metastatic colorectal cancer. Advances in ablation techniques have emerged as an efficacious method in regional control for liver metastasis from colorectal cancer; however, the degree of increased risk of infectious complications when ablation is performed in combination with colon resection has not been defined. METHODS: An analysis of a single institution's prospective database from August 1998 to December 2012 was performed for patients undergoing colon resection. Patients were stratified into a colon resection combined with either microwave ablation (MWA) or radiofrequency ablation (RFA) compared to a colon resection only group. Variables included baseline clinicopathologic data, type of operation, complication grade, and infectious outcome. Fisher exact test, Student t test, and analysis of variance were used to detect significance levels of P values less than .05. RESULTS: A total of 132 patients with colon cancer of various origins were identified. The group of colon resection combined with RFA and/or MWA was 53 patients (34 male:19 female) and was compared to a matched group of 79 patients (40 male:39 female) who underwent colon resection alone. Median age (58 vs 60 years; P = .209), complication rate (60.7% vs 62.5%; P = .722), infection rate (28.7% vs 35.4%; P = 1.0), mean blood loss (352.7 vs 468.4 mL; P = .452), mean blood transfused (1.36 vs .76 U; P = .247), and receipt of neoadjuvant chemotherapy (47.1% vs 51.85%; P = .724) were all similar between the ablation group and colon only group, respectively. Transfusion rate was higher in the ablation group (39.6% vs 18.9%; P = .016). Overall complication rate was 60.6%, with 32.6% infections. One mortality was observed in each group. High-grade (grade, III to V) complications (35.8% vs 18.9%; P = .0112) and liver-specific complications (n = 4; P = .024) were significantly increased in the combined ablation group. CONCLUSIONS: Combining MWA or RFA techniques with colon resection for liver metastasis appears to have similar infectious and overall complication rates when compared to performing an isolated resection of the primary colon cancer alone, although there may be a higher degree of complication seen in the more aggressive approach for curative intent in patients with colorectal liver metastasis.

Is radioembolization ((90)Y) better than doxorubicin drug eluting beads (DEBDOX) for hepatocellular carcinoma with portal vein thrombosis? A retrospective analysis.

INTRODUCTION: This study compares radioembolization ((90)Y) versus doxorubicin drug eluting beads (DEBDOX) in the treatment of unresectable hepatocellular carcinoma with portal vein thrombosis. METHODS: Using our prospectively maintained, multi-center, non-controlled intra-arterial therapy registry, we identified 28 consecutive patients with hepatocellular carcinoma (HCC) and portal vein thrombosis (PVT) treated with DEBDOX and 20 with (90)Y. Follow-up protocol consisted of a 3-phase CT scan of the liver within 3 months post-treatment. Tumor response rates were measured according to modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria. RESULTS: There were 65 and 29 treatments in the DEBDOX and (90)Y groups respectively. Median age of DEBDOX was 59.8 (35-81) and (90)Y was 66.5 (49-82) years. A defined number of lesions were seen in 78% DEBDOX and 50% (90)Y patients. Patients were similar in the remaining 8 baseline characteristics including performance status, Child Pugh and extent of PVT. There were fewer overall side effects in the DEBDOX group compared to the (90)Y group (11% vs 39%; P = 0.03). There was better disease control (mRECIST) in the DEBDOX group compared to the (90)Y group (67% vs 20%; P = 0.0014). Median survival times were 10 months in DEBDOX and 3 months in the (90)Y group respectively from first treatment (log-rank, P = 0.037). CONCLUSION: DEBDOX is safe for patients with HCC and PVT and may have lower toxicity than (90)Y. It may also provide better disease control and survival benefit. Further studies are warranted to validate our observations and to determine if current clinical practice should be altered.

Combined pancreas and liver therapies: resection and ablation in hepato-pancreatico-biliary malignancies.

BACKGROUND: Combined pancreatic and liver resection for hepato-pancreatico-biliary disease is generally considered contraindicated since it is thought to provide little if any survival benefit with high risk of morbidity. Our goal was to review our experience with combined pancreatic and liver resections to better define characteristics that increase risk for perioperative complications after combined resections. METHODS: A review of prospectively collected IRB approved hepato-pancreatico-biliary database was performed from October 2002 to April 2012. RESULTS: Twenty-one cases were identified including all histologies. Perioperative outcomes were examined and the overall mean length of stay was 12.1 days (range: 6-26 days) and no perioperative mortalities (<90 days) were observed. With respect to morbidity 43% of patients experienced any grade of complication, 29% were Grade 3 with no Grade 4 or 5 complications noted. We found a statistically indicated association between BMI > 25 and risk of Grade 3 complications (P = 0.149). The median survival following operation was 11 months (range: 3-148 months). CONCLUSION: Combined pancreas and liver resection for metastatic disease should only be considered in highly selected patients. Tumor histology as well as BMI > 25 (overweight and obese patients) should be considered in the decision making process in an effort to minimize surgical morbidity while potentially improving survival.