Benefits and opportunities of the transgenic Oncopig cancer model

Cancer remains a leading cause of morbidity and mortality, and a paradigm shift is needed to fundamentally revisit drug development efforts. Pigs share close similarities to humans and may serve as an alternative model. Recently, a transgenic 'Oncopig' line has been generated to induce solid tumors with organ specificity, opening the potential of Oncopigs as a platform for developing novel therapeutic regimens.

Circulating Tumor Cells: How Far Have We Come with Mining These Seeds of Metastasis?

Circulating tumor cells (CTCs) are cancer cells that slough off from the tumor and circulate in the peripheral blood and lymphatic system as micro metastases that eventually results in macro metastases. Through a simple blood draw, sensitive CTC detection from clinical samples has proven to be a useful tool for determining the prognosis of cancer. Recent technological developments now make it possible to detect CTCs reliably and repeatedly from a simple and straightforward blood test. Multicenter trials to assess the clinical value of CTCs have demonstrated the prognostic value of these cancer cells. Studies on CTCs have filled huge knowledge gap in understanding the process of metastasis since their identification in the late 19th century. However, these rare cancer cells have not been regularly used to tailor precision medicine and or identify novel druggable targets. In this review, we have attempted to summarize the milestones of CTC-based research from the time of identification to molecular characterization. Additionally, the need for a paradigm shift in dissecting these seeds of metastasis and the possible future avenues to improve CTC-based discoveries are also discussed.

Red Cabbage Juice-Mediated Gut Microbiota Modulation Improves Intestinal Epithelial Homeostasis and Ameliorates Colitis

Gut microbiota plays a crucial role in inflammatory bowel diseases (IBD) and can potentially prevent IBD through microbial-derived metabolites, making it a promising therapeutic avenue. Recent evidence suggests that despite an unclear underlying mechanism, red cabbage juice (RCJ) alleviates Dextran Sodium Sulfate (DSS)-induced colitis in mice. Thus, the study aims to unravel the molecular mechanism by which RCJ modulates the gut microbiota to alleviate DSS-induced colitis in mice. Using C57BL/6J mice, we evaluated RCJ's protective role in DSS-induced colitis through two cycles of 3% DSS. Mice were daily gavaged with PBS or RCJ until the endpoint, and gut microbiota composition was analyzed via shotgun metagenomics. RCJ treatment significantly improved body weight (p ≤ 0.001), survival in mice (p < 0.001) and reduced disease activity index (DAI) scores. Further, RCJ improved colonic barrier integrity by enhancing the expression of protective colonic mucins (p < 0.001) and tight junction proteins (p ≤ 0.01) in RCJ + DSS-treated mice compared to the DSS group. Shotgun metagenomic analysis revealed an enrichment of short-chain fatty acids (SCFAs)-producing bacteria (p < 0.05), leading to increased Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ) activation (p ≤ 0.001). This, in turn, resulted in repression of the nuclear factor κB (NFκB) signaling pathway, causing decreased production of inflammatory cytokines and chemokines. Our study demonstrates colitis remission in a DSS-induced mouse model, showcasing RCJ as a potential modulator for gut microbiota and metabolites, with promising implications for IBD prevention and treatment.

Red cabbage juice-mediated gut microbiota modulation improves intestinal epithelial homeostasis and ameliorates colitis

Gut microbiota plays a crucial role in inflammatory bowel disease (IBD) and has therapeutic benefits. Thus, targeting the gut microbiota is a promising therapeutic approach for IBD treatment. We recently found that red cabbage juice (RCJ) ameliorates dextran sulfate sodium (DSS)-induced colitis in mice. However, the underlying mechanisms remain unknown. The current study investigated the modulation of gut microbiota in response to treatment with RCJ to ameliorate the DSS colitis. The initial results demonstrated that mice treated with DSS + RCJ showed increased body weight and decreased diarrhea and blood in feces compared to the DSS alone group. RCJ ameliorated colitis by regulating the intestinal barrier function by reducing the number of apoptotic cells, improving colonic protective mucin, and increasing tight junction protein in RCJ + DSS groups compared to the DSS group. Short-gun metagenomic analysis revealed significant enrichment of short-chain fatty acid (SCFAs)-producing bacteria (Butyrivibrio, Ruminococcaceae, Acetatifactor muris, Rosburia Sp. CAG:303 , Dorea Sp. 5-2) increased PPAR-© activation, leading to repression of the nuclear factor κB (NFκB) signaling pathway, thus decreasing the production of crucial inflammatory cytokines and chemokines in the RCJ + DSS groups compared to the DSS group. Pathway abundance analysis showed an increased abundance of the SCFA pathway, reduced histidine degradation ( Bacteroides sartorii, and Bacteroides caecimuris ), and LCFA production in the RCJ+DSS treated group, suggesting the promotion of good colonic health. Furthermore, increased T-reg (FOXP3+) cells in the colon were due to SCFAs produced by the gut microbiota, which was corroborated by an increase in IL-10, a vital anti-inflammatory cytokine. Thus, our study provides the first evidence that RCJ ameliorates colonic inflammation by modulating the gut microbiota.

Abstract 205: Patient-derived organoids from surgically treated, localized non-small cell lung cancer as high-throughput drug testing platforms for conventional and repurposed drugs

Background: Non-metastatic NSCLC treated with curative surgery has a five-year survival of ~50%, mostly due to development of recurrences. Despite being considered as potential drug screening platforms, patient-derived xenograft (PDX) models are inefficient due to low tumor engraftment rates and complex animal care. Patient-derived organoid (PDO) models overcome these limitations as potential clinically applicable drug testing platforms. Our objective was to develop PDO models from non-metastatic NSCLC patients to study epithelial cell type heterogeneity and drug sensitivities for precision medicine.

Hypothesis: PDO models reliably capitulate the patient primary tumor and serve as versatile platforms for high-throughput screening of standard-of-care and repurposed drugs.

Methods: Single cell suspensions prepared from resected lung tumor tissues from ten NSCLC patients (both adenocarcinoma and squamous cell carcinoma) were mixed with Matrigel (growth factor-reduced) and cultured in organoid growth medium. Organoids and matched primary tumors were compared by histopathology [H&E staining and immunohistochemistry for cytokeratin (CK) 5/6, CK7, Napsin A, Thyroid transcription factor-1 (TTF-1) and p40] and by bulk RNA sequencing. Upon passaging, PDOs were seeded in triplicates, treated with carboplatin/paclitaxel doublet chemotherapy, and drug responses were determined using bright-field 3D imaging (z-stack method). Tumor growth (%) was determined on day 3 and 6 of treatments. RNA sequencing analyses identified a potential drug targets and repurposed drug (aldoketoreductase inhibitor Epalrestat) was tested to overcome chemoresistance in PDOs.

Results: NSCLC PDO growth was established from 11/12 (91.7%) primary tumors with a median time of 11 days (range 4-18 days) to reach volume of 100 μm3. PDOs retained histopathological features and biomarker expression of the matched tumors. As determined by growth differences (p&lt;0.05), 5/9 (55.6%) PDOs were chemosensitive and 4/9 (44.4%) PDOs were chemoresistant against carboplatin/paclitaxel. Whole transcriptome analysis confirmed conservation of the epithelial cell composition in all PDOs in comparison to the matched primary tumors. Potentially druggable genes associated with chemotherapy resistance were identified and the aldoketoreductase inhibitor Epalrestat was repurposed and shown to be effective in overcoming chemoresistance towards carboplatin/paclitaxel.

Conclusions: PDOs can be established from resectable NSCLC patients with high success rates, while preserving histopathological, cellular, and molecular characteristics of the matched primary tumors. Considering the time frames of growth and drug testing, PDOs can serve as clinically applicable drug response testing platforms to traditional and repurposed drugs.

Citation Format: Yariswamy Manjunath, Suvilesh Kanve Nagaraj, Yulia I. Nussbaum, Mohamed Gadelkarim, Kevin F. Staveley-O’Carroll, Eric T. Kimchi, Guangfu Li, Wesley Warren, Chi-Ren Shyu, Matthew Ciorba, Jonathan B. Mitchem, Jussuf T. Kaifi. Patient-derived organoids from surgically treated, localized non-small cell lung cancer as high-throughput drug testing platforms for conventional and repurposed drugs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 205.

Preclinical models to study patient-derived circulating tumor cells and metastasis

Circulating tumor cells (CTCs) that are detached from the tumor can be precursors of metastasis. The majority of studies focus on enumeration of CTCs from patient blood to predict recurrence and therapy outcomes. Very few studies have managed to expand CTCs to investigate their functional dynamics with respect to genetic changes, tumorigenic potential, and response to drug treatment. A growing amount of evidence based on successful CTC expansion has revealed novel therapeutic targets that are associated with the process of metastasis. In this review, we summarize the successes, challenges, and limitations that collectively contribute to the better understanding of metastasis using patient-derived CTCs as blood-borne seeds of metastasis. The roadblocks and future avenues to move CTC-based scientific discoveries forward are also discussed.

Somatic mutation variant analysis in rural, resectable non-small cell lung carcinoma patients

Rural non-small cell lung cancer (NSCLC) patients do worse, largely related to lack of access to care. In this study, the mutational characteristics and potential for targeted therapy in rural, resectable NSCLC patients using whole exome sequencing (WES) were analyzed. WES was performed on tumor-adjacent normal pairs from rural patients undergoing resection for NSCLC. Sequencing alignment, variant-calling, annotation, and tumor mutational burden (TMB) calculations were performed using standard methods. cBioportal and OncoKB were used for comparisons of mutational frequencies and actionable targets. Thirty-four NSCLC patients underwent WES after surgical resection. The gene most frequently containing somatic variants was TP53. The median number of somatic variants was 188 (Range 11-1056), and median TMB was 3.30 (0.33-18.56) nonsynonymous mutations per Mb. Tumor stage and survival were not associated with number of variants, TMB or TP53 mutational status. Significant concordance among the most common mutations when cross-referenced to cBioportal (R = 0.78, p < 0.0001) was observed. 24% of patients had variants in actionable genes based on OncoKB annotation. In summary, we demonstrate baseline mutational frequency and establish foundations for targeted adjuvant trials in rural NSCLC patients with specific differences. Future studies must ensure to include rural patients to improve NSCLC patient outcomes.

TBX21 Methylation as a Potential Regulator of Immune Suppression in CMS1 Subtype Colorectal Cancer

Cytotoxic T lymphocyte (CTL) infiltration is associated with survival, recurrence, and therapeutic response in colorectal cancer (CRC). Immune checkpoint inhibitor (ICI) therapy, which requires CTLs for response, does not work for most CRC patients. Therefore, it is critical to improve our understanding of immune resistance in this disease. We utilized 2391 CRC patients and 7 omics datasets, integrating clinical and genomic data to determine how DNA methylation may impact survival and CTL function in CRC. Using comprehensive molecular subtype (CMS) 1 patients as reference, we found TBX21 to be the only gene with altered expression and methylation that was associated with CTL infiltration. We found that CMS1 patients with high TBX21 expression and low methylation had a significant survival advantage. To confirm the role of Tbx21 in CTL function, we utilized scRNAseq data, demonstrating the association of TBX21 with markers of enhanced CTL function. Further analysis using pathway enrichment found that the genes TBX21, MX1, and SP140 had altered expression and methylation, suggesting that the TP53/P53 pathway may modify TBX21 methylation to upregulate TBX21 expression. Together, this suggests that targeting epigenetic modification more specifically for therapy and patient stratification may provide improved outcomes in CRC.

Abstract 267: Xenograft models of non-metastatic non-small cell lung cancer reveals micrometastasis-associated single cell composition

Background: Circulating tumor cells (CTCs) represent micrometastatic disease and may offer unique insights into future recurrences in lethal malignancies, including non-small cell lung cancer (NSCLC). Due to CTC rarity and limited stability, no CTC-derived xenograft (CDX) models have ever been generated from non-metastatic NSCLC patients directly. Alternative strategies are needed to molecularly characterize CTCs in this potentially curable patient group.

Methods: Surgically resected NSCLC primary tumor tissues were implanted in immunodeficient mice to establish ten patient-derived xenografts (PDXs). CTCs from 2/10 PDX models led to generation of two stable metastatic models that were studied by single cell sequencing.

Results: Single cell analysis revealed an additional alveolar epithelial type II (AT2) population in metastatic tumors, besides a common AT2 cluster in PDX/metastatic tumors. This was consistent with an external validation set analysis in primary and metastatic NSCLC patient tumors. Further, AT2 clusters of metastatic tumors expressed higher cancer stemness genes versus primary PDX tumor that was recapitulated in patients primary and metastatic tumors.

Conclusions: Stable metastatic models from early stage NSCLC patients can be generated with CTCs from PDX models. The distinct AT2 population identified in CDX tumors with cancer stemness features might be critical mediator of metastasis that deserves further study to discover personalized strategies against NSCLC micrometastases.

Citation Format: Kanve Nagaraj Suvilesh, Yulia I. Nussbaum, Vijay Radhakrishnan, Yariswamy Manjunath, Diego M. Avella, Kevin F. Staveley-O’Carroll, Eric T. Kimchi, Aadel A. Chaudhuri, Chi-Ren Shyu, Guangfu Li, Klaus Pantel, Wesley C. Warren, Jonathan B. Mitchem, Jussuf T. Kaifi. Xenograft models of non-metastatic non-small cell lung cancer reveals micrometastasis-associated single cell composition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 267.

Combining plasma extracellular vesicle Let-7b-5p, miR-184 and circulating miR-22-3p levels for NSCLC diagnosis and drug resistance prediction

Low-dose computed tomography (LDCT) Non-Small Cell Lung (NSCLC) screening is associated with high false-positive rates, leading to unnecessary expensive and invasive follow ups. There is a need for minimally invasive approaches to improve the accuracy of NSCLC diagnosis. In addition, NSCLC patients harboring sensitizing mutations in epidermal growth factor receptor EGFR (T790M, L578R) are treated with Osimertinib, a potent tyrosine kinase inhibitor (TKI). However, nearly all patients develop TKI resistance. The underlying mechanisms are not fully understood. Plasma extracellular vesicle (EV) and circulating microRNA (miRNA) have been proposed as biomarkers for cancer screening and to inform treatment decisions. However, the identification of highly sensitive and broadly predictive core miRNA signatures remains a challenge. Also, how these systemic and diverse miRNAs impact cancer drug response is not well understood. Using an integrative approach, we examined plasma EV and circulating miRNA isolated from NSCLC patients versus screening controls with a similar risk profile. We found that combining EV (Hsa-miR-184, Let-7b-5p) and circulating (Hsa-miR-22-3p) miRNAs abundance robustly discriminates between NSCLC patients and high-risk cancer-free controls. Further, we found that Hsa-miR-22-3p, Hsa-miR-184, and Let-7b-5p functionally converge on WNT/βcatenin and mTOR/AKT signaling axes, known cancer therapy resistance signals. Targeting Hsa-miR-22-3p and Hsa-miR-184 desensitized EGFR-mutated (T790M, L578R) NSCLC cells to Osimertinib. These findings suggest that the expression levels of circulating hsa-miR-22-3p combined with EV hsa-miR-184 and Let-7b-5p levels potentially define a core biomarker signature for improving the accuracy of NSCLC diagnosis. Importantly, these biomarkers have the potential to enable prospective identification of patients who are at risk of responding poorly to Osimertinib alone but likely to benefit from Osimertinib/AKT blockade combination treatments.

Circulating Tumor-Macrophage Fusion Cells and Circulating Tumor Cells Complement Non-Small-Cell Lung Cancer Screening in Patients With Suspicious Lung-RADS 4 Nodules

PURPOSE

Low-dose computed tomography (LDCT) screening of high-risk patients decreases lung cancer-related mortality. However, high false-positive rates associated with LDCT result in unnecessary interventions. To distinguish non-small-cell lung cancer (NSCLC) from benign nodules, in the present study, we integrated cellular liquid biomarkers in patients with suspicious lung nodules (lung cancer screening reporting and data system [Lung-RADS] 4).

METHODS

Prospectively, 7.5 mL of blood was collected from 221 individuals (training set: 90 nonscreened NSCLC patients, 74 high-risk screening patients with no/benign nodules [Lung-RADS 1-3], and 20 never smokers; validation set: 37 patients with suspicious nodules [Lung-RADS 4]). Circulating tumor cells (CTCs), CTC clusters, and tumor-macrophage fusion (TMF) cells were identified by blinded analyses. Screening patients underwent a median of two LDCTs (range, 1-4) with a median surveillance time of 30 (range, 11-50) months.

RESULTS

In the validation set of 37 Lung-RADS 4 patients, all circulating cellular biomarker counts (P < .005; Wilcoxon test) and positivity rates were significantly higher in 23 biopsy-proven NSCLC patients (CTCs: 23 of 23 [100%], CTC clusters: 6 of 23 [26.1%], and TMF cells: 15 of 23 [65.2%]) than in 14 patients with biopsy-proven benign nodules (6 of 14 [42.9%], 0 of 14 [0%], and 2 of 14 [14.3%]). On the basis of cutoff values from the training set, logistic regression with receiver operating characteristic and area under the curve analyses demonstrated that CTCs (sensitivity: 0.870, specificity: 1.0, and area under the curve: 0.989) and TMF cells (0.652; 0.880; 0.790) complement LDCT in diagnosing NSCLC in Lung-RADS 4 patients.

CONCLUSION

Cellular liquid biomarkers have a potential to complement LDCT interpretation of suspicious Lung-RADS 4 nodules to distinguish NSCLC from benign lung nodules. A future prospective, large-scale, multicenter clinical trial should validate the role of cellular liquid biomarkers in improving diagnostic accuracy in high-risk patients with Lung-RADS 4 nodules.

Nanoliposome C6-Ceramide in combination with anti-CTLA4 antibody improves anti-tumor immunity in hepatocellular cancer

Combination therapy represents an effective therapeutic approach to overcome hepatocellular cancer (HCC) resistance to immune checkpoint blockade (ICB). Based upon previous work demonstrating that nanoliposome C6‐ceramide (LipC6) not only induces HCC apoptosis but also prevents HCC‐induced immune tolerance, we now investigate the potential of LipC6 in combination with ICB in HCC treatment. We generated orthotopic HCC‐bearing mice, which have typical features in common with human patients, and then treated them with LipC6 in combination with the antibodies (Abs) for programmed cell death protein 1 (PD‐1) or cytotoxic T‐lymphocyte antigen 4 (CTLA4). The tumor growth was monitored by magnetic resonance imaging (MRI) and the intrahepatic immune profiles were checked by flow cytometry in response to the treatments. Realtime PCR (qPCR) was used to detect the expression of target genes. The results show that LipC6 in combination with anti‐CTLA4 Ab, but not anti‐PD‐1 Ab, significantly slowed tumor growth, enhanced tumor‐infiltrating CD8⁺ T cells, and suppressed tumor‐resident CD4⁺CD25⁺FoxP3⁺ Tregs. Further molecular investigation indicates that the combinational treatment suppressed transcriptional factor Krüppel‐like Factor 2 (KLF2), forkhead box protein P3 (FoxP3), and CTLA4. Our studies suggest that LipC6 in combination with anti‐CTLA4 Ab represents a novel therapeutic approach with significant potential in activating anti‐HCC immune response and suppressing HCC growth.

Tumorigenic circulating tumor cells from xenograft mouse models of non-metastatic NSCLC patients reveal distinct single cell heterogeneity and drug responses

Background

Circulating tumor cells (CTCs) are liquid biopsies that represent micrometastatic disease and may offer unique insights into future recurrences in non-small cell lung cancer (NSCLC). Due to CTC rarity and limited stability, no stable CTC-derived xenograft (CDX) models have ever been generated from non-metastatic NSCLC patients directly. Alternative strategies are needed to molecularly characterize CTCs and means of potential future metastases in this potentially curable patient group.

Methods

Surgically resected NSCLC primary tumor tissues from non-metastatic patients were implanted subcutaneously in immunodeficient mice to establish primary tumor patient-derived xenograft (ptPDX) models. CTCs were isolated as liquid biopsies from the blood of ptPDX mice and re-implanted subcutaneously into naïve immunodeficient mice to generate liquid biopsy CTC-derived xenograft (CDX) tumor models. Single cell RNA sequencing was performed and validated in an external dataset of non-xenografted human NSCLC primary tumor and metastases tissues. Drug response testing in CDX models was performed with standard of care chemotherapy (carboplatin/paclitaxel). Blockade of MYC, which has a known role in drug resistance, was performed with a MYC/MAX dimerization inhibitor (10058-F4).

Results

Out of ten ptPDX, two (20%) stable liquid biopsy CDX mouse models were generated. Single cell RNA sequencing analysis revealed an additional regenerative alveolar epithelial type II (AT2)-like cell population in CDX tumors that was also identified in non-xenografted NSCLC patients’ metastases tissues. Drug testing using these CDX models revealed different treatment responses to carboplatin/paclitaxel. MYC target genes and c-MYC protein were upregulated in the chemoresistant CDX model, while MYC/MAX dimerization blocking could overcome chemoresistance to carboplatin/paclitaxel.

Conclusions

To overcome the lack of liquid biopsy CDX models from non-metastatic NSCLC patients, CDX models can be generated with CTCs from ptPDX models that were originally established from patients’ primary tumors. Single cell analyses can identify distinct drug responses and cell heterogeneities in CDX tumors that can be validated in NSCLC metastases tissues. CDX models deserve further development and study to discover personalized strategies against micrometastases in non-metastatic NSCLC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01553-5.

Single Circulating-Tumor-Cell-Targeted Sequencing to Identify Somatic Variants in Liquid Biopsies in Non-Small-Cell Lung Cancer Patients

Non-small-cell lung cancer (NSCLC) accounts for most cancer-related deaths worldwide. Liquid biopsy by a blood draw to detect circulating tumor cells (CTCs) is a tool for molecular profiling of cancer using single-cell and next-generation sequencing (NGS) technologies. The aim of the study was to identify somatic variants in single CTCs isolated from NSCLC patients by targeted NGS. Thirty-one subjects (20 NSCLC patients, 11 smokers without cancer) were enrolled for blood draws (7.5 mL). CTCs were identified by immunofluorescence, individually retrieved, and DNA-extracted. Targeted NGS was performed to detect somatic variants (single-nucleotide variants (SNVs) and insertions/deletions (Indels)) across 65 oncogenes and tumor suppressor genes. Cancer-associated variants were classified using OncoKB database. NSCLC patients had significantly higher CTC counts than control smokers (p = 0.0132; Mann–Whitney test). Analyzing 23 CTCs and 13 white blood cells across seven patients revealed a total of 644 somatic variants that occurred in all CTCs within the same subject, ranging from 1 to 137 per patient. The highest number of variants detected in ≥1 CTC within a patient was 441. A total of 18/65 (27.7%) genes were highly mutated. Mutations with oncogenic impact were identified in functional domains of seven oncogenes/tumor suppressor genes (NF1, PTCH1, TP53, SMARCB1, SMAD4, KRAS, and ERBB2). Single CTC-targeted NGS detects heterogeneous and shared mutational signatures within and between NSCLC patients. CTC single-cell genomics have potential for integration in NSCLC precision oncology.

Analysis of tumor-associated macrophages' heterogeneity in colorectal cancer patients using single-cell RNA-seq data

146

Background: Colorectal cancer (CRC) is one of the deadliest malignancies worldwide. Though immune checkpoint inhibition has proven effective for a number of other tumors, it offers benefits in only a small group of CRC. In general, heterogenous cell groups in the tumor microenvironment (TME) are considered as the major barrier for unveiling the causes of low immune response. Therefore, deconvolution of cellular components in highly heterogeneous microenvironments is crucial for understanding those mechanisms. Single cell sequencing technology revolutionized TME research enabling profiling cells in high resolution. Methods: We have analyzed scRNA-seq data from 23 CRC patients with pre-treatment primary tumors using Seurat V3 pipeline. To investigate intercellular ligand-receptor interactions, we used CellPhoneDB and CellChat methods. The results of two independent analyses showed 4 CRC samples with no SPP1-CD44 interaction. It is known, that OPN which is the protein encoded by SPP1 gene, binds to CD44 and can cause cell survival, proliferation, and angiogenesis. Interestingly, analysis of the cellular composition of all 23 samples did not reveal differences in SPP1+ macrophages’ content for those 4 “no SPP1-CD44” samples. To investigate the mechanisms that could cause differences in SPP1-CD44 expression across the samples, we analyzed developmental trajectories of single cells using Slingshot trajectory inference method. Results: Ligand-receptor interactions analysis revealed 4 CRC samples that lacked SPP1-CD44 interaction that is known to be responsible for tumor progression in CRC. But the proportion of SPP1+ cells was not significantly different in those 4 samples compared to other samples. Trajectory inference analysis showed that the cells from “no SPP1-CD44” samples had high expression of anti-inflammatory macrophage markers in the end of the trajectory. While cells from “high SPP1-CD44” samples had high expression of pro-inflammatory macrophage markers at the same point. Conclusions: Based on our data-driven study, we suggest that SPP1+ macrophages’ heterogeneity may affect SPP1-CD44 interaction. Thus, targeting SPP1+ macrophages that have anti-inflammatory phenotype can potentially interrupt SPP1-CD44 interaction and therefore reduce tumor progression and immune suppression.

Single-cell RNA sequencing to characterize the response of pancreatic cancer to anti-PD-1 immunotherapy

Pancreatic cancer (PaC) is resistant to immune checkpoint therapy, but the underlying mechanisms are largely unknown. In this study, we have established four orthotopic PaC murine models with different PaC cell lines by intra-pancreatic inoculation. Therapeutic examinations demonstrate that only tumors induced with Panc02-H7 cells respond to αPD-1 antibody treatment, leading to significantly reduced tumor growth and increased survival in the recipient mice. Transcriptomic profiling at a single-cell resolution characterizes the molecular activity of different cells within tumors. Comparative analysis and validated experiments demonstrate that αPD-1-sensitive and -resistant tumors differently shape the immune landscape in the tumor microenvironment (TME) and markedly altering effector CD8⁺ T cells and tumor-associated macrophages (TAMs) in their number, frequency, and gene profile. More exhausted effector CD8⁺ T cells and increased M2-like TAMs with a reduced capacity of antigen presentation are detected in resistant Panc02-formed tumors versus responsive Panc02-H7-formed tumors. Together, our data highlight the correlation of tumor-induced imbalance of macrophages with the fate of tumor-resident effector CD8⁺ T cells and PaC response to αPD-1 immunotherapy. TAMs as a critical regulator of tumor immunity and immunotherapy contribute to PaC resistance to immune checkpoint blockade.

Breast metastases from primary lung cancer: a retrospective case series on clinical, ultrasonographic, and immunohistochemical features

Background

Lung cancer metastases to the breast are less common and consequently have received much less attention in clinical practice. The purpose of this study was to provide a better understanding of clinical, ultrasonographic, and immunohistochemical features of breast metastases from primary lung cancer.

Methods

This retrospective case series included patients with breast metastases from primary lung cancer between January 2012 and December 2020. Clinical features, ultrasonographic characteristics, and immunohistochemical findings were evaluated in this analysis.

Results

In all, 7 cases (mean ± standard deviation age: 57.4±8.3 years; range, 49–70 years) were evaluated. The maximum size of breast lesions in 6 cases ranged from 1.2 to 4.5 cm, while 1 case showed a diffused pattern. Ultrasound features of breast metastases from lung cancer were irregular (5/7, 71.4%), indistinct (6/7, 85.7%), hypoechoic (7/7, 100.0%), and parallel (6/7, 85.7%) masses without calcification. Immunohistochemical staining test was positive for thyroid transcription factor 1 (TTF-1) in all patients (7/7, 100.0%), 3 cases (3/5, 60.0%) were negative for p63, 5 cases (5/5, 100.0%) were positive for cytokeratin 7 (CK7), 4 cases (4/5, 80.0%) were positive for napsin A.

Conclusions

The ultrasonographic features of lung metastases to the breast are clinically important to understand. A known history of the primary lung cancer is of great importance when evaluating patients with a breast nodule. The presence of an ipsilateral lung cancer, breast nodule and axillary lymphadenopathy should be considered with pathological and immunohistochemical data to differentiate breast metastases from a primary breast malignancy in this setting.

Clog-free high-throughput microfluidic cell isolation with multifunctional microposts

Microfluidics have been applied to filtration of rare tumor cells from the blood as liquid biopsies. Processing is highly limited by low flow rates and device clogging due to a single function of fluidic paths. A novel method using multifunctional hybrid functional microposts was developed. A swift by-passing route for non-tumor cells was integrated to prevent very common clogging problems. Performance was characterized using microbeads (10 µm) and human cancer cells that were spiked in human blood. Design-I showed a capture efficiency of 96% for microbeads and 87% for cancer cells at 1 ml/min flow rate. An improved Design-II presented a higher capture efficiency of 100% for microbeads and 96% for cancer cells. Our method of utilizing various microfluidic functions of separation, bypass and capture has successfully guaranteed highly efficient separation of rare cells from biological fluids.

Abstract 596: Single circulating tumor cell enumeration and targeted sequencing in non-small cell lung cancer

Purpose: Circulating tumor cells (CTCs) may be novel biomarkers to predict cancer prognosis and monitor therapeutic efficacy. In the current study, we investigated the use of the time-dependent enumeration and targeted DNA sequensing of single CTCs as liquid biopsy based biomarkers of non-small cell lung cancer (NSCLC) patients for diagnosis, prognosis, therapeutic choice and outcome monitoring.

Experimental Design: In a prospective study, we tested the AccuCyte® system (RareCyte®, Inc. Seattle, WA) for CTC enumeration in NSCLC using FDA criteria (CK/EpCAM+/CD45- with a nucleus). Whole blood (7.5 ml) from healthy donors was spiked with human lung adenocarcinoma (A549 cell line) cells at specific numbers (N=0, 100, 200, 1000). CTC detection and single-CTC picking was performed. NSCLC subjects' (N=20) and chronic smokers without cancer on screening low-dose CT subjects' (N=10) blood were collected (amount, method, biotechnology). For all blood samples, CTC detection and single CTC picking was performed. DNA was isolated from CTCs (N=3) and white blood cells (N=2) per sample. DNA libraries were prepared for targeted oncogene characterization using the CleanPlex® OncoZoom® panel. Somatic variant analysis and comparisons were performed.

Results: AccuCyte enumeration of A549 cells spiked at four levels in healthy subjects' whole blood showed (Spiked #, Detected #): (0, 0); (100, 76); (200, 208); (1000, 1223). NSCLC subjects' (N=20; age: 64.85±6.64; BMI: 28.00±8.15sex ratio: 0.42) blood had a mean CTC count of 13.4 (SD=52, median=0, range [0, 237]). Ten screening controls without cancer (64.2±5.81, 1, 28.50±6.13, 0.66) had a mean CTC count of 0.20 (0.42, 0, [0, 1]). Significant association was noted regarding a higher number of CTCs found in NSCLC compared to screening subjects without cancer according to the (p= 0.020, Wilcoxon signed rank). CTC numbers increased with NSCLC AJCC stage. Somatic variant analysis on patient-matched single CTCs and WBCs is ongoing.

Conclusions: The molecular investigation of patient matched single CTCs and white blood cells will fundamentally advance understanding on the NSCCL carcinogenic signature of these blood born cells and their potential value as cancer detection and therapy management liquid biopsy-based biomarkers.

Citation Format: Mouadh Barbirou, Yariswamy Manjunath, Amanda Miller, Arturo Ramirez, Nolan Ericson, Kevin F. Kevin F. Staveley-O'Carroll, Wes Warren, Guangfu Li, Peter J. Tonellato, Jussuf T. Kaifi. Single circulating tumor cell enumeration and targeted sequencing in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 596.

Current and Prospective Methods for Assessing Anti-Tumor Immunity in Colorectal Cancer

Colorectal cancer (CRC) remains one of the deadliest malignancies worldwide despite recent progress in treatment strategies. Though immune checkpoint inhibition has proven effective for a number of other tumors, it offers benefits in only a small group of CRC patients with high microsatellite instability. In general, heterogenous cell groups in the tumor microenvironment are considered as the major barrier for unveiling the causes of low immune response. Therefore, deconvolution of cellular components in highly heterogeneous microenvironments is crucial for understanding the immune contexture of cancer. In this review, we assimilate current knowledge and recent studies examining anti-tumor immunity in CRC. We also discuss the utilization of novel immune contexture assessment methods that have not been used in CRC research to date.

Explainable artificial intelligence in high-throughput drug repositioning for subgroup stratifications with interventionable potential

Enabling precision medicine requires developing robust patient stratification methods as well as drugs tailored to homogeneous subgroups of patients from a heterogeneous population. Developing de novo drugs is expensive and time consuming with an ultimately low FDA approval rate. These limitations make developing new drugs for a small portion of a disease population unfeasible. Therefore, drug repositioning is an essential alternative for developing new drugs for a disease subpopulation. This shows the importance of developing data-driven approaches that find druggable homogeneous subgroups within the disease population and reposition the drugs for these subgroups. In this study, we developed an explainable AI approach for patient stratification and drug repositioning. Contrast pattern mining and network analysis were used to discover homogeneous subgroups within a disease population. For each subgroup, a biomedical network analysis was done to find the drugs that are most relevant to a given subgroup of patients. The set of candidate drugs for each subgroup was ranked using an aggregated drug score assigned to each drug. The proposed method represents a human-in-the-loop framework, where medical experts use the data-driven results to generate hypotheses and obtain insights into potential therapeutic candidates for patients who belong to a subgroup. Colorectal cancer (CRC) was used as a case study. Patients' phenotypic and genotypic data was utilized with a heterogeneous knowledge base because it gives a multi-view perspective for finding new indications for drugs outside of their original use. Our analysis of the top candidate drugs for the subgroups identified by medical experts showed that most of these drugs are cancer-related, and most of them have the potential to be a CRC regimen based on studies in the literature.

LMO7 as an Unrecognized Factor Promoting Pancreatic Cancer Progression and Metastasis

Pancreatic cancer (PC) is one of the most lethal human malignancies without effective treatment. In an effort to discover key genes and molecular pathways underlying PC growth, we have identified LIM domain only 7 (LMO7) as an under-investigated molecule, which highly expresses in primary and metastatic human and mouse PC with the potential of impacting PC tumorigenesis and metastasis. Using genetic methods with siRNA, shRNA, and CRISPR-Cas9, we have successfully generated stable mouse PC cells with LMO7 knockdown or knockout. Using these cells with loss of LMO7 function, we have demonstrated that intrinsic LMO7 defect significantly suppresses PC cell proliferation, anchorage-free colony formation, and mobility in vitro and slows orthotopic PC tumor growth and metastasis in vivo. Mechanistic studies demonstrated that loss of LMO7 function causes PC cell-cycle arrest and apoptosis. These data indicate that LMO7 functions as an independent and unrecognized druggable factor significantly impacting PC growth and metastasis, which could be harnessed for developing a new targeted therapy for PC.

CT-guided cryoablation for post-thoracotomy pain syndrome: a retrospective analysis

PURPOSE Post-thoracotomy pain syndrome is a common condition affecting up to 50% of post-thoracotomy patients. However, percutaneous computed tomography (CT)-guided intercostal nerve cryoablation may provide symptomatic benefit in chronic and/or refractory cases. METHODS A retrospective review of our institution's comprehensive case log from October 2017 to September 2018 for patients who underwent cryoablation was analyzed. Thirteen patients with post-thoracotomy pain syndrome, refractory to medical management, were treated with CT-guided intercostal nerve cryoablation. Most patients had treatment of the intercostal nerve at the level of their thoracotomy scar, two levels above and below. The safety and technical success of this technique and the clinical outcomes of the study population were then retrospectively reviewed. RESULTS Of the patients, 69% experienced significant improvement in their pain symptoms with a median pain improvement score of 3 points (range, -1 to 8 points) over a median follow-up of 11 months (range, 2-18.6 months). Complications included pneumothorax in 8% and pseudohernia in 23% of patients. CONCLUSION CT-guided intercostal nerve cryoablation may be an effective technique in the treatment of post-thoracotomy pain syndrome and requires further study.

Synergizing sunitinib and radiofrequency ablation to treat hepatocellular cancer by triggering the antitumor immune response

Background

Minimally invasive radiofrequency ablation (RFA) is used as a first-line treatment option for hepatocellular cancer (HCC) with the weaknesses of incomplete ablation, tumor recurrence, and inferior outcomes. To overcome this limitation, we proposed to develop sunitinib-RFA integrated therapy with a potential of activating anti-HCC immune response.

Methods

Using our unique murine model, we developed a novel RFA platform with a modified human cardiac RF generator. Therapeutic efficacy of sunitinib–RFA combined treatment in HCC was tested in this platform. Tumor progression was monitored by MRI; tumor necrosis and apoptosis were detected by H&E and terminal deoxynucleotidyl transferase dUTP nick end labeling; immune reaction was defined by flow cytometry; and signaling molecules were examined with real-time PCR (qPCR), western blot, and immunohistochemical staining.

Results

A significantly reduced tumor growth and extended lift span were observed in the mice receiving combined treatment with RFA and sunitinib. This combined treatment significantly increased the frequency of CD8⁺ T cell, memory CD8⁺ T cell, and dendritic cells (DCs); decreased the frequency of regulatory T cells; and activated tumor-specific antigen (TSA) immune response in tumor microenvironment. We found that RFA caused PD-1 upregulation in tumor-infiltrated T cells by boosting hepatocyte growth factor (HGF) expression, which was suppressed by sunitinib treatment. We have also demonstrated that sunitinib suppressed VEGF’s effect in enhancing PD-L1 expression in DCs and attenuated heat-sink effect. The results indicate that RFA induced tumor destruction and release of in situ TSAs which can activate a tumoricidal immune response in sunitinib-treated mice, significantly improving anti-HCC therapeutic efficacy.

Conclusions

Sunitinib enables RFA-released in situ TSA to ignite an effective anti-tumor immune response by suppressing HGF and VEGF signaling pathways. Sunitinib–RFA as a synergistic therapeutic approach significantly suppresses HCC growth.

Benign Tracheoenteric Fistula to a Zenker's Diverticulum With Complete Esophageal Obstruction

A fistula between a Zenker's diverticulum and the trachea has only been reported once, in 1983. Here, we report a case of a fistula between a large Zenker's diverticulum and the trachea with complete occlusion of the esophagus. The fistula was repaired, first by an esophageal myotomy, followed by proximal resection of the diverticulum, completion of the esophageal myotomy, transection of the fistula, and repair of the trachea. The surgical repair provided complete resolution of symptoms without complications.

Abstract 5375: Large, polymorphonuclear circulating cancer-associated cell with dual epithelial and macrophage/myeloid phenotype is prognostic in non-small cell lung cancer and has an impact on anti-tumor immune responses

Purpose: In addition to the FDA-approved definition of a circulating tumor cell (CTC), various phenotypes of circulating cancer-associated cells have been described. A distinct large (&gt;30µm), polymorphonuclear, circulating, cancer-associated cell (CCAC) with a dual epithelial and macrophage/myeloid phenotype has been identified in solid cancer patients. Aims of the study were to identify and characterize these hybrid CCACs in non-small cell lung cancer (NSCLC) patients and to determine their impact on cancer-associated immune responses in vitro and in vivo in a murine model of lung cancer.

Experimental Design: In a prospective trial, 7.5ml of peripheral blood was collected from 167 subjects. CTCs and CCACs were enriched by size-based microfilter and immunostaining was performed (CK 8/18/19, EpCAM, CD14/45, DAPI). To mimic circulating hybrid cells, polyethylene glycol was used to induce fusion of murine RAW 264.7 macrophage cells and Lewis Lung Carcinoma (LLC) cells; fused cells were validated by flow cytometry, electron microscopy and fluorescence microscopy. Immunomodulatory effects of fused cells were determined in LLC-tumor bearing mice.

Results: 78 NSCLC patients and 89 control subjects (69 chronic smokers with and without lung nodules on screening LDCT, 20 healthy never-smokers) were enrolled. Distinct, large, polymorphonuclear CK+/EpCAM+/CD14/45+ CCACs were detected at lower rates than traditional CK+/EpCAM+/CD45- CTCs, but significantly higher in subjects with NSCLC in comparison to controls (p&lt;0.05). CCACs and traditional CTCs were absent in 20 healthy controls. ≥2 CCACs correlated with significantly poorer survival and higher recurrence rates by uni- and multivariate analysis (p&lt;0.05). To support these findings, PEG-induced fusion cells suppressed immune responses decreased T-cell activation and increased Tregs in vitro and in LLC tumor-bearing mice.

Conclusions and future perspectives: These investigations show that CCAC with a dual epithelial and macrophage/myeloid phenotype is associated with aggressive clinical behavior in NSCLC. Pro-tumorigenic mechanisms are suggested by macrophage-tumor cell fusion leading to suppressed T cell-mediated anti-tumor immune responses. In future, the impact of CCACs on tumor progression and immune responses will need to be further studied in NSCLC patients.

CCACs presentCCACs mean (±SEM); median (range)CTCs presentCTCs mean (±SEM); median (range)p valueSubjects analyzed (total)167NSCLC7861 (78.2%)3.12 (±0.37); 2 (0-17)78 (100%)21.95 (±1.24); 19 (8-80)&lt;0.05† (CCACs vs. CTCs)Median Age (range)69 (41-81)Gender• Females (%)41 (52.6%)• Males (%)37 (47.4%)Stage (AJCC 8th ed.)&lt;0.05* (CCACs vs. CTCs)• I39 (50%)26 (66.7%)1.26 (±0.21); 1 (0-5)39 (100%)14.59 (±0.62); 14 (8-28)• II15 (19.2%)11 (73.3%)2.67 (±0.64); 2 (0-7)15 (100%)22.67 (±1.12); 23 (18-33)• III12 (15.4%)12 (100%)6.17 (±0.81); 6 (2-11)12 (100%)29.42 (±1.58); 29 (23-42)• IV12 (15.4%)12 (100%)6.67 (±1.21); 5 (3-17)12 (100%)37.5 (±4.23); 36 (25-80)(p&lt;0.05*)(p&lt;0.05*)Control long-term smoker subjects69Median Age (range)63 (54-74)Gender• Females (%)32 (46.4%)• Males (%)37 (53.6%)No lung nodules14007 (50%)1.36 (±0.45); 0 (0-4)Benign lung nodules5511 (20%)0.33 (±0.09); 0 (0-2)41 (74.5%)3.26 (±0.39); 3 (0-11)Healthy, never-smoker controls200 (0%)00 (0%)0

Citation Format: Yariswamy Manjunath, Kanve N. Suvilesh, Diego M. Avella, Eric T. Kimchi, Kevin F. Staveley-O'Carroll, Chelsea B. Deroche, Guangfu Li, Jussuf T. Kaifi. Large, polymorphonuclear circulating cancer-associated cell with dual epithelial and macrophage/myeloid phenotype is prognostic in non-small cell lung cancer and has an impact on anti-tumor immune responses [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5375.

Abstract LB-271: Multi-omics characterization of tumor tissues from CTC derived xenograft (CDX) mouse models of early-stage NSCLC patients reveals novel diagnostic/therapeutic target(s)

Introduction: Circulating tumor cells (CTCs) are liquid biomarkers with high potential for application in precision medicine cancer care. However, no robust methods have been developed to culture CTCs from early-stage cancer patients owing to their rarity and instability. Here, we describe a successful protocol to establish CTC culturing and CTC-derived xenograft (CDX) mouse models from early-stage non-small cell lung cancer (NSCLC) patients. Further, comparative multi-omics characterization of these CDX tumors revealed novel diagnostic/therapeutic target(s). Methods: Surgically resected primary tumor fragments from patients with early stage NSCLCs were subcutaneously (s.c.) implanted to immunodeficient NOD SCID gamma (NSG) mice to generate patient-derived xenograft (PDX) models. Once palpable tumor reached a diameter of ~1.5 cm, animals were euthanized and blood was collected, CTCs were enriched with OncoQuick® and cultured in vitro. These patient-derived CTCs were further stained with anti-human antibodies against CK7, Napsin, TTF-1, CK5/6, PDL1 and CD45. Once human CTCs were confirmed, we then injected expanded CTCs s.c. to naïve NSG mice to establish CDX models. Single cell suspension from CDX tumors was cultured and fibroblasts were depleted using specific beads (Miltenyi biotec) to establish stable CTC lines. Further, advanced proteomics, single cell RNA sequencing (transcriptomics) and whole genome sequencing of patient-matched peritumoral and primary tumor tissues along with PDX and CDX tumors were carried out. Results: Human NSCLC primary tumor fragments implanted in NSG mice were tumorigenic at the s.c. implantation site, metastatic to distant organs, and passaged successfully to naïve NSG generations to maintain the PDX colonies. CTCs enriched from the PDX models were successfully cultured in vitro and positive for human NSCLC-specific markers but negative for human leukocyte marker CD45. Cultured PDX-derived CTCs that were xenografted into naïve NSG mice by s.c. demonstrated tumorigenicity and metastatic potential in CDX models. Stable CTC lines established using CDX tumors sustained &gt;30 passages. Global proteomic profiling of tumor tissues revealed 19 new proteins that were upregulated and 9 proteins that are down regulated. Single cell RNA sequence analysis depicts top rank genes that are overexpressed in tumor cluster. Whole genome sequencing of these samples identified somatic variants that needs further validation. Conclusion and future perspectives: This approach establishes CDX models from early-stage NSCLC patients at a high rate for personalized precision medicine. Models provide a unique opportunity to characterize rare patient-derived CTCs that helps in understanding CTC tumor biology and developing effective anti-cancer therapeutic strategies. Multi-omics characterization of these tissues identified a set of novel genes/proteins that needs to be validated in large patient population. Further, studying tumorigenic potential of established CTC lines after knockdown and overexpression of these genes will provide more information about translating these targets into therapeutics.

Citation Format: Kanve N. Suvilesh, Yariswamy Manjunath, Vijay Radhakrishnan, Diego M. Avella, Eric T. Kimchi, Kevin F. Staveley-O'Carroll, Guangfu Li, Jussuf T. Kaifi. Multi-omics characterization of tumor tissues from CTC derived xenograft (CDX) mouse models of early-stage NSCLC patients reveals novel diagnostic/therapeutic target(s) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-271.

Author Correction: RNA cargos in extracellular vesicles derived from blood serum in pancreas associated conditions

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Role of Computed Tomography-guided Biopsies in the Era of Electromagnetic Navigational Bronchoscopy: A Retrospective Study of Factors Predicting Diagnostic Yield in Electromagnetic Navigational Bronchoscopy and Computed Tomography Biopsies

Objectives:

Over 25% of the high-risk population screened for lung cancer have an abnormal computed tomography (CT) scan. Conventionally, these lesions have been biopsied with CT guidance with a high diagnostic yield. Electromagnetic navigational bronchoscopy (ENB) with transbronchial biopsy has emerged as a technology that improves the diagnostic sensitivity of conventional bronchoscopic biopsy. It has been used to biopsy lung lesions, due to the low risk of pneumothorax. It is, however, a new technology that is expensive and its role in the diagnosis of the solitary pulmonary nodule (SPN) is yet to be determined. The purpose of this study was to evaluate the diagnostic yield of CT-guided biopsy (CTB) following non-diagnostic ENB biopsy and identify characteristics of the lesion that predicts a low diagnostic yield with ENB, to ensure appropriate use of ENB in the evaluation of SPN.

Materials and Methods:

One hundred and thirty-five lung lesions were biopsied with ENB from January 2017 to August 2019. Biopsies were considered diagnostic if pathology confirmed malignancy or inflammation in the appropriate clinical and imaging setting. We evaluated lesions for several characteristics including size, lobe, and central/peripheral distribution. The diagnostic yield of CTB in patients who failed ENB biopsies was also evaluated. Logistic regression was used to identify factors likely to predict a non-diagnostic ENB biopsy.

Result:

Overall, ENB biopsies were performed in 135 patients with solitary lung lesions. ENB biopsies were diagnostic in 52% (70/135) of the patients. In 23 patients with solitary lung lesions, CTBs were performed following a non-diagnostic ENB biopsy. The CTBs were diagnostic in 87% of the patients (20/23). ENB biopsies of lesions <21.5 mm were non-diagnostic in 71% of cases (42/59); 14 of these patients with non-diagnostic ENB biopsies had CTBs, and 86% of them were diagnostic (12/14). ENB biopsies of lesions in the lower lobes were non- diagnostic in 59% of cases (35/59); 12 of these patients with non-diagnostic ENB biopsies had CTBs, and 83% were diagnostic (10/12). ENB biopsies of lesions in the outer 2/3 were non-diagnostic in 57% of cases (50/87); 21 of these patients with non-diagnostic ENB biopsies had CTBs, and 86% were diagnostic (18/21).

Conclusion:

CTBs have a high diagnostic yield even following non-diagnostic ENB biopsies. Lesions <21.5 mm, in the outer 2/3 of the lung, and in the lower lung have the lowest likelihood of a diagnostic yield with ENB biopsies. Although CTBs have a slightly higher pneumothorax rate, these lesions would be more successfully diagnosed with CTB as opposed to ENB biopsy, in the process expediting the diagnosis and saving valuable medical resources.

Abstract B28: Large and polymorphonuclear circulating cancer-associated cell with dual epithelial and macrophage/myeloid phenotype as a liquid biomarker in non-small cell lung cancer patients

Purpose: In addition to the FDA-approved definition of a circulating tumor cell (CTC), various phenotypes of circulating cancer-associated cells in the blood have been described. A distinct large (&gt;30μm), polymorphonuclear, circulating, cancer-associated cell (CCAC) with a dual epithelial and macrophage/myeloid phenotype has been identified in solid cancer patients. The goal of the study was to identify and further characterize these hybrid CCACs in non-small cell lung cancer (NSCLC) patients.

Experimental Design: In a prospective trial, 7.5 mL of peripheral blood was collected from 167 subjects. CTCs and CCACs were isolated by size-based exclusion with a microfilter and immunofluorescence staining was performed (cytokeratin (CK) 8/18/19, EpCAM, CD14/45, DAPI).

Results: 78 NSCLC patients and 89 control subjects (69 chronic smokers with and without lung nodules on screening LDCT, 20 healthy never-smokers) were enrolled. Distinct, large, polymorphonuclear CKpos/EpCAMpos/CD14/45pos CCACs were detected at lower rates than traditional CKpos/EpCAMpos/CD45negCTCs, but significantly higher in subjects with NSCLC in comparison to controls (p&lt;0.05). These cells and traditional CTCs were absent in 20 healthy controls. In contrast to CTCs, counts of large and polymorphonuclear CCACs were not associated with tumor stages. However, ≥2 CCACs correlated with significantly poorer survival and higher recurrence rates by uni- and multivariate analysis (p&lt;0.05).

Conclusions and Future Perspectives: This study shows that in addition to CTCs, a distinct, large, polymorphonuclear CCAC with a dual epithelial and macrophage/myeloid phenotype is associated with an aggressive clinical behavior in NSCLC patients. The biologic role of these unique cells will need to be further investigated, as these may have a potential impact on the immune response towards the cancer.

Citation Format: Yariswamy Manjunath, Diego M. Avella, Eric T. Kimchi, Kevin F. Staveley-O'Carroll, Chelsea B. Deroche, Gunagfu Li, Jussuf T. Kaifi. Large and polymorphonuclear circulating cancer-associated cell with dual epithelial and macrophage/myeloid phenotype as a liquid biomarker in non-small cell lung cancer patients [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B28.

18F-FDG PET/CT total lesion glycolysis is associated with circulating tumor cell counts in patients with stage I to IIIA non-small cell lung cancer

Background

In non-small cell lung cancer (NSCLC), ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) uptake determined by PET and presence of circulating tumor cells (CTCs) in the peripheral blood independently predict outcomes. For ¹⁸F-FDG PET/CT staging interpretation, standardized uptake values (SUV_max/avg) are routinely used in clinical reporting. The goal was to investigate whether ¹⁸F-FDG uptake measured by SUV_max/avg, but also measures of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) (MTV × SUV_avg), are associated with CTCs.

Methods

Prospectively, 7.5 mL blood was drawn from NSCLC patients at the time of staging 18F-FDG PET/CT and from healthy control subjects. CTCs were identified by immunofluorescent staining (CK8/18/19^pos/EpCAM^pos/CD45^neg/DAPI^pos nucleus). ¹⁸F-FDG PET/CTs were analyzed for SUV_max, SUV_avg, MTV, and TLG.

Results

In 16 NSCLC patients with stage I–IIIA, MTV and TLG, in contrast to SUV_max and SUV_avg, were positively associated with CTCs (linear regression analysis). No CTCs were detectable in 20 healthy control subjects.

Conclusions

This pilot study demonstrates that ¹⁸F-FDG PET/CT TLG correlates with CTCs in NSCLC patients without distant metastases. TLG might be a more appropriate marker for hematogenous micrometastatic potential than SUVs.

Tumor-Cell-Macrophage Fusion Cells as Liquid Biomarkers and Tumor Enhancers in Cancer

Although molecular mechanisms driving tumor progression have been extensively studied, the biological nature of the various populations of circulating tumor cells (CTCs) within the blood is still not well understood. Tumor cell fusion with immune cells is a longstanding hypothesis that has caught more attention in recent times. Specifically, fusion of tumor cells with macrophages might lead to the development of metastasis by acquiring features such as genetic and epigenetic heterogeneity, chemotherapeutic resistance, and immune tolerance. In addition to the traditional FDA-approved definition of a CTC (CD45-, EpCAM+, cytokeratins 8+, 18+ or 19+, with a DAPI+ nucleus), an additional circulating cell population has been identified as being potential fusions cells, characterized by distinct, large, polymorphonuclear cancer-associated cells with a dual epithelial and macrophage/myeloid phenotype. Artificial fusion of tumor cells with macrophages leads to migratory, invasive, and metastatic phenotypes. Further studies might investigate whether these have a potential impact on the immune response towards the cancer. In this review, the background, evidence, and potential relevance of tumor cell fusions with macrophages is discussed, along with the potential role of intercellular connections in their formation. Such fusion cells could be a key component in cancer metastasis, and therefore, evolve as a diagnostic and therapeutic target in cancer precision medicine.

An Oncogenic Hepatocyte-Induced Orthotopic Mouse Model of Hepatocellular Cancer Arising in the Setting of Hepatic Inflammation and Fibrosis

The absence of a clinically relevant animal model addressing the typical immune characteristics of hepatocellular cancer (HCC) has significantly impeded elucidation of the underlying mechanisms and development of innovative immunotherapeutic strategies. To develop an ideal animal model recapitulating human HCC, immunocompetent male C57BL/6J mice first receive a carbon tetrachloride (CCl4) injection to induce liver fibrosis, then receive histologically-normal oncogenic hepatocytes from young male SV40 T antigen (TAg)-transgenic mice (MTD2) by intra-splenic (ISPL) inoculation. Androgen generated in recipient male mice at puberty initiates TAg expression under control of a liver-specific promoter. As a result, the transferred hepatocytes become cancer cells and form tumor masses in the setting of liver fibrosis/cirrhosis. This novel model mimics human HCC initiation and progression in the context of liver fibrosis/cirrhosis and reflects the most typical features of human HCC including immune dysfunction.

Disruption of oncogenic liver-intestine cadherin (CDH17) drives apoptotic pancreatic cancer death

Liver-intestine cadherin (CDH17) has been known to function as a tumor stimulator and diagnostic marker for almost two decades. However, its function in highly malignant pancreatic cancer (PC) has yet to be elucidated. Using different strategies including siRNA, shRNA, and CRISPR technology, we successfully induced knockdown and knockout of CDH17 in Panc02-H7 cells and established the corresponding stable cell lines. With these cells, we demonstrated that loss of CDH17 function not only suppressed Panc02-H7 cell growth in vitro but also significantly slowed orthotopic tumor growth in vivo, resulting in the significant life extension. In vitro studies demonstrated that impairing CDH17 inhibited cell proliferation, colony formation, and motility by mechanistically modulating pro- and anti-apoptosis events in PC cells, as CDH17 suppression obviously increased expression of Bad, cytochrome C, cleaved caspase 3, and cleaved PARP, and reduced expression of Bcl-2, Survivin, and pAkt. In vivo studies showed CDH17 knockout resulted in apoptotic PC tumor death through activating caspase-3 activity. Taken together, CDH17 functions as an oncogenic molecule critical to PC growth by regulating tumor apoptosis signaling pathways and CDH17 could be targeted to develop an anti-PC therapeutic approach.

Pulmonary metastasectomy for thyroid cancer as salvage therapy for radioactive iodine-refractory metastases

OBJECTIVES

Distant metastasis arising from thyroid cancer is rare but has been associated with significantly reduced long-term survival, especially when refractory to radioactive iodine ablation. We provide one of the largest studies worldwide reporting the outcome after salvage pulmonary metastasectomy for this entity, aiming to identify prognostic factors and to analyse surgical indication.

METHODS

We retrospectively analysed the medical records of 43 patients who had undergone pulmonary metastasectomy for radioactive iodine-refractory thyroid cancer from 1985 to 2016.

RESULTS

The median follow-up period was 77 (95% confidence interval 41-113) months. Twenty-three (53%) patients were alive at the time of analysis. The majority of tumours were follicular thyroid cancer by histology, with 23% identified as Hurthle cell subtype. Five- and 10-year disease-specific (DS) survival was 84% and 59%, respectively. Thirty-one (72%) patients underwent R0-resection with a 5- and 10-year DS survival of 100% and 77%, respectively. This was significantly reduced to 62% and 22% (P = 0.013) in case of incomplete resection, respectively. Ten years after R0-metastasectomy, 17 (55%) patients were recurrence-free. Systematic mediastinal lymphadenectomy was performed in 16 (37%) patients and was associated with improved long-term DS survival (10 years 88% vs 46%, P = 0.034). Moreover, a reduction of > 80% in serum thyroglobulin levels post-metastasectomy correlates with better long-term DS survival (10 years 81% vs 36%, P = 0.007).

CONCLUSIONS

Pulmonary metastasectomy is associated with good survival for selected patients with radioactive iodine-refractory metastases of differentiated thyroid cancer, especially if R0-resection can be achieved. Moreover, it is worth considering whether a significant reduction of tumour load, as indicated by thyroglobulin serum levels, seems possible.

Oesophageal Doppler guided goal-directed haemodynamic therapy in thoracic surgery - a single centre randomized parallel-arm trial

Background

Postoperative pulmonary and renal complications are frequent in patients undergoing lung surgery. Hyper- and hypovolaemia may contribute to these complications. We hypothesized that goal-directed haemodynamic management based on oesophageal Doppler monitoring would reduce postoperative pulmonary complications in a randomized clinical parallel-arm trial.

Methods

One hundred patients scheduled for thoracic surgery were randomly assigned to either standard haemodynamic management (control group) or goal-directed therapy (GDT group) guided by an oesophageal Doppler monitoring-based algorithm. The primary endpoint was postoperative pulmonary complications, including spirometry. Secondary endpoints included haemodynamic variables, renal, cardiac, and neurological complications, and length of hospital stay. The investigator assessing outcomes was blinded to group assignment.

Results

Forty-eight subjects of each group were analysed. Compared to the control group, fewer subjects in the GDT group developed postoperative pulmonary complications (6 vs. 15 patients; P  = 0.047), while spirometry did not differ between groups. Compared to the control group, patients of the GDT group showed higher cardiac index (2.9 vs. 2.1 [l min - 1 m  - 2 ]; P  < 0.001) and stroke volume index (43 vs. 34 [ml m 2 ]; P  < 0.001) during surgery. Renal, cardiac and neurological complications did not differ between groups. Length of hospital stay was shorter in the GDT compared to the control group (9 vs. 11 days; P  = 0.005).

Conclusions

Compared to standard haemodynamic management, oesophageal Doppler monitor-guided GDT was associated with fewer postoperative pulmonary complications and a shorter hospital stay.

Clinical trial registration.

The study was registered in the German Clinical Trials Register (DRKS 00006961). https://drks-neu.uniklinik-freiburg.de/drks_web/.

Sunitinib and Sorafenib Modulating Antitumor Immunity in Hepatocellular Cancer

Sorafenib and sunitinib are multiple tyrosine kinase inhibitors. Both of them have been approved by the US FDA in the treatment of patients with malignancies. In order to develop an effective and clinically useful chemoimmunotherapy modality against hepatocellular cancer (HCC), we investigate their tumoricidal and immune modulatory effect in the setting of HCC. In vitro experiments suggested that sunitinib and sorafenib both induced HCC cell apoptosis at an equivalent level, but stronger suppressive function to cell proliferation was detected in sorafenib. Correspondingly, treatment of tumor-bearing mice with sorafenib led to the suppression of tumor growth to a larger extent than sunitinib. Flow cytometry showed that treatment with sunitinib, not sorafenib, significantly reduced the frequency of regulatory T cells (Tregs) and myeloid-derived suppressive cells (MDSCs) in tumor-bearing mice; and allowed splenic lymphocytes to produce equivalent levels of IFN-γ and TNF-α in response to vaccination as that in wild type mice. This activation was not detected in control and sorafenib-treated tumor mice. In addition, treatment of tumor-bearing mice with sunitinib followed by adoptive transfer of tumor antigen-specific CD8⁺ T cells and immunization resulted in the additional suppression to tumor growth compared to sunitinib monotherapy. These results imply treatment with sunitinib, not sorafenib, is able to prevent tumor-induced immunotolerance and activate antitumorimmunity. Our data suggest that sunitinib may be a preferable chemotherapeutic agent to use in combination with immunotherapy for the treatment of HCC.

Nanoliposome C6-Ceramide Increases the Anti-tumor Immune Response and Slows Growth of Liver Tumors in Mice

BACKGROUND & AIMS

Ceramide, a sphingolipid metabolite, affects T-cell signaling, induces apoptosis of cancer cells, and slows tumor growth in mice. However, it has not been used as a chemotherapeutic agent because of its cell impermeability and precipitation in aqueous solution. We developed a nanoliposome-loaded C6-ceremide (LipC6) to overcome this limitation and investigated its effects in mice with liver tumors.

METHODS

Immune competent C57BL/6 mice received intraperitoneal injections of carbon tetrachloride and intra-splenic injections of oncogenic hepatocytes. As a result, tumors resembling human hepatocellular carcinomas developed in a fibrotic liver setting. After tumors formed, mice were given an injection of LipC6 or vehicle via tail vein every other day for 2 weeks. This was followed by administration, also via tail vein, of tumor antigen-specific (TAS) CD8⁺ T cells isolated from the spleens of line 416 mice, and subsequent immunization by intraperitoneal injection of tumor antigen-expressing B6/WT-19 cells. Tumor growth was monitored with magnetic resonance imaging. Tumor apoptosis, proliferation, and AKT expression were analyzed using immunohistochemistry and immunoblots. Cytokine production, phenotype, and function of TAS CD8⁺ T cells and tumor-associated macrophages (TAMs) were studied with flow cytometry, real-time polymerase chain reaction (PCR), and ELISA. Reactive oxygen species (ROS) in TAMs and bone marrow-derived macrophages, induced by colony stimulating factor 2 (GMCSF or CSF2) or colony stimulating factor 1 (MCSF or CSF1), were detected using a luminescent assay.

RESULTS

Injection of LipC6 slowed tumor growth by reducing tumor cell proliferation and phosphorylation of AKT, and increasing tumor cell apoptosis, compared with vehicle. Tumors grew more slowly in mice given the combination of LipC6 injection and TAS CD8⁺ T cells followed by immunization compared with mice given vehicle, LipC6, the T cells, or immunization alone. LipC6 injection also reduced numbers of TAMs and their production of ROS. LipC6 induced TAMs to differentiate into an M1 phenotype, which reduced immune suppression and increased activity of CD8⁺ T cells. These results were validated by experiments with bone marrow-derived macrophages induced by GMCSF or MCSF.

CONCLUSIONS

In mice with liver tumors, injection of LipC6 reduces the number of TAMs and the ability of TAMs to suppress the anti-tumor immune response. LipC6 also increases the anti-tumor effects of TAS CD8⁺ T cells. LipC6 might therefore increase the efficacy of immune therapy in patients with hepatocellular carcinoma.

Sunitinib represses regulatory T cells to overcome immunotolerance in a murine model of hepatocellular cancer

Successful development of immunotherapeutic strategies for hepatocellular cancer (HCC) has been impeded by limited understanding of tumor-induced profound tolerance and lack of a clinically faithful HCC model. Recently, we developed a novel model that recapitulates typical features of human HCC. Using this clinically relevant model, we demonstrate that tumor growth impairs host immunity and causes a profound exhaustion of tumor antigen-specific (TAS) CD8⁺ T cells. Increase in frequency and suppressive function of regulatory T cells (Tregs) is critically involved in this tumor-induced immune dysfunction. We further demonstrate that sunitinib suppresses Tregs and prevents tumor-induced immune tolerance, allowing TAS immunization to activate endogenous CD8⁺ T cells. As a result, this combinational strategy delays tumor growth. Importantly, the additional integration of exogenous naïve TAS CD8⁺ T cells by adoptive cell transfer (ACT) leads to the elimination of the established tumors without recurrence and promotes long-term survival of the treated mice. Mechanistically, sunitinib treatment primes the antitumor immune response by significantly decreasing Treg frequency, reducing TGF-β and IL-10 production by Tregs, and also protecting TAS CD8⁺ T cells from tumor-induced deletion in the setting of HCC. Taken together, sunitinib quantitatively and qualitatively modifies Tregs to overcome tumor-induced immune deficiency, suggesting the potential of sunitinib as a therapeutic immune activator for HCC control.

The Diagnosis and Treatment of Bronchopulmonary Carcinoid

BACKGROUND

The spectrum of primary neuroendocrine tumors of the lungs ranges from typical carcinoid tumors, which are relatively benign, to highly aggressive small-cell carcinoma. In this review, we summarize the treatment of bronchopulmonary carcinoid, a disease with an incidence of 0.5 per 100,000 persons per year in Western countries.

METHOD

We selectively searched the PubMed database for scientific evidence on the treatment of bronchopulmonary carcinoid, considering only articles published up to February 2015. We also performed a survival analysis of 84 patients with this disease who underwent interdisciplinary treatment at the University of Freiburg Medical Center.

RESULTS

Carcinoid tumors account for less than 1% of all lung tumors. They manifest themselves clinically with cough (35%), hemoptysis (25%), and/or bronchial obstruction (40%), depending on their location, size, and pattern of growth. 30% of patients are asymptomatic, and less than 1% have hormone-associated symptoms. Typical and atypical carcinoid tumors are distinguished on a histological basis; the histologic differential diagnosis also includes large-cell neuroendocrine tumors and small-cell carcinoma of the lung. 80% of patients who undergo resection of typical carcinoid tumors survive at least 10 years. Atypical carcinoid tumors recur more commonly than typical ones. If the mediastinal lymph nodes are involved, adjuvant treatment should be considered.

CONCLUSION

Because of their rarity, the treatment of bronchopulmonary carcinoid tumors presents an interdisciplinary challenge. Surgical resection, the treatment of choice for local carcinoid tumors, generally leads to long-term survival. The existing registers should be made more comprehensive so that the treatment of this disease can be better in the future.

Perioperative circulating tumor cell detection: Current perspectives

Primary cancer resections and in selected cases surgical metastasectomies significantly improve survival, however many patients develop recurrences. Circulating tumor cells (CTCs) function as an independent marker that could be used in the prognostication of different cancers. Sampling of blood and bone marrow compartments during cancer resections is a unique opportunity to increase individual tumor cell capture efficiency. This review will address the diagnostic and therapeutic potentials of perioperative tumor isolation and highlight the focus of future studies on characterization of single disseminated cancer cells to identify targets for molecular therapy and immune escape mechanisms.

Circulating tumor cell isolation during resection of colorectal cancer lung and liver metastases: a prospective trial with different detection techniques

BACKGROUND

Colorectal cancer (CRC) metastasectomy improves survival, however most patient develop recurrences. Circulating tumor cells (CTCs) are an independent prognostic marker in stage IV CRC. We hypothesized that CTCs can be enriched during metastasectomy applying different isolation techniques.

METHODS

25 CRC patients undergoing liver (16 (64%)) or lung (9 (36%)) metastasectomy were prospectively enrolled (clinicaltrial.gov identifier: NCT01722903). Central venous (liver) or radial artery (lung) tumor outflow blood (7.5 ml) was collected at incision, during resection, 30 min after resection, and on postoperative day (POD) 1. CTCs were quantified with 1. EpCAM-based CellSearch® system and 2. size-based isolation with a novel filter device (FMSA). CTCs were immunohistochemically identified using CellSearch®'s criteria (cytokeratin 8/18/19+, CD45- cells containing a nucleus (DAPI+)). CTCs were also enriched with a centrifugation technique (OncoQuick®).

RESULTS

CTC numbers peaked during the resection with the FMSA in contrast to CellSearch® (mean CTC number during resection: FMSA: 22.56 (SEM 7.48) (p = 0.0281), CellSearch®: 0.87 (SEM ± 0.44) (p = 0.3018)). Comparing the 2 techniques, CTC quantity was significantly higher with the FMSA device (range 0-101) than CellSearch® (range 0-9) at each of the 4 time points examined (P < 0.05). Immunofluorescence staining of cultured CTCs revealed that CTCs have a combined epithelial (CK8/18/19) and macrophage (CD45/CD14) phenotype.

CONCLUSIONS

Blood sampling during CRC metastasis resection is an opportunity to increase CTC capture efficiency. CTC isolation with the FMSA yields more CTCs than the CellSearch® system. Future studies should focus on characterization of single CTCs to identify targets for molecular therapy and immune escape mechanisms of cancer cells.

Circulating tumor cell levels are elevated in colorectal cancer patients with high tumor burden in the liver

BACKGROUND

Metastatic spread is the most common cause of cancer-related death in colorectal cancer (CRC) patients, with the liver being the mostly affected organ. Circulating tumor cells (CTCs) are a prognostic marker in stage IV CRC. We hypothesized that tumor burden in the liver correlates with CTC quantity.

METHODS

Blood (7.5 ml) was prospectively collected from 24 patients with novel stage IV CRC diagnosis. Baseline EpCAM+ CTCs were analyzed with the FDA-approved CellSearch® system. Clinicopathological data were collected, and hepatic tumor burden was determined by radiographic liver volumetry with contrast-enhanced CT scans. CRC primary tumors were immunohistochemically stained for EpCAM expression with BerEP4 monoclonal antibody. Statistical analyses were performed using 2-sample T-test, non-parametric Wilcoxon Rank-Sum test, and Fisher's exact test.

RESULTS

CTCs were detected n 17 (71%) of 24 patients. The overall mean CTC number as determined by EpCAM-based CellSearch® detection was 6.3 (SEM 2.9). High baseline CTC numbers (≥3) correlated significantly with a high tumor/liver ratio (≥30%), and with high serum CEA levels, as determined by two-sample T-test on log-transformed data and by Fisher's Exact test on categorical data analysis (P < 0.05). The CRC primary tumors were consistently expressing EpCAM by immunostaining.

CONCLUSIONS

High tumor burden in the liver and high baseline serum CEA levels are associated with high number of baseline CTCs in stage IV CRC patients. Future studies should further investigate the biological role and expression patterns of single CTCs in cancer patients to further improve personalized treatment strategies.

[Typical and Atypical Carcinoids of the Lung: a Surgical Treatment Strategy]

Pulmonary typical (TC) and atypical carcinoids (AC) are lung tumors with neuroendocrine differentiation. Pulmonary carcinoids account for < 2 % of all lung cancers and the incidence is around 0,5/100 000. Depending on localization and extension they present incidentally or symptomatically with cough, hemoptysis and postobstructive pneumonia. Less than 1 % are associated with endocrine activity. TC and AC are differentiated by defined histopathologic criteria (mitotic rate, necrosis). Patients with TC have excellent long-term survival after non-anatomical lung resection. AC are associated with higher recurrence rates and anatomical lung resection should be preferred. Radical mediastinal lymph node dissection should be performed for both TC and AC. Complete surgical resection is the most significant prognostic factor for localized carcinoids. Surgical metastasectomy should also be considered in case of resectable metastatic disease.

Pleural space infections after image-guided percutaneous drainage of infected intraabdominal fluid collections: a retrospective single institution analysis

Background

Percutaneous drainage of infected intraabdominal fluid collections is preferred over surgical drainage due to lower morbidity and costs. However, it can be a challenging procedure and catheter insertion carries the potential to contaminate the pleural space from the abdomen. This retrospective analysis demonstrates the clinical and radiographic correlation between percutaneous drainage of infected intraabdominal collections and the development of iatrogenic pleural space infections.

Methods

A retrospective single institution analysis of 550 consecutive percutaneous drainage procedures for intraabdominal fluid collections was performed over 24 months. Patient charts and imaging were reviewed with regard to pleural space infections that were attributed to percutaneous drain placements. Institutional review board approval was obtained for conduct of the study.

Results

6/550 (1.1%) patients developed iatrogenic pleural space infections after percutaneous drainage of intraabdominal fluid collections. All 6 patients presented with respiratory symptoms and required pleural space drainage (either by needle aspiration or chest tube placement), 2 received intrapleural fibrinolytic therapy and 1 patient had to undergo surgical drainage. Pleural effusion cultures revealed same bacteria in both intraabdominal and pleural fluid in 3 (50%) cases. A video with a dynamic radiographic sequence demonstrating the contamination of the pleural space from percutaneous drainage of an infected intraabdominal collection is included.

Conclusions

Iatrogenic pleural space infections after percutaneous drainage of intraabdominal fluid collections occur at a low incidence, but the pleural empyema can be progressive requiring prompt chest tube drainage, intrapleural fibrinolytic therapy or even surgery. Expertise in intraabdominal drain placements, awareness and early recognition of this complication is critical to minimize incidence, morbidity and mortality in these patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12893-015-0030-4) contains supplementary material, which is available to authorized users.

Determinants of repeat curative intent surgery in colorectal liver metastasis

INTRODUCTION

Following curative intent surgery (CIS) for colorectal liver metastasis (CRLM), repeat CIS for recurrence improves survival. The factors associated with repeat CIS are not widely reported.

METHODS

An institutional database (January 2002-December 2012) was reviewed to evaluate factors influencing repeat CIS.

RESULTS

One hundred sixty-three patients with colorectal liver metastasis (CRLM) underwent successful CIS. Median follow-up and disease-free interval (DFI) was 33 and 16 months, respectively. After initial CIS, 102 patients (63%) recurred. Fifty-three patients (52%) underwent a repeat CIS. After repeat CIS, 33 patients (62%) developed a second recurrence, and in 13 patients (39%), a third CIS was possible. DFI decreased following initial CIS (first CIS vs. second CIS vs. third CIS [20 vs. 15 vs. 8.5 months], p < 0.001). Overall 5-year survival in all patients was 55%; patients who recurred had a 5-year survival of 67% if they underwent repeat CIS vs. 7.8% if they were managed palliatively. Second CIS was less likely with a postoperative complication, other/multifocal recurrence, or DFI <12 months.

CONCLUSION

Despite high recurrence and decreasing DFI, repeat CIS provides a survival benefit. Postoperative complications, DFI, number, and pattern of recurrence influence the decision to pursue repeat CIS.

Overall survival by pattern of recurrence following curative intent surgery for colorectal liver metastasis

BACKGROUND

Following curative intent surgery (CIS) for colorectal liver metastasis (CRLM), patterns of recurrence and subsequent survival outcomes are not widely reported.

METHODS

An institutional database (January 2002-December 2012) was reviewed to evaluate patterns of recurrence following CIS for CRLM.

RESULTS

163 patients with CRLM underwent successful CIS. Median follow-up and disease-free interval were 33 and 16 months, respectively. 5-year overall survival (OS) was 55%. After initial CIS, 102 (63%) patients recurred: liver-44% (5-year OS 55%), lung-15% (5-year OS 45%), and other/multifocal-41% (5-year OS 24%). OS for isolated liver and lung recurrences were not significantly different. Liver only recurrence was associated with 1-5 mm liver resection margins (P = 0.048). Lung only recurrence was associated with extrahepatic metastasis (at the time of initial CRLM) (P = 0.025). Other/multifocal recurrence was associated with bilobar CRLM (P = 0.026), and extrahepatic metastasis (P = 0.028).

CONCLUSIONS

Patterns of recurrence following CIS for CRLM have important implications for OS. 5-year OS was similar between isolated lung and liver recurrences. During CIS, decreased liver resection margin may be associated with increased risk of liver only recurrence. Patients with aggressive primary or metastatic liver disease are at higher risk for pulmonary or other/multifocal recurrence.