In-Depth Proteome Profiling of Small Extracellular Vesicles Isolated from Cancer Cell Lines and Patient Serum.

Extracellular vesicle (EV) secretion has been observed in many types of both normal and tumor cells. EVs contain a variety of distinctive cargoes, allowing tumor-derived serum proteins in EVs to act as a minimally invasive method for clinical monitoring. We have undertaken a comprehensive study of the protein content of the EVs from several cancer cell lines using direct data-independent analysis. Several thousand proteins were detected, including many classic EV markers such as CD9, CD81, CD63, TSG101, and Syndecan-1, among others. We detected many distinctive cancer-specific proteins, including several known markers used in cancer detection and monitoring. We further studied the protein content of EVs from patient serum for both normal controls and pancreatic cancer and hepatocellular carcinoma. The EVs for these studies have been isolated by various methods for comparison, including ultracentrifugation and CD9 immunoaffinity column. Typically, 500-1000 proteins were identified, where most of them overlapped with the EV proteins identified from the cell lines studied. We were able to identify many of the cell-line EV protein markers in the serum EVs, in addition to the large numbers of proteins specific to pancreatic and HCC cancers.

Dietary intake, obesity, and physical activity in association with biliary tract cancer risk: Results from meta-analyses of individual-level data from prospective cohort studies of 723,326 adults.

Biliary tract cancer (BTC) is a rare and aggressive malignancy with increasing incidence. Most BTC cases are diagnosed with metastatic disease which carries a 5-year survival rate of <5%. Physical activity, diet, and obesity might be associated with BTC risk, but studies have been limited particularly in African descendants. We addressed this knowledge gap by evaluating associations of BTC risk with obesity, physical activity, and dietary intakes in 723,326 adult participants in four cohort studies conducted in China, the United Kingdom, and the United States. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) in each cohort; results were combined using meta-analysis. All cohorts had ≥11 median follow-up years with 839 incident BTC cases combined. BTC risk was positively associated with body mass index (BMI) and waist-to-hip ratio (WHR) whereas physical activity, fruit intake, and fish intake were inversely associated. HR and (95% CI) comparing BMI >35.0 to 18.5-24.9: 1.71 (1.26, 2.31), p-trend <.0001; comparing BMI-adjusted WHR top to bottom quartile: 1.20 (0.94, 1.53), p-trend = .05; comparing ≥15-0 metabolic equivalent task-hours/week 0.76 (0.61, 0.94), p-trend = .009; comparing highest to lowest intake tertile for fruit and fish 0.79 (0.66, 0.95), p-trend = .01; 0.82 (0.68, 0.98), p-trend = .04, respectively. Associations were, in general, similar across ancestry groups. Our study provides strong evidence for important roles of obesity, diet, and physical activity in BTC etiology and stresses the need for lifestyle modification to combat the rising incidence of this fatal malignancy.

Associations between pre-diagnostic plasma metabolites and biliary tract cancer risk in the prospective UK Biobank cohort.

Biliary tract cancer (BTC) is potentially influenced by metabolic dysregulation yet previous metabolomic evaluations are limited. To address this gap, we prospectively investigated associations of blood metabolites and BTC risk in the UK biobank cohort study. We used Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) between 249 plasma metabolites per standard deviation and BTC risk in 232,781 participants. We implemented exploratory factor analyses and evaluated associations between factors and BTC risk. Associations at p-value<0.001 were considered statistically significant after multiple comparison adjustments. In a median follow-up of 11.8 years, we identified 268 first primary incident BTC cases. Of 49 biomarkers significantly associated with BTC risk, 12% were fatty acids, and 49%, 31%, and 8% were cholesterol, triglyceride, and phospholipid to total lipids ratios, respectively. Multiple cholesterol ratios were inversely associated with BTC with HRs (95% CIs) of 0.74 (0.65-0.84), p<6.0x10-6. Conversely, a triglyceride ratio was positively associated with BTC with an HR (95% CI) of 1.40 (1.22-1.61), p=2.5x10-6. Congruently, a factor high in cholesterol measures and low in triglyceride measures was inversely associated with BTC. Multiple metabolite biomarkers were associated with BTC risk, suggesting metabolism has a substantial role in BTC etiology.

PARP inhibitor therapy in patients with IDH1 mutated cholangiocarcinoma.

BACKGROUND: Isocitrate dehydrogenase 1 (IDH1) missense mutations occur at a frequency of 10%-15% in intrahepatic cholangiocarcinoma (iCCA). IDH1 mutations result in accumulation of (R)-2-hydroxyglutarate, an oncometabolite that leads to DNA hypermethylation and impairment of homologous recombination (HR). Impairment of HR results in a "BRCAness" phenotype which may confer sensitivity to poly(ADP ribose) polymerase (PARP) inhibition. METHODS: We conducted a retrospective cohort review to identify patients with advanced, IDH1 mutated iCCA treated with a PARP inhibitor (PARPi) at the University of Michigan between 2018 and 2023. Patients are described with respect to prior lines of therapy, response to platinum-based chemotherapy, and progression-free survival (PFS) and overall survival (OS) from the time of PARPi initiation. RESULTS: Between 2018 and 2023 we identified 40 patients with IDH1 mutated iCCA of which 6 patients were treated with a PARPi as monotherapy or in combination with an ATR inhibitor or anti-PD-1 immune checkpoint inhibitor. Majority of patients (n = 5) carried an IDH1 R132C mutation per tissue-based next generation sequencing. All patients had previously received at least one line of cisplatin-based systemic therapy for advanced disease prior to treatment with PARPi. PFS and OS from time of PARPi initiation ranged from 1.4 to 18.5 months and 2.8 to 42.4 months, respectively. Best response on PARPi therapy included 2 partial responses. CONCLUSION: This is the first case series to describe PARPi treatment in IDH1 mutated iCCA. Results underscore the limitation of PARPi monotherapy, potentially support combined PARPi therapies, and highlight a need for effective treatment options for patients with IDH1 mutated iCCA.

Survival Analysis of 1140 Patients with Biliary Cancer and Benefit from Concurrent Renin-Angiotensin Antagonists, Statins, or Aspirin with Systemic Therapy.

BACKGROUND: Patients with advanced biliary tract cancers (BTCs) have poor prognoses and limited therapeutic options. Renin-angiotensin antagonists (ACE-I/ARBs), statins, and aspirin may have potential anti-tumorigenic effects and decrease mortality per retrospective analyses in some solid tumors. OBJECTIVE: To evaluate the efficacy of ACE-Is/ARBs, statins, and/or aspirin concurrent to first-line systemic therapy in patients with advanced or metastatic BTC. METHODS: Adult patients at University of Michigan with pathologic confirmation of BTC between January 2010 and December 2020 were included in this retrospective analysis. RESULTS: Of 1140 patients who met eligibility, a total of 509 patients received one or more concomitant medication(s) of interest in conjunction with systemic therapy for advanced cancer. In the total cohort, the overall survival for locally advanced patients (N = 305) was 16.3 months (95% CI: 12.1-18.6), and metastatic patients (N = 512) 8.6 months (95% CI: 7.6-9.5); P < .0001. Within this concomitant medication cohort, patients with locally advanced stage (n = 132) experienced significantly longer progression-free survival (9.8 vs 4.5; P < 0.0001), and overall survival (17.4 vs 10.6; P < 0.0001) than those with metastatic (n = 297) cancer, respectively. Patients who received ACE-Is/ARBs, statins, and/or aspirin (n = 245) versus not (n = 264) concurrent with systemic anti-cancer therapy did not experience improved progression-free (5.5 vs 5.5 months; hazard ratio (HR) 1.1; P = 0.51), or overall survival (12.3 vs 12.6 months; HR 1.1; P = 0.18), respectively. CONCLUSION: In contrast to prior studies, no progression free or overall survival benefit in patients with advanced BTC from concurrent use of ACE-I/ARBs, statin, and/or aspirin with systemic therapy was observed when assessed by BTC subtype or specific systemic therapy regimen.

Integrated Workflow for the Label-Free Isolation and Genomic Analysis of Single Circulating Tumor Cells in Pancreatic Cancer.

As pancreatic cancer is the third deadliest cancer in the U.S., the ability to study genetic alterations is necessary to provide further insight into potentially targetable regions for cancer treatment. Circulating tumor cells (CTCs) represent an especially aggressive subset of cancer cells, capable of causing metastasis and progressing the disease. Here, we present the Labyrinth-DEPArray pipeline for the isolation and analysis of single CTCs. Established cell lines, patient-derived CTC cell lines and freshly isolated CTCs were recovered and sequenced to reveal single-cell copy number variations (CNVs). The resulting CNV profiles of established cell lines showed concordance with previously reported data and highlight several gains and losses of cancer-related genes such as FGFR3 and GNAS. The novel sequencing of patient-derived CTC cell lines showed gains in chromosome 8q, 10q and 17q across both CTC cell lines. The pipeline was used to process and isolate single cells from a metastatic pancreatic cancer patient revealing a gain of chromosome 1q and a loss of chromosome 5q. Overall, the Labyrinth-DEPArray pipeline offers a validated workflow combining the benefits of antigen-free CTC isolation with single cell genomic analysis.

Morphomics, Survival, and Metabolites in Patients With Metastatic Pancreatic Cancer.

Importance: Associations of body mass index (BMI) with survival in pancreatic ductal adenocarcinoma (PDA) have substantial variability in literature, potentially due to heterogeneous patient populations and retrospective analyses. Additionally, BMI may inadequately describe body composition (ie, morphomics; including subcutaneous and visceral fats, muscle, and fascia), which might have independent biological roles and associations with survival. Objective: To study the associations of BMI and morphomics with survival and metabolomics in metastatic PDA. Design, Setting, and Participants: This cohort study prospectively collected patient data, imaging, and serum on the phase 3 trial (Avenger500), which investigated the efficacy and safety of 5-fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFIRINOX) versus modified FOLFIRINOX plus devimistat. The randomized trial accrued 528 patients with chemotherapy-naive, metastatic PDA from Europe, Israel, Korea, and the US between 2018 and 2020. In the present study, per-protocol patients with L1 to L4, T10 to T12 vertebral levels were evaluated. Data analysis occurred from January 2023 to April 2024. Exposure: Patient data were collected by clinical staff. Morphomics were analyzed from baseline imaging. Metabolites were extracted from baseline serum. Main Outcome and Measures: A multifaceted statistical approach evaluated associations of BMI and morphomics with progression-free survival (PFS) and overall survival (OS). Associations of morphomics with metabolites were also studied. Results: Of the 528 initial patients, 476 (median [IQR] age, 63 [56-68] years; 280 male [58.8%]; median [IQR] BMI, 25.0 [22.1-25.9]) were evaluable for the present study. BMI (obese [≥30] compared with normal [18.5-24.9]) was not associated with OS (hazard ratio [HR], 0.90; 95% CI, 0.67-1.22; P for trend = .33). More subcutaneous fat was associated with longer OS (HR, 0.62; 95% CI, 0.41-0.94; P for trend = .02). Higher visceral fat density was associated with shorter PFS (HR, 1.74; 95% CI, 1.23-2.48; P for trend = .002) and OS (HR, 1.50; 95% CI, 1.12-2.00; P for trend = .008). A higher muscle-to-fascia ratio was associated with longer PFS (HR, 0.58; 95% CI, 0.40-0.84; P for trend = .005) and OS (HR, 0.56; 95% CI, 0.41-0.75; P for trend = 1.7 × 10-4). Subcutaneous fat was positively associated with long-chain fatty acid metabolism including pristanic acid, decanoylcarnitine, decenoylcarnitine, and octanoylcarnitine. Muscle-to-fascia was positively associated with metabolites including acetylcarnosine (ß = 0.34; 95% CI, 0.21-0.47; P = 1.27 × 10-6). Conclusions and Relevance: In cohort study of patients with metastatic PDA, BMI was not associated with survival. Higher visceral fat density, subcutaneous fat area, and muscle-to-fascia ratio were associated with survival independent of BMI. The latter 2 were associated with higher levels of animal product metabolism. These findings could represent novel focuses for prognostication and intervention to improve survival of patients with PDA.

Characterization of undifferentiated carcinomas of the pancreas with and without osteoclast-like giant cells.

BACKGROUND: Undifferentiated carcinoma (UC) is a rare subtype of pancreatic cancer differentiated from UC with osteoclast-like giant cells (UC-OGC) in 2019, impacting interpretation of literature that does not distinguish these subtypes. We sought to identify translationally relevant differences between these two variants and as compared to pancreatic ductal adenocarcinoma (PDAC). METHODS: We characterized clinical and multiomic differences between UC (n = 32) and UC-OGC (n = 15) using DNA-sequencing (seq), RNA-seq, and multiplex immunofluorescence (mIF) and compared these findings to PDAC. RESULTS: Characteristics at diagnosis were similar between UC and UC-OGC, though UC-OGC was more resectable (p = .009). Across all stages, median overall survival (OS) was shorter for UC than UC-OGC (0.4 vs 10.8 years, respectively; p = .003). This shorter survival was retained after stratification by resection, albeit without statistical significance (1.8 vs 11.9 years, respectively; p = .08). In a subset of patients with available tissue, the genomic landscape was similar between UC (n = 9), UC-OGC (n = 5), and PDAC (n = 159). Bulk RNA-seq was deconvoluted and, along with mIF in UC (n = 13), UC-OGC (n = 5), and PDAC (n = 16), demonstrated statistically significantly increased antigen-presenting cells (APCs), including M2 macrophages and NK cells, and decreased cytotoxic and regulatory T cells (Tregs) in UC and UC-OGC vs PDAC. Findings were similar between UC and UC-OGC except decreased Tregs in UC-OGC (p = .04). CONCLUSIONS: In this series, UC is more aggressive than UC-OGC with these variants having more APCs and fewer Tregs than PDAC, suggesting potential for immune-modulating therapies in treatment of these pancreatic cancer subtypes.

Devimistat in Combination with Gemcitabine and Cisplatin in Biliary Tract Cancer: Preclinical Evaluation and Phase Ib Multicenter Clinical Trial (BilT-04).

PURPOSE: Devimistat (CPI-613) is a novel inhibitor of tumoral mitochondrial metabolism. We investigated the effect of devimistat in vitro and in a phase Ib clinical trial in patients with advanced biliary tract cancer (BTC). PATIENTS AND METHODS: Cell viability assays of devimistat ± gemcitabine and cisplatin (GC) were performed and the effect of devimistat on mitochondrial respiration via oxygen consumption rate (OCR) was evaluated. A phase Ib/II trial was initiated in patients with untreated advanced BTC. In phase Ib, devimistat was infused over 2 hours in combination with GC on days 1 and 8 every 21 days with a primary objective to determine the recommended phase II dose (RP2D). Secondary objectives included safety, overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). RESULTS: In vitro, devimistat with GC had a synergistic effect on two cell lines. Devimistat significantly decreased OCR at higher doses and in arms with divided dosing. In the phase Ib trial, 20 patients received a median of nine cycles (range, 3-19). One DLT was observed, and the RP2D of devimistat was determined to be 2,000 mg/m2 in combination with GC. Most common grade 3 toxicities included neutropenia (n = 11, 55%), anemia (n = 4, 20%), and infection (n = 3, 15%). There were no grade 4 toxicities. After a median follow-up of 15.6 months, ORR was 45% and median PFS was 10 months (95% confidence interval, 7.1-14.9). Median OS is not yet estimable. CONCLUSIONS: Devimistat in combination with GC is well tolerated and has an acceptable safety profile in patients with untreated advanced BTC.

Genomics driven precision oncology in advanced biliary tract cancer improves survival.

BACKGROUND: Biliary tract cancers (BTCs) including intrahepatic, perihilar, and distal cholangiocarcinoma as well as gallbladder cancer, are rare but aggressive malignancies with few effective standard of care therapies. METHODS: We implemented integrative clinical sequencing of advanced BTC tumors from 124 consecutive patients who progressed on standard therapies (N=92 with MI-ONCOSEQ and N=32 with commercial gene panels) enrolled between 2011-2020. RESULTS: Genomic profiling of paired tumor and normal DNA and tumor transcriptome (RNA) sequencing identified actionable somatic and germline genomic alterations in 54 patients (43.5%), and potentially actionable alterations in 79 (63.7%) of the cohort. Of these, patients who received matched targeted therapy (22; 40.7%) had a median overall survival of 28.1 months compared to 13.3 months in those who did not receive matched targeted therapy (32; P < 0.01), or 13.9 months in those without actionable mutations (70; P < 0.01). Additionally, we discovered recurrent activating mutations in FGFR2, and a novel association between KRAS and BRAF mutant tumors with high expression of immune modulatory protein NT5E (CD73) that may represent novel therapeutic avenues. CONCLUSIONS: Overall, the identification of actionable/ potentially actionable aberrations in a large proportion of cases, and improvement in survival with precision oncology supports molecular analysis and clinical sequencing for all patients with advanced BTC.

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.

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.

KRT17High/CXCL8+ tumor cells display both classical and basal features and regulate myeloid infiltration in the pancreatic cancer microenvironment.

PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) is generally divided in two subtypes, classical and basal. Recently, single cell RNA sequencing has uncovered the co-existence of basal and classical cancer cells, as well as intermediary cancer cells, in individual tumors. The latter remains poorly understood; here, we sought to characterize them using a multimodal approach. EXPERIMENTAL DESIGN: We performed subtyping on a single cell RNA sequencing dataset containing 18 human PDAC samples to identify multiple intermediary subtypes. We generated patient-derived PDAC organoids for functional studies. We compared single cell profiling of matched blood and tumor samples to measure changes in the local and systemic immune microenvironment. We then leveraged longitudinally patient-matched blood to follow individual patients over the course of chemotherapy. RESULTS: We identified a cluster of KRT17-high intermediary cancer cells that uniquely express high levels of CXCL8 and other cytokines. The proportion of KRT17High/CXCL8+ cells in patient tumors correlated with intra-tumoral myeloid abundance, and, interestingly, high pro-tumor peripheral blood granulocytes, implicating local and systemic roles. Patient-derived organoids maintained KRT17High/CXCL8+cells and induced myeloid cell migration in an CXCL8-dependent manner. In our longitudinal studies, plasma CXCL8 decreased following chemotherapy in responsive patients, while CXCL8 persistence portended worse prognosis. CONCLUSIONS: Through single cell analysis of PDAC samples we identified KRT17High/CXCL8+ cancer cells as an intermediary subtype, marked by a unique cytokine profile and capable of influencing myeloid cells in the tumor microenvironment and systemically. The abundance of this cell population should be considered for patient stratification in precision immunotherapy.

Synergistic Analysis of Circulating Tumor Cells Reveals Prognostic Signatures in Pilot Study of Treatment-Naïve Metastatic Pancreatic Cancer Patients.

Pancreatic ductal adenocarcinoma is typically diagnosed at late stages and has one of the lowest five-year survival rates of all malignancies. In this pilot study, we identify signatures related to survival and treatment response found in circulating tumor cells (CTCs). Patients with poor survival had increased mutant KRAS expression and deregulation of connected pathways such as PI3K-AKT and MAPK signaling. Further, in a subset of these patients, expression patterns of gemcitabine resistance mechanisms were observed, even prior to initiating treatment. This work highlights the need for identifying patients with these resistance profiles and designing treatment regimens to circumvent these mechanisms.

Pancreatic cancer is marked by complement-high blood monocytes and tumor-associated macrophages.

Pancreatic ductal adenocarcinoma (PDA) is accompanied by reprogramming of the local microenvironment, but changes at distal sites are poorly understood. We implanted biomaterial scaffolds, which act as an artificial premetastatic niche, into immunocompetent tumor-bearing and control mice, and identified a unique tumor-specific gene expression signature that includes high expression of C1qa, C1qb, Trem2, and Chil3 Single-cell RNA sequencing mapped these genes to two distinct macrophage populations in the scaffolds, one marked by elevated C1qa, C1qb, and Trem2, the other with high Chil3, Ly6c2 and Plac8 In mice, expression of these genes in the corresponding populations was elevated in tumor-associated macrophages compared with macrophages in the normal pancreas. We then analyzed single-cell RNA sequencing from patient samples, and determined expression of C1QA, C1QB, and TREM2 is elevated in human macrophages in primary tumors and liver metastases. Single-cell sequencing analysis of patient blood revealed a substantial enrichment of the same gene signature in monocytes. Taken together, our study identifies two distinct tumor-associated macrophage and monocyte populations that reflects systemic immune changes in pancreatic ductal adenocarcinoma patients.

Role of pelvic CT during surveillance of patients with resected biliary tract cancer.

BACKGROUND: The aim of the study was to identify the frequency of isolated pelvic metastasis with the goal of determining the utility of pelvic CT as a surveillance strategy in patients with resected biliary tract cancer (BTC). METHODS: Study eligibility criteria included patients 18 years or older with BTC who underwent R0 or R1 surgical resection at University of Michigan between 2004 and 2018, with a minimum 6-month disease-free surveillance period. CT and MRI reports were independently graded by two radiologists as positive (organ metastasis, peritoneal carcinomatosis, or enlarged lymph nodes), equivocal (borderline lymph nodes or non-nodular ascites), or negative (absence of or benign findings) in the abdomen and pelvis separately. A 3rd blinded radiologist reviewed all positive and equivocal scans. Clinic notes were reviewed to identify new or worsening signs and symptoms that would warrant an earlier pelvic surveillance scan. A 95% binomial proportion confidence interval was used to find the probability of isolated pelvic metastasis. RESULTS: BTC were anatomically classified as extra-hepatic (distal and hilar) cholangiocarcinoma (38; 25%), intra-hepatic cholangiocarcinoma (57; 38%), and gallbladder cancer (56; 37%). 151 patients met eligibility criteria, of which 123 (81%) had no pelvic metastasis, 51 (34%) had localized upper abdominal metastasis, and 23 (15%) had concomitant abdominal and pelvic metastasis. Median follow-up time was 19.2 months. One (0%) subject with resected BTC (intra-hepatic) developed isolated osseous pelvic metastasis during surveillance (95% CI 0.004-0.1; p = 0.0003). 3 (2%) subjects developed isolated simple ascites (equivocal grade) without concurrent upper abdominal metastasis. CONCLUSION: Isolated pelvic metastasis is a rare occurrence during surveillance in patients with resected BTCs, and therefore, follow-up pelvic CT in absence of specific symptoms may be unnecessary.

Multi-institutional retrospective analysis of FOLFIRI in patients with advanced biliary tract cancers.

BACKGROUND: Gemcitabine plus platinum is the standard of care first-line treatment for advanced biliary tract cancers (BTC). There is no established second-line therapy, and retrospective reviews report median progression-free survival (PFS) less than 3 mo on second-line therapy. 5-Fluorouracil plus irinotecan (FOLFIRI) is a commonly used regimen in patients with BTC who have progressed on gemcitabine plus platinum, though there is a paucity of data regarding its efficacy in this population. AIM: To assess the efficacy of FOLFIRI in patients with biliary tract cancers. METHODS: We retrospectively identified patients with advanced BTC who were treated with FOLFIRI at MD Anderson, University of Michigan and Mayo Clinic in Jacksonville. Data were collected on patient demographics, BTC subtype, response per RECIST v1.1, progression and survival. RESULTS: Ninety-eight patients were included of which 74 (75%) had metastatic and 24 (25%) had locally advanced disease at the time of treatment with FOLFIRI. The median age was 60 (range, 22-86) years. The number of patients with extrahepatic cholangiocarcinoma, gall bladder cancer and intrahepatic cholangiocarcinoma were 10, 17 and 71, respectively. FOLFIRI was used as 1st, 2nd, 3rd or 4th - Nth lines in 8, 50, 36 and 4 patients, respectively. Median duration on FOLFIRI in the entire cohort was 2.2 (range, 0.5-8.4) mo. The median PFS and overall survival were 2.4 (95% confidence interval (CI): 1.7-3.1) and 6.6 (95%CI: 4.7-8.4) mo, respectively. Median PFS for patients treated with FOLFIRI in 1st, 2nd, 3rd or 4th - Nth lines were 3.1, 2.5, 2.3 and 1.5 mo, respectively. Eighteen patients received concurrent bevacizumab (n = 13) or EGFR-targeted therapy (n = 5) with FOLFIRI, with a median PFS of 2.7 mo (95%CI: 1.7-5.1). CONCLUSION: In this largest multi-institution retrospective review of 98 patients with BTC treated with FOLFIRI, efficacy appears to be modest with outcomes similar to other cytotoxic chemotherapy regimens.

Tumour-reprogrammed stromal BCAT1 fuels branched-chain ketoacid dependency in stromal-rich PDAC tumours.

Branched-chain amino acids (BCAAs) supply both carbon and nitrogen in pancreatic cancers, and increased levels of BCAAs have been associated with increased risk of pancreatic ductal adenocarcinomas (PDACs). It remains unclear, however, how stromal cells regulate BCAA metabolism in PDAC cells and how mutualistic determinants control BCAA metabolism in the tumour milieu. Here, we show distinct catabolic, oxidative and protein turnover fluxes between cancer-associated fibroblasts (CAFs) and cancer cells, and a marked reliance on branched-chain α-ketoacid (BCKA) in PDAC cells in stroma-rich tumours. We report that cancer-induced stromal reprogramming fuels this BCKA demand. The TGF-ß-SMAD5 axis directly targets BCAT1 in CAFs and dictates internalization of the extracellular matrix from the tumour microenvironment to supply amino-acid precursors for BCKA secretion by CAFs. The in vitro results were corroborated with circulating tumour cells (CTCs) and PDAC tissue slices derived from people with PDAC. Our findings reveal therapeutically actionable targets in pancreatic stromal and cancer cells.

Multimodal Mapping of the Tumor and Peripheral Blood Immune Landscape in Human Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDA) is characterized by an immune-suppressive tumor microenvironment that renders it largely refractory to immunotherapy. We implemented a multimodal analysis approach to elucidate the immune landscape in PDA. Using a combination of CyTOF, single-cell RNA sequencing, and multiplex immunohistochemistry on patient tumors, matched blood, and non-malignant samples, we uncovered a complex network of immune-suppressive cellular interactions. These experiments revealed heterogeneous expression of immune checkpoint receptors in individual patient's T cells and increased markers of CD8+ T cell dysfunction in advanced disease stage. Tumor-infiltrating CD8+ T cells had an increased proportion of cells expressing an exhausted expression profile that included upregulation of the immune checkpoint TIGIT, a finding that we validated at the protein level. Our findings point to a profound alteration of the immune landscape of tumors, and to patient-specific immune changes that should be taken into account as combination immunotherapy becomes available for pancreatic cancer.