Immunotherapy and transplantation for hepatocellular carcinoma.

Immune checkpoint inhibitors (ICIs) have emerged as the primary treatment for advanced hepatocellular carcinoma (HCC) and have shown promise in the neoadjuvant setting prior to resection. Liver transplantation (LT) is the preferred treatment for unresectable early HCC or locally advanced disease post locoregional therapy, but the need for immunosuppression after LT conflicts with ICIs' immune augmenting effects. Neoadjuvant ICI may benefit select LT candidates, but challenges arise in understanding response indicators and managing post-LT risks. Reports of severe rejection after LT have raised concerns, though liver-specific factors may mitigate rejection risks, prompting exploration of pre-LT ICI usage. While focus has been on PD-1/PD-L1 inhibitors, the optimal pre-LT ICI regimen remains uncertain, and trials must emphasize careful patient selection and management. Living donor LT is advantageous because ICIs can be withheld for a predefined washout period. In the post-LT setting, use of ICIs is generally avoided, though a few reports suggest that PD-L1 expression in the transplanted liver may be a safety biomarker and that, despite the risk, ICI therapy may be better than supportive care for patients with otherwise-untreatable HCC recurrence. This expert opinion highlights the complexities in the management of HCC vis-à-vis LT. Prospective studies and biomarkers are needed to define safe and effective pre- and post-LT immunotherapy protocols.

Impact of pre-transplant immune checkpoint inhibitor use on post-transplant outcomes in HCC: A systematic review and individual patient data meta-analysis.

BACKGROUND & AIMS: Treatment with immune checkpoint inhibitors (ICIs) for hepatocellular carcinoma (HCC) prior to liver transplantation (LT) has been reported; however, ICIs may elevate the risk of allograft rejection and impact other clinical outcomes. This study aims to summarize the impact of ICI use on post-LT outcomes. METHODS: In this individual patient data meta-analysis, we searched databases to identify HCC cases treated with ICIs before LT, detailing allograft rejection, HCC recurrence, and overall survival. We performed Cox regression analysis to identify risk factors for allograft rejection. RESULTS: Among 91 eligible patients, with a median (IQR) follow-up of 690.0 (654.5) days, there were 24 (26.4%) allograft rejections, 9 (9.9%) HCC recurrences, and 9 (9.9%) deaths. Age (adjusted hazard ratio [aHR] per 10 years 0.72, 95% CI 0.53-0.99, p = 0.044) and ICI washout time (aHR per 1 week 0.92, 95% CI 0.86-0.99, p = 0.022) were associated with allograft rejection. The median (IQR) washout period for patients with ≤20% probability of allograft rejection was 94 (196) days. Overall survival did not differ between cases with and without allograft rejection (log-rank test, p = 0.2). Individuals with HCC recurrence had fewer median (IQR) ICI cycles than those without recurrence (4.0 [1.8] vs. 8.0 [9.0]; p = 0.025). The proportion of patients within Milan post-ICI was lower for those with recurrence vs. without (16.7% vs. 65.3%, p = 0.032). CONCLUSION: Patients have acceptable post-LT outcomes after ICI therapy. Age and ICI washout length relate to the allograft rejection risk, and a 3-month washout may reduce it to that of patients without ICI exposure. Number of ICI cycles and tumor burden may affect recurrence risk. Large prospective studies are necessary to confirm these associations. IMPACT AND IMPLICATIONS: This systematic review and individual patient data meta-analysis of 91 patients with hepatocellular carcinoma and immune checkpoint inhibitor use prior to liver transplantation suggest acceptable overall post-transplant outcomes. Older age and longer immune checkpoint inhibitor washout period have a significant inverse association with the risk of allograft rejection. A 3-month washout may reduce it to that of patients without immune checkpoint inhibitor exposure. Additionally, a higher number of immune checkpoint inhibitor cycles and tumor burden within Milan criteria at the completion of immunotherapy may predict a decreased risk of hepatocellular carcinoma recurrence, but this observation requires further validation in larger prospective studies.

Association of personalized and tumor-informed ctDNA with patient survival outcomes in pancreatic adenocarcinoma.

INTRODUCTION: Personalized and tumor-informed circulating tumor DNA (ctDNA) testing is feasible and allows for molecular residual disease (MRD) identification in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: In this retrospective analysis of commercial cases from multiple US institutions, personalized, tumor-informed, whole-exome sequenced, and germline-controlled ctDNA levels were quantified and analyzed in patients with PDAC. Plasma samples (n = 1329) from 298 clinically validated patients were collected at diagnosis, perioperatively (MRD-window; within 2-12 weeks after surgery, before therapy), and during surveillance (>12 weeks post-surgery if no ACT or starting 4 weeks post-ACT) from November 2019 to March 2023. RESULTS: Of the initially diagnosed patients with stages I-III PDAC who went for resection, the median follow-up time from surgery was 13 months (range 0.1-214). Positive ctDNA detection rates were 29% (29/100) and 29.6% (45/152) during the MRD and surveillance windows, respectively. Positive ctDNA detection was significantly associated with shorter DFS within the MRD window (median DFS of 6.37 months for ctDNA-positive vs 33.31 months for ctDNA-negative patients; HR: 5.45, P < .0001) as well as during the surveillance period (median DFS: 11.40 months for ctDNA-positive vs NR for ctDNA-negative; HR: 12.38, P < .0001). Additionally, DFS was significantly better with KRAS wildtype status followed by KRASG12R (HR: 0.99, P = .97), KRASG12D (HR: 1.42, P = .194), and worse with KRASG12V (HR: 2.19, P = .002) status. In multivariate analysis, ctDNA detection at surveillance was found to be the most significant prognostic factor for recurrence (HR: 24.28, P < .001). CONCLUSIONS: Perioperative tumor-informed ctDNA detection in PDAC is feasible across all stages and is associated with patient survival outcomes.

Molecular profiling in the management of hepatocellular carcinoma.

PURPOSE OF REVIEW: The purpose of this review is to both summarize the current knowledge of hepatocellular carcinoma molecular biology and to suggest a framework in which to prospectively translate this knowledge into patient care. This is timely as recent guidelines recommend increased use of these technologies to advance personalized liver cancer care. RECENT FINDINGS: The main themes covered here address germline and somatic genetic alterations recently discovered in hepatocellular carcinoma, largely owing to next generation sequencing technologies, and nascent efforts to translate these into contemporary practice. SUMMARY: Early efforts of translating molecular profiling to hepatocellular carcinoma care demonstrate a growing number of potentially actionable alterations. Still lacking are a consensus on what biomarkers and technologies to adopt, at what scale and cost, and how to integrate them most effectively into care.

The Uncharted Territories of Esophageal Cancer with Cardiac and Skeletal Muscle Metastasis: A Case Report and Literature Review.

Background: Esophageal cancer (EC) comprises 1% of all diagnosed cancers in the USA. It is more common in other parts of the world. If there is distant metastasis, the relative survival rate is 6%. There are no standardized screening methods for EC. Case Presentation: We reported a four-year case of esophageal cancer, a P53-positive mutation with atypical distant metastasis to the cardiac and skeletal muscles. The patient was managed with multimodal therapy, including immunotherapy, which could have been a factor in prolonged survival. Conclusions: Distant metastases are typically seen postmortem, and with prolonged survival, we are able to find such unique metastases antemortem. Despite a history of negative scans, the patient's ctDNA (circulating tumor DNA) remained positive, which was a better predictor of recurrence in this case. Future research is required to establish cost-effective screening methods and standardized treatments.

Bis-indole-derived NR4A1 antagonists inhibit colon tumor and splenic growth and T-cell exhaustion.

There is evidence that the orphan nuclear receptor 4A1 (NR4A1, Nur77) is overexpressed in exhausted CD8 + T cells and regulates PD-L1 in tumors. This study investigated the effects of potent bis-indole-derived NR4A1 antagonists on reversing T-cell exhaustion and downregulating PD-L1 in colon tumors/cells. NR4A1 antagonists inhibited colon tumor growth and downregulated expression of PD-L1 in mouse colon MC-38-derived tumors and cells. TILs from MC-38 cell-derived colon tumors and splenic lymphocytes exhibited high levels of the T-cell exhaustion markers including PD-1, 2B4, TIM3+ and TIGIT and similar results were observed in the spleen, and these were inhibited by NR4A1 antagonists. In addition, treatment with NR4A1 antagonists induced cytokine activation markers interferon γ, granzyme B and perforin mRNAs and decreased TOX, TOX2 and NFAT in TIL-derived CD8 + T cells. Thus, NR4A1 antagonists decrease NR4A1-dependent pro-oncogenic activity and PD-L1 expression in colon tumors and inhibit NR4A1-dependent T-cell exhaustion in TILs and spleen and represent a novel class of mechanism-based drugs that enhance immune surveillance in tumors.

Survival following liver transplantation for locally advanced, unresectable intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (iCCA) has previously been considered a contraindication to liver transplantation (LT). However, recent series showed favorable outcomes for LT after neoadjuvant therapy. Our center developed a protocol for neoadjuvant therapy and LT for patients with locally advanced, unresectable iCCA in 2010. Patients undergoing LT were required to demonstrate disease stability for 6 months on neoadjuvant therapy with no extrahepatic disease. During the study period, 32 patients were listed for LT and 18 patients underwent LT. For transplanted patients, the median number of iCCA tumors was 2, and the median cumulative tumor diameter was 10.4 cm. Patients receiving LT had an overall survival at 1-, 3-, and 5-years of 100%, 71%, and 57%. Recurrences occurred in seven patients and were treated with systemic therapy and resection. The study population had a higher than expected proportion of patients with genetic alterations in fibroblast growth factor receptor (FGFR) and DNA damage repair pathways. These data support LT as a treatment for highly selected patients with locally advanced, unresectable iCCA. Further studies to identify criteria for LT in iCCA and factors predicting survival are warranted.

A multi-center study on safety and efficacy of immune checkpoint inhibitors in cancer patients with kidney transplant.

Immune checkpoint inhibitors (ICIs) are widely used for various malignancies. However, their safety and efficacy in patients with a kidney transplant have not been defined. To delineate this, we conducted a multicenter retrospective study of 69 patients with a kidney transplant receiving ICIs between January 2010 and May 2020. For safety, we assessed the incidence, timing, and risk factors of acute graft rejection. For efficacy, objective response rate and overall survival were assessed in cutaneous squamous cell carcinoma and melanoma, the most common cancers in our cohort, and compared with stage-matched 23 patients with squamous cell carcinoma and 14 with melanoma with a kidney transplant not receiving ICIs. Following ICI treatment, 29 out of 69 (42%) patients developed acute rejection, 19 of whom lost their allograft, compared with an acute rejection rate of 5.4% in the non-ICI cohort. Median time from ICI initiation to rejection was 24 days. Factors associated with a lower risk of rejection were mTOR inhibitor use (odds ratio 0.26; 95% confidence interval, 0.09-0.72) and triple-agent immunosuppression (0.67, 0.48-0.92). The objective response ratio was 36.4% and 40% in the squamous cell carcinoma and melanoma subgroups, respectively. In the squamous cell carcinoma subgroup, overall survival was significantly longer in patients treated with ICIs (median overall survival 19.8 months vs. 10.6 months), whereas in the melanoma subgroup, overall survival did not differ between groups. Thus, ICIs were associated with a high risk of rejection in patients with kidney transplants but may lead to improved cancer outcomes. Prospective studies are needed to determine optimal immunosuppression strategies to improve patient outcomes.

Renal Toxicity.

With the increasing use of immunotherapy, there has been an associated increased survival in many cancers but has also resulted in unregulated organ-specific toxicities. In this review, we will discuss the renal toxicities associated with a checkpoint inhibitor (CPI) from the typical acute tubulointerstitial nephritis to glomerulonephritis and their proposed mechanisms and treatments. We also discuss the use of CPI and reactivation of preexisting autoimmune disease with a focus on renal cell cancer in setting of chronic kidney disease (CKD). Transplant rejection in setting of CPI use has been further evaluated with single-center and multicenter retrospective studies, and available data will be presented in this chapter.

Development and validation of a risk assessment tool for BKPyV Replication in allogeneic stem cell transplant recipients.

BACKGROUND: BK polymavirus (BKPyV), a member of the family Polyomaviridae, is associated with increased morbidity and mortality in allogeneic stem cell transplant recipients. METHODS: In our previous retrospective study of 2477 stem cell transplant patients, BKPyV replication independently predicted chronic kidney disease and poor survival. In this study, using the same cohort, we derived and validated a risk grading system to identify patients at risk of BKPyV replication after transplantation in a user-friendly modality. We used 3 baseline variables (conditioning regimen, HLA match status, and underlying cancer diagnosis) that significantly predicted BKPyV replication in our initial study in a subdistribution hazard model with death as a competing risk. We also developed a nomogram of the hazard model as a visual aid. The AUC of the ROC of the risk-score-only model was 0.65. We further stratified the patients on the basis of risk score into low-, moderate-, and high-risk groups. RESULTS: The total risk score was significantly associated with BKPyV replication (P < .0001). At 30 days after transplantation, the low-risk (score ≤ 0) patients had a 9% chance of developing symptomatic BKPyV replication, while the high-risk (score ≥ 8) of the population had 56% of developing BKPyV replication. We validated the risk score using a separate cohort of 1478 patients. The AUC of the ROC of the risk-score-only model was 0.59. Both the total risk score and 3-level risk variable were significantly associated with BKPyV replication in this cohort (P < .0001). CONCLUSIONS: This grading system for the risk of symptomatic BKPyV replication may help in early monitoring and intervention to prevent BKPyV-associated morbidity, mortality, and kidney function decline.

Renal Toxicity.

With the increasing use of immunotherapy, there has been an associated increased survival in many cancers but has also resulted in unregulated organ-specific toxicities. In this chapter, we discuss the renal toxicities associated with a checkpoint inhibitor (CPI) from the typical acute tubulointersitial nephritis to glomerulonephritis, their proposed mechanisms, and treatments. We also discuss the use of CPI and reactivation of preexisting auto-immune diseases and focus on renal cell cancer in setting of Chronic kidney disease (CKD). Transplant rejection in the setting of CPI use is yet to be further studied, and available data is presented in this chapter.

Ruxolitinib therapy is associated with improved renal function in patients with primary myelofibrosis.

Recent evidence suggests that renal dysfunction may be a direct consequence of primary myelofibrosis (PMF). We performed a retrospective analysis of 100 patients with previously untreated PMF, receiving frontline treatment with single agent ruxolitinib, and compared them to 105 patients, receiving frontline treatment with a non-ruxolitinib-based therapy, matched by age, sex, DIPSS plus, and estimated glomerular filtration rate (eGFR). Use of ruxolitinib associated with a significantly higher rate of renal improvement (RI) > 10% (73% vs 50%, p = 0.01) confirmed on multivariate analysis (MVA) [odds ratio 3, 95% confidence interval (CI) 1.6-5.5, p < 0.001]. After a median follow-up of 41 months (range, 1-159 months), median failure-free survival (FFS) was 14 months (range, 1-117 months). Achievement of a RI > 10% maintained its independent association with prolonged FFS on MVA (hazard ratio 1.4, 95% CI 1.1-2, p = 0.02). Ruxolitinib can significantly improve renal function in patients with PMF, significantly impacting failure-free survival.

Oncogenic targets Mmp7, S100a9, Nppb and Aldh1a3 from transcriptome profiling of FAP and Pirc adenomas are downregulated in response to tumor suppression by Clotam.

Intervention strategies in familial adenomatous polyposis (FAP) patients and other high-risk colorectal cancer (CRC) populations have highlighted a critical need for endoscopy combined with safe and effective preventive agents. We performed transcriptome profiling of colorectal adenomas from FAP patients and the polyposis in rat colon (Pirc) preclinical model, and prioritized molecular targets for prevention studies in vivo. At clinically relevant doses in the Pirc model, the drug Clotam (tolfenamic acid, TA) was highly effective at suppressing tumorigenesis both in the colon and in the small intestine, when administered alone or in combination with Sulindac. Cell proliferation in the colonic crypts was reduced significantly by TA, coincident with increased cleaved caspase-3 and decreased Survivin, ß-catenin, cyclin D1 and matrix metalloproteinase 7. From the list of differentially expressed genes prioritized by transcriptome profiling, Mmp7, S100a9, Nppb and Aldh1a3 were defined as key oncogene candidates downregulated in colon tumors after TA treatment. Monthly colonoscopies revealed the rapid onset of tumor suppression by TA in the Pirc model, and the temporal changes in Mmp7, S100a9, Nppb and Aldh1a3, highlighting their value as potential early biomarkers for prevention in the clinical setting. We conclude that TA, an "old drug" repurposed from migraine, offers an exciting new therapeutic avenue in FAP and other high-risk CRC patient populations.

Poor immune reconstitution is associated with symptomatic BK polyomavirus viruria in allogeneic stem cell transplant recipients.

BACKGROUND: BK polyomavirus (BKPyV) infections are known indicators of immune suppression in hematopoietic stem cell transplant (HSCT) recipients; they can lead to hemorrhagic cystitis, ureteral stenosis, renal dysfunction, and prolonged hospital stays. In this study, we determined transplant-associated variables and immune parameters that can predict for the risk of BKPyV viruria. We hypothesized that BKPyV infection is a marker of poor immune recovery. METHODS: We analyzed all engrafted patients undergoing first allogeneic HSCT at MD Anderson Cancer Center in Houston between January 2004 and December 2012. We evaluated their immune parameters and their transplant-associated factors. BKPyV positivity was defined as BKPyV detection in urine by polymerase chain reaction testing. Cox proportional hazards model, as well as competing risk analysis method using subdistribution hazard models with death as competing risk, were applied to assess risk of BKPyV viruria. RESULTS: We identified a total of 2477 patients with a median age of 52 years. BKPyV viruria was manifest in 25% (n=629) of the patients. The median time from transplantation to BKPyV viruria development was 42 days among the patients who had BKPyV viruria. On multivariate analysis, tumor type, acute GVHD, chronic GVHD, myeloablative conditioning regimen, cord blood as the graft source, CD3+ , CD4+ , CD8+ , CD56+ , NK counts, and low platelet count were shown to be significantly associated with BKPyV infection. These finding were further confirmed when models incorporating the competing risk of death yielded similar findings. CONCLUSION: In this study, we report significant associations between BKPyV reactivation following allogeneic HSCT and suppressed immune variables. In addition, this study provides valuable information on the immune status of HSCT recipients as a predictor of BKPyV infections that may in turn help us formulate plans for more effective prevention and treatment of this infection.

Mechanism of metformin-dependent inhibition of mammalian target of rapamycin (mTOR) and Ras activity in pancreatic cancer: role of specificity protein (Sp) transcription factors.

The antidiabetic drug metformin exhibits both chemopreventive and chemotherapeutic activity for multiple cancers including pancreatic cancer; however, the underlying mechanism of action of metformin is unclear. A recent study showed that metformin down-regulated specificity protein (Sp) transcription factors (TFs) Sp1, Sp3, and Sp4 in pancreatic cancer cells and tumors, and this was accompanied by down-regulation of several pro-oncogenic Sp-regulated genes. Treatment with metformin or down-regulation of Sp TFs by RNAi also inhibits two major pro-oncogenic pathways in pancreatic cancer cells, namely mammalian target of rapamycin (mTOR) signaling and epidermal growth factor (EGFR)-dependent activation of Ras. Metformin and Sp knockdown by RNAi decreased expression of the insulin-like growth factor-1 receptor (IGF-1R), resulting in inhibition of mTOR signaling. Ras activity was also decreased by metformin and Sp knockdown of EGFR, another Sp-regulated gene. Thus, the antineoplastic activities of metformin in pancreatic cancer are due, in part, to down-regulation of Sp TFs and Sp-regulated IGF-1R and EGFR, which in turn results in inhibition of mTOR and Ras signaling, respectively.

Olanzapine for cachexia in patients with advanced cancer: an exploratory study of effects on weight and metabolic cytokines.

BACKGROUND: Olanzapine is used for treatment of psychiatric conditions but causes substantial weight gain. This study assessed safety, efficacy, and changes in metabolic cytokines associated with olanzapine administration in patients with cachexia due to advanced cancer. METHODS: Patients with cancer-related cachexia were treated with olanzapine (doses ranging from 2.5 to 20 mg daily by mouth). Patients also received anti-neoplastic treatments. Serum samples were collected at baseline and after weeks 1, 2, 4, and 8 for analysis of levels of leptin, growth hormone, ghrelin, and interleukin-6 (IL-6). RESULTS: Of the 39 participants, 31 were evaluable for weight change (N = 6 excluded for new ascites; N = 2, incomplete body weight of data). Toxicities related to olanzapine were somnolence (n = 1), pancreatitis (n = 1), extrapyramidal symptoms (n = 1), and nausea/vomiting (n = 1) (all grade 2). The recommended dose of Olanzapine is 20 mg PO daily for cancer patients (same as FDA approved dose for psychiatric conditions). Samples from 29 patients were eligible for analysis of serum cytokine levels. Mean values of leptin, ghrelin, and growth hormone did not change on treatment, though IL-6 levels increased, perhaps due to tumor progression. There was no association between changes in cytokines and weight. The mean change in slope of weight loss before versus after therapy was 0.24 (95 % CI, -0.08, 0.56; p = 0.13) indicating a trend, albeit not reaching statistical significance, toward attenuation of weight loss. CONCLUSION: Changes in metabolic cytokines and body weight did not correlate. Treatment with olanzapine had only a modest effect in altering the trajectory of weight loss.

Primary myelofibrosis associated glomerulopathy: significant improvement after therapy with ruxolitinib.

BACKGROUND: Primary myelofibrosis (PMF) is a type of myeloproliferative neoplasm (MPN) characterized by the predominant proliferation of megakaryocytes and granulocytes in the bone marrow, leading to the deposition of fibrous tissue, and by a propensity toward extramedullary hematopoiesis. Renal involvement in PMF is rare, but kidney tissue samples from these patients reveal MPN-related glomerulopathy, a recently discovered condition, in the late stages of the disease. CASE PRESENTATION: We present the first case described in the medical literature of a patient with early renal glomerular involvement in PMF/MPN. A 60-year-old man with stage 4 chronic kidney disease and a recent diagnosis of PMF (within 4 weeks of presentation at our renal division) presented with generalized body swelling, acute kidney injury, and massive nephrotic-range proteinuria. Kidney biopsy was performed to determine the etiology of the patient's renal dysfunction and revealed early renal glomerular involvement that was histologically characteristic of MPN-related glomerulopathy. Early diagnosis and prompt medical management returned the patient's kidney functionality to the levels seen on initial presentation at our hospital. CONCLUSION: Large studies with long follow-up durations are necessary to identify and categorize the risk factors for the development of MPN-related glomerulopathy, to standardize therapeutic regimens, and to determine whether aggressive management of the myelofibrosis slows the progression of kidney disease.

Focal Update on Immunotherapy and Liver Transplantation in the Era of Transplant Oncology.

Transplant oncology is an expanding area of cancer therapy that specifically emphasizes the use of liver transplantation (LT) as the preferred treatment for patients with manageable, but unresectable, tumors. The management and optimization of overall survival strategies, accompanied by an arguably decent quality of life, have been at the forefront of liver oncology treatment, as a plurality of all primary liver cancers are identified as either hepatocellular carcinoma (HCC) or cholangiocarcinoma (CCA), which are classified as highly aggressive malignancies and frequently remain asymptomatic until they progress to advanced stages, rendering curative procedures, such as resection, impractical. This has led to an increase in utilization of neoadjuvant interventions conducted prior to surgery, which has yielded favorable outcomes. Though this treatment modality has prompted further investigations into the efficacy of immune checkpoint inhibitors (ICPIs) as standalone treatments and in combination with locoregional treatments (LRTs) to bridge more patients into curative eligibility. This multidisciplinary methodology and treatment planning has seen multiple successful trials of immunotherapy regimes and combinate treatments, setting the groundwork for increasing eligibility through downstaging and "bridging" previously ineligible patients within stringent LT criteria. Surveillance after LT is a crucial component of transplant oncology. The emergence of circulating tumor DNA (ctDNA) has provided a novel approach to identifying the recurrence of cancer in its early stages. Recent research has focused on liquid biopsy, a technique that effectively identifies the dynamics of cancer. This is another innovation to demonstrate the rate at which transplant oncology is rapidly advancing, making the focus of care feel disorienting. Modalities of care are constantly evolving, but when a field is changing as rapidly as this one, it is imperative to reorient to the data and the needs of the patients. In this commentary, we reflect on the update's utilization of ICPIs in neoadjuvant settings as well as the updates on the utilization of liquid biopsy in post-LT follow-up surveillance.

Advances in Immunotherapy for Transplant Oncology.

The increasing incidence of global cancer rates has created an entirely new demand for curative treatment modalities to improve patient outcomes [...].

Comparative molecular profiling of pancreatic ductal adenocarcinoma of the head versus body and tail.

Pancreatic ductal adenocarcinoma (PDAC) of the head (H) and body/tail (B/T) differ in embryonic origin, cell composition, blood supply, lymphatic and venous drainage, and innervation. We aimed to compare the molecular and tumor immune microenvironment (TIME) profiles of PDAC of the H vs. B/T. A total of 3499 PDAC samples were analyzed via next-generation sequencing (NGS) of RNA (whole transcriptome, NovaSeq), DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing), and immunohistochemistry (Caris Life Sciences, Phoenix, AZ). Significance was determined as p values adjusted for multiple corrections (q) of <0.05. Anatomic subsites of PDAC tumors were grouped by primary tumor sites into H (N = 2058) or B/T (N = 1384). There were significantly more metastatic tumors profiled from B/T vs. H (57% vs. 44%, p < 0.001). KRAS mutations (93.8% vs. 90.2%), genomic loss of heterozygosity (12.7% vs. 9.1%), and several copy number alterations (FGF3, FGF4, FGF19, CCND1, ZNF703, FLT4, MUTYH, TNFRS14) trended higher in B/T when compared to H (p < 0.05 but q > 0.05). Expression analysis of immuno-oncology (IO)-related genes showed significantly higher expression of CTLA4 and PDCD1 in H (q < 0.05, fold change 1.2 and 1.3) and IDO1 and PDCD1LG2 expression trended higher in B/T (p < 0.05, fold change 0.95). To our knowledge, this is one of the largest cohorts of PDAC tumors subjected to broad molecular profiling. Differences in IO-related gene expression and TIME cell distribution suggest that response to IO therapies may differ in PDAC arising from H vs. B/T. Subtle differences in the genomic profiles of H vs. B/T tumors were observed.