A Modified Floxuridine Reduced-Dose Protocol for Patients with Unresectable Colorectal Liver Metastases Treated with Hepatic Arterial Infusion.

BACKGROUND: Most patients treated with the standard dosing protocol (SDP) of hepatic arterial infusion (HAI) floxuridine require dose holds and reductions, thereby limiting their HAI therapy. We hypothesized that a modified dosing protocol (MDP) with a reduced floxuridine starting dose would decrease dose holds, dose reductions, and have similar potential to convert patients with unresectable colorectal liver metastases (uCRLM) to resection. PATIENTS AND METHODS: We reviewed our institutional database of patients with uCRLM treated with HAI between 2016 and 2022. In 2019, we modified the floxuridine starting dose to 50% (0.06 mg/kg) of the SDP (0.12 mg/kg). We compared treatment related outcomes between the SDP and MDP cohorts. RESULTS: Of n = 33 patients, 15 (45%) were treated on the SDP and 18 (55%) with our new institutional MDP. The MDP cohort completed more cycles before a dose reduction (mean 4.2 vs. 2), received more overall cycles (median 7.5 vs. 5), and averaged 39 more days of treatment (all P < 0.05). The SDP experienced more dose reductions (1.4 vs. 0.61) and dose holds (1.2 vs. 0.2; both P < 0.01). Of the patients in each group potentially convertible to hepatic resection, three patients (23%) in the SDP and six patients (35%) in the MDP group converted to resection (P = 0.691). Overall, four patients (27%) in the SDP developed treatment ending biliary toxicity compared with one patient (6%) in the MDP. CONCLUSIONS: A 50% starting dose of HAI floxuridine provides fewer treatment disruptions, more consecutive floxuridine cycles, and a similar potential to convert patients with initially uCRLM for disease clearance.

Atezolizumab Plus PEGPH20 Versus Chemotherapy in Advanced Pancreatic Ductal Adenocarcinoma and Gastric Cancer: MORPHEUS Phase Ib/II Umbrella Randomized Study Platform.

BACKGROUND: The MORPHEUS platform comprises multiple open-label, randomized, phase Ib/II trials designed to identify early efficacy and safety signals of treatment combinations across cancers. Atezolizumab (anti-programmed cell death 1 ligand 1 [PD-L1]) was evaluated in combination with PEGylated recombinant human hyaluronidase (PEGPH20). METHODS: In 2 randomized MORPHEUS trials, eligible patients with advanced, previously treated pancreatic ductal adenocarcinoma (PDAC) or gastric cancer (GC) received atezolizumab plus PEGPH20, or control treatment (mFOLFOX6 or gemcitabine plus nab-paclitaxel [MORPHEUS-PDAC]; ramucirumab plus paclitaxel [MORPHEUS-GC]). Primary endpoints were objective response rates (ORR) per RECIST 1.1 and safety. RESULTS: In MORPHEUS-PDAC, ORRs with atezolizumab plus PEGPH20 (n = 66) were 6.1% (95% CI, 1.68%-14.80%) vs. 2.4% (95% CI, 0.06%-12.57%) with chemotherapy (n = 42). In the respective arms, 65.2% and 61.9% had grade 3/4 adverse events (AEs); 4.5% and 2.4% had grade 5 AEs. In MORPHEUS-GC, confirmed ORRs with atezolizumab plus PEGPH20 (n = 13) were 0% (95% CI, 0%-24.7%) vs. 16.7% (95% CI, 2.1%-48.4%) with control (n = 12). Grade 3/4 AEs occurred in 30.8% and 75.0% of patients, respectively; no grade 5 AEs occurred. CONCLUSION: Atezolizumab plus PEGPH20 showed limited clinical activity in patients with PDAC and none in patients with GC. The safety of atezolizumab plus PEGPH20 was consistent with each agent's known safety profile. (ClinicalTrials.gov Identifier: NCT03193190 and NCT03281369).

Neoadjuvant therapy does not impact the biliary microbiome in patients with pancreatic cancer.

BACKGROUND: Pancreatic adenocarcinoma (PDAC) often impinges on the biliary tree and obstruction necessitates stent placement increasing the risk of surgical site infections (SSIs). We sought to explore the impact of neoadjuvant therapy on the biliary microbiome and SSI risk in patients undergoing resection. METHODS: A retrospective analysis was performed on 346 patients with PDAC who underwent resection at our institution from 2008 to 2021. Univariate and multivariate methods were utilized for analysis. RESULTS: Biliary stenting rates were similar between groups but resulted in increased bile culture positivity (97% vs. 15%, p < 0.001). Culture positivity did not differ between upfront resection or neoadjuvant chemotherapy (NAC) (77% vs. 80%, p = 0.60). NAC-alone versus neoadjuvant chemoradiotherapy did not impact biliary positivity (80% vs. 79%, p = 0.91), nor did 5-fluorouracil versus gemcitabine-based regimens (73% vs. 85%, p = 0.19). While biliary stenting increased incisional SSI risk (odds ratios [OR]: 3.87, p = 0.001), NAC did not (OR: 0.83, p = 0.54). Upfront resection, NAC, and chemoradiotherapy were not associated with biliary organism-specific changes or antibiotic resistance patterns. CONCLUSIONS: Biliary stenting is the greatest predictor for positive biliary cultures and SSIs in resected PDAC patients. Neither NAC nor radiotherapy impact bile culture positivity, speciation, rates, or antibiotic resistance patterns, and perioperative antibiotic prophylaxis should not differ.

Alternative splicing of Apoptosis Stimulating Protein of TP53-2 (ASPP2) results in an oncogenic isoform promoting migration and therapy resistance in soft tissue sarcoma (STS).

BACKGROUND: Metastatic soft tissue sarcoma (STS) are a heterogeneous group of malignancies which are not curable with chemotherapy alone. Therefore, understanding the molecular mechanisms of sarcomagenesis and therapy resistance remains a critical clinical need. ASPP2 is a tumor suppressor, that functions through both p53-dependent and p53-independent mechanisms. We recently described a dominant-negative ASPP2 isoform (ASPP2κ), that is overexpressed in human leukemias to promote therapy resistance. However, ASPP2κ  has never been studied in STS.  MATERIALS AND METHODS: Expression of ASPP2κ was quantified in human rhabdomyosarcoma tumors using immunohistochemistry and qRT-PCR from formalin-fixed paraffin-embedded (FFPE) and snap-frozen tissue. To study the functional role of ASPP2κ in rhabdomyosarcoma, isogenic cell lines were generated by lentiviral transduction with short RNA hairpins to silence ASPP2κ expression. These engineered cell lines were used to assess the consequences of ASPP2κ silencing on cellular proliferation, migration and sensitivity to damage-induced apoptosis. Statistical analyses were performed using Student's t-test and 2-way ANOVA. RESULTS: We found elevated ASPP2κ mRNA in different soft tissue sarcoma cell lines, representing five different sarcoma sub-entities. We found that ASSP2κ mRNA expression levels were induced in these cell lines by cell-stress. Importantly, we found that the median ASPP2κ expression level was higher in human rhabdomyosarcoma in comparison to a pool of tumor-free tissue. Moreover, ASPP2κ levels were elevated in patient tumor samples versus adjacent tumor-free tissue within individual patients. Using isogenic cell line models with silenced ASPP2κ expression, we found that suppression of ASPP2κ enhanced chemotherapy-induced apoptosis and attenuated cellular proliferation. CONCLUSION: Detection of oncogenic ASPP2κ in human sarcoma provides new insights into sarcoma tumor biology. Our data supports the notion that ASPP2κ promotes sarcomagenesis and resistance to therapy. These observations provide the rationale for further evaluation of ASPP2κ as an oncogenic driver as well as a prognostic tool and potential therapeutic target in STS.

Hepatic arterial infusion pump chemotherapy combined with systemic therapy for patients with advanced colorectal liver metastases: Outcomes in a newly established program.

BACKGROUND AND OBJECTIVES: Colorectal liver metastasis (CRLM) is a leading cause of morbidity and mortality in patients with colorectal cancer. Hepatic arterial infusion (HAI) chemotherapy has been demonstrated to improve survival in patients with resected CRLM and to facilitate conversion of technically unresectable disease. METHODS: Between 2016 and 2018, n = 22 HAI pumps were placed for CRLM. All patients received systemic chemotherapy concurrently with HAI floxuridine/dexamethasone. Overall survival (OS) and progression-free survival (PFS) were assessed using the Kaplan-Meier method. RESULTS: HAI pumps were placed in seven patients with completely resected CRLM and 15 patients with unresectable disease. Twenty-one patients received HAI floxuridine with a median of 5 total HAI cycles (interquartile range: 4-7). Biliary sclerosis was the most common HAI-related complication (n = 5, 24%). Of the 13 patients treated to convert unresectable CRLM, 3 (23%) underwent hepatic resection with curative intent after a median of 7 HAI cycles (range: 4-10). For all HAI patients, the mean OS was 26.7 months from CRLM diagnosis, while the median PFS and hepatic PFS from pump placement were 9 and 13 months, respectively. CONCLUSION: Concomitant HAI and systemic therapy can be utilized at multidisciplinary programs for patients with advanced CRLM, both in the adjuvant setting and to facilitate conversion of unresectable disease.

Circulating Hybrid Cells: A Novel Liquid Biomarker of Treatment Response in Gastrointestinal Cancers.

BACKGROUND: Real-time monitoring of treatment response with a liquid biomarker has potential to inform treatment decisions for patients with rectal adenocarcinoma (RAC), esophageal adenocarcinoma (EAC), and colorectal liver metastasis (CRLM). Circulating hybrid cells (CHCs), which have both immune and tumor cell phenotypes, are detectable in the peripheral blood of patients with gastrointestinal cancers, but their potential as an indicator of treatment response is unexplored. METHODS: Peripheral blood specimens were collected from RAC and EAC patients after neoadjuvant therapy (NAT) or longitudinally during therapy and evaluated for CHC levels by immunostaining. Receiver operating characteristics (ROCs) and the Kaplan-Meier method were used to analyze the CHC level as a predictor of pathologic response to NAT and disease-specific survival (DSS), respectively. RESULTS: Patients with RAC (n = 23) and EAC (n = 34) were sampled on the day of resection, and 11 patients (32%) demonstrated a pathologic complete response (pCR) to NAT. On ROC analysis, CHC levels successfully discriminated pCR from non-pCR with an area under the curve of 0.82 (95% confidence interval [CI], 0.71-0.92; P < 0.001). Additionally, CHC levels in the EAC patients correlated with residual nodal involvement (P = 0.026) and 1-year DSS (P = 0.029). The patients with RAC who were followed longitudinally during NAT (n = 2) and hepatic arterial infusion therapy for CRLM (n = 2) had CHC levels that decreased with therapy response and increased before clinical evidence of disease progression. CONCLUSION: Circulating hybrid cells are a novel blood-based biomarker with potential for monitoring treatment response and disease progression to help guide decisions for further systemic therapy, definitive resection, and post-therapy surveillance. Additional validation studies of CHCs are warranted.

Geographic Disparities in Referral Rates and Oncologic Outcomes of Intrahepatic Cholangiocarcinoma: A Population-Based Study.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is a rare cancer. Patients in rural areas may face reduced access to advanced treatments often only available at referral centers. We evaluated the association of referral center treatment with treatment patterns, outcomes, and geography in patients with ICC. METHODS: We queried the Oregon State Cancer Registry for ICC between 1997 and 2016, collecting clinicopathologic, demographic, and oncologic data. Patients were classified by treatment at a referral center or non-referral center. 'Crowfly' distance to the nearest referral center (DRC) was calculated. Outcomes were evaluated using Kaplan-Meier, Cox proportional hazards modeling, and logistic regression. RESULTS: Over 20 years, 740 patients with ICC had a median age of 66 years. Slightly more than half (n = 424, 57%) were non-referral center treated and 316 (43%) were referral center treated. Referral center treatment increased over time (odds ratio [OR] 1.03/year, p < 0.05). Referral center-treated patients had improved overall survival in all patients (median 9 vs. 4 months, p < 0.001), in the non-metastatic group (median 13 vs. 6 months, p < 0.001), and in patients not receiving liver resection (median 6 vs. 3 months, p < 0.05). On multivariable analysis, referral center-treated patients more often underwent chemotherapy, resection, or radiation (all p < 0.05). Increasing DRC (OR 0.98/20 km, p < 0.05) was independently associated with non-referral center treatment. CONCLUSION: Patients with ICC who are evaluated at a referral center are more likely to receive treatments associated with better oncologic outcomes, including patients who are not managed with hepatic resection. Increasing the DRC is associated with treatment at a non-referral center; interventions to facilitate referral, such as telemedicine, may lead to improved outcomes for patients with ICC in rural states.

Degree of biliary tract violation during treatment of gallbladder adenocarcinoma is independently associated with development of peritoneal carcinomatosis.

BACKGROUND: Gallbladder cancer (GBC) is often incidentally diagnosed after cholecystectomy. Intra-operative biliary tract violations (BTV) have been recently associated with development of peritoneal disease (PD). The degree of BTV may be associated with PD risk, but has not been previously investigated. METHODS: We reviewed patients with initially non-metastatic GBC treated at our institution from 2003 to 2018. Patients were grouped based on degree of BTV during their treatment: major (e.g., cholecystotomy with bile spillage, n = 27, 29%), minor (e.g., intra-operative cholangiogram, n = 18, 19%), and no violations (n = 48, 55%). Overall survival (OS) and peritoneal disease-free survival (PDFS) were evaluated with Kaplan-Meier and Cox proportional hazards modeling. RESULTS: Ninety-three patients were identified; the median age was 64 years (range 31-87 years). Seventy-six (82%) were incidentally diagnosed. The median follow-up was 23 months; 20 (22%) patients developed PD. The 3-year PDFS for patients with major, minor, and no BTV was 52%, 83%, and 98%, respectively (major vs. none: p < 0.001; minor vs. none: p < 0.01). BTV was not associated with 5-year OS (HR 1.53, p = 0.16). CONCLUSION: Increasing degree of BTV is associated with higher risk of peritoneal carcinomatosis in patients with GBC and should be considered during preoperative risk stratification. Reporting biliary tract violations during cholecystectomy is encouraged.

Localized muscle spasm as a manifestation of pembrolizumab-induced infusion reaction.

INTRODUCTION: As immune checkpoint inhibitors increasingly gain oncological utility, the incidence of unique adverse events may rise as well. The description and management of localized, recurrent muscle spasms secondary to pembrolizumab infusions has not previously been reported. CASE REPORT: A 64-year-old male receiving pembrolizumab infusions experienced acute-onset, isolated spasms and pain occurring in cycles 2 through 5.Management and outcome: Pretreatment with intravenous lorazepam, diphenhydramine, famotidine, ondansetron, and fluids have led to spasm-free pembrolizumab infusions. DISCUSSION: The purpose of this report is to provide the first known incidence and successful corrective measures taken for localized muscle spasms secondary to pembrolizumab infusion.

Implementing a comprehensive translational oncology platform: from molecular testing to actionability.

BACKGROUND: In order to establish the workflows required to implement a real-time process involving multi-omic analysis of patient samples to support precision-guided therapeutic intervention, a tissue acquisition and analysis trial was implemented. This report describes our findings to date, including the frequency with which mutational testing led to precision-guided therapy and outcome for those patients. METHODS: Eligible patients presenting to Oregon Health and Science University Knight Cancer Institute were enrolled on the study. Patients with biopsy proven metastatic or locally advanced unresectable prostate cancer, breast cancer, pancreatic adenocarcinoma, or refractory acute myelogenous leukemia receiving standard of care therapy were eligible. Metastatic site biopsies were collected and analyzed using the Knight Diagnostic Lab GeneTrails comprehensive solid tumor panel (124 genes). CLIA certified genomic information was made available to the treating physician. RESULTS: Between 1/26/2017 and 5/30/2018, 38 patients were enrolled, with 28 successfully undergoing biopsy. Of these, 25 samples yielded sufficient tumor for analysis. The median biopsy cellularity and number of cores collected were 70% (15-90%) and 5 (2-20), respectively. No procedure-related complications occurred. GeneTrails analysis revealed that 22 of 25 (88%) tumor samples harbored at least one potentially actionable mutation, and 18 (72%) samples harbored 2 or more potentially actionable mutations. The most common genetic alterations identified involved: DNA damage repair genes, cell cycle regulating genes, PIK3CA/Akt/mTOR pathway, and FGF gene family. To date, CLIA certified genomic results were used by treating physicians for precision-guided therapy in 5 (23%) patients. CONCLUSION: We report the feasibility of real-time tissue acquisition and analysis to support a successful translational oncology platform. The workflow will provide the foundation to improve access and accrual to biomarker driven precision oncology trials.

Phase II open label pilot trial of aprepitant and palonosetron for the prevention of chemotherapy-induced nausea and vomiting (CINV) in patients receiving moderately emetogenic FOLFOX chemotherapy for the treatment of colorectal cancer.

PURPOSE: Chemotherapy-induced nausea and vomiting (CINV) causes significant morbidity among colorectal cancer patients, receiving fluorouracil, oxaliplatin, and leucovorin (FOLFOX) chemotherapy even with standard antiemetic prophylaxis. The purpose of this study is to determine if the addition of aprepitant to standard antiemetic therapy improves CINV in these patients. METHODS: Patients receiving FOLFOX for colorectal cancer were given antiemetic prophylaxis with aprepitant 125 mg orally on day 1 and 80 mg on days 2 and 3. Palonosetron 0.25 mg was given IV push on day 1 only. Dexamethasone 12 mg was administered orally on day 1 and 8 mg each morning on days 2 through 4. Assessments including emetic events, rescue doses, nutritional intake, and appetite were recorded in a patient diary which was returned to study personnel in the following cycle. RESULTS: Of the 53 patients screened, 50 were evaluable and had a complete dataset for cycle 1. For the first cycle, 74% of patients achieved a complete response (CR), 22% achieved a major response and 4% experienced treatment failure. The percentage of patients achieving a CR remained high throughout each cycle at 83, 83, and 86% for cycles 2, 3, and 4, respectively. Appetite and nutritional status remained largely unchanged throughout treatment. Adverse events occurring in more than 10% of patients included diarrhea (13.6%), fatigue (12.6%), and neutropenia (11%). CONCLUSIONS: Aprepitant added to standard antiemetic therapy appears to be an effective and safe regimen for prevention of CINV in patients receiving FOLFOX.

ΔN-ASPP2, a novel isoform of the ASPP2 tumor suppressor, promotes cellular survival.

ASPP2 is a tumor suppressor that works, at least in part, through enhancing p53-dependent apoptosis. We now describe a new ASPP2 isoform, ΔN-ASPP2, generated from an internal transcription start site that encodes an N-terminally truncated protein missing a predicted 254 amino acids. ΔN-ASPP2 suppresses p53 target gene transactivation, promoter occupancy, and endogenous p53 target gene expression in response to DNA damage. Moreover, ΔN-ASPP2 promotes progression through the cell cycle, as well as resistance to genotoxic stress-induced growth inhibition and apoptosis. Additionally, we found that ΔN-ASPP2 expression is increased in human breast tumors as compared to adjacent normal breast tissue; in contrast, ASPP2 is suppressed in the majority of these breast tumors. Together, our results provide insight into how this new ASPP2 isoform may play a role in regulating the ASPP2-p53 axis.

N terminus of ASPP2 binds to Ras and enhances Ras/Raf/MEK/ERK activation to promote oncogene-induced senescence.

The ASPP2 (also known as 53BP2L) tumor suppressor is a proapoptotic member of a family of p53 binding proteins that functions in part by enhancing p53-dependent apoptosis via its C-terminal p53-binding domain. Mounting evidence also suggests that ASPP2 harbors important nonapoptotic p53-independent functions. Structural studies identify a small G protein Ras-association domain in the ASPP2 N terminus. Because Ras-induced senescence is a barrier to tumor formation in normal cells, we investigated whether ASPP2 could bind Ras and stimulate the protein kinase Raf/MEK/ERK signaling cascade. We now show that ASPP2 binds to Ras-GTP at the plasma membrane and stimulates Ras-induced signaling and pERK1/2 levels via promoting Ras-GTP loading, B-Raf/C-Raf dimerization, and C-Raf phosphorylation. These functions require the ASPP2 N terminus because BBP (also known as 53BP2S), an alternatively spliced ASPP2 isoform lacking the N terminus, was defective in binding Ras-GTP and stimulating Raf/MEK/ERK signaling. Decreased ASPP2 levels attenuated H-RasV12-induced senescence in normal human fibroblasts and neonatal human epidermal keratinocytes. Together, our results reveal a mechanism for ASPP2 tumor suppressor function via direct interaction with Ras-GTP to stimulate Ras-induced senescence in nontransformed human cells.

Neoadjuvant immunotherapy leads to complete pathologic response in locally advanced colon cancer.

Immunotherapy is considered first line in patients with dMMR metastatic colorectal cancer (CRC). Recent studies have also shown promising results with neoadjuvant immunotherapy in locally advanced CRC. We report a case in which neoadjuvant immunotherapy with pembrolizumab resulted in complete pathologic response at time of resection as well as saved the patient the morbidity associated with a hepatectomy. We also completed a scoping review of the literature which suggests promising tumor responses with treatment in dMMR CRC. Further randomized control trials to determine the magnitude of response and optimal regimen are needed.

Gastroenteropancreatic neuroendocrine tumors: Epigenetic landscape and clinical implications.

Neuroendocrine tumors (NETs) are a rare, heterogenous group of neoplasms arising from cells of the neuroendocrine system. Amongst solid tumor malignancies, NETs are notable for overall genetic stability and recent data supports the notion that epigenetic changes may drive NET pathogenesis. In this review, major epigenetic mechanisms of NET pathogenesis are reviewed, including changes in DNA methylation, histone modification, chromatin remodeling, and microRNA. Prognostic implications of the above are discussed, as well as the expanding diagnostic utility of epigenetic markers in NETs. Lastly, preclinical and clinical evaluations of epigenetically targeted therapies in NETs and are reviewed, with a focus on future directions in therapeutic advancement.

Devimistat (CPI-613) With Modified Fluorouarcil, Oxaliplatin, Irinotecan, and Leucovorin (FFX) Versus FFX for Patients With Metastatic Adenocarcinoma of the Pancreas: The Phase III AVENGER 500 Study.

PURPOSE: Metastatic pancreatic adenocarcinoma (mPC) remains a difficult-to-treat disease. Fluorouarcil, oxaliplatin, irinotecan, and leucovorin (FFX) is a standard first-line therapy for mPC for patients with a favorable performance status and good organ function. In a phase I study, devimistat (CPI-613) in combination with modified FFX (mFFX) was deemed safe and exhibited promising efficacy in mPC. METHODS: The AVENGER 500 trial (ClinicalTrials.gov identifier: NCT03504423) is a global, randomized phase III trial conducted at 74 sites across six countries to investigate the efficacy and safety of devimistat in combination with mFFX (experimental arm) compared with standard-dose FFX (control arm) in treatment-naïve patients with mPC. Treatment, administered in once-every-2-weeks cycles until disease progression or intolerable toxicity, included intravenous devimistat at 500 mg/m2 total per day on days 1 and 3 in the experimental arm. The primary end point of the study was overall survival (OS). RESULTS: Five hundred and twenty-eight patients were randomly assigned (266 in the experimental arm and 262 in the control arm). The median OS was 11.10 months for devimistat plus mFFX versus 11.73 months for FFX (hazard ratio [HR], 0.95 [95% CI, 0.77 to 1.18]; P = .655) and median progression-free survival was 7.8 months versus 8.0 months, respectively (HR, 0.99 [95% CI, 0.76 to 1.29]; P = .94). Grade ≥3 treatment-emergent adverse events with >10% frequency in the devimistat plus mFFX arm versus the FFX arm were neutropenia (29.0% v 34.5%), diarrhea (11.2% v 19.6%), hypokalemia (13.1% v 14.9%), anemia (13.9% v 13.6%), thrombocytopenia (11.6% v 13.6%), and fatigue (10.8% v 11.5%), respectively. CONCLUSION: Devimistat in combination with mFFX did not improve long- and short-term mPC patient outcomes compared with standard FFX. There were no new toxicity signals with the addition of devimistat.

Putting the pieces together: necrolytic migratory erythema and the glucagonoma syndrome.

Glucagonomas are slow-growing, rare pancreatic neuroendocrine tumors. They may present with paraneoplastic phenomena known together as the "glucagonoma syndrome." A hallmark sign of this syndrome is a rash known as necrolytic migratory erythema (NME). In this paper, the authors describe a patient with NME and other features of the glucagonoma syndrome. The diagnosis of this rare tumor requires an elevated serum glucagon level and imaging confirming a pancreatic tumor. Surgical and medical treatment options are reviewed. When detected early, a glucagonoma is surgically curable. It is therefore imperative that clinicians recognize the glucagonoma syndrome in order to make an accurate diagnosis and refer for treatment.

Socioeconomic and Geographic Disparities in the Referral and Treatment of Pancreatic Cancer at High-Volume Centers.

Importance: Treatment at high-volume centers (HVCs) has been associated with improved overall survival (OS) in patients with pancreatic ductal adenocarcinoma (PDAC); however, it is unclear how patterns of referral affect these findings. Objective: To understand the relative contributions of treatment site and selection bias in driving differences in outcomes in patients with PDAC and to characterize socioeconomic factors associated with referral to HVCs. Design, Setting, Participants: A population-based retrospective review of the Oregon State Cancer Registry was performed from 1997 to 2019 with a median 4.3 months of follow-up. Study participants were all patients diagnosed with PDAC in Oregon from 1997 to 2018 (n = 8026). Exposures: The primary exposures studied were diagnosis and treatment at HVCs (20 or more pancreatectomies for PDAC per year), low-volume centers ([LVCs] less than 20 per year), or both. Main Outcomes and Measures: OS and treatment patterns (eg, receipt of chemotherapy and primary site surgery) were evaluated with Kaplan-Meier analysis and logistic regression, respectively. Results: Eight thousand twenty-six patients (male, 4142 [52%]; mean age, 71 years) were identified (n = 3419 locoregional, n = 4607 metastatic). Patients receiving first-course treatment at a combination of HVCs and LVCs demonstrated improved median OS for locoregional and metastatic disease (16.6 [95% CI, 15.3-17.9] and 6.1 [95% CI, 4.9-7.3] months, respectively) vs patients receiving HVC only (11.5 [95% CI, 10.7-12.3] and 3.9 [95% CI, 3.5-4.3] months, respectively) or LVC-only treatment (8.2 [95% CI, 7.7-8.7] and 2.1 [95% CI, 1.9-2.3] months, respectively; all P < .001). No differences existed in disease burden by volume status of diagnosing institution. When stratifying by site of diagnosis, HVC-associated improvements in median OS were smaller (locoregional: 10.4 [95% CI, 9.5-11.2] vs 9.9 [95% CI, 9.4-10.4] months; P = .03; metastatic: 3.6 vs 2.7 months, P < .001) than when stratifying by the volume status of treating centers, indicating selection bias during referral. A total of 94% (n = 1103) of patients diagnosed at an HVC received HVC treatment vs 18% (n = 985) of LVC diagnoses. Among patients diagnosed at LVCs, later year of diagnosis and higher estimated income were independently associated with higher odds of subsequent HVC treatment, while older age, metastatic disease, and farther distance from HVC were independently associated with lower odds. Conclusions and Relevance: LVC-to-HVC referrals for PDAC experienced improved OS vs HVC- or LVC-only care. While disease-related features prompting referral may partially account for this finding, socioeconomic and geographic disparities in referral worsen OS for disadvantaged patients. Measures to improve access to HVCs are encouraged.