The divergent role of the GM-CSF/GM-CSFR signaling pathway in cholangiocarcinoma and pancreatic ductal adenocarcinoma

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Background: The granulocyte-macrophage colony-stimulating factor ligand and receptor (GM-CSF/GM-CSFR) pathway plays a multifaceted role in the setting of cancer, exerting an anti-tumorigenic or pro-tumorigenic effect depending on GM-CSF expression. In previous work, we and others have shown increased GM-CSF expression to correlate with poor prognosis in patients with cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC). We also demonstrated how GM-CSF neutralization leads to reduced tumor size in murine CCA models, in part due to inhibition of alternative macrophage polarization. Here, we explore the impact of blocking GM-CSFR signaling in CCA and PDAC, two immunologically cold tumors with poor prognoses. Methods: Immunohistochemistry (IHC) and digital quantification of staining was performed on tissue from a human PDAC and CCA databank. Murine F4/80+ bone marrow-derived macrophages were cultured in tumor-conditioned media (TCM) derived from PDAC (KP2) or CCA (URCCA4.3) cell lines, with and without anti-GM-CSFR antibody. Quantitative real time PCR (qRT-PCR) analysis was performed for gene expression. URCCA4.3 and a luciferase-labeled PDAC (KCKO) cell line were orthotopically implanted into Bc/BIL3 knockout (KO) mice which lack GM-CSFR and C57BL/6 mice. Mice implanted with URCCA4.3 were enrolled into vehicle or gemcitabine treatment groups. Mice implanted with KCKO were untreated. Tumor growth was monitored by ultrasonography or bioluminescence imaging. Results: Digital analysis of IHC staining for GM-CSFR in human PDAC tumors revealed low expression to be associated with improved overall survival (OS) and greater number of days to recurrence, while high levels were associated with worse OS and fewer days to recurrence (p<0.01). In addition, human CCA specimens had greater GM-CSFR expression compared to normal uninvolved liver (p<0.01). qRT-PCR analysis of RNA from bone marrow-derived macrophages exposed to either CCA or PDAC TCM demonstrated lower expression of genes associated with alternative macrophage polarization ( Arg1, Cd274, Pdcd1lg2) and chronic inflammation ( Ccl2, Ccl17, Irf4) (all p<0.01) in response to GM-CSFR blockade. GM-CSFR KO mice implanted with URCCA4.3 demonstrated no differences in tumor growth with or without chemotherapy, compared to wild-type controls. Similarly, KO mice implanted with an immunogenic PDAC cell line (KCKO) had no differences in tumor size compared to wild-type controls. Conclusions: GM-CSFR expression is prognostic in the setting of PDAC and elevated in human CCA compared to normal liver. In vitro, GM-CSFR blockade downregulated pro-tumor genes associated with immunosuppression and inflammation. However, complete disruption of GM-CSFR signaling reversed the efficacy generated with GM-CSF ligand neutralization, suggesting some signaling is required for inducing anti-tumor immune responses.

Implementation of a new definition for acute kidney injury in the National Surgical Quality Improvement Project: What is the impact?

BACKGROUND

The National Surgical Quality Improvement Project is the preeminent surgical quality database, but it undercaptures acute kidney injury. Recently, the National Surgical Quality Improvement Project lowered the thresholds for acute kidney injury for the first time, so we assessed the impact of implementing the definition change on the rate of acute kidney injuries.

METHODS

For this interrupted time series analysis, we assembled 2 institutional National Surgical Quality Improvement Project files to identify adults undergoing inpatient noncardiac nonvascular surgery. The acute kidney injury definition changed on July 1, 2021, so patients were stratified by their operative date into 12-month pre and post groups. Weighted covariate propensity score matching and logistic regression were used to balance the periods and compare outcomes.

RESULTS

In total, 4,784 adults were eligible (55% pre and 45% post change). The overall rate of postoperative outcomes was similar, aside for acute kidney injury (pre 0.3%, post 5.6%, P < .0001). Regardless of the period, patients with acute kidney injuries had significantly longer lengths of stay and morbidity and mortality rates compared to those without an acute kidney injury. After the definition change, 81% of acute kidney injuries were stage I, and none were identified by urine output alone. After matching, surgery after the definition change was associated with an increased weighted odds of an acute kidney injury compared to surgery before the change (odds ratio 26.2; 95% confidence interval, 12.1-56.8).

CONCLUSION

In the year after the definition change, there was a 1,700% relative increase in the rate of reported acute kidney injuries. Newly identified acute kidney injuries are associated with high complication rates, and this definition change has implications for patient counseling, research, and quality reporting.

Surgery in combination with systemic chemotherapy is associated with improved survival in stage IV gallbladder cancer

BACKGROUND

Gallbladder cancer (GBC) is the most common biliary malignancy frequently metastatic at diagnosis with poor prognosis. While surgery remains the standard for early-stage GBC, the role of surgery in patients with metastatic gastrointestinal cancers is expanding due to improvements in systemic therapies. We sought to evaluate the survival of patients with stage IV GBC undergoing surgery in an era of improved multi-agent systemic therapy.

METHODS

A retrospective review of the National Cancer Database was performed. Patients with stage IV GBC who underwent systemic therapy were included. Patients who received radiation therapy, palliative therapy or had missing survival data were excluded. Univariable and multivariable analysis was performed.

RESULTS

4,145 patients were identified between 2004 and 2016. Mean age was 69. Surgery combined with systemic therapy predicted improved median survival compared with chemotherapy alone (11.1mo versus 6.8mo, HR 0.65, p < 0.001). Additionally, receipt of treatment after 2011 predicted improved survival (HR 0.86, p < 0.001). Patients treated with multi-agent chemotherapy in combination with surgery were associated with the greatest hazard ratio benefit (0.40, p < 0.001) versus single agent therapy alone.

CONCLUSION

Patients with stage IV gallbladder cancer treated with a combination of surgery and chemotherapy are associated with an improved overall survival compared to chemotherapy alone. Patients receiving care during the more recent era demonstrated improved survival. These results support a role for surgery in selected patients with stage IV gallbladder cancer receiving chemotherapy.

The Impact of Carbohydrate Antigen 19-9 on Survival in Patients with Clinical Stage I and II Pancreatic Cancer

BACKGROUND

Carbohydrate antigen (CA) 19-9 is a biomarker to monitor treatment effect. A threshold to predict prognostic significance remains undefined. We evaluated the impact of CA19-9 on overall survival (OS) in patients with early-stage pancreatic cancer (PC) utilizing the National Cancer Database (NCDB).

METHODS

The NCDB was queried from 2010 to 2014 to identify patients with clinical stage I-II PC. Patients who had undocumented pretreatment CA19-9 were excluded. Patients were stratified into two cohorts: CA19-9 < 98 U/mL and CA19-9 ≥ 98 U/mL, and further categorized into surgery versus no surgery. Twelve- and 24-month OS rates are reported.

RESULTS

Overall, 32,382 patients (stage I: 12,173; stage II: 20,209) were included. The majority of stage I (52.1%) and II (60%) patients had CA19-9 ≥ 98 U/mL. Stage I-II patients with CA19-9 < 98 U/mL had improved OS rates (stage I: 67.5%, 42.6%; stage II: 59.8%, 32.8%) compared with stage I and II patients with CA19-9 ≥ 98 U/mL (stage I: 50.7%, 26.9%; stage II: 48.1%, 22%). Among resected stage I patients, CA19-9 <98 U/mL was associated with improved OS (< 98: 80.5%, 56%; ≥ 98: 70.2%, 42.8%), and a similar trend was seen in resected stage II patients (< 98: 77.6%, 49.9%; ≥ 98: 71%, 39.2%). Unresected stage I patients with lower CA19-9 had improved OS (< 98: 42.1%, 17.5; ≥ 98: 29.9%, 10%), with similar findings in unresected stage II patients (< 98: 41.1%, 15.3%; ≥ 98: 33.4%, 10.6%).

CONCLUSIONS

Our study demonstrated the prognostic value of CA19-9 in patients with clinical stage I-II PC, with a value < 98 U/mL demonstrating improved survival. Surgery significantly improved survival at 12 and 24 months irrespective of CA19-9.

A review of hepatic epithelioid hemangioendothelioma-Analyzing patient characteristics and treatment strategies

BACKGROUND

Hepatic epithelioid hemangioendothelioma (HEH) is a rare vascular tumor of unknown etiology and unpredictable natural history. To date, no large-scale studies have been published evaluating this disease due to its rare occurrence.

METHODS

The National Cancer Database was reviewed between 2004 and 2016 to identify patients with HEH. Univariate analysis with overall survival (OS) was performed by Cox proportional hazards model. Kaplan-Meier method was used to create OS curves and compared using the log-rank test.

RESULTS

We identified 229 patients with HEH. The majority of patients were female (61.1%), white (84.3%), and had a Charlson-Deyo score of 0 (75%). Chemotherapeutic intervention was seen in 26% of the patients while 33% received surgical intervention in the form of wedge/segmental liver resection (n = 27), hepatectomy lobectomy/extended lobectomy (n = 18), and liver transplant (n = 22). Five-year survival in surgical patients was 90.5%, 66.5% and 81%, respectively (p = 0.485). Age greater than 55 years (hazard ratio [HR], 2.78; p < 0.001), Asian ethnicity compared to white (HR, 2.84; p = 0.012), and a higher Charlson-Deyo score (score 1: HR, 2.28; p < 0.001 and score ≥2: HR, 2.76; p = 0.011) were associated with worse OS.

CONCLUSION

Treatment for HEH remains variable with only a third of the patients undergoing surgery. International collaboration is necessary to determine the optimal treatment for this rare disease.

Abstract PO033: A phase 1b/2 trial of PXS-5505 combined with first line atezolizumab plus bevacizumab for treating patients with unresectable or metastatic hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) accounts for 90% of primary liver malignancies with just 20-30% resectable at presentation. Combination of atezolizumab and bevacizumab has brought immunotherapy to the forefront of combating this disease and represents an attractive immunotherapeutic backbone for pairing HCC therapy with means to improve intratumoral drug delivery and boost response. Lysyl oxidases (LOX) are a family of 5 secreted amine oxidases that catalyze the cross-linking of collagen and elastin in the extracellular matrix. PXS-5505 is a novel pan-LOX inhibitor that we have utilized in a pre-clinical model of primary liver malignancy and demonstrated improved survival when combined with systemic therapy through increased intratumoral drug delivery and enhanced host anti-tumor immunity. To study the impact of PXS-5505 in HCC, we designed a phase Ib/II trial of PXS-5505 in combination with atezolizumab and bevacizumab for treating patients with unresectable or metastatic HCC.Methods: This phase Ib/II trial includes patients with newly diagnosed, systemic therapy naïve, unresectable or metastatic HCC. Patients who received previous locoregional therapies remain eligible. Phase Ib consists of an open-label safety and tolerability assessment of PXS-5505 with a dose escalation design incorporating first-line combination therapy with atezolizumab and bevacizumab. The primary endpoint will be the maximal tolerated dose (MTD) of PXS-5505 through the Bayesian optimal interval (BOIN) design, targeting a dose limiting toxicity (DLT) rate of 30%. Secondary endpoints include the confirmed objective response rate (ORR) in evaluable patients after completing at least 4 cycles (12 weeks) of treatment. Once 12 patients have accrued to a particular dose, the MTD dose is established. Based on Simon’s two-stage design, if there are 4 or more responses with the MTD cohort, an expansion cohort will begin for phase II. Phase II will enroll an additional 30 patients at the MTD for a total evaluable sample size of 42. The primary endpoint will be the confirmed ORR in evaluable patients after completing at least 4 cycles of treatment. Assessment of ORR will be performed 3-6 months after start of treatment at the MTD with confirmatory assessment 28-56 days afterwards. If there are 15 or more responses among these 42 patients, we reject the null hypothesis and claim that the treatment is promising. A confirmed ORR of 45% will afford a 10% type 1 error with 80% power to detect a difference. Secondary endpoints include assessment of progression free survival (median from time of enrollment) and overall survival (median overall survival from time of enrollment). Exploratory endpoints include paired biopsies (at baseline and after the 4th cycle of treatment) for assessment of immunophenotypic and stromal changes to the tumor microenvironment in response to treatment with immunohistochemistry, flow cytometry, and RNA qRT-PCR analysis. The trial identification number is NCT05109052 and is expected to start enrollment in May of 2022.

Citation Format: Paul R Burchard, Luis I Ruffolo, Nicholas Ullman, Yatee Dave, Brian A Belt, David C Linehan, Roberto Hernandez-Alejandro, Nabeel Badri. A phase 1b/2 trial of PXS-5505 combined with first line atezolizumab plus bevacizumab for treating patients with unresectable or metastatic hepatocellular carcinoma [abstract]. In: Proceedings of the AACR Special Conference: Advances in the Pathogenesis and Molecular Therapies of Liver Cancer; 2022 May 5-8; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(17_Suppl):Abstract nr PO033.

Intrathecal Morphine and Effect on Opioid Consumption and Functional Recovery after Pancreaticoduodenectomy

BACKGROUND

Single-shot intrathecal morphine (ITM) is an effective strategy for postoperative analgesia, but there are limited data on its safety, efficacy, and relationship with functional recovery among patients undergoing pancreaticoduodenectomy.

STUDY DESIGN

This was a retrospective review of patients undergoing pancreaticoduodenectomy from 2014 to 2020 as identified by the institutional NSQIP Hepato-pancreato-biliary database. Patients were categorized by having received no spinal analgesia, ITM, or ITM with transversus abdominus plane block (ITM+TAP). The primary outcomes were average daily pain scores from postoperative days (POD) 0 to 3, total morphine equivalents (MEQ) consumed over POD 0 to 3, and average daily inpatient MEQ from POD 4 to discharge. Secondary outcomes included the incidence of opioid related complications, length of stay, and functional recovery.

RESULTS

A total of 233 patients with a median age of 67 years were included. Of these, 36.5% received no spinal analgesia, 49.3% received ITM, and 14.2% received ITM+TAP. Average pain scores in POD 0 to 3 were similar by mode of spinal analgesia (none [2.8], ITM [2.6], ITM+TAP [2.3]). Total MEQ consumed from POD 0 to 3 were lower for patients who received ITM (121 mg) and ITM+TAP (132 mg), compared with no spinal analgesia (232 mg) (p < 0.0001). Average daily MEQ consumption from POD 4 to discharge was lower for ITM (18 mg) and ITM+TAP (13.1 mg) cohorts compared with no spinal analgesia (32.9 mg) (p = 0.0016). Days to functional recovery and length of stay were significantly reduced for ITM and ITM+TAP compared with no spinal analgesia. These findings remained consistent through multivariate analysis, and there were no differences in opioid-related complications among cohorts.

CONCLUSIONS

ITM was associated with reduced early postoperative and total inpatient opioid utilization, days to functional recovery, and length of stay among patients undergoing pancreaticoduodenectomy. ITM is a safe and effective form of perioperative analgesia that may benefit patients undergoing pancreaticoduodenectomy.

Abstract PO025: GM-CSF neutralization enhances the efficacy of chemotherapy in an orthotopic murine model of cholangiocarcinoma

Introduction: With current effective treatments in cholangiocarcinoma (CCA) lacking, we expounded on our prior work highlighting the critical role of the granulocyte-macrophage-colony stimulating factor ligand/receptor (GM-CSF/GM-CSFRα) signaling pathway by evaluating GM-CSF neutralization combined with first-line chemotherapy in a novel murine model of CCA. Methods: Resected CCA specimens were used to construct a human tissue macro-array. Immunohistochemistry (IHC) staining for GM-CSFRα and digital quantification of staining intensity was performed. A novel syngeneic CCA cell line derived from spontaneous murine CCA from LSL-KrasG12D; Tp53Flox/Flox −; Alb-Cre (KPPC) mice was surgically injected into the left hepatic lobes of C57BL/6J mice. Disease onset and extent of progression was monitored over time using ultrasonography (US) in groups of mice enrolled into treatment with vehicle, gemcitabine, anti-GM-CSF, and gemcitabine plus anti-GM-CSF. Mice were sacrificed at predetermined endpoints for flow cytometry analysis. Results: IHC analysis and digital quantification of resected human tumors demonstrated that CCA expresses significantly higher levels of GM-CSFRα (p&lt;0.01) compared to uninvolved normal liver. Mice injected with a novel syngeneic CCA cell line expressing high levels of GM-CSF protein uniformly developed tumors fourteen days after orthotopic implantation. Histopathological evaluation of orthotopic CCA tumors demonstrated faithful recapitulation of both spontaneous murine and human disease with marked development of malignant biliary ductal epithelium (CK7), desmoplastic stroma (Sirius red, trichrome), and prominent inflammatory leukocytic infiltrate (CD45). Flow cytometry analysis of end-stage orthotopically implanted tumors demonstrated a progressive expansion of myeloid cells (70.7% CD11b+) compared to CD8+ (0.8%) and CD4+ (2.0%) T cells, indicative of a highly immunosuppressive tumor immune microenvironment. Combination therapy with GM-CSF neutralization and chemotherapy significantly reduced tumor size as screened via US compared to vehicle (p&lt;0.0001), anti-GM-CSF (p&lt;0.01), and chemotherapy alone (p&lt;0.01). In addition, combination therapy reduced the rate of tumor growth compared to each of the three other treatment groups (all p&lt;0.0001). Finally, tumor weights were significantly reduced in the combination therapy group versus the vehicle (p&lt;0.0001), anti-GM-CSF (p&lt;0.001), and chemotherapy alone (p&lt;0.05) cohorts. Conclusion: Human CCA demonstrates elevated levels of GM-CSFRα compared to normal liver. Neutralization of GM-CSF in combination with chemotherapy reduced tumor growth and weight in a novel murine model of CCA. Targeting the GM-CSF/GM-CSFRα pathway represents an innovative means of improving tumor control in CCA.

Citation Format: Yatee A Dave, Paul R Burchard, Nicholas A Ullman, Mary Georger, Luis I Ruffolo, Brian A Belt, David C Linehan. GM-CSF neutralization enhances the efficacy of chemotherapy in an orthotopic murine model of cholangiocarcinoma [abstract]. In: Proceedings of the AACR Special Conference: Advances in the Pathogenesis and Molecular Therapies of Liver Cancer; 2022 May 5-8; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(17_Suppl):Abstract nr PO025.

Abstract PO024: Combination therapy with PXS-5505 improves chemotherapeutic efficacy and reduces myeloid immune suppression in murine cholangiocarcinoma – a novel therapeutic strategy for clinical translation

Introduction: Despite growing prevalence, 5-year survival for cholangiocarcinoma remains poor due to an immunosuppressive fibroinflammatory stroma, featuring abundant collagen and cancer-associated fibroblasts. Lysyl oxidases (LOX) consist of 5 secreted enzymes that catalyze collagen cross-linking, resulting in increased tumor stroma density and facilitate immune evasion. Here, we present our findings of pan-LOX inhibition with a novel orally dosed agent (PXS-5505) in a murine model of CCA. Methods: Immunohistochemistry (IHC) analysis was performed on a human tissue macro-array of CCA. Mice that develop spontaneous CCA (KPPC) or orthotopically injected with a syngeneic cell line derived from a KPPC tumor were screened for disease onset and progression with ultrasonography (U/S). Groups of KPPC mice or mice bearing orthotopic tumors were enrolled into treatment cohorts of chemotherapy with or without PXS-5505 to evaluate survival and to perform fixed time point studies with treated tumors including assessment of intratumoral interstitial fluid pressure (IFP), IHC analysis of tumor markers, chemotherapy drug perfusion into tumors by mass spectrometry, and flow cytometry analysis of tumor single cell suspensions for stromal and immune cell populations. Results: IHC analysis demonstrated significantly elevated LOX expression in both human and KPPC CCA (p&lt;0.0001 and p=0.0025, respectively) compared to normal liver controls. High LOX expression was associated with worse disease-free (p=0.02) and overall (p=0.03) survival in resected human CCA specimens. KPPC mice treated with the combination of chemotherapy plus PXS-5505 demonstrated delayed tumor growth (p&lt;0.0001) and ascites onset (p=0.005) with improved survival (median 77 vs. 59 days, p=0.001) compared to chemotherapy alone. In addition, combination therapy reduced IFP (p=0.002) and was associated with increased mean blood vessel area (p&lt;0.0001) and increased concentration of intratumoral chemotherapy levels (p=0.02) compared to chemotherapy alone. Subsequent IHC revealed increased cell death through cleaved caspase-3 (p=0.0003) and damage-associated molecular pattern (DAMP) release through HMGB1 (p=0.0004). Flow cytometry analysis of tumors treated with combination therapy demonstrated reduced prevalence of tumor-infiltrating monocytic and granulocytic myeloid-derived suppressor cell populations (p=0.002 and p=0.01, respectively) and tumor associated macrophages (TAMs; p=0.02). There were increased CD4+ (p=0.01) T-cells with a reduced proportion of Treg+CD4+ (p&lt;0.0001) T-cells. The ratio of CD8:Treg was significantly elevated in the combination therapy cohort (p=0.001) and depletion of T-cells in orthotopic tumors abrogated the improved survival with combination therapy. Conclusions: LOX is elevated in human CCA and its expression correlates with prognosis following resection. Combination therapy with PXS-5505 delays tumor progression and improves survival in murine CCA models. Thus, chemotherapy combined with PXS-5505 represents a novel therapeutic strategy for treating CCA.

Citation Format: Paul R Burchard, Luis I Ruffolo, Nicholas A Ullman, Yatee Dave, Benjamin Dale, Mary Georger, Rachel Jewell, Nabeel Badri, Brian A Belt, David C Linehan, Roberto Hernandez-Alejandro. Combination therapy with PXS-5505 improves chemotherapeutic efficacy and reduces myeloid immune suppression in murine cholangiocarcinoma – a novel therapeutic strategy for clinical translation [abstract]. In: Proceedings of the AACR Special Conference: Advances in the Pathogenesis and Molecular Therapies of Liver Cancer; 2022 May 5-8; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(17_Suppl):Abstract nr PO024.

Immunologic Strategies in Pancreatic Cancer: Making Cold Tumors Hot

The rising incidence and persistent dismal 5-year overall survival of pancreatic ductal adenocarcinoma (PDAC) highlight the need for new effective systemic therapies. Immunotherapy has shown significant benefits in solid organ tumors, but has thus far been disappointing in the treatment of PDAC. There have been several promising preclinical studies, but translation into the clinic has proved to be challenging. This is likely a result of PDAC's complex immunosuppressive tumor microenvironment that acts to insulate the tumor against an effective cytotoxic immune response. Here, we summarize the mechanisms of immunosuppression within the PDAC tumor microenvironment and provide an up-to-date review of completed and ongoing clinical trials using various immunotherapy strategies.

GM-CSF drives myelopoiesis, recruitment and polarisation of tumour-associated macrophages in cholangiocarcinoma and systemic blockade facilitates antitumour immunity

OBJECTIVE

Intrahepatic cholangiocarcinoma (iCCA) is rising in incidence, and at present, there are limited effective systemic therapies. iCCA tumours are infiltrated by stromal cells, with high prevalence of suppressive myeloid populations including tumour-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs). Here, we show that tumour-derived granulocyte-macrophage colony-stimulating factor (GM-CSF) and the host bone marrow is central for monopoiesis and potentiation of TAMs, and abrogation of this signalling axis facilitates antitumour immunity in a novel model of iCCA.

METHODS

Blood and tumours were analysed from iCCA patients and controls. Treatment and correlative studies were performed in mice with autochthonous and established orthotopic iCCA tumours treated with anti-GM-CSF monoclonal antibody.

RESULTS

Systemic elevation in circulating myeloid cells correlates with poor prognosis in patients with iCCA, and patients who undergo resection have a worse overall survival if tumours are more infiltrated with CD68+ TAMs. Mice with spontaneous iCCA demonstrate significant elevation of monocytic myeloid cells in the tumour microenvironment and immune compartments, and tumours overexpress GM-CSF. Blockade of GM-CSF with a monoclonal antibody decreased tumour growth and spread. Mice bearing orthotopic tumours treated with anti-GM-CSF demonstrate repolarisation of immunosuppressive TAMs and MDSCs, facilitating T cell response and tumour regression. GM-CSF blockade dampened inflammatory gene networks in tumours and TAMs. Human tumours with decreased GM-CSF expression exhibit improved overall survival after resection.

CONCLUSIONS

iCCA uses the GM-CSF-bone marrow axis to establish an immunosuppressive tumour microenvironment. Blockade of the GM-CSF axis promotes antitumour T cell immunity.

Abstract 254: Dietary fish oil and aspirin to augment anti-PD-1 immunotherapy in metastatic melanoma

Introduction: First line anti-PD-1 immune checkpoint inhibition (αPD-1 ICI) induces objective responses in less than 50% of metastatic melanoma patients. Aspirin (ASA) use is associated with improved responsiveness to ICI, with inhibition of myeloid-induced immunosuppression in the tumor microenvironment (TME) a purported mechanism. Cyclooxygenase modulators ASA (pharmacologic inhibitor) and dietary fish oil (FO, substrate) shift myeloid and T cell populations to anti-inflammatory, pro-resolution phenotypes in immunity and cancer.

Methods: C57-BL6/J mice were injected with YUMM 1.7 melanoma in the flank. Mice were fed control chow and water (CTL) or omega-3 rich (FO) chow (10% w/w, 30%kcal/kcal), given ASA in drinking water (600 ug/mL), or FO/ASA combined (COMBO) starting 12 days post tumor implantation, the same day as starting intraperitoneal αPD1 or IgG2a vehicle (q3-4 days). An alternative cohort received pre-αPD-1 treatment ASA and FO starting day 7. Tumors were assessed for growth, harvested, and characterized via flow cytometry on day 32.

Results: When diets and water were started concurrent with αPD-1/IgG2a, FO decreased tumor volume vs. CTL for both vehicle (28%) and αPD-1 (27%) treatments; ASA and COMBO (p = 0.0501) did not. Compared to CTL, FO and COMBO increased monocytes (CD45+, CD11b+, Ly6C+, Ly6G-) and PD-L1+ monocytes in the TME with no effect on tumor associated macrophages (TAMS); ASA decreased the percent of Arginase 1+, CD206+ TAMs. ASA increased PD1+ CD8 T cells, while COMBO increased CD4 and CD8 T cells including LAG3+ and PD1+ CD8 T cells.

When diets and water were started on day 7, FO + αPD-1 decreased tumor volume (21%) vs. αPD-1 controls; ASA and COMBO did not. Compared to CTL, FO and COMBO similarly altered immune populations as above, with FO additionally increasing total CD3+ T-cells, PD-L1+ CD4 T cells, and PD-1+ CD8 T cells; COMBO increased dendritic cells (CD11c+, MHCII+, F4/80-). TAMS were not assessed.

Results significant (p&lt; 0.05) by ANOVA or t-test unless specified. Food eaten, water imbibed, and weight did not vary between groups.

Conclusions: Dietary fish oil impaired in vivo melanoma tumor growth with and without αPD-1 ICI despite increases in classically deleterious monocyte populations, while aspirin decreased M2-like macrophages in the TME without alterations in tumor growth. Modulation of the cyclooxygenase axis may be a cost-effective method to skew TME immune populations to favor αPD-1 immunotherapy responses in metastatic melanoma.

Citation Format: Alexander C. Chacon, Shuyang S. Qin, Alexa D. Melucci, Katherine M. Jackson, Paul R. Burchard, Yatee A. Dave, Rachel Jewell, Brian A. Belt, William Tabayoyong, David C. Linehan, Peter A. Prieto. Dietary fish oil and aspirin to augment anti-PD-1 immunotherapy in metastatic melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 254.

Dietary fish oil augments the tumor immune microenvironment in anti-PD-1 treated melanoma

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Background: Less than half of metastatic melanoma patients experience objective responses to first line anti-PD-1 immune checkpoint inhibition (αPD-1 ICI). Omega-3 fatty acids in dietary fish oil (FO) shift myeloid and T-cell populations to anti-inflammatory, pro-resolution phenotypes in immunity and cancer. We investigated whether dietary FO supplementation could augment tumor microenvironment (TME) immune profiles and improve ICI response in melanoma. Methods: C57-BL6/J mice were injected with YUMM 1.7 melanoma in the flank. Mice were fed control chow (CTL) or omega-3 rich (FO) chow (10% w/w, 30%kcal/kcal) starting 7 days post tumor implantation. Intraperitoneal αPD1 or IgG2a vehicle were injected q3-4 days starting day 12. To assess the temporal flux of TME immune populations, tumors from mice in analogous experiments were assessed for growth, harvested on day 12, day 22, or day 32, and characterized via flow cytometry. Results: In multiple models, FO decreased YUMM tumor growth vs. CTL by day 32 (> 21% for all models). FO halved tumor associated macrophage content, including M2 macrophages (Arg1+, CD206+, CD68+, F480+), at day 12. Conversely, FO increased M2 macrophages at day 22, leveling even with CTL at day 32. At all three timepoints, FO increased TME monocytes (Ly6C+, Ly6G-). In the T cell compartment, FO decreased TME CD4 and CD8 T cell content (including PD1+ CD4 and PD1+ CD8) at day 12, an effect which was reversed by day 22 (increased CD4 and CD8s vs CTL). FO increased PD-L1+ CD4 T cells and CD8+ T cells, including PD1+ CD8 T cells, on day 32. When fish oil diets were started on day 12 (concurrent with immunotherapy), FO decreased tumor volume, increased monocytes (and PD-L1+ monocytes), and increased CD4 and PD1+ CD8 T cells by day 32, all less significantly than when starting diets 5 days prior to initiation of immunotherapy. All results significant (p < 0.05) by 2-way ANOVA or t-test unless specified. Food eaten, water imbibed, and weight change did not vary between groups. Conclusions: Fish oil impairs in vivo murine melanoma tumor growth with and without αPD-1 ICI. Fish oil modulated myeloid and T cell lineages via delaying M2 macrophage and CD4 / CD8 T-cell appearance in the tumor microenvironment, with concomitant increases in monocytes and key T cell effectors involved in αPD-1 ICI responsiveness by the time decrements in tumor growth were noted. Dietary fish oil may benefit patients with advanced melanoma treated with αPD-1 immunotherapy; further study in humans is warranted.

Glycerin Suppositories and Enemas in Premature Infants: A Meta-analysis

BACKGROUND AND OBJECTIVES

Premature infants are often given glycerin suppositories or enemas to facilitate meconium evacuation and the transition to enteral feeds. We reviewed the best-available evidence for the use of glycerin suppositories and enemas in premature infants.

METHODS

We searched MEDLINE, Embase, and Cochrane Central for randomized controlled trials (RCTs) of premature infants treated with glycerin suppositories or enemas through January 2022. Studies were screened and data extracted independently and in duplicate. We included RCTs of premature infants <32 weeks gestation and/or birth weight <1500 g who were treated with glycerin suppositories or enemas. Meta-analysis was performed using random effects and reported as relative risk or mean difference.

RESULTS

We identified 6 single-center, RCTs of 389 premature infants treated with glycerin suppositories (n = 207) or enemas (n = 182). Mortality rates ranged from 0% to 17%, and the meta-analysis revealed no differences between treatment groups (P = .86). Active treatment was associated with earlier meconium evacuation (mean, 1.5 days; 95% confidence interval, 3.0 to 0.01; P = .05) but not a faster time to enteral feeds (mean, 0.5 days; P = .48). We identified 1 ongoing trial with a target recruitment of 220 premature infants. The quality of evidence was very low to moderate because of inadequate statistical power and other methodologic issues.

CONCLUSIONS

The use of glycerin suppositories and enemas in premature infants is associated with earlier meconium evacuation, but the clinical significance of this finding is uncertain. Treatment has no definitive effects on mortality, necrotizing enterocolitis, or enteral feeds.

The impact of CA 19-9 on survival in patients with clinical stage I pancreatic cancer

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Background: Standard of care for early-stage resectable pancreatic cancer (PC) includes a combination of surgical resection and chemotherapy. Frequently, CA 19-9 is used as a biomarker to monitor treatment effect and has prognostic significance. We evaluated the impact of CA 19-9 on overall survival (OS) in patients with clinical stage I PC (cT1N0 and cT2N0) utilizing the National Cancer Database (NCDB). Methods: The NCDB was queried between 2010 and 2014 to identify patients with clinical stage I PC. Patients who had missing or undocumented CA 19-9 value at diagnosis were excluded. Demographic and clinical characteristics were analyzed. Patients were stratified into two cohorts based on the CA 19-9 value at diagnosis – CA 19-9 < 98 U/mL and CA 19-9 > 98 U/mL. Univariable and multivariable analyses were performed, and variables associated with OS were identified. Kaplan-Meier survival curves were computed to compare the OS between the two cohorts. Results: A total of 12,480 patients met our inclusion criteria. A majority of patients were female (51.9%), white (84.4%), with a median age of 70 years. Nearly, half the patients received care in an academic/research program (49.5%). A majority of patients had tumors located in the head of the pancreas (71.9%), and received single-agent (35.1%) or multiagent (22.9%) chemotherapy. Over half the patients (6505 patients, 52.1%) had a CA 19-9 value > 98 U/mL. A CA 19-9 value > 98 U/mL in patients predicted a significantly shorter median OS of 12.1 months compared to 19.4 months in patients with a CA 19-9 < 98 U/mL, p<0.0001 (Table). The 5-year OS rate was 9.9% in patients with a CA 19-9 value of > 98 U/mL compared to a 5-year OS rate of 18.1% for patients with a CA 19-9 value < 98 U/mL. On multivariable analysis, CA 19-9 > 98 compared to CA 19-9 < 98 (HR 1.53, p<0.001) and black race compared to white race (HR 1.10, p<0.001) was associated with worse survival, whereas tumor location in the body and tail compared to the head (HR 0.82, p<0.001), single-agent (HR 0.55, p<0.001) and multiagent (HR 0.55, p<0.001) chemotherapy compared to no chemotherapy, independently predicted improved OS. Conclusions: This is the first National Cancer Database study to demonstrate the prognostic value of CA 19-9 in patients with clinical stage I pancreatic cancer, with a value < 98 U/mL predicting improved survival. Clinical stage I pancreatic cancer patients appear to derive a significant benefit from chemotherapy, including single and multiagent chemotherapy, irrespective of the CA 19-9 value.[Table: see text]

Defining the role of systemic therapy in resectable pancreatic acinar cell carcinoma

INTRODUCTION

Following resection of pancreatic acinar cell carcinoma (PACC) distant recurrence remains high. We utilized the national cancer database (NCDB) to evaluate the role of systemic therapy in early-stage resected PACC.

METHODS

We queried the NCDB registry from 2004 to 2015 for patients with pathologic stage I-IIB PACC. For each stage, patients who underwent surgery alone (SA) were compared to patients who received systemic and/or radiation therapy in addition to surgery (surgery + therapy [S + T]).

RESULTS

A total of 271 patients (101 pI, 81 pIIA, and 89 pIIB) were analyzed. Of all clinically node positive patients (n = 41), the majority (n = 32, 78%) had node-positive disease at resection (pIIB). SA was performed in 112 patients (41.3%), whereas 159 (58.7%) patients received S + T. There was no difference in overall survival (OS) between S + T and SA with respect to pI or pIIA disease. In pIIB disease, S + T was associated with improved OS compared to SA (34.9 vs. 16.9 months, p = 0.031). Single-agent chemotherapy was associated with improved OS for pIIB disease when compared to SA (hazard ratio: 0.38, 95% confidence interval: 0.16, 0.83).

CONCLUSION

In resectable PACC, the survival benefit of adjuvant therapy is limited to pathologic stage IIB disease. This benefit is evident even in patients treated with single-agent chemotherapy.

Early Prediction of Length of Stay After Pancreaticoduodenectomy

BACKGROUND

Enhanced recovery after surgery (ERAS) is an evidence-based clinical pathway designed to standardize and optimize care. We studied the impact of ERAS and sought to identify the most important recommendations to predict shorter length of stay (LOS) after pancreaticoduodenectomy (PD).

METHODS

We retrospectively reviewed all patients undergoing PD at our institution between January 2014 and June 2018. We compared clinicopathologic outcomes for patients before and after ERAS implementation. We defined "A-recommendations" as those that were graded "strong" and had "moderate" or "high" levels of evidence. We then compared outcomes of the ERAS group with adherence to "A-recommendations" and performed a subset analysis of "A-recommendations" over the first 72 h after surgery, which we termed "early factors".

RESULTS

A total of 191 patients underwent PD during the study period. We excluded 87 patients who had minimally invasive PD (22), vascular reconstruction (53), or both (12). Of the 104 patients studied, 56 (54%) were pre-ERAS and 48 (46%) were ERAS. There were no differences in comorbidities or demographics between these groups, and morbidity, mortality, and readmission rates were also similar (P > 0.6). Median LOS was 3.5 d shorter in the ERAS group (7 versus 10.5 d, P < 0.001). Adherence to "A-recommendations" within ERAS was associated with a decreased LOS (r = -0.52 P = 0.0001). Patients with >5 "early factors" had a median LOS of 6 d, whereas patients with <5 "early factors" had a median LOS of 9 d (P = 0.008).

CONCLUSIONS

ERAS is an effective protocol that standardizes care and reduces LOS after PD. Implementation of ERAS resulted in a 3.5-day reduction in our LOS with no change in morbidity, mortality, or readmissions. Adherence to ERAS protocol "A-recommendations" and ≥5 "early factors" may be predictive of shortened LOS.

Appendiceal intussusception in the setting of ulcerative colitis

Appendiceal intussusception is a very rare condition with an estimated incidence of 0.01%. Most cases present in adults with chronic waxing and waning of symptoms over a period of weeks to months. We report a case of a 39-year-old Caucasian female with a 5-week history of worsening right-sided abdominal pain. Computed tomography revealed cecal thickening without visualization of the appendix. A colonoscopy revealed mild diffuse erythema and edema in the ascending colon as well as a mass within the lumen of the cecum. Biopsies of the colon were suggestive of mild ulcerative colitis (UC). The patient's symptoms continued and laparoscopic assisted ileocecectomy was performed revealing an inverted appendix protruding into the cecal lumen. The patient was discharged without any complications and began mesalamine therapy for her UC.

A multiplex PCR assay for the simultaneous detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis

INTRODUCTION

For developing countries, sexually transmitted infections (STIs) and their complications are ranked in the top 5 disease categories for which adults seek medical treatment. Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) are the three most common STIs worldwide, with TV accounting for over half of the cases. In developing countries, traditional methods for diagnosing STIs are laborious, often not very sensitive, and have a long turnaround time with most recent commercially available diagnostic tests targeting one or, at most, two of these STIs at a time. Here, we describe the development of a highly sensitive, rapid and affordable sample-to-answer multiplex PCR-based assay for the simultaneous detection of Trichomonas vaginalis, Neisseria gonorrhoeae, and Chlamydia trachomatis.

MATERIALS AND METHODS

We designed a multiplex PCR assay for the detection of 4 targets (CT, TV, NG, and process/PCR control) using melt curve analysis. To establish the limit of detection (LOD) for each pathogen, we used previously extracted and quantified TV, NG, and CT genomic DNA (Vircell, Spain). For each target, the LOD was determined by lowering its copy number while increasing the other two STI loads in a stepwise fashion. The process/PCR control remained constant in the optimized assay and was spiked into each sample before extraction. For a concordance study, we tested urine, vaginal and rectal swab specimens from 26 patients positive for one or more of the tested STIs. In addition, 56 liquid cytology specimens (Thinprep) were used to assess specificity.

RESULTS

This assay has a turnaround time of less than 2h and has a limit of detection as low as 7-31 copies for each STI in the presence of the other 2 targets. Our assay also demonstrated 100% concordance with 26 known clinical samples from urine, vaginal and rectal swab specimens. TV, NG, CT, and our process/PCR control were consistently identified at 78°C, 82.3°C, 85.7°C, and ~92°C, respectively. When applied to DNA extracted from residual Thinprep specimens, the assay was negative in 54/56 samples. Two samples were found to be co-infected with CT.

CONCLUSIONS

Our multiplex assay combines a rapid and cost-effective approach to molecular diagnostics with the versatility required for use within a variety of laboratory settings. These performance characteristics make this multiplex STI assay highly suitable for use in a clinical laboratory.

Development of a rapid clinical TPMT genotyping assay

OBJECTIVES

Thiopurine compounds are commonly used in the treatment of childhood acute lymphoblastic leukemia, and as immunosuppressants following organ transplantation or for treatment of various autoimmune disorders. Thiopurine S-methyltransferase (TPMT) is required for detoxification, through S-methylation, of 6-thioguanine nucleotides (TGNs), a byproduct of thiopurine metabolism. Single nucleotide polymorphisms (SNPs) in the TPMT gene have been shown to affect its function, with some variants associated with serious clinical manifestations including severe to fatal myelosuppression and organ transplant rejection following treatment with standard thiopurine doses. In this study, we describe a TaqMan real time PCR allelic discrimination assay requiring minimal DNA input for TPMT genotyping.

DESIGN AND METHODS

We designed controls for the homozygous wild type and allelic variants of TPMT*2, *3B, and *3C. Genomic DNA was extracted from an additional 412 human blood samples. The samples were tested for the TPMT*2, *3B, *3C, and *3A polymorphisms by TaqMan genotyping assays using the AB 7500 FAST Real-Time PCR instrument. Allelic discrimination plots were used to identify each mutation.

RESULTS

The TaqMan assay correctly genotyped all custom control DNA samples. Of the 412 tested samples, our assay identified 375 samples as wild-type *1/*1 (91.02%), 3 as *1/*2 (0.73%), 1 as *1/*3B (0.24%), 3 as *1/*3C (0.73%), 27 presumed to be *1/*3A (6.55%), and 3 as *3B/*3A (0.73%).

CONCLUSIONS

The clinical implications of TPMT genotyping, along with the simplicity and specificity of the TaqMan genotyping assays make this test highly suitable for use in a clinical laboratory.

A rapid RT-PCR assay for the detection of HIV-1 in human plasma specimens

INTRODUCTION

The CDC estimates that there are currently over 1million people living with human immunodeficiency virus (HIV-1) in the United States, with new cases increasing by approximately 50,000 each year. HIV-1 consists of four distinct groups: the major M group, and the rare N, O, and P groups, each comprising of various subtypes. Without proper care, HIV-1 can lead to cardiovascular, kidney, and liver diseases, cancer, and rapid progression into acquired immune deficiency syndrome (AIDS). Here, we describe a novel, rapid, and highly sensitive assay for the detection of HIV-1 using intercalating dye based RT-PCR and melt curve analysis.

MATERIALS AND METHODS

We designed an RT-PCR assay for the detection of the major M subtypes in addition to the rare (O, N, and P) HIV-1 groups, as well as an extraction/RT-PCR control, using melt curve analysis. Viral RNA was extracted using the automated Qiagen EZ1 robotic system (Qiagen, Valencia, CA). To establish the limit of detection (LOD) for this assay, we diluted the AcroMetrix HIV-1 panel (LifeTechnologies, Grand Island, NY) to concentrations ranging from 25 to 500 copies/ml. Armored RNA BCR/ABL b3/a2 (Asuragen, Austin, Texas) was used as our extraction and RT-PCR control. Specificity and accuracy were assessed by testing plasma specimens from 48 anonymized patients negative for HIV-1.

RESULTS

This assay has a turnaround time of less than 2.5h and has a limit of detection of 50 copies/ml of plasma. Our assay also demonstrated 100% concordance with 53 previously quantified plasma patient specimens, including 48 negative samples and 5 positive samples. HIV-1 and our extraction/RT-PCR control were consistently identified at 79 °C and 82.5 °C, respectively.

CONCLUSIONS

We developed a comprehensive, easy to use assay for the detection of HIV-1 in human plasma. Our assay combines a rapid and cost-effective method for molecular diagnostics with the versatility necessary for widespread laboratory use. These performance characteristics make this HIV-1 detection assay highly suitable for use in a clinical laboratory.

Democratizing molecular diagnostics for the developing world

OBJECTIVES

Infectious diseases that are largely treatable continue to pose a tremendous burden on the developing world despite the availability of highly potent drugs. The high mortality and morbidity rates of these diseases are largely due to a lack of affordable diagnostics that are accessible to resource-limited areas and that can deliver high-quality results. In fact, modified molecular diagnostics for infectious diseases were rated as the top biotechnology to improve health in developing countries.

METHODS

In this review, we describe the characteristics of accessible molecular diagnostic tools and discuss the challenges associated with implementing such tools at low infrastructure sites.

RESULTS

We highlight our experience as part of the "Grand Challenge" project supported by the Gates Foundation for addressing global health inequities and describe issues and solutions associated with developing adequate technologies or molecular assays needed for broad access in the developing world.

CONCLUSIONS

We believe that sharing this knowledge will facilitate the development of new molecular technologies that are extremely valuable for improving global health.

Abstract B179: Targeted next generation sequencing for somatic mutations in human cancer

Objective: We have replaced single gene PCR-based methods for the detection of BRAF, KRAS and EGFR variants in routine clinical practice with next generation sequencing assays for the Ion Torrent AmpliSeq Cancer Hotspot Panel v2 (50 genes) and the Illumina TruSeq Amplicon Cancer panel (48 genes). Implementation of these panels requires constant optimization of technical and analytical procedures as reagents and software continue to be developed. In this study we describe somatic mutation findings from our clinical laboratory service.

Methods: DNA was extracted from 90 formalin fixed, paraffin embedded tissue specimens that included 50 lung cancer, 24 colon cancer and 16 other cancers. Barcoded libraries were prepared from up to 10ng of extracted DNA and multiplexed on single 318 chips. Data analysis was performed using Golden Helix SVS for the Ion Torrent panel and Variant Studio for the Illumina panel. Variants that remained after the analysis pipeline were individually interrogated using the Integrative Genomics Viewer (IGV).

Results: Of the 90 cancer cases sequenced, each panel returned on average 20 variants. Of these, there was 100% concordance between the two panels with respect to the clinically actionable mutations identified.

Conclusions: We have implemented next generation sequencing technologies for the detection of somatic mutations in human cancers. Two platforms, the Ion Torrent PGM and the Illumina MiSeq, have been used for the routine analysis of FFPE cancer tissues in a clinical setting with actionable and non-actionable variants reported and archived.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B179.

Citation Format: Jason D. Peterson, Francine de Abreu, Torrey L. Gallagher, Paul R. Burchard, Christopher I. Amos, Wendy A. Wells, J. Marc Pipas, Marc S. Ernstoff, Camilo E. Fadul, James R. Rigas, Gregory J. Tsongalis. Targeted next generation sequencing for somatic mutations in human cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B179.

Detection of the FCGR3a polymorphism using a real-time polymerase chain reaction assay

The fragment crystallizable (Fc) region of the immunoglobulin G, low affinity III A receptor (FCGR3a, also known as CD16) belongs to the Fc gamma receptor family (FCGR), which plays an important role in immunoinflammatory processes. It is a low affinity, transmembrane receptor that is mainly expressed in monocytes, natural killer cells, and macrophages. It has been implicated in various inflammatory conditions, and recently a polymorphism (rs396991) in this gene has been shown to influence response to rituximab (anti-CD20) therapy in various disorders. We evaluated two molecular methods to genotype this polymorphism. Archived, formalin-fixed, paraffin-embedded samples from 26 biopsies of diffuse large B-cell lymphoma were retrieved and DNA was extracted. The samples were tested for the FCGR3a polymorphism using real-time polymerase chain reaction (PCR) followed by melt curve analysis or by a standard TaqMan allelic discrimination assay using the ABI 7500 FAST real-time PCR instrument. With the TaqMan allelic discrimination assay, we found that 16 cases were the wild type genotype, homozygous phenylalanine (F/F), for the FCGR3a receptor, whereas two cases had the homozygous valine (V/V) polymorphism and eight cases were heterozygous with a V/F genotype. Results with the real-time PCR followed by melt curve analysis were similar for 25 cases; however, four samples did not have sufficient DNA for the melt curve analysis method, and the result from one sample was discordant. The new TaqMan assay offers several advantages over previously published assays, such as faster turnaround time and ease of interpretation. These performance characteristics make it highly suitable for use in a clinical laboratory.