Dominic E. Sanford

Targeting Tumor-Infiltrating Macrophages Decreases Tumor-Initiating Cells, Relieves Immunosuppression, and Improves Chemotherapeutic Responses

Tumor-infiltrating immune cells can promote chemoresistance and metastatic spread in aggressive tumors. Consequently, the type and quality of immune responses present in the neoplastic stroma are highly predictive of patient outcome in several cancer types. In addition to host immune responses, intrinsic tumor cell activities that mimic stem cell properties have been linked to chemoresistance, metastatic dissemination, and the induction of immune suppression. Cancer stem cells are far from a static cell population; rather, their presence seems to be controlled by highly dynamic processes that are dependent on cues from the tumor stroma. However, the impact immune responses have on tumor stem cell differentiation or expansion is not well understood. In this study, we show that targeting tumor-infiltrating macrophages (TAM) and inflammatory monocytes by inhibiting either the myeloid cell receptors colony-stimulating factor-1 receptor (CSF1R) or chemokine (C-C motif) receptor 2 (CCR2) decreases the number of tumor-initiating cells (TIC) in pancreatic tumors. Targeting CCR2 or CSF1R improves chemotherapeutic efficacy, inhibits metastasis, and increases antitumor T-cell responses. Tumor-educated macrophages also directly enhanced the tumor-initiating capacity of pancreatic tumor cells by activating the transcription factor STAT3, thereby facilitating macrophage-mediated suppression of CD8(+) T lymphocytes. Together, our findings show how targeting TAMs can effectively overcome therapeutic resistance mediated by TICs.

Inflammatory Monocyte Mobilization Decreases Patient Survival in Pancreatic Cancer: A Role for Targeting the CCL2/CCR2 Axis

Purpose: To determine the role of the CCL2/CCR2 axis and inflammatory monocytes (CCR2+/CD14+) as immunotherapeutic targets in the treatment of pancreatic cancer. Experimental Design: Survival analysis was conducted to determine if the prevalence of preoperative blood monocytes correlates with survival in patients with pancreatic cancer following tumor resection. Inflammatory monocyte prevalence in the blood and bone marrow of patients with pancreatic cancer and controls was compared. The immunosuppressive properties of inflammatory monocytes and macrophages in the blood and tumors, respectively, of patients with pancreatic cancer were assessed. CCL2 expression by human pancreatic cancer tumors was compared with normal pancreas. A novel CCR2 inhibitor (PF-04136309) was tested in an orthotopic model of murine pancreatic cancer. Results: Monocyte prevalence in the peripheral blood correlates inversely with survival, and low monocyte prevalence is an independent predictor of increased survival in patients with pancreatic cancer with resected tumors. Inflammatory monocytes are increased in the blood and decreased in the bone marrow of patients with pancreatic cancer compared with controls. An increased ratio of inflammatory monocytes in the blood versus the bone marrow is a novel predictor of decreased patient survival following tumor resection. Human pancreatic cancer produces CCL2, and immunosuppressive CCR2+ macrophages infiltrate these tumors. Patients with tumors that exhibit high CCL2 expression/low CD8 T-cell infiltrate have significantly decreased survival. In mice, CCR2 blockade depletes inflammatory monocytes and macrophages from the primary tumor and premetastatic liver resulting in enhanced antitumor immunity, decreased tumor growth, and reduced metastasis. Conclusions: Inflammatory monocyte recruitment is critical to pancreatic cancer progression, and targeting CCR2 may be an effective immunotherapeutic strategy in this disease. Clin Cancer Res; 19(13); 3404–15. ©2013 AACR.

Targeting tumour-associated macrophages with CCR2 inhibition in combination with FOLFIRINOX in patients with borderline resectable and locally advanced pancreatic cancer: a single-centre, open-label, dose-finding, non-randomised, phase 1b trial

BACKGROUND In pancreatic ductal adenocarcinoma, the CCL2-CCR2 chemokine axis is used to recruit tumour-associated macrophages for construction of an immunosuppressive tumour microenvironment. This pathway has prognostic implications in pancreatic cancer, and blockade of CCR2 restores anti-tumour immunity in preclinical models. We aimed to establish the safety, tolerability, and recommended phase 2 oral dose of the CCR2 inhibitor PF-04136309 in combination with FOLFIRINOX chemotherapy (oxaliplatin and irinotecan plus leucovorin and fluorouracil). METHODS We did this open-label, dose-finding, non-randomised, phase 1b study at one centre in the USA. We enrolled treatment-naive patients aged 18 years or older with borderline resectable or locally advanced biopsy-proven pancreatic ductal adenocarcinoma, an Eastern Cooperative Oncology Group performance status of 1 or less, measurable disease as defined by Response Evaluation Criteria in Solid Tumors version 1.1, and normal end-organ function. Patients were allocated to receive either FOLFIRINOX alone (oxaliplatin 85 mg/m(2), irinotecan 180 mg/m(2), leucovorin 400 mg/m(2), and bolus fluorouracil 400 mg/m(2), followed by 2400 mg/m(2) 46-h continuous infusion), administered every 2 weeks for a total of six treatment cycles, or in combination with oral PF-04136309, administered at a starting dose of 500 mg twice daily in a standard 3 + 3 dose de-escalation design. Both FOLFIRINOX and PF-04136309 were simultaneously initiated with a total treatment duration of 12 weeks. The primary endpoints were the safety, tolerability, and recommended phase 2 dose of PF-04136309 plus FOLFIRINOX, with an expansion phase planned at the recommended dose. We analysed the primary outcome by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01413022. RESULTS Between April 19, 2012, and Nov 12, 2014, we treated 47 patients with FOLFIRINOX alone (n=8) or with FOLFIRINOX plus PF-04136309 (n=39). One patient had a dose-limiting toxic effect in the dose de-escalation group receiving FOLFIRINOX plus PF-04136309 at 500 mg twice daily (n=6); this dose was established as the recommended phase 2 dose. We pooled patients in the expansion-phase group (n=33) with those in the dose de-escalation group that received PF-04136309 at the recommended phase 2 dose for assessment of treatment-related toxicity. Six (75%) of the eight patients receiving FOLFIRINOX alone were assessed for treatment toxicity, after exclusion of two (25%) patients due to insurance coverage issues. The median duration of follow-up for treatment toxicity was 72·0 days (IQR 49·5-89·0) in the FOLFIRINOX alone group and 77·0 days (70·0-90·5) in the FOLFIRINOX plus PF-04136309 group. No treatment-related deaths occurred. Two (5%) patients in the FOLFIRINOX plus PF-04136309 group stopped treatment earlier than planned due to treatment-related toxic effects. Grade 3 or higher adverse events reported in at least 10% of the patients receiving PF-04136309 included neutropenia (n=27), febrile neutropenia (n=7), lymphopenia (n=4), diarrhoea (n=6), and hypokalaemia (n=7). Grade 3 or higher adverse events reported in at least 10% of patients receiving FOLFIRINOX alone were neutropenia (n=6), febrile neutropenia (n=1), anaemia (n=2), lymphopenia (n=1), diarrhoea (n=2), hypoalbuminaemia (n=1), and hypokalaemia (n=3). Therapy was terminated because of treatment-related toxicity in one (17%) of the six patients receiving FOLFIRINOX alone. 16 (49%) of 33 patients receiving FOLFIRINOX plus PF-04136309 who had undergone repeat imaging achieved an objective tumour response, with local tumour control achieved in 32 (97%) patients. In the FOLFIRINOX alone group, none of the five patients with repeat imaging achieved an objective response, although four (80%) of those patients achieved stable disease. INTERPRETATION CCR2-targeted therapy with PF-04136309 in combination with FOLFIRINOX is safe and tolerable. FUNDING Washington University-Pfizer Biomedical Collaborative.

Tumor-induced STAT3 activation in monocytic myeloid-derived suppressor cells enhances stemness and mesenchymal properties in human pancreatic cancer

Pancreatic cancer (PC) mobilizes myeloid cells from the bone marrow to the tumor where they promote tumor growth and proliferation. Cancer stem cells (CSCs) are a population of tumor cells that are responsible for tumor initiation. Aldehyde dehydrogenase-1 activity in PC identifies CSCs, and its activity has been correlated with poor overall prognosis in human PC. Myeloid cells have been shown to impact tumor stemness, but the impact of immunosuppressive tumor-infiltrating granulocytic and monocytic myeloid-derived suppressor cells (Mo-MDSC) on ALDH1Bright CSCs and epithelial to mesenchymal transition is not well understood. In this study, we demonstrate that Mo-MDSC (CD11b+/Gr1+/Ly6G−/Ly6Chi) significantly increase the frequency of ALDH1Bright CSCs in a mouse model of PC. Additionally, there was significant upregulation of genes associated with epithelial to mesenchymal transition. We also found that human PC converts CD14+ peripheral blood monocytes into Mo-MDSC (CD14+/HLA-DRlow/−) in vitro, and this transformation is dependent on the activation of the STAT3 pathway. In turn, these Mo-MDSC increase the frequency of ALDH1Bright CSCs and promote mesenchymal features of tumor cells. Finally, blockade of STAT3 activation reversed the increase in ALDH1Bright CSCs. These data suggest that the PC tumor microenvironment transforms monocytes to Mo-MDSC by STAT3 activation, and these cells increase the frequency of ALDH1Bright CSCs. Therefore, targeting STAT3 activation may be an effective therapeutic strategy in targeting CSCs in PC.

Are readmission rates on a neurosurgical service indicators of quality of care

OBJECT The goal of this study was to examine the reasons for early readmissions within 30 days of discharge to a major academic neurosurgical service. METHODS A database of readmissions within 30 days of discharge between April 2009 and September 2010 was retrospectively reviewed. Clinical and administrative variables associated with readmission were examined, including age, sex, race, days between discharge and readmission, and insurance type. The readmissions were then assigned independently by 2 neurosurgeons into 1 of 3 categories: scheduled, adverse event, and unrelated. The adverse event readmissions were further subcategorized into patients readmitted although best practices were followed, those readmitted due to progression of their underlying disease, and those readmitted for preventable causes. These variables were compared descriptively. RESULTS A total of 348 patients with 407 readmissions were identified, comprising 11.5% of the total 3552 admissions. The median age of readmitted patients was 55 years (range 16-96 years) and patients older than 65 years totaled 31%. There were 216 readmissions (53% of 407) for management of an adverse event that was classified as either preventable (149 patients; 37%) or unpreventable (67 patients; 16%). There were 113 patients (28%) who met readmission criteria but who were having an electively scheduled neurosurgical procedure. Progression of disease (48 patients; 12%) and treatment unrelated to primary admission (30 patients; 7%) were additional causes for readmission. There was no significant difference in the proportion of early readmissions by payer status when comparing privately insured patients and those with public or no insurance (p = 0.09). CONCLUSIONS The majority of early readmissions within 30 days of discharge to the neurosurgical service were not preventable. Many of these readmissions were for adverse events that occurred even though best practices were followed, or for progression of the natural history of the neurosurgical disease requiring expected but unpredictably timed subsequent treatment. Judicious care often requires readmission to prevent further morbidity or death in neurosurgical patients, and penalties for readmission will not change these patient care obligations.

Down-regulation of PLCγ2–β-catenin pathway promotes activation and expansion of myeloid-derived suppressor cells in cancer

Down-regulation of PLCγ2 and β-catenin signaling in tumor associated myeloid cells allows for their expansion and tumor growth in mice and humans.

A Simple Effective Method for Generation of a Permanent Record of the Critical View of Safety during Laparoscopic Cholecystectomy by Intraoperative “Doublet” Photography

BACKGROUND The Critical View of Safety (CVS) is an established method for identifying the cystic duct during laparoscopic cholecystectomy. Its goal is to prevent misidentification of the bile ducts and avoid biliary injury. However, a visual record of CVS is not usually made. Intraoperative photography has the potential to record CVS and increase the safety of laparoscopic cholecystectomy. The objective of this study was to develop a simple and effective technique for recording CVS during laparoscopic cholecystectomy. STUDY DESIGN Techniques for photographing and rating photographs of CVS were developed. Surgeons were trained in methods of photographing both anterior and posterior views of CVS during laparoscopic cholecystectomy. Independent observers scored these views individually and together. The term doublet view was used when both anterior and posterior views of CVS were used for rating. Three criteria for CVS were used for scoring photographs. A total score of ≥ 5 of 6 points was considered satisfactory, and a total score <5 of 6 points was considered unsatisfactory. RESULTS Photographs of 28 patients were obtained. Critical View of Safety photographs were satisfactory in either anterior or posterior single images in 43 of 56 (76.8%) instances, and doublet photographs were satisfactory in 27 of 28 (96.4%) instances (p = 0.02). Body mass index >40 predicted a higher likelihood of unsatisfactory individual CVS photos (p = 0.02); however, there was no correlation between patient or pathologic factors and the scores of doublet views. CONCLUSIONS With training and adherence to straightforward photographic techniques, intraoperative doublet photography can record CVS accurately. This method is performed easily, and could be used for recording of CVS in the medical record.

Jaundice: an important, poorly recognized risk factor for diminished survival in patients with adenocarcinoma of the head of the pancreas

OBJECTIVES Jaundice impairs cellular immunity, an important defence against the dissemination of cancer. Jaundice is a common mode of presentation in pancreatic head adenocarcinoma. The purpose of this study was to determine whether there is an association between preoperative jaundice and survival in patients who have undergone resection of such tumours. METHODS Thirty possible survival risk factors were evaluated in a database of over 400 resected patients. Univariate analysis was used to determine odds ratio for death. All factors for which a P-value of <0.30 was obtained were entered into a multivariate analysis using the Cox model with backward selection. RESULTS Preoperative jaundice, age, positive node status, poor differentiation and lymphatic invasion were significant indicators of poor outcome in multivariate analysis. Absence of jaundice was a highly favourable prognostic factor. Interaction emerged between jaundice and nodal status. The benefit conferred by the absence of jaundice was restricted to patients in whom negative node status was present. Five-year overall survival in this group was 66%. Jaundiced patients who underwent preoperative stenting had a survival advantage. CONCLUSIONS Preoperative jaundice is a negative risk factor in adenocarcinoma of the pancreas. Additional studies are required to determine the exact mechanism for this effect.

Targeting both tumour-associated CXCR2+ neutrophils and CCR2+ macrophages disrupts myeloid recruitment and improves chemotherapeutic responses in pancreatic ductal adenocarcinoma

Objective Chemokine pathways are co-opted by pancreatic adenocarcinoma (PDAC) to facilitate myeloid cell recruitment from the bone marrow to establish an immunosuppressive tumour microenvironment (TME). Targeting tumour-associated CXCR2+neutrophils (TAN) or tumour-associated CCR2+ macrophages (TAM) alone improves antitumour immunity in preclinical models. However, a compensatory influx of an alternative myeloid subset may result in a persistent immunosuppressive TME and promote therapeutic resistance. Here, we show CCR2 and CXCR2 combined blockade reduces total tumour-infiltrating myeloids, promoting a more robust antitumour immune response in PDAC compared with either strategy alone. Methods Blood, bone marrow and tumours were analysed from PDAC patients and controls. Treatment response and correlative studies were performed in mice with established orthotopic PDAC tumours treated with a small molecule CCR2 inhibitor (CCR2i) and CXCR2 inhibitor (CXCR2i), alone and in combination with chemotherapy. Results A systemic increase in CXCR2+ TAN correlates with poor prognosis in PDAC, and patients receiving CCR2i showed increased tumour-infiltrating CXCR2+ TAN following treatment. In an orthotopic PDAC model, CXCR2 blockade prevented neutrophil mobilisation from the circulation and augmented chemotherapeutic efficacy. However, depletion of either CXCR2+ TAN or CCR2+ TAM resulted in a compensatory response of the alternative myeloid subset, recapitulating human disease. This was overcome by combined CCR2i and CXCR2i, which augmented antitumour immunity and improved response to FOLFIRINOX chemotherapy. Conclusion Dual targeting of CCR2+ TAM and CXCR2+ TAN improves antitumour immunity and chemotherapeutic response in PDAC compared with either strategy alone.

Severe Nutritional Risk Predicts Decreased Long-Term Survival in Geriatric Patients Undergoing Pancreaticoduodenectomy for Benign Disease

BACKGROUND Weight loss and malnutrition are poorly tolerated by geriatric patients, and pancreaticoduodenectomy (PD) can result in chronic malabsorption and weight loss. We sought to determine how preoperative severe nutritional risk (SNR), as defined by the American College of Surgeons National Surgical Quality Improvement Program/American Geriatric Society Best Practice Guidelines, affects long-term survival after PD for benign disease among geriatric and nongeriatric patients. STUDY DESIGN All patients undergoing PD for nonmalignant conditions at a single center between 1995 and 2013 were followed for survival, excluding patients who died within 90 days of surgery. Survival of geriatric (age ≥65 years) and nongeriatric (age <65 years) patients with and without SNR was compared using Kaplan Meier methods. Cox regression was performed. RESULTS There were 320 patients who underwent PD for benign disease. Over the course of the study, the proportion of geriatric patients undergoing PD for benign conditions increased from 25% to 46%. In addition to being older, geriatric patients undergoing PD for benign disease were significantly more likely to have coronary artery disease (CAD) and hypertension. Geriatric patients with preoperative SNR had significantly decreased long-term survival after PD for benign disease (p < 0.001), with roughly 1 in 3 patients dead at 5 years compared with 1 in 14 patients without SNR. Survival was not significantly different among nongeriatric patients with and without SNR. In geriatric patients, age, CAD, and SNR were significantly associated with decreased survival on both univariate and multivariate analysis. CONCLUSIONS Severe nutritional risk can be a useful predictor of long-term survival in geriatric patients undergoing PD, and could improve patient risk stratification preoperatively. Nonoperative management should be strongly considered in geriatric patients with SNR, when malignancy is not suspected.