Platelet-activating factor (PAF) promotes immunosuppressive neutrophil differentiation within tumors.

Chronic inflammatory milieu in the tumor microenvironment (TME) leads to the recruitment and differentiation of myeloid-derived suppressor cells (MDSCs). Polymorphonuclear (PMN)-MDSCs, which are phenotypically and morphologically defined as a subset of neutrophils, cause major immune suppression in the TME, posing a significant challenge in the development of effective immunotherapies. Despite recent advances in our understanding of PMN-MDSC functions, the mechanism that gives rise to immunosuppressive neutrophils within the TME remains elusive. Both in vivo and in vitro, newly recruited neutrophils into the tumor sites remained activated and highly motile for several days and developed immunosuppressive phenotypes, as indicated by increased arginase 1 (Arg1) and dcTrail-R1 expression and suppressed anticancer CD8 T cell cytotoxicity. The strong suppressive function was successfully recapitulated by incubating naive neutrophils with cancer cell culture supernatant in vitro. Cancer metabolite secretome analyses of the culture supernatant revealed that both murine and human cancers released lipid mediators to induce the differentiation of immunosuppressive neutrophils. Liquid chromatography-mass spectrometry (LC-MS) lipidomic analysis identified platelet-activation factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) as a common tumor-derived lipid mediator that induces neutrophil differentiation. Lysophosphatidylcholine acyltransferase 2 (LPCAT2), the PAF biosynthetic enzyme, is up-regulated in human pancreatic ductal adenocarcinoma (PDAC) and shows an unfavorable correlation with patient survival across multiple cancer types. Our study identifies PAF as a lipid-driven mechanism of MDSC differentiation in the TME, providing a potential target for cancer immunotherapy.

HE4 Overexpression by Ovarian Cancer Promotes a Suppressive Tumor Immune Microenvironment and Enhanced Tumor and Macrophage PD-L1 Expression.

Ovarian cancer is a highly fatal malignancy characterized by early chemotherapy responsiveness but the eventual development of resistance. Immune targeting therapies are changing treatment paradigms for numerous cancer types but have had minimal success in ovarian cancer. Through retrospective patient sample analysis, we have determined that high human epididymis protein 4 (HE4) production correlates with multiple markers of immune suppression in ovarian cancer, including lower CD8+ T cell infiltration, higher PD-L1 expression, and an increase in the peripheral monocyte to lymphocyte ratio. To further understand the impact that HE4 has on the immune microenvironment in ovarian cancer, we injected rats with syngeneic HE4 high- and low-expressing cancer cells and analyzed the differences in their tumor and ascites immune milieu. We found that high tumoral HE4 expression promotes an ascites cytokine profile that is rich in myeloid-recruiting and differentiation factors, with an influx of M2 macrophages and increased arginase 1 production. Additionally, CTL activation is significantly reduced in the ascites fluid, and there is a trend toward lower CTL infiltration of the tumor, whereas NK cell recruitment to the ascites and tumor is also reduced. PD-L1 expression by tumor cells and macrophages is increased by HE4 through a novel posttranscriptional mechanism. Our data have identified HE4 as a mediator of tumor-immune suppression in ovarian cancer, highlighting this molecule as a potential therapeutic target for the treatment of this devastating disease.

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.

Early postoperative ERAS compliance predicts decreased length of stay and complications following liver resection.

BACKGROUND: Enhanced recovery after surgery (ERAS) components for liver resection lack standardization and compliance. We evaluated our ERAS protocol and describe the association of postoperative ERAS compliance with length of stay (LOS) and complications. METHODS: We retrospectively reviewed patients undergoing liver resection at our institution from 2016 to 2020. Pre- and post-ERAS outcomes and compliance at 72 h were compared with LOS and complications. LOS beyond 72 h was defined as LOS72. RESULTS: 210 patients were included. Post-ERAS patients had significantly shorter LOS (5.1 vs. 7.3 days, p = 0.0014) with no difference in 30-day mortality, morbidity, or readmissions. ERAS components associated with shorter LOS72 were regular diet (HR 1.73), fluid discontinuation (HR 1.63), drain removal (HR 1.94), multimodal and oral analgesia (HR 1.51), and ambulation >100 ft (HR 2.23). LOS72 was 1-day for ≥9 ERAS component compliance, 4-days for 6-8 components, and 6-days for <6 components. 30-day complication rates for patients with ≥9 components by postoperative day 3 (POD3) were significantly lower than those with 6-8 (12 vs 32%). CONCLUSION: ERAS decreases LOS after liver resection. Nutritional advancement, drain discontinuation, multimodal and oral analgesia, and ambulation >100 ft by POD3 are associated with decreased LOS72. Achieving ≥6 components by POD3 predicts decreased LOS72 and complications.

Narcotic Free Cervical Endocrine Surgery: A Shift in Paradigm.

BACKGROUND AND OBJECTIVE: The opioid epidemic has stimulated initiatives to reduce the number of unnecessary narcotic prescriptions. We adopted an opt-in prescription system for patients undergoing ambulatory cervical endocrine surgery (CES). We hypothesized that empowering patients to decide whether or not to receive narcotics for pain control would result in fewer unnecessary opioid prescriptions. METHODS: We enrolled all patients scheduled for outpatient CES between July 2017 and June 2018 in a narcotic opt-in program. Patient demographics, procedure characteristics, and postoperative pain scores were collected prospectively. Statistical analyses were performed to correlate clinical predictors with narcotic request. Results were compared against a historical control group. The study was approved by the University IRB. RESULTS: A total of 216 consecutive patients underwent outpatient CES following implementation of the program. Only nine (4%) requested prescription narcotic medication at discharge, and no patient called after discharge to request analgesic medications. Compared with our prior treatment paradigm, we achieved a 96.6% reduction in the number of narcotic tablets prescribed, and a 98% reduction in unconsumed tablets. Univariate analysis suggested history of substance abuse (P < 0.001), anxiety (P = 0.01), depression (P < 0.001), baseline narcotic use (P = 0.004), highest pain postoperatively (P = 0.004), and incision length (P = 0.007) as predictive for narcotic request. Multivariate analysis retained significance with incision length and history of substance abuse. CONCLUSION: By empowering patients undergoing ambulatory CES to accept or decline a prescription, we reduced the number of prescribed narcotic tablets by 96.6%. Although longer incisions and prior substance abuse predict higher likelihood of requesting pain medication on discharge, 207 of 216 patients were treated with acetaminophen alone.

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.

Phase 1b study of a small molecule antagonist of human chemokine (C-C motif) receptor 2 (PF-04136309) in combination with nab-paclitaxel/gemcitabine in first-line treatment of metastatic pancreatic ductal adenocarcinoma.

Background In pancreatic ductal adenocarcinoma (PDAC), the chemokine (C-C motif) ligand 2 (CCL2)/chemokine (C-C motif) receptor 2 (CCR2) axis plays a key role in immunosuppressive properties of the tumor microenvironment, patient prognosis, and chemoresistance. This phase Ib study assessed the effects of the orally administered CCR2 inhibitor PF-04136309 in combination with nab-paclitaxel and gemcitabine in patients with previously untreated metastatic PDAC. Methods Patients received PF-04136309 twice daily (BID) continuously plus nab-paclitaxel (125 mg/m2) and gemcitabine (1000 mg/m2) administered on days 1, 8, and 15 of each 28-day cycle. The primary objectives were to evaluate safety and tolerability, characterize dose-limiting toxicities (DLTs), and determine the recommended phase II dose (RP2D) of PF-04136309. Results In all, 21 patients received PF-04136309 at a starting dose of 500 mg or 750 mg BID. The RP2D was identified to be 500 mg BID. Of 17 patients treated at the 500 mg BID starting dose, three (17.6%) experienced a total of four DLTs, including grade 3 dysesthesia, diarrhea, and hypokalemia and one event of grade 4 hypoxia. Relative to the small number of patients (n = 21), a high incidence (24%) of pulmonary toxicity was observed in this study. The objective response rate for 21 patients was 23.8% (95% confidence interval: 8.2-47.2%). Levels of CD14 + CCR2+ inflammatory monocytes (IM) decreased in the peripheral blood, but did not accumulate in the bone marrow. Conclusions PF-04136309 in combination with nab-paclitaxel plus gemcitabine had a safety profile that raises concern for synergistic pulmonary toxicity and did not show an efficacy signal above nab-paclitaxel and gemcitabine. ClinicalTrials.gov identifier: NCT02732938.

Microspheres Encapsulating Immunotherapy Agents Target the Tumor-Draining Lymph Node in Pancreatic Ductal Adenocarcinoma.

INTRODUCTION: The tumor-draining lymph node (TDLN) plays a role in tumor immunity. Intratumorally administered microspheres (MS) that encapsulate immunomodulatory agents have emerged as a treatment strategy capable of causing profound changes in the tumor microenvironment (TME) and eliciting potent antitumor effects. We hypothesized that local delivery of MS to the TME may also drain to and therefore target the TDLN to initiate antitumor immune responses. METHODS: Fluorescent MS were injected into orthotopically implanted murine pancreatic tumors, and tissues were examined by whole-mount microscopy and imaging flow cytometry. The role of the TDLN was investigated for mice treated with intratumoral interleukin-12 (IL-12)-encapsulated MS in combination with stereotactic body radiotherapy (SBRT) by cytokine profile and TDLN ablation. RESULTS: Fluorescent AF-594 MS delivered intratumorally were detected in the tumor, peritumoral lymphatics, and the TDLN 2 h after injection. Phagocytic cells were observed with internalized fluorescent MS. SBRT + IL-12 MS-induced upregulation of Th1 and antitumor factors IL-12, IFN-γ, CXCL10, and granzyme B in the TDLN, and excision of the TDLN partially abrogated treatment efficacy. CONCLUSIONS: Our results demonstrate that intratumorally administered MS not only target the TME, but also drain to the TDLN. Furthermore, MS encapsulated with a potent antitumor cytokine, IL-12, induce an antitumor cytokine profile in the TDLN, which is essential for treatment efficacy.

Germline cancer susceptibility gene variants, somatic second hits, and survival outcomes in patients with resected pancreatic cancer.

PURPOSE: Germline variants in double-strand DNA damage repair (dsDDR) genes (e.g., BRCA1/2) predispose to pancreatic adenocarcinoma (PDAC) and may predict sensitivity to platinum-based chemotherapy and poly(ADP) ribose polymerase (PARP) inhibitors. We sought to determine the prevalence and significance of germline cancer susceptibility gene variants in PDAC with paired somatic and survival analyses. METHODS: Using a customized next-generation sequencing panel, germline/somatic DNA was analyzed from 289 patients with resected PDAC ascertained without preselection for high-risk features (e.g., young age, personal/family history). All identified variants were assessed for pathogenicity. Outcomes were analyzed using multivariable-adjusted Cox proportional hazards regression. RESULTS: We found that 28/289 (9.7%; 95% confidence interval [CI] 6.5-13.7%) patients carried pathogenic/likely pathogenic germline variants, including 21 (7.3%) dsDDR gene variants (3 BRCA1, 4 BRCA2, 14 other dsDDR genes [ATM, BRIP1, CHEK2, NBN, PALB2, RAD50, RAD51C]), 3 Lynch syndrome, and 4 other genes (APC p.I1307K, CDKN2A, TP53). Somatic sequencing and immunohistochemistry identified second hits in the tumor in 12/27 (44.4%) patients with germline variants (1 failed sequencing). Compared with noncarriers, patients with germline dsDDR gene variants had superior overall survival (hazard ratio [HR] 0.54; 95% CI 0.30-0.99; P = 0.05). CONCLUSION: Nearly 10% of PDAC patients harbor germline variants, although the majority lack somatic second hits, the therapeutic significance of which warrants further study.

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.

Lymph node metastases in resected pancreatic ductal adenocarcinoma: predictors of disease recurrence and survival.

BACKGROUND: Few studies have simultaneously assessed the prognostic value of the multiple classification systems for lymph node (LN) metastases in resected pancreatic ductal adenocarcinoma (PDAC). METHODS: In 600 patients with resected PDAC, we examined the association of LN parameters (AJCC 7th and 8th editions, LN ratio (LNR), and log odds of metastatic LN (LODDS)) with pattern of recurrence and patient survival using logistic regression and Cox proportional hazards regression, respectively. Regression models adjusted for age, sex, margin status, tumour grade, and perioperative therapy. RESULTS: Lymph node metastases classified by AJCC 7th and 8th editions, LNR, and LODDS were associated with worse disease free-survival (DFS) and overall survival (OS) (all Ptrend<0.01). American Joint Committee on Cancer 8th edition effectively predicted DFS and OS, while minimising model complexity. Lymph node metastases had weaker prognostic value in patients with positive margins and distal resections (both Pinteraction<0.03). Lymph node metastases by AJCC 7th and 8th editions did not predict the likelihood of local disease as the first site of recurrence. CONCLUSIONS: American Joint Committee on Cancer 8th edition LN classification is an effective and practical tool to predict outcomes in patients with resected PDAC. However, the prognostic value of LN metastases is attenuated in patients with positive resection margins and distal pancreatectomies.

Interferon-based chemoradiation followed by gemcitabine for resected pancreatic adenocarcinoma: long-term follow-up.

To report long-term follow up of a phase II, single-arm trial of resectable pancreatic ductal adenocarcinoma (PDAC) treated with adjuvant interferon-based chemoradiation followed by gemcitabine to determine survival, recurrence, and complications. METHODS: From 2002 to 2005, 53 patients with PDAC underwent pancreaticoduodenectomy and received adjuvant interferon-based chemoradiation consisting of external-beam irradiation and simultaneous 3-drug chemotherapy of continuous daily 5-fluorouracil infusion, weekly intravenous bolus cisplatin, and subcutaneous interferon-α, followed by two months of weekly intravenous gemcitabine. RESULTS: Actual overall survival for the 5- and 10-year periods were 26% and 10%, respectively, with a median overall survival of 25 months (95% CI: 16.4-38.5). Adverse prognostic factors on multivariate analysis were positive tumor margin (p < 0.035), lymphovascular invasion (p < 0.015), and perineural invasion (p < 0.026). Median time to recurrence was 11 months. Positive tumor margin was associated with lymph node involvement (p < 0.005), portal vein resection (p < 0.038), and metastases (p < 0.018). Late complications were frequent and predominated by gastrointestinal and infectious complications. CONCLUSIONS: Adjuvant interferon-based chemoradiation for PDAC improves long-term survival compared to standard therapy. However, recurrence rates and long-term complications remain high, thus further studies are indicated to assess patient characteristics that indicate a favorable treatment profile.

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.

Interaction of Postoperative Morbidity and Receipt of Adjuvant Therapy on Long-Term Survival After Resection for Gastric Adenocarcinoma: Results From the U.S. Gastric Cancer Collaborative.

BACKGROUND: Postoperative complications (POCs) can negatively impact survival after oncologic resection. POCs may also decrease the rate of adjuvant therapy completion. We evaluated the impact of complications on gastric cancer survival and analyzed the combined effect of complications and adjuvant therapy on survival. METHODS: We analyzed 824 patients from 7 institutions of the U.S. Gastric Cancer Collaborative who underwent curative resection for gastric adenocarcinoma between 2000 and 2012. POC were graded using the modified Clavien-Dindo system. Survival probabilities were estimated using the method of Kaplan and Meier and analyzed using multivariate Cox regression. RESULTS: Median follow-up was 35 months. The overall complication rate was 41 %. The 5-year overall survival (OS) and recurrence-free survival (RFS) of patients who experienced complications were 27 and 23 %, respectively, compared with 43 and 40 % in patients who did not have complications (p < 0.0001 for OS and RFS). On multivariate analysis, POC remained an independent predictor for decreased OS and RFS (HR 1.3, 95 % CI 1.1-1.6, p = 0.03 for OS; HR 1.3, 95 % CI 1.01-1.6, p = 0.03 for RFS). Patients who experienced POC were less likely to receive adjuvant therapy (OR 0.5, 95 % CI 0.3-0.7, p < 0.001). The interaction of complications and failure to receive adjuvant therapy significantly increased the hazard of death compared with patients who had neither complications nor adjuvant therapy (HR 2.3, 95 % CI 1.6-3.2, p < 0.001). CONCLUSIONS: Postoperative complications adversely affect long-term outcomes after gastrectomy for gastric cancer. Not receiving adjuvant therapy in the face of POC portends an especially poor prognosis following gastrectomy for gastric cancer.

Colorectal liver metastases: disappearing lesions in the era of Eovist hepatobiliary magnetic resonance imaging.

BACKGROUND: Hepatobiliary contrast enhanced MRI is known to be the most sensitive imaging modality for detection of colorectal hepatic metastasis. To date no study has investigated the rate of disappearing lesions with gadoxetic acid MR (Eovist/Primovist), or characterized the pathologic response of lesions which disappear on gadoxetic acid MR. METHODS: Retrospective review of hepatic resections for colorectal metastases between 01/2008 and 01/2014 was performed to evaluated the rate of disappearance of lesions on gadoxetic acid MR and the rate of complete pathologic response in the lesions that disappear. "Disappearing lesions" were lesions on baseline imaging that were not identifiable on pre-operative Eovist MRI. Complete pathologic response was defined as no viable tumor on pathology or by lack of recurrence within 1 year. RESULTS: In 23 patients, 200 colorectal metastases were identified on baseline imaging. On pre-operative Eovist MR 77 of the 200 lesions (38.5%) were "disappearing" lesions. At surgical pathology or 1 year follow-up imaging, 42 of 77 lesions (55%) demonstrated viable tumor (21) or recurrence (21). Thirty of 77 lesions (39%) were nonviable at pathology (10) or without evidence of recurrence at 1 year (20). 5 lesions were indeterminate. DISCUSSION: Despite disappearance on Eovist MR imaging (the most sensitive available imaging modality), 38.5% of all colorectal metastases disappeared and of those, 55% were viable.

Natural history of preoperative subcentimeter pulmonary nodules in patients with resectable pancreatic adenocarcinoma: a retrospective cohort study.

OBJECTIVE: To determine the detection rate, radiologic characteristics, and natural history of incidental subcentimeter pulmonary nodules (SCPN) among patients with resectable pancreatic adenocarcinoma and to clarify whether further preoperative evaluation should be considered. BACKGROUND: The clinical significance of SCPN detected by routine preoperative abdominal imaging in patients with pancreatic adenocarcinoma is unknown. METHODS: Patients who underwent resection for pancreatic adenocarcinoma between 2000 and 2010 were queried from a prospectively maintained database at a single institution. Pre- and postoperative computed tomographic (CT) imaging was independently reviewed and the presence and radiologic features of SCPNs were analyzed for associations with overall survival (OS). RESULTS: Of the 463 patients who met inclusion criteria, 329 (71%) had reviewable preoperative imaging. Preoperative SCPNs were described in 59 patients (18%), and 41 patients had follow-up imaging available for review. Only increasing age (67.1 vs 63.5 years; P = 0.005) was associated with the presence of SCPN. Six patients (1.8%) had new or enlarging nodules after surgery, of whom 5 (1.5%) had confirmed metastatic adenocarcinoma. There was no difference in OS between patients with or without preoperative SCPN (16.1 vs 19.1 months; P = 0.201). No radiographic criterion of SCPN (including number, size, laterality, calcification, or contour) was associated with OS. CONCLUSIONS: Neither the presence of preoperative SCPN nor nodule characteristics was associated with OS among patients who underwent pancreaticoduodenectomy (PD) for pancreatic cancer. These data do not support routine additional workup of preoperative SCPN in patients with resectable pancreatic adenocarcinoma.

Factors Associated With Recurrence and Survival in Lymph Node-negative Gastric Adenocarcinoma: A 7-Institution Study of the US Gastric Cancer Collaborative.

OBJECTIVES: To determine pathologic features associated with recurrence and survival in patients with lymph node-negative gastric adenocarcinoma. STUDY DESIGN: Multi-institutional retrospective analysis. BACKGROUND: Lymph node status is among the most important predictors of recurrence after gastrectomy for gastric adenocarcinoma. Pathologic features predictive of recurrence in patients with node-negative disease are less well established. METHODS: Patients who underwent curative resection for gastric adenocarcinoma between 2000 and 2012 from 7 institutions of the US Gastric Cancer Collaborative were analyzed, excluding 30-day mortalities and stage IV disease. Competing risks regression and multivariate Cox regression were used to determine pathologic features associated with time to recurrence and overall survival. Differences in cumulative incidence of recurrence were assessed using the Gray method (for univariate nonparametric analyses) and the Fine and Gray method (for multivariate analyses) and shown as subhazard ratios (SHRs) and adjusted subhazard ratios (aSHRs), respectively. RESULTS: Of 805 patients who met inclusion criteria, 317 (39%) had node-negative disease, of which 54 (17%) recurred. By 2 and 5 years, 66% and 88% of patients, respectively, experienced recurrence. On multivariate competing risks regression, only T-stage 3 or higher was associated with shorter time to recurrence [aSHR = 2.7; 95% confidence interval (CI), 1.5-5.2]. Multivariate Cox regression showed T-stage 3 or higher [hazard ratio (HR) = 1.8; 95% CI, 1.2-2.8], lymphovascular invasion (HR = 2.2; 95% CI, 1.4-3.4), and signet ring histology (HR = 2.1; 95% CI, 1.2-3.6) to be associated with decreased overall survival. CONCLUSIONS: Despite absence of lymph node involvement, patients with T-stage 3 or higher have a significantly shorter time to recurrence. These patients may benefit from more aggressive adjuvant therapy and postoperative surveillance regimens.

Regional lymphadenectomy is indicated in the surgical treatment of pancreatic neuroendocrine tumors (PNETs).

OBJECTIVE: To explore the prognostic importance and preoperative predictors of lymph node metastasis in an effort to guide surgical decision making in patients with pancreatic neuroendocrine tumors (PNETs). BACKGROUND: PNETs are uncommon, and the natural history of the disease is not well described. As a result, there remains controversy regarding the optimal management of regional lymph nodes during resection of the primary tumor. METHODS: A retrospective review of a prospectively maintained database of patients who underwent surgery for locoregional PNET between 1994 and 2012 was performed. Logistic regression was used to identify predictors of nodal metastasis. Overall survival and disease-free survival were calculated using Kaplan-Meier method. Results were expressed as P values and odds ratio estimates, with 95% confidence intervals. RESULTS: One hundred thirty-six patients were identified, of whom 50 (38%) patients had nodal metastasis. The frequency of lymph node metastasis was higher for larger tumors [> 1.5 cm (odds ratio [OR] = 4.7)], tumors of the head as compared with body-tail of the pancreas (OR = 2.8), tumors with Ki-67 greater than 20% (OR = 6.7), and tumors with lymph vascular invasion (OR = 3.6) (P < 0.05). Median disease-free survival was lower for patients with nodal metastases (4.5 vs 14.6 years, P < 0.0001). CONCLUSIONS: Lymph node metastasis is predictive of poor outcomes in patients with PNETs. Preoperative variables are not able to reliably predict patients where the probability of lymph node involvement was less than 12%. These data support inclusion of regional lymphadenectomy in patients undergoing pancreatic resections for PNET.

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 ALDH1(Bright) CSCs and epithelial to mesenchymal transition is not well understood. In this study, we demonstrate that Mo-MDSC (CD11b(+)/Gr1(+)/Ly6G(-)/Ly6C(hi)) significantly increase the frequency of ALDH1(Bright) 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-DR(low/-)) in vitro, and this transformation is dependent on the activation of the STAT3 pathway. In turn, these Mo-MDSC increase the frequency of ALDH1(Bright) CSCs and promote mesenchymal features of tumor cells. Finally, blockade of STAT3 activation reversed the increase in ALDH1(Bright) CSCs. These data suggest that the PC tumor microenvironment transforms monocytes to Mo-MDSC by STAT3 activation, and these cells increase the frequency of ALDH1(Bright) CSCs. Therefore, targeting STAT3 activation may be an effective therapeutic strategy in targeting CSCs in PC.

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.