The Prognostic and Predictive Role of the Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), and Lymphocyte-to-Monocyte Ratio (LMR) as Biomarkers in Resected Pancreatic Cancer.

Pancreatic cancer has poor survival despite modern-day advances in its management. At present, there are no available biomarkers that can predict chemotherapy response or help inform prognosis. In more recent years, there has been increased interest in potential inflammatory biomarkers, with studies revealing a worse prognosis of patients with a higher neutrophil-to-lymphocyte ratio in a range of tumour types. Our aim was to assess the role of three inflammatory biomarkers in peripheral blood in predicting chemotherapy response in patients with earlier disease treated with neoadjuvant chemotherapy and as a prognostic marker in all patients that underwent surgery for pancreatic cancer. Using retrospective records, we discovered that patients with a higher neutrophil-to-lymphocyte ratio (>5) at the time of diagnosis had worse median overall survival than those with ratios ≤5 at 13 and 32.4 months (p = 0.001, HR 2.43), respectively. We were able to appreciate a correlation between a higher platelet-to-lymphocyte ratio and increased residual tumour in the histopathological specimen in patients receiving neoadjuvant chemotherapy; however, the association was weak (p = 0.03, coefficient 0.21). Due to the dynamic relationship between the immune system and pancreatic cancer, it is unsurprising that immune markers may be useful as potential biomarkers; however, larger prospective studies are needed to validate these findings.

Metastatic primary breast neuroendocrine neoplasms: a case series.

BACKGROUND: Breast neuroendocrine neoplasms represent a rare subtype of breast cancer which have not been well studied or characterised, particularly in the metastatic setting. AIM: To present clinicopathological characteristics, treatment and outcomes of a series of patients with metastatic neuroendocrine carcinoma of the breast and review the current literature. METHODS: We performed a retrospective review to identify and describe patients with metastatic neuroendocrine carcinoma of the breast at our centre between 2011 and 2021. Medical records, pathology and imaging results were examined to evaluate the clinical and histopathological features as well as the treatment pathways and prognosis of these patients. RESULTS: We present a series of seven female patients with metastatic neuroendocrine carcinoma of the breast, as defined by the World Health Organization classification, over a period of 10 years (2011-2021) from a single centre. Median age at diagnosis was 48 years (range 39-63). Six of seven tissue samples expressed synaptophysin and chromogranin and were also oestrogen and progesterone receptor positive; median Ki-67 index was 50% (range 20-90%). All seven patients had demonstrated avidity on 18 F-FDG PET imaging, and the six who underwent 68 Ga-DOTATATE PET all had significant avidity. Treatment modalities and sequencing varied, but all patients received chemotherapy during their disease course. Six patients received three or more lines of treatment. Median overall survival was 31.8 months (range 3.7-108.6). Median progression-free survival (PFS) with first-line therapy for metastatic disease was 5.8 months (range 1.8-37.8). CONCLUSIONS: This series shows the use of multiple modalities in treating this disease, with different sequencing in different patients. Despite multiple modalities used in the first-line setting, first-line PFS remains short. Larger series and further molecular characterisation are required to aid clinicians in managing this condition and to guide optimal treatment sequencing to improve outcomes in this rare patient group.

Australasian Consensus Statement on the Identification, Prevention, and Management of Hormonal Crises in Patients with Neuroendocrine Neoplasms Undergoing Peptide Receptor Radionuclide Therapy.

Hormonal crises are a rare but increasingly recognized phenomenon following peptide receptor radionuclide therapy (PRRT) in patients with neuroendocrine neoplasms (NENs). Due to the paucity of published studies, approaches to the identification, prevention, and management of risk factors are inconsistent between different institutions. This consensus statement aimed to provide guidance for NEN patients undergoing PRRT. Our statement has been created on the basis of clinical demand and concerns regarding the precipitation of hormonal crises. A formal literature review was conducted to identify available studies. A total of 19 Australian and New Zealand experts in the fields of medical oncology, nuclear medicine, anaesthetics, and endocrinology collaborated on this consensus statement. The main focus is on carcinoid crises. Other hormonal crises seen in patients with functional pancreatic NENs are addressed briefly. These recommendations are relevant to PRRT centres internationally and should be tailored to local experience and available resources.

Overall survival with circulating tumor DNA-guided therapy in advanced non-small-cell lung cancer.

Circulating tumor DNA (ctDNA) sequencing guides therapy decisions but has been studied mostly in small cohorts without sufficient follow-up to determine its influence on overall survival. We prospectively followed an international cohort of 1,127 patients with non-small-cell lung cancer and ctDNA-guided therapy. ctDNA detection was associated with shorter survival (hazard ratio (HR), 2.05; 95% confidence interval (CI), 1.74-2.42; P < 0.001) independently of clinicopathologic features and metabolic tumor volume. Among the 722 (64%) patients with detectable ctDNA, 255 (23%) matched to targeted therapy by ctDNA sequencing had longer survival than those not treated with targeted therapy (HR, 0.63; 95% CI, 0.52-0.76; P < 0.001). Genomic alterations in ctDNA not detected by time-matched tissue sequencing were found in 25% of the patients. These ctDNA-only alterations disproportionately featured subclonal drivers of resistance, including RICTOR and PIK3CA alterations, and were associated with short survival. Minimally invasive ctDNA profiling can identify heterogeneous drivers not captured in tissue sequencing and expand community access to life-prolonging therapy.

Synchronous Operable Pancreatic and Breast Cancer Without Genetic Mutation: A Literature Review and Discussion.

Background: Synchronous cancers are rarely detected when working-up a patient for a primary cancer. Neoadjuvant management of synchronous breast and pancreatic cancers, without a germline mutation, has yet to be discussed. Two patients were diagnosed with synchronous breast and pancreatic cancers at our institution over the last decade. A literature review was performed to evaluate the current evidence stance. Results: The first patient was 61-years old and diagnosed with a HER2+ breast cancer. The second patient was 77-years old and diagnosed with a Luminal B breast cancer. The inability to provide concurrent breast and pancreatic neoadjuvant therapy for the HER2+ patient, resulted in upfront surgery. The second patient was able to have both cancers treated simultaneously - neoadjuvant chemotherapy to the pancreas, and neoadjuvant endocrine therapy to the breast. Discuss: There is no single neoadjuvant regimen that treats both pancreatic and breast cancer. The differences in breast cancer sub-types impacted our neoadjuvant options. Our recent experience led us to the hypothesis that breast cancer care dictates treatment, while pancreatic cancer determines survival. There is a significant paucity in the literature regarding synchronous breast and pancreatic cancer.

Prognostic Models Incorporating RAS Mutation to Predict Survival in Patients with Colorectal Liver Metastases: A Narrative Review.

Recurrence and survival vary widely among patients who undergo curative-intent resection of colorectal liver metastases (CRLM). Prognostic models provide estimated probabilities of these outcomes and allow the effects of multiple potentially interacting variables to be adjusted and assessed simultaneously. Although many prognostic models based on clinicopathologic factors have been developed since the 1990s to predict survival after resection of CRLM, these models vary in their predictive performance when applied to contemporary cohorts. Rat sarcoma viral oncogene homolog (RAS) mutation status is routinely tested in patients with metastatic colorectal cancer to predict response to anti-epidermal growth factor therapy. In addition, mutations in RAS predict survival and recurrence in patients undergoing hepatectomy for CRLM. Several recent prognostic models have incorporated RAS mutation status as a surrogate of tumor biology and combined revised clinicopathologic variables to improve the prediction of recurrence and survival. This narrative review aims to evaluate the differences between contemporary prognostic models incorporating RAS mutation status and their clinical applicability in patients considered for curative-intent resection of CRLM.

Proteomic Profiling and Biomarker Discovery in Colorectal Liver Metastases.

Colorectal liver metastases (CRLM) are the leading cause of death among patients with metastatic colorectal cancer (CRC). As part of multimodal therapy, liver resection is the mainstay of curative-intent treatment for select patients with CRLM. However, effective treatment of CRLM remains challenging as recurrence occurs in most patients after liver resection. Proposed clinicopathologic factors for predicting recurrence are inconsistent and lose prognostic significance over time. The rapid development of next-generation sequencing technologies and decreasing DNA sequencing costs have accelerated the genomic profiling of various cancers. The characterisation of genomic alterations in CRC has significantly improved our understanding of its carcinogenesis. However, the functional context at the protein level has not been established for most of this genomic information. Furthermore, genomic alterations do not always result in predicted changes in the corresponding proteins and cancer phenotype, while post-transcriptional and post-translational regulation may alter synthesised protein levels, affecting phenotypes. More recent advancements in mass spectrometry-based technology enable accurate protein quantitation and comprehensive proteomic profiling of cancers. Several studies have explored proteomic biomarkers for predicting CRLM after oncologic resection of primary CRC and recurrence after curative-intent resection of CRLM. The current review aims to rationalise the proteomic complexity of CRC and explore the potential applications of proteomic biomarkers in CRLM.

Recurrence patterns predict survival after resection of colorectal liver metastases.

BACKGROUND: Effective treatment of colorectal liver metastases (CRLM) is challenging because recurrence occurs in many patients after curative-intent resection. This study evaluates the recurrence patterns after resection of CRLM and its association with survival. METHODS: A retrospective review of prospectively collected data of patients with CRLM managed with curative-intent resection from January 2007 to December 2017 was performed. The main outcomes and measures were the timing of recurrence, initial sites of recurrence, overall survival and recurrence-free survival. Early recurrence was defined as the detection of any organ recurrence ≤6 months from resection of CRLM. RESULTS: A cohort of 194 patients was included for analysis. After a median follow-up of 85.3 months, 145 patients (74.7%) were diagnosed with recurrence. The median overall survival was 67.6 months (95% CI 50.4-80.2) and the 5-year overall survival was 54.1%. After initial recurrence was detected, the median survival was 28.9 months (95% CI 23.6-37.8) months and the 5-year overall survival was 28.8%. Early recurrence occurred in 58 patients (29.9%). Initial recurrence patterns included: liver only in 53 patients (36.5%), multiple sites in 48 patients (33.1%), lung only in 30 patients (20.7%), and other single extrahepatic sites in 14 patients (9.6%). Early recurrence and initial multi-site recurrence were independent predictors of worse overall survival for patients who develop recurrence after resection of CLRM. CONCLUSION: The timing and initial sites of recurrence are prognostic factors in determining survival after curative-intent resection of CRLM.

Clinical and molecular profile of young adults with early-onset colorectal cancer: Experience from four Australian tertiary centers.

BACKGROUND: Patients with early-onset colorectal cancer (EO-CRC) have unique characteristics. Contemporary data on the pathological and molecular features, and survival of EO-CRC are limited in the Australian context. AIM: To determine the demographic, histopathological and molecular characteristics of adults with EO-CRC, and their survival. METHODS: We conducted a retrospective study of adults aged 18-49 years with EO-CRC who were referred to the Illawarra Shoalhaven Local Health District, South Eastern Sydney Local Health District and Royal North Shore Hospital in New South Wales, Australia, between 2014 and 2018. RESULTS: Of 257 patients included, 94 (37%) patients presented with de novo metastatic CRC, 80% patients had near-average risk family history and 89% had a symptomatic presentation. In 159 patients with nonmetastatic disease at diagnosis, stage III disease (OR 3.88 [95% CI: 1.13-13.3]; p = .03) and the presence of perineural invasion (PNI) (OR 6.63 [95% CI: 2.21-19.84]; p = .001) were risk factors associated with the development of metastatic disease. Among 94 patients with de novo metastatic disease, 43 (43%) and 12 (14%) patients harbored a KRAS or BRAF V600E mutation, respectively. The median overall survival was 29.6 months (95% CI: 20.4-38.7). BRAF mutation was associated with inferior survival (HR 3.00 [95% CI: 1.30-6.94]; p = .01). CONCLUSION: The prevalence of KRAS and BRAF mutations in our cohort is similar to the overseas experience. Stage III disease at diagnosis, presence of PNI and BRAF mutation are adverse prognostic indicators. A better understanding of the molecular landscape is needed for this patient cohort, so as to better tailor prevention strategies, screening and treatment pathways.

Differential effects of radiation fractionation regimens on glioblastoma.

BACKGROUND: Radiotherapy (RT) is a mainstay of treatment for patients with glioblastoma (GB). Early clinical trials show that short course hypofractionation showed no survival benefit compared to conventional regimens with or without temozolomide chemotherapy (TMZ) but reduces the number of doses required. Concerns around delayed neurological deficits and reduced cognition from short course hypofractionated RT remain a concern. The aim of this study was to evaluate the effect of increased interfractional time using two different radiation fractionation regimens on GB. METHODS: The radiobiological effect of increasing doses 0-20 Gy x-ray photon RT on Gl261 and CT2A GB cell lines was compared by colony forming assay, DNA damage by alkaline comet assay, oxidative stress, DNA damage, cell cycle, and caspase-3/7 by MUSE® flow cytometric analyses, and protein expression by western blot analyses. Conventional (20 Gy/10 fractions) and hypofractionated (20 Gy/4 fractions spaced 72 h apart) RT regimens with and without TMZ (200 mg/kg/day) were performed in syngeneic Gl261 and CT2A intracranial mouse models using the Small Animal Radiation Research Platform (Xstrahl Inc.). RESULTS: X-ray photon radiation dose-dependently increased reactive oxygen species, DNA damage, autophagy, and caspase 3/7-mediated apoptotic cell death. While the conventional fractionated dose regimen of 20 Gy/10 f was effective at inducing cell death via the above mechanism, this was exceeded by a 20 Gy/4 f regimen which improved median survival and histopathology in Gl261-tumor bearing mice, and eradicated tumors in CT2A tumors with no additional toxicity. CONCLUSIONS: Spacing of hypofractionated RT doses 72 h apart showed increased median survival and tumor control via increased activation of RT-mediated cell death, with no observed increased in radiotoxicity. This supports further exploration of differential RT fractionated regimens in GB clinical trials to reduce delayed neurological radiotoxicity.

Performance of prognostic models incorporating KRAS mutation status to predict survival after resection of colorectal liver metastases.

BACKGROUND: The Genetic And Morphologic Evaluation (GAME) score and modified clinical score (m-CS) are two novel prognostic models that incorporate KRAS mutation status to predict survival after resection of colorectal liver metastases (CRLM). This retrospective cohort study evaluated the performance of these two models. METHODS: A total of 103 patients who underwent resection of CRLM between 2007 and 2017 and had known KRAS mutation status were included, 39 (37.9%) of whom had KRAS mutated tumours. Complete case analysis of the patients was performed according to the Clinical Risk Score (CRS), m-CS, and GAME score. The primary outcome was overall survival stratified according to low-risk and high-risk scores. Harrell's C-index and Akaike information criterion (AIC) were used to compare the discrimination of the evaluated prognostic models. RESULTS: The GAME score demonstrated the largest difference in overall survival for patients stratified according to low-risk and high-risk groups. Harrell's C-index values for the CRS, m-CS, and GAME models were 0.583, 0.600, and 0.668, respectively. AIC values for the CRS, m-CS, and GAME models were 441, 439, and 427, respectively. CONCLUSION: The GAME score outperforms the CRS and m-CS in predicting overall survival after resection of CRLM in patients with known KRAS mutation status.

Computed tomography (CT)-defined sarcopenia and myosteatosis are prevalent in patients with neuroendocrine neoplasms (NENs) treated with peptide receptor radionuclide therapy (PRRT).

BACKGROUND/OBJECTIVES: Neuroendocrine neoplasms (NEN) may predispose patients to malnutrition. CT-defined sarcopenia and myosteatosis are common in other tumour types and recognized adverse prognostic factors. However, the prevalence and prognostic impact of sarcopenia and myosteatosis remain undetermined in NEN patients to date. METHODS: A retrospective study of NEN patients treated with peptide receptor radionuclide therapy (PRRT) at a tertiary institution from 2012 to 2017. Patients with PET/CT imaging at baseline and follow-up were included. The L3 slice of the co-localizing CT was analysed using the Alberta Protocol. Skeletal muscle cross-sectional area and muscle attenuation were measured and compared with pre-defined cut-offs. The primary endpoint was the prevalence of sarcopenia and myosteatosis according to previously published cut-offs. RESULTS: Fourty-nine patients (median age 64 (range 26-80) years) were included. The most common primary sites of tumour were the small bowel (51%) and pancreas (26%). Baseline sarcopenia was prevalent in 67% of patients and myosteatosis in 71%. Forty-five percent of patients gained weight over the course of PRRT. The presence of baseline sarcopenia was not associated with progression-free survival (20.8 mo vs. 20.7 mo, HR 0.86, p = 0.70) nor overall survival. Similarly, baseline myosteatosis (PFS 19.5 mo vs. 20.8 mo, HR 0.77, p = 0.47) was not significantly associated with survival outcomes. The mean (SD) age of those with myosteatosis was 60.8 ± 11.6 years compared to 49.7 ± 12.7 years for those without (p = 0.003). CONCLUSIONS: Body composition analysis is feasible using routinely acquired PET/CT data for patients with NEN. CT-defined sarcopenia and myosteatosis are prevalent in NEN patients, although myosteatosis is more common with increasing age. These findings were not associated with worsened overall or progression-free survival in the current study.

Correction: Serum bicarbonate is a marker of peri-operative mortality but is not associated with long term survival in colorectal cancer.

[This corrects the article DOI: 10.1371/journal.pone.0228466.].

Survival in borderline resectable and locally advanced pancreatic cancer is determined by the duration and response of neoadjuvant therapy.

BACKGROUND: Pancreatic cancer is the 8th commonest cancer and the 5th commonest cause of cancer-related death in Australia, with a 9% average 5-year survival. This study aims to investigate the effects of neoadjuvant treatment on overall survival (OS) and recurrence-free survival (RFS) in borderline resectable (BRPC) and locally advanced (LAPC) pancreatic adenocarcinoma followed by curative resection. MATERIALS AND METHODS: Prospectively-collected demographic, medical, surgical and pathological data of patients with BRPC and LAPC treated with both neoadjuvant therapy (NAT) and surgery at a single tertiary referral centre in Australia were reviewed and analysed. RESULTS: Between 2012 and 2018, 60 patients, 34 with BRPC and 26 with LAPC, were treated with NAT followed by curative resection. The commonest neoadjuvant chemotherapy regimens were Gemcitabine + Abraxane (51.7%) and FOLFIRINOX (35.0%), with 48.3% of patients additionally receiving neoadjuvant radiotherapy. Median RFS was 30 months and median OS was 35 months. On multivariable analysis, inferior OS was predicted by enlarged loco-regional lymph nodes on initial computed tomography (p = 0.032), larger tumour size post-NAT (p = 0.006) and Common Terminology Criteria for Adverse Events post-NAT toxicity greater than grade 2 (p = 0.015). LAPC patients received more neoadjuvant chemotherapy (p = 0.008) and radiotherapy (p = 0.021) than BRPC and achieved a superior pathological response (p = 0.010). CONCLUSION: Patients who respond to NAT likely have a favourable disease biology and will progress well following resection. It is these patients who should be selected for more aggressive upfront management, and those with resistant disease should be spared from high-risk surgery.

Glycolysis and Fatty Acid Oxidation Inhibition Improves Survival in Glioblastoma.

Glioblastoma (GBM) is the most aggressive adult glioma with a median survival of 14 months. While standard treatments (safe maximal resection, radiation, and temozolomide chemotherapy) have increased the median survival in favorable O(6)-methylguanine-DNA methyltransferase (MGMT)-methylated GBM (~21 months), a large proportion of patients experience a highly debilitating and rapidly fatal disease. This study examined GBM cellular energetic pathways and blockade using repurposed drugs: the glycolytic inhibitor, namely dicholoroacetate (DCA), and the partial fatty acid oxidation (FAO) inhibitor, namely ranolazine (Rano). Gene expression data show that GBM subtypes have similar glucose and FAO pathways, and GBM tumors have significant upregulation of enzymes in both pathways, compared to normal brain tissue (p < 0.01). DCA and the DCA/Rano combination showed reduced colony-forming activity of GBM and increased oxidative stress, DNA damage, autophagy, and apoptosis in vitro. In the orthotopic Gl261 and CT2A syngeneic murine models of GBM, DCA, Rano, and DCA/Rano increased median survival and induced focal tumor necrosis and hemorrhage. In conclusion, dual targeting of glycolytic and FAO metabolic pathways provides a viable treatment that warrants further investigation concurrently or as an adjuvant to standard chemoradiation for GBM.

Are In Vitro Human Blood-Brain-Tumor-Barriers Suitable Replacements for In Vivo Models of Brain Permeability for Novel Therapeutics?

BACKGROUND: High grade gliomas (HGG) are incapacitating and prematurely fatal diseases. To overcome the poor prognosis, novel therapies must overcome the selective and restricted permeability of the blood-brain barrier (BBB). This study critically evaluated whether in vitro human normal BBB and tumor BBB (BBTB) are suitable alternatives to "gold standard" in vivo models to determine brain permeability. METHODS: A systematic review utilizing the PRISMA guidelines used English and full-text articles from the past 5 years in the PubMed, Embase, Medline and Scopus databases. Experimental studies employing human cell lines were included. RESULTS: Of 1335 articles, the search identified 24 articles for evaluation after duplicates were removed. Eight in vitro and five in vivo models were identified with the advantages and disadvantages compared within and between models, and against patient clinical data where available. The greatest in vitro barrier integrity and stability, comparable to in vivo and clinical permeability data, were achieved in the presence of all cell types of the neurovascular unit: endothelial cells, astrocytes/glioma cells, pericytes and neurons. CONCLUSIONS: In vitro co-culture BBB models utilizing stem cell-derived or primary cells are a suitable proxy for brain permeability studies in order to reduce animal use in medical research.

Increased rates of cetuximab reactions in tick prevalent regions and a proposed protocol for risk mitigation.

BACKGROUND: Cetuximab is an anti-epidermal growth factor receptor mouse-human chimeric monoclonal antibody used to treat advanced colorectal cancers. Initial data suggest that severe infusion reactions occurred in 4.5%, many on first exposure. The majority of those with anaphylactic reactions possess predeveloped IgE antibodies to galactose-alpha-1,3-galactose. It is thought that the vector for preexposure to alpha-gal is antigen inoculation via tick bites. This retrospective study reviews the experience of two community cancer centers in high tick exposure areas in Sydney with cetuximab anaphylaxis and proposes a protocol to avoid this. METHOD: Severe cetuximab infusion reactions occurring in the Northern Cancer Institute Frenchs Forest and St Leonards clinics, Sydney, from May 2014 to February 2019 were recorded. Area of residence was then compared to areas of known high tick prevalence. RESULTS: A total of 87 patients received cetuximab in this period. Six patients (6.9%) experienced at least a grade 3 reaction, three females, age range 41-72 years (median 57.5 years). All were receiving cetuximab for metastatic colorectal cancer and their anaphylaxis occurred with the first infusion in all cases. CONCLUSION: These cases support the existing theory of increased rates of cetuximab anaphylaxis in areas of high tick prevalence. Given this, we recommend the following protocol for patients being considered for cetuximab therapy: known mammalian meat allergy as an absolute contraindication; all patients receiving cetuximab should have RAST (ImmunoCAP® ) testing for alpha-gal specific-IgE-specific antibodies before first infusion and those who test positive to be considered alternate therapy.

Why pathologists and oncologists should know about tumour-infiltrating lymphocytes (TILs) in triple-negative breast cancer: an Australian experience of 139 cases.

The presence of increased tumour infiltrating lymphocytes (TILs) is established as a positive prognostic factor in triple-negative breast cancer (TNBC). The majority of studies have examined the role of TILs in predicting response to chemotherapy, but their role as a general prognostic marker in TNBC is unclear. Moreover, there is a lack of consensus in the literature regarding a suitable cut-off point by which to stratify patients into prognostic groups. Therefore, we sought to confirm the prognostic value of TILs in an independent cohort of unselected TNBCs, and to determine an appropriate cut-off point by which to stratify TIL scores into prognostically significant categories. We used the International TILs Working Group (ITWG) methodology to assess the density of stromal TILs in our cohort of 139 TNBC patients undergoing curative resection at our institution. The percentage TILs scores were categorised first into three groups: low (0-10%), intermediate (15-50%), and high (55-100%). A second binary variable was also created by separating cases into low TILs (≤50%) and high TILs (>50%) groups. Using the three-tiered system, mean disease-free survival was 156, 99 and 94 months for the high, intermediate and low TILs groups, respectively (p=0.030). However, no statistically significant improvement was observed for overall survival. Using the two-tiered system, statistically significant improvements in both overall survival (p=0.030) and disease-free survival (p=0.010) were observed. This survival benefit remained statistically significant in multivariate analyses (p=0.010, p=0.014). We conclude that TILs scored using the ITWG system and dichotomised at a cut-off score of 50%, are a powerful predictor of all-cause and disease-free survival in TNBC regardless of chemotherapy treatment.

Temporal and spatial modulation of the tumor and systemic immune response in the murine Gl261 glioma model.

Glioblastoma, the most aggressive form of glioma, has a 5-year survival rate of <5%. While radiation and immunotherapies are routinely studied in the murine Gl261 glioma model, little is known about its inherent immune response. This study quantifies the temporal and spatial localization of immune cell populations and mediators during glioma development. Eight-week old male C57Bl/6 mice were orthotopically inoculated with 1x106 Gl261 cells and tumor morphology, local and systemic immune cell populations, and plasma cytokines/chemokines assessed at day 0, 1, 3, 7, 14, and 21 post-inoculation by magnetic resonance imaging, chromogenic immunohistochemistry, multiplex immunofluorescent immunohistochemistry, flow cytometry and multiplex immunoassay respectively. From day 3 tumors were distinguishable with >30% Ki67 and increased tissue vascularization (p<0.05). Increasing tumor proliferation/malignancy and vascularization were associated with significant temporal changes in immune cell populations within the tumor (p<0.05) and systemic compartments (p = 0.02 to p<0.0001). Of note, at day 14 16/24 plasma cytokine/chemokines levels decreased coinciding with an increase in tumor cytotoxic T cells, natural killer and natural killer/T cells. Data derived provide baseline characterization of the local and systemic immune response during glioma development. They reveal that type II macrophages and myeloid-derived suppressor cells are more prevalent in tumors than regulatory T cells, highlighting these cell types for further therapeutic exploration.