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Supplementary Figure S1. PPP2R2A mRNA levels in the excised tumors from 5637 bearing mouse xenografts. Supplementary Figure S2. PPP2R2A mRNA and protein levels upon transient silencing.Supplementary Figure S3. PPP2R2A protein levels upon transient overexpression. Supplementary Table S1. Bioinformatics prediction of the top networks regulated by PPP2R2A. Supplementary Table S2. Bioinformatics prediction of the top canonical pathways regulated by PPP2R2A. Supplementary Table S3. Xcelligence Cell Index and P values of siPPP2R2RA-treated versus control BC cells. Supplementary Table S4. Xcelligence Cell Index and P values of PPP2R2A-overexpressing versus control BC cells, all treated with miR-21 mimic.

Bladder cancer represents a disease associated with significant morbidity and mortality. MiR-21 has been found to have oncogenic activity in multiple cancers, including bladder cancer, whereas inhibition of its expression suppresses tumor growth. Here, we examine the molecular network regulated by miR-21 in bladder cancer and evaluate the effects of i.v. and i.p. administration of a novel miR-21 chemical inhibitor in vivo. LNA miR-21 reduced the oncogenic potential of bladder cancer cells, whereas the MKAD-21 chemically modified antisense oligo against miR-21 dose-dependently blocked xenograft growth. I.v. administration of LNA miR-21 was more effective in suppressing tumor growth than was i.p. administration. Integration of computational and transcriptomic analyses in a panel of 28 bladder cancer lines revealed a 15-gene signature that correlates with miR-21 levels. Protein Phosphatase 2 Regulatory Subunit Balpha (PPP2R2A) was one of these 15 genes and was experimentally validated as a novel miR-21 direct target gene. Gene network and molecular analyses showed that PPP2R2A is a potent negative regulator of the ERK pathway activation and bladder cancer cell proliferation. Importantly, we show that PPP2R2A acts as a mediator of miR-21–induced oncogenic effects in bladder cancer. Integrative analysis of human bladder cancer tumors and a large panel of human bladder cancer cell lines revealed a novel 15-gene signature that correlates with miR-21 levels. Importantly, we provide evidence that PPP2R2A represents a new miR-21 direct target and regulator of the ERK pathway and bladder cancer cell growth. Furthermore, i.v. administration of the MKAD-21 inhibitor effectively suppressed tumor growth through regulation of the PPP2R2A–ERK network in mice. Mol Cancer Ther; 17(7); 1430–40. ©2018 AACR.

Detection of CTCs represents a poor prognostic factor in patients with early and metastatic breast cancer (mBC) and treatment with everolimus–exemestane (E/E) is an established effective treatment in hormone receptor-positive/HER2-negative mBC patients. The effect of E/E on CTCs in mBC patients was prospectively investigated. CTCs from 50 pre-treated patients with mBC receiving E/E were analyzed using the CellSearch (CS) platform and triple immunofluorescence (IF) staining for cytokeratin, M30 and Ki67 expression to assess their proliferative and apoptotic status. CTCs (by CS) were detected in 64% of patients before treatment and E/E administration resulted in their decreased prevalence [(n = 18; 36%, p = 0.004) and (n = 7; 19.4%, p = 0.019) post-1st and post-3rd treatment cycle, respectively] whereas it was significantly increased at disease progression (PD: 61%) compared to post-1st and post-3rd cycle (p = 0.049 and p = 0.021, respectively). Ki67-positive CTCs were detected in 60%, 60%, 17% and 50% of patients before treatment, post-1st, post-3rd cycle and at PD, respectively, while the opposite was observed for M30-positive CTCs (0% at baseline, 10% after the 1st cycle, 50% after the 3rd cycle and 0% at PD). The detection of even ≥ 1 CTC/5 ml after one cycle was associated with decreased PFS (3.3 vs 9.0 months, p = 0.025) whereas the detection of even ≥ 2 CTCs at PD was associated with decreased OS (32.4 vs 19.5 months; p = 0.009). The combination of E/E resulted in early elimination of proliferating CTCs in mBC patients and this effect was associated with a favorable clinical outcome.

In the present study, we evaluated the expression of JUNB and CXCR4 in circulating tumor cells (CTCs) of lung cancer patients and investigated whether these proteins have prognostic clinical relevance. Peripheral blood from 30 patients with non-small-cell lung cancer (NSCLC) was filtered using ISET membranes, and cytospins from 37 patients with small-cell lung cancer (SCLC) were analyzed using confocal and VyCAP microscopy. Both JUNB and CXCR4 were expressed in the vast majority of lung cancer patients. Interestingly, the phenotypic patterns differed between NSCLC and SCLC patients; the (CK+/JUNB+/CXCR4+) phenotype was present in 50% of NSCLC vs. 71% of SCLC patients. Similarly, the (CK+/JUNB+/CXCR4–) was present in 44% vs. 71%, the (CK+/JUNB–/CXCR4+) in 6% vs. 71%, and the (CK+/JUNB–/CXCR4–) phenotype in 38% vs. 84%. In NSCLC, the presence of ≥1 CTCs with the (CK+/JUNB+/CXCR4+) phenotype was associated with worse progression-free survival (PFS) (p = 0.007, HR = 5.21) while ≥2 with poorer overall survival (OS) (p < 0.001, HR = 2.16). In extensive stage SCLC patients, the presence of ≥4 CXCR4-positive CTCs was associated with shorter OS (p = 0.041, HR = 5.01). Consequently, JUNB and CXCR4 were expressed in CTCs from lung cancer patients, and associated with patients’ survival, underlying their key role in tumor progression.

The Hippo pathway regulates and contributes to several hallmarks of prostate cancer (PCa). Although the elucidation of YAP function in PCa is in its infancy, emerging studies have shed light on the role of aberrant Hippo pathway signaling in PCa development and progression. YAP overexpression and nuclear localization has been linked to poor prognosis and resistance to treatment, highlighting a therapeutic potential that may suggest innovative strategies to treat cancer. This review aimed to summarize available data on the biological function of the dysregulated Hippo pathway in PCa and identify knowledge gaps that need to be addressed for optimizing the development of YAP-targeted treatment strategies in patients likely to benefit.

Utility measures are urgently needed for clinical application of new, more sensitive diagnostics to reduce the risk of excessive intervention.

e24118 Background: Diagnostic imaging may be a major source of distress in patients with advanced cancer, a condition known as “scanxiety”. Scanxiety represents a complex array of negative and stressful emotions linked with cancer scans, and the uncertainties and fears that may accompany them. We aimed to evaluate the prevalence and characterize risk factors for scanxiety among cancer patients and their caregivers and evaluate the impact of scanxiety on quality of life (QoL), during the COVID-era. Methods: We conducted a cross-sectional survey study of metastatic cancer patients treated at the University Hospital of Larisa and their caregivers. Eligible patients met the following inclusion criteria: age > 18 years old, ability to speak and write fluently in Greek, having had at least one imaging study during the period of the study ( seven days before the survey), approval of the patient’s oncologist to approach the patient. Patients/caregivers with pre-existing (prior to cancer diagnosis anxiety disorder) were excluded from the study. After completion of the informed consent process, patients/caregivers completed all survey items. We used a modified version of the Greek version of the Impact of Event Scale-Revised (IES-R-Gr) to specifically assess distress associated with scans, and QoL was measured using the EORTC QLQ-C30 questionnaire. Results: 218 patients with metastatic cancer and their caregivers were included in the study. Patient's mean age was 66 years (range 35-88). The majority were men (61%) and were diagnosed with Non-Small-Cell Lung Cancer. 71% had an IES-R-Gr score that was suggestive of scanxiety. Their symptoms were more severe symptoms while waiting for the results. Patients with a recent diagnosis (< 6 months) had higher levels. Interestingly, 16% of the patients had postponed a check-up due to scanxiety, while 77% reported that stress does not decrease over time. The majority of caregivers (81%) reported scanxiety, without a strong correlation with the score of the respective patients. Unlike patients, the majority of caregivers reported an increase in stress during the COVID-19 period. The presence of scanxiety was associated with decreased QoL in patients (p = 0.004). Conclusions: Scanxiety is a common problem among patients with metastatic cancer and is associated with impaired QoL. To our knowledge this is the first study implying that caregivers also experience scanxiety and may be a persistent problem.

Detection of CTCs represents a poor prognostic factor in patients with early and metastatic breast cancer (mBC) and treatment with everolimus-exemestane (E/E) is an established effective treatment in hormone receptor-positive/HER2-negative mBC patients. The effect of E/E on CTCs in mBC patients was prospectively investigated.CTCs from 50 pre-treated patients with mBC receiving E/E were analyzed using the CellSearch (CS) platform and triple immunofluorescence (IF) staining for cytokeratin, M30 and Ki67 expression to assess their proliferative and apoptotic status.CTCs (by CS) were detected in 64% of patients before treatment and E/E administration resulted in their decreased prevalence [(n = 18; 36%, p = 0.004) and (n = 7; 19.4%, p = 0.019) post-1st and post-3rd treatment cycle, respectively] whereas it was significantly increased at disease progression (PD: 61%) compared to post-1st and post-3rd cycle (p = 0.049 and p = 0.021, respectively). Ki67-positive CTCs were detected in 60%, 60%, 17% and 50% of patients before treatment, post-1st, post-3rd cycle and at PD, respectively, while the opposite was observed for M30-positive CTCs (0% at baseline, 10% after the 1st cycle, 50% after the 3rd cycle and 0% at PD). The detection of even ≥ 1 CTC/5 ml after one cycle was associated with decreased PFS (3.3 vs 9.0 months, p = 0.025) whereas the detection of even ≥ 2 CTCs at PD was associated with decreased OS (32.4 vs 19.5 months; p = 0.009).The combination of E/E resulted in early elimination of proliferating CTCs in mBC patients and this effect was associated with a favorable clinical outcome.

Bladder cancer represents a disease associated with significant morbidity and mortality. MiR-21 has been found to have oncogenic activity in multiple cancers, including bladder cancer, whereas inhibition of its expression suppresses tumor growth. Here, we examine the molecular network regulated by miR-21 in bladder cancer and evaluate the effects of i.v. and i.p. administration of a novel miR-21 chemical inhibitor in vivo. LNA miR-21 reduced the oncogenic potential of bladder cancer cells, whereas the MKAD-21 chemically modified antisense oligo against miR-21 dose-dependently blocked xenograft growth. I.v. administration of LNA miR-21 was more effective in suppressing tumor growth than was i.p. administration. Integration of computational and transcriptomic analyses in a panel of 28 bladder cancer lines revealed a 15-gene signature that correlates with miR-21 levels. Protein Phosphatase 2 Regulatory Subunit Balpha (PPP2R2A) was one of these 15 genes and was experimentally validated as a novel miR-21 direct target gene. Gene network and molecular analyses showed that PPP2R2A is a potent negative regulator of the ERK pathway activation and bladder cancer cell proliferation. Importantly, we show that PPP2R2A acts as a mediator of miR-21–induced oncogenic effects in bladder cancer. Integrative analysis of human bladder cancer tumors and a large panel of human bladder cancer cell lines revealed a novel 15-gene signature that correlates with miR-21 levels. Importantly, we provide evidence that PPP2R2A represents a new miR-21 direct target and regulator of the ERK pathway and bladder cancer cell growth. Furthermore, i.v. administration of the MKAD-21 inhibitor effectively suppressed tumor growth through regulation of the PPP2R2A–ERK network in mice. Mol Cancer Ther; 17(7); 1430–40. ©2018 AACR.

Background: We directly compared CTC detection rates and prognostic significance, using three different methods in patients with breast cancer (BC). Methods: Early (n=200) and metastatic (n=164) patients were evaluated before initiating adjuvant or first-line chemotherapy, using the CellSearchTM System, an RT-qPCR for CK-19 mRNA detection and by double immunofluorescence (IF) microscopy using A45-B/B3 and CD45 antibodies. Results: Using the CellSearchTM System, 37% and 16.5% of early BC patients were CTC-positive (at ≥1 and ≥2 CTCs/23 ml of blood), 18.0% by RT-qPCR and 16.9% by IF; no agreement was observed between methods. By the CellSearchTM 34.8% and 53.7% (at≥ 5 and ≥ 2 CTCs/7.5 ml) of metastatic patients were CTC-positive, 37.8% by RT-qPCR and 28.5% by IF. A significant agreement existed only between the CellSearchTM and RT-qPCR. In 60.8% of cases, differential EpCAM and CK-19 expression on CTCs by IF could explain the discrepancies between the CellSearchTM and RT-qPCR. CTC-positivity by either method was associated with decreased overall survival in metastatic patients. Conclusion: A significant concordance was observed between the CellSearchTM and RT-qPCR in metastatic but not in early BC. Discordant results could be explained in part by CTC heterogeneity. CTC detection by all methods evaluated had prognostic relevance in metastatic patients.

Background: Since tumor cells may escape from immune surveillance through the programmed cell death 1 (PD-1)/programmed death ligand (PD-L)1 axis, this study was designed in order to evaluate whether there is a correlation between the levels of PD-1+ and PD-L1+-expressing immune cells (ICs) and circulating tumor cells (CTCs) in patients with non-small cell lung cancer (NSCLC). Patients and methods: Peripheral blood was obtained from 37 chemotherapy-naïve patients with metastatic NSCLC before treatment. PD-1 and PD-L1 expression was evaluated (1) on ICs with anti-tumor function (CD4+ and CD8+ T-cells, B-cells, monocytes/dendritic cells) using flow cytometry, (2) on CTCs by immunofluorescence and (3) on cells from tumor tissues by immunohistochemistry. The levels of PD-1+ and PD-L1+-expressing ICs were correlated with progression-free survival (PFS). Results: The presence of PD-1+ CD8+ cells, with reduced interferon (IFN)-γ expression, but not other ICs, were positively correlated with PD-L1+ CTCs ( p < 0.04). Increased percentages of PD-1+ CD8+ T-cells, were associated with a worse response to treatment ( p = 0.032) and shorter PFS ( p = 0.023) which, in multivariate analysis, was revealed as an independent predictor for decreased PFS [hazard ratio (HR): 4.1, p = 0.0007]. Conclusion: The results of the current study, for first time, provide evidence for a possible interaction between ICs and CTCs in NSCLC patients via the PD-1/PD-L1 axis and strongly support that the levels of PD-1+ CD8+ in these patients may be of clinical relevance.

A major challenge in cancer treatment is predicting the clinical response to anti-cancer drugs on a personalized basis. The success of such a task largely depends on the ability to develop computational resources that integrate big "omic" data into effective drug-response models. Machine learning is both an expanding and an evolving computational field that holds promise to cover such needs. Here we provide a focused overview of: 1) the various supervised and unsupervised algorithms used specifically in drug response prediction applications, 2) the strategies employed to develop these algorithms into applicable models, 3) data resources that are fed into these frameworks and 4) pitfalls and challenges to maximize model performance. In this context we also describe a novel in silico screening process, based on Association Rule Mining, for identifying genes as candidate drivers of drug response and compare it with relevant data mining frameworks, for which we generated a web application freely available at: https://compbio.nyumc.org/drugs/. This pipeline explores with high efficiency large sample-spaces, while is able to detect low frequency events and evaluate statistical significance even in the multidimensional space, presenting the results in the form of easily interpretable rules. We conclude with future prospects and challenges of applying machine learning based drug response prediction in precision medicine.

To evaluate the predictive value of genes involved in resistance to platinum-taxane chemotherapy in patients with epithelial ovarian cancer (EOC). Microdissected formalin-fixed tumoral samples from 187 EOC patients' primary tumors (90 and 97 samples from matched patients in the experimental and validation sets, respectively) were analyzed. All specimens were analyzed for ATP7b, BRCA1, BRCA2, PARP1, UIMC1(RAP80), HOXA9, DAXX, TXN (TRX1), THBS1 (TSP1) and PRR13 (TXR1) mRNA expression by quantitative real-time PCR. Most of the patients (172 out of 187) received front-line carboplatin-paclitaxel regimen. Expression levels were correlated with overall (OS) and progression-free (PFS) survival by multivariate analysis. Patients with high TXN and THBS1 expression presented longer PFS (P=0.001 and P

Introduction Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature cells of myeloid origin whose expression is induced by, among others things, vascular endothelial growth factor. We have previously identified two monocytic and one granulocytic MDSC subpopulations associated with the clinical outcome in patients with non–small cell lung cancer (NSCLC). The aim of the present study was to evaluate the effect of chemotherapy on these MDSC subpopulations. Methods Circulating immune cells from 46 patients with unresectable NSCLC were analyzed by flow cytometry before the initiation of chemotherapy and after three cycles. Changes in the frequencies of the MDSC subpopulations were correlated with clinical outcome. Results Chemotherapy had no uniform effect on either the number or the functionality of monocytic and granulocytic MDSCs. However, three cycles of bevacizumab-containing regimens significantly reduced the percentage of the granulocytic-MDSCs compared with non–bevacizumab-based regimens ( p = 0.0086). At the time of evaluation of response, disease progression was associated with significantly higher levels of all three MDSC subpopulations compared with in patients with disease control. Ιn patients with disease progression after three cycles of chemotherapy, the percentage of CD15-positive monocytic MDSCs was significantly increased compared with baseline. Conclusions In the peripheral blood of patients with NSCLC, bevacizumab-based chemotherapy significantly reduced the levels of granulocytic MDSCs. An increase in the levels of CD15-positive monocytic MDSCs was associated with poor response to treatment and disease progression, providing evidence of their clinical relevance in patients with NSCLC.

Background: Since tumor cells may escape from immune surveillance through the programmed cell death 1 (PD-1)/programmed death ligand (PD-L)1 axis, this study was designed in order to evaluate whether there is a correlation between the levels of PD-1+ and PD-L1+-expressing immune cells (ICs) and circulating tumor cells (CTCs) in patients with non-small cell lung cancer (NSCLC). Patients and methods: Peripheral blood was obtained from 37 chemotherapy-naïve patients with metastatic NSCLC before treatment. PD-1 and PD-L1 expression was evaluated (1) on ICs with anti-tumor function (CD4+ and CD8+ T-cells, B-cells, monocytes/dendritic cells) using flow cytometry, (2) on CTCs by immunofluorescence and (3) on cells from tumor tissues by immunohistochemistry. The levels of PD-1+ and PD-L1+-expressing ICs were correlated with progression-free survival (PFS). Results: The presence of PD-1+ CD8+ cells, with reduced interferon (IFN)-γ expression, but not other ICs, were positively correlated with PD-L1+ CTCs (p < 0.04). Increased percentages of PD-1+ CD8+ T-cells, were associated with a worse response to treatment (p = 0.032) and shorter PFS (p = 0.023) which, in multivariate analysis, was revealed as an independent predictor for decreased PFS [hazard ratio (HR): 4.1, p = 0.0007]. Conclusion: The results of the current study, for first time, provide evidence for a possible interaction between ICs and CTCs in NSCLC patients via the PD-1/PD-L1 axis and strongly support that the levels of PD-1+ CD8+ in these patients may be of clinical relevance.

Chemotherapy-induced neutropenia (CIN) is a common adverse event during treatment of cancer patients, associated with increased morbidity, mortality, health care costs and impairment of patients' quality of life which necessitate dose reductions.A computerized systematic literature search was performed through Medline, PubMed, Google Scholar and the Cochrane Library to identify peer reviewed publications relevant to CIN, pathophysiology and epidemiology, patient risk-assessment and existing treatment approaches. Additionally, emerging issues such as alternative therapeutic options and implications in elderly care were addressed.Although CIN represents a common adverse event in the management of patients with solid tumors, the heterogeneity in clinical practice across different settings underlines the need to improve existing tools for accurate patient classification. Moreover, the definition of the optimal implementation of out-patient treatment and the use of colony-stimulating factor as add-on treatment together with antibiotics should be further investigated in order to accumulate more solid data. Finally, physician education is required to ensure that scientific knowledge is implemented in the daily clinical practice.

The increasing burden of lung cancer (LC) in Crete, Greece, has raised certain concerns about the potential association of environmental risk factors with LC. The aim of this study was to assess outdoor air pollution (OAP) and the risk for LC mortality for the first time in Crete using LC primary data. 5057 LC cases (diagnosed from 1992 to 2013) were obtained from the Cancer Registry of Crete (http://www.crc.uoc.gr) and followed up until 2014. The age-standardized incidence and mortality rates (ASIR) were calculated. Data on OAP indicators [particulate matter (PM)2.5, between 2.5 and 10 μm (PM2.5-10), PM10, PM2.5 absorbance (black carbon measure), nitrogen dioxide (NO2), and nitrogen oxides (NOx)] were collected. Spatial statistics were calculated and the binary logistic regression model was constructed at α=0.05 in IBM SPSS 24 and ArcMap 10.3.1. LC in Crete accounts for 40.2 new cases/100 000/year for both sexes (ASIRmales=73.1 new cases/100 000/year; ASIRfemales=11.8 new cases/100 000/year). Annual median estimates of environmental concentrations in Crete were as follows: PM2.5=20.7 (±1.5) µg/m, PM10=38.9 (±2.5) µg/m, PM2.5-10=59.6 (±3.7) µg/m, PM2.5 absorbance=1.2 (±0.3)×10/m, NO2=15.2 (±3.8) µg/m, and NOx=20.1 (±4.9) µg/m. A statistically significant association was observed between OAP and LC mortality (mean correlation coefficient=0.75; P0.05). The highest risk for 5-year LC mortality was found in the major urban centers and several south-east and north-west rural regions of Crete (relative risk=3.2, 95% confidence interval=1.6-4.7). OAP seems to be an important determinant of LC mortality. Targeted interventions should be performed in the high-risk areas.

Introduction To assess the smoking behaviour of Lung Cancer (LC) and Colorectal (CRC) patients at the time of diagnosis and one year after diagnosis. Material and Methods The study took place in the island of Crete, Greece. Data (LC patients=4,421; CRC patients=3,609) were derived from the Cancer Registry of Crete (1992-2010). Participants with I-III stage primary cancer and confirmed diagnosis (histologically/cytologically) were included. Patients with unknown stage were excluded after testing for potential statistical bias. Kruskal-Wallis (one-way analyses of variance) and logistic regression models estimated the risk of not quitting smoking after diagnosis. All tests were two-tailed (a=0.05). Results Overall, 75.1% of LC and 51.4% of CRC patients were current smokers at the time of diagnosis. One year after diagnosis 49.5%% of the LC and 38.1% of the CRC patients were still smoking. Males, public insurance, high number of pack/years, not receiving chemotherapy/radiotherapy, not undergoing surgery, higher number of co-morbidities, advanced cancer stage (III) and alcohol consumption were significant predictors of not quitting smoking one year after diagnosis (p

Introduction Τo provide insights on Lung Cancer (LC) and the associated risk factors before-after the economic crisis in Crete, Greece. To assess the smoking habits of LC patients during the austerity period. Material and Methods The study was conducted in Crete, Greece. Data (5,057 LC cases) were obtained from the Cancer Registry of Crete (CRC). Age-Standardized Incidence and Mortality Rates (ASIR, ASMR/100,000/year), adjusted Charlson’s Comorbidity Index (CCI%), deprivation index (HPI-2) and exposure to Outdoor Air Pollution (OAP) were estimated. The analysis was performed for two time periods (Period A: 1992-2008; Period B: 2009-2013). Results ASIR presented a significant increase during the economic crisis, while even higher increase was observed in ASMR (Period A: ASMR=30.5/100,000/year; Period B: ASMR=43.8/100,000/year; p

Background This study evaluated the safety and efficacy of nab-paclitaxel as second-line treatment in patients with advanced gastric adenocarcinoma. Methods Thirty-nine pretreated patients [33 with taxane-based regimens (docetaxel, cisplatin, and fluorouracil)] and 6 with combination of fluoropyrimidines plus cisplatin with locally advanced inoperable and metastatic gastric and gastroesophageal junction adenocarcinoma were treated with weekly nab-paclitaxel (150 mg/m2 d1, d8, d15 in cycles of 28 days). Results Partial response (PR) was documented in nine patients (23.1%; 95% confidence interval 10.1-37.2%), stable disease (SD) in 11 (28.2%) and disease progression in 18 (46.2%). The disease control rate (SD + PR + complete response) was 51.3%. Grade 3 and 4 neutropenia occurred in 10.2% and 5.1% of patients, respectively; grade 3 anemia in 5.1%; grade 3 neurotoxicity in 5.1%; and grade 2 pain in 5.1%. The median progression-free survival was 3.0 months (range 0.3-13.6) and the median overall survival 6.8 months (range 0.3-22). Conclusion Nab-paclitaxel as second-line treatment in locally advanced inoperable or metastatic gastric and gastroesophageal junction carcinoma is an active chemotherapy regimen with a manageable toxicity profile and merits further evaluation.

Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous population of cells with immunosuppressive properties and might confer to worse prognosis in cancer patients. The presence of phenotypically newly described subpopulations of MDSCs and their association with the clinical outcome were investigated in non-small cell lung cancer (NSCLC) patients. The percentages and correlation between MDSCs and distinct immune cells in the peripheral blood of 110 chemotherapy-naive patients before treatment and healthy controls were investigated using flow cytometry. Two monocytic [CD14+CD15−CD11b+CD33+HLA-DR−Lin−and CD14+CD15+CD11b+CD33+HLA-DR−Lin−] and a granulocytic [CD14−CD15+CD11b+CD33+HLA-DR−Lin−] subpopulations of MDSCs were identified, expressing inducible nitric oxide synthase, and reactive oxygen species, respectively. Increased percentages of both monocytic-MDSCs’ subpopulations were inversely correlated to dendritic/monocyte levels(P≤0.04), while granulocytic-MDSCs were inversely correlated to CD4+T cells(P=0.006). Increased percentages of monocytic-MDSCs were associated with worse response to treatment(P=0.02)and patients with normal levels of CD14+CD15+CD11b+CD33+HLA-DR−Lin−had longer overall survival and progression free-survival compared to those with high levels(P=0.008andP=0.005, resp.). Multivariate analysis revealed that the increased percentages of CD14+CD15+CD11b+CD33+HLA-DR−Lin−MDSCs were independently associated with decreased progression free-survival and overall survival. The data provide evidence that increased percentages of new monocytic-MDSCs’ subpopulations in advanced NSCLC patients are associated with an unfavourable clinical outcome.

e20086 Background: The aim of the study was to characterize and evaluate the presence of DLL3-positive Circulating Tumor Cells (CTCs) in SCLC patients receiving front-line chemotherapy and assess their clinical relevance. Methods: Peripheral blood was obtained from treatment-naïve patients with SCLC (n = 108 patients), after one-etoposide/platinum cycle (n = 68 patients) and on disease progression (n = 48 patients). CTCs were detected after immunofluorescence staining using antibodies against the DLL3, cytokeratins (CK), CD45 and vimentin (Vim). Results: Before treatment, 74.1% of patients had detectable CTCs (DLL3+/CD45-). One-treatment cycle significantly decreased both the detection rate of DLL3+/CD45- CTCs ( p< 0.001) and their absolute number ( p< 0.001). Triple immunofluorescence staining using anti-CK, anti-Vim and anti-DLL3 antibodies revealed an important CTC heterogeneity since DLL3 could be detected in Vim+, Vim-, CK+ and CK- CTCs. On disease progression, both the detection rate of DLL3+/CD45- CTCs as well as their number were significantly increased compared to post-1st cycle values ( p< 0.001 and p= 0.002, respectively). In addition, 22.7% of patients had detectable DLL3+/CD45- cells which could not be captured by the CellSearch assay. In multivariate analysis, the detection of DLL3+/CD45- CTCs at baseline was significantly associated with decreased progression-free survival (HR = 10.8; p= 0.005) whereas their detection on disease progression was associated with decreased overall survival (HR: 28.2; p= 0.016). Conclusions: These findings demonstrate an important heterogeneity of CTCs, based on the expression of CK, Vim and DLL3, in patients with SCLC and the changes of DLL3+/CD45- CTCs during treatment seem to be a dynamic biomarker associated with treatment efficacy and patients’ clinical outcome.

Introduction: Circulating tumor cells (CTCs) are considered as a “liquid biopsy” that allows the assessment of tumor changes over time. Tumor cells may escape from the immune system through the activation of PD-1/PD-L1 axis. Targeting these molecules with monoclonal antibodies has shown encouraging results at many types of cancers, including NSCLC. In the current study we investigated the expression of PD-1/PD-L1 molecules on the CTCs isolated from NSCLC patients treated with Nivolumab. Methods: CTCs were isolated based on their size using the ISET platform from 27 patients before treatment, after 1 cycle and 3 cycles. CTCs were detected with Giemsa staining and immunofluorescence (IF) experiments, using either pancytokeratin (A45-B/B3) (CK7)/PD-1/CD45 or (A45-B/B3)(CK7)/PD-L1/CD45 combination of antibodies and analysis with the ARIOL system. Spiking experiments using the NSCLC cell lines: H460, H1299, HCC827 and SKMES in normal blood were used to evaluate the detection method. Results: Giemsa evaluation in Nivolumab-treated patients at baseline (25 evaluable samples), after the 1st (9 evaluable samples) and the 3rd (8 evaluable patients) cycle of treatment showed that CTCs could be detected in 48% (12/25), 33.3% (3/9) and 50% (4/8) of patients, respectively. IF could also reveal the presence of CK-positive cells in 44.4% (12/27), 22% (2/9) and 75% (6/8) patients, respectively. PD-1 (+) CTCs were detected in 33.3% (4/12) of patients at baseline, in, 0% after the 1 and 16.7% (1/6) of patients after the 3rd cycle. The same percentages were identified for PD-L1 expression in the same cohort of patients. The expression of PD-1 at baseline was associated with poorer OS (p=0.022) and PFS (p=0.011), while the expression of PD-L1 was associated with shorter PFS (p=0.011). Multivariate analysis revealed that the presence of CK-positive cells is an independent prognostic factor for OS (p=0.028) Conclusion: Nivolumab reduced the number of PD-1- and PD-L1-expressing CTCs in advanced NSCLC patients. Furthermore the expression of both markers at baseline is associated with the clinical outcome. Citation Format: Galatea Kallergi, Anastasios Koutsopoulos, Eleni Lagoudaki, Despoina Agouraki, Eleni-Kiriaki Vetsika, Anastasia Voumvouraki, Stuart S. Martin, Filippos Koinis, Christos Stournaras, Vassilis Georgoulias, Athanasios Kotsakis. Detection of PD-L1 and PD-1 positive circulating tumor cells (CTCs) in non-small cell lung cancer (NSCLC) patients treated with nivolumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1587.

ObjectivesIn patients with advanced incurable lung cancer deciding as to the most appropriate treatment (e.g. chemotherapy or supportive care only) is challenging. In such patients the TNM classification system has reached its ceiling therefore other factors are used to assess prognosis and as such guide treatment. Performance status (PS), weight loss and inflammatory biomarkers (Glasgow Prognostic Score (mGPS)) predict survival in advanced lung cancer however these have not been compared. This study compares key prognostic factors in advanced lung cancer.Materials and methodsPatients with newly diagnosed advanced lung cancer were recruited and demographics, weight loss, other prognostic factors (mGPS, PS) were collected. Kaplan-Meier and Cox regression methods were used to compare these prognostic factors.Results390 patients with advanced incurable lung cancer were recruited; 341 were male, median age was 66 years (IQR 59-73) and patients had stage 4 non-small cell (n = 288) (73.8%) or extensive stage small cell lung cancer (n = 102) (26.2%). The median survival was 7.8 months. On multivariate analysis only performance status (HR 1.74 CI 1.50-2.02) and mGPS (HR 1.67, CI 1.40-2.00) predicted survival (p < 0.001). Survival at 3 months ranged from 99% (ECOG 0-1) to 74% (ECOG 2) and using mGPS, from 99% (mGPS0) to 71% (mGPS2). In combination, survival ranged from 99% (mGPS 0, ECOG 0-1) to 33% (mGPS2, ECOG 3).ConclusionPerformance status and the mGPS are superior prognostic factors in advanced lung cancer. In combination, these improved survival prediction compared with either alone.

Introduction Clinical dormancy is frequently observed in breast cancer. In the present study, we aimed to characterize circulating tumor cells (CTCs) in dormancy candidates (DC) with early breast cancer in terms of proliferation and apoptosis. Methods Cytospins of peripheral blood mononuclear cells (PBMCs) were obtained from DC (n = 122) who were disease-free for at least 5 years and from metastatic patients (n = 40) who relapsed more than 5 years after surgery. Sequential samples from eight DC (n = 36) who maintained a prolonged disease-free status and from eight DC (n = 27) presenting late relapse during follow-up, were also analyzed. PBMCs were triple stained with a pancytokeratin, antibody along with anti-Ki67 and anti-M30 antibodies as proliferation and apoptosis markers, respectively. Results CTCs were identified in 40 (33%) of 122 DC and in 15 (37.5%) of 40 metastatic patients. In total, twenty-five (62.5%) DC had exclusively dormant (Ki67(-)/M30(-)), seven (17.5%) had proliferative Ki67(+)/M30(-), four (10%) had apoptotic Ki67(-)/M30(+) and four (10%) had both phenotypes of proliferative and apoptotic CTCs. In comparison, 53.4% of CTC-positive metastatic patients had exclusively dormant and 46.6% had proliferative CTCs; none had apoptotic CTCs (P = 0.039). Among all CTCs detected in DC patients, 82.4% were dormant, whereas in the nondormant population, 32.5% were proliferative and 67.5% apoptotic. The respective percentages in metastatic patients were 59.1%, 100% and 0% (P

Introduction: Circulating tumour cells (CTCs) are responsible for the metastatic dissemination of the tumor. They have been shown to express Programmed Death-Ligand1 (PD-L1) to escape from the immune system surveillance through its ligation with the PD-1receptor on the surface of effector immune cells. We investigated the expression of PD-1/PD-L1 on CTCs isolated from NSCLC patients treated with chemotherapy. Methods: CTCs were isolated based on their size using the ISET platform from 30 stage IV chemo-naïve NSCLC patients (before and after chemotherapy). CTCs were detected after staining with Giemsa and immunofluorescence (IF). Double and triple staining experiments with different combination of antibodies: [Cytokeratins(CK)/PD-1/CD45 and CK/PD-L1/CD45] were performed and the samples were analyzed with the ARIOL system. Results Giemsa staining showed that twenty-three (77%) out of 30 and six (54.5%) out of 11 patients had detectable CTCs at baseline and after the 3rd cycle of front-line chemotherapy. IF staining revealed seventeen out of 30 (56.7%) patients positive for CTCs at baseline level and 8 out of 11 (72.7%) samples after the 3rd cycle of treatment. PD-1 and PD-L1 expression was observed in 53% (9/17) and in 47% of the CTC-positive patients at baseline; in addition, 13% (1/8) and 63% (5/8) patients had PD-1 and PD-L1, respectively after the 3rd cycle. Among the total number of detected CTCs, 67% were PD-1(+) at baseline and 25% after the 3rd cycle (p=0.069). In addition, 26% and 80% were PD-L1(+) at baseline and after the 3rd cycle, respectively. Patients with more than 3 PD-1 positive CTCs showed shorter PFS (p=0.022). Primary tissue from ten of the examined patients was also available. More than 5% of PD-L1 (+) tumor infiltrating lymphocytes (TILs) were observed in 20% (2/10) of the patients. More than 5% PD-L1 positive cells in the primary tumor were observed in 20%. However the two group of the patients were different. In addition both patients with PD-L1 (+) TILs harvested CTCs with PD-1 expression and one of them had also PD-L1 positive CTCs. Conclusion: PD-1- and PD-L1-positive CTCs could be detected before and during 1st line treatment in metastatic NSCLC. This expression was related to patients’ prognosis, implying that these molecules can be served as targets for metastasis restoration. Furthermore the expression of PD-1 on CTCs suggests a bilateral cross-talk between tumor and immune cells. Citation Format: Galaktea Kallergi, Eleni Kyriaki Vetsika, Despoina Aggouraki, Eleni Lagoudaki, Anastasios Koutsopoulos, Filippos Koinis, Panagiotis Katsarlinos, Maria Trypaki, Christos Stournaras, Vassilis Georgoulias, Athanasios Kotsakis. Evaluation of PD-L1/PD-1 on circulating tumor cells (CTCs) and on primary tumor in advanced non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1726. doi:10.1158/1538-7445.AM2017-1726

Background: Programmed cell death-1 (PD-1), an inhibitory immune check-point, plays a pivotal role in tumor immune escape. The interaction of PD-1 with its ligand (PD-L1) results in T cells exhaustion, and the blockade of this interaction can partially restore T cell function. Recently, antibodies targeting PD-1 and PD-L1 have been approved for treatment of advanced Non Small Cell Lung Cancer (NSCLC). In this pilot study, we aimed to investigate the effect of anti-PD1 treatment or chemotherapy on the frequencies of circulating PD-1+ T cells and PD-L1+ immunosuppressive cells in NSCLC patients. Patients & Methods: Peripheral blood samples were collected from 35 advanced NSCLC patients before initiation of treatment and after 3 cycles. Twelve treatment-naïve patients received front-line chemotherapy, whereas 23 patients received anti-PD1 treatment in the second-line setting. Flow cytometry was used to quantify PD-1- and PD-L1-expressing immune cells. Changes in the frequencies of these cells were compared between the two settings and correlated with the clinical outcome. Results: Chemotherapy had no effect on the percentages of PD-1+CD4+ and PD-1+CD8+ T cells after 3 cycles, whereas there was a significant decrease in PD-1+CD4+ and PD-1+CD8+ T cells in patients who received 3 administrations of anti-PD1 antibody (p=0.007 and p=0.05, respectively). Moreover, the levels of PD-1-CD4+ (p=0.009) and PD-1-CD8+ (p=0.009) were augmented in response to anti-PD-1 therapy. The frequencies of both peripheral CD4+ Tregs (CD3+CD4+CD25highCD127-/lowCD152+FoxP3+) and granulocytic MDSCs (G-MDSC; CD14-CD15+CD33+CD11b+HLA-DR-Lin-) expressing PD-L1 were decreased following anti-PD1 therapy (p=0.01 and p=0.02, respectively). In contrast, chemotherapy affected only the PD-L1+CD4+ Tregs, but not the PD-L1+G-MDSC, by increasing their levels after 3 cycles (p=0.04). Anti-PD-1 treatment induced a superior reduction of the PD-1+CD4+, PD-1+CD8+ T cells, PD-L1+CD4+ Tregs and PD-L1+G-MDSCs percentages compared to the effect of first line chemotherapy (p=0.04, p=0.05, p=0.002 and p=0.01, respectively). Furthermore, a significant decrease in PD-1+CD8+ T cells, PD-L1+CD4+ Tregs and PD-L1+G-MDSCs after 3 doses of anti-PD-1 was observed in patients who experienced stable disease compared to baseline (p=0.006, p=0.05 and p=0.03, respectively). At the time of response evaluation to chemotherapy, the percentage of the PD-L1+CD4+ Tregs after 3 cycles was significantly inferior compared to baseline, in disease progressors (p=0.04). Conclusion: These data indicate that although chemotherapy affected the levels of PD-L1+CD4+ Tregs, anti-PD1 therapy seems to exert an effect on both PD1+ T cells and PD-L1+ immunosuppressive cells. Additional studies are needed in a larger cohort in order to document its impact on their clinical relevance in NSCLC patients. This study is ongoing and updated data will be presented at the meeting. Citation Format: Eleni-Kyriaki Vetsika, Galatea Kallergi, Despoina Aggouraki, Zaharoula Lyristi, Aristeidis Koukos, Despoina Kourougkiaouri, Filippos Koinis, Vassilis Georgoulias, Athanasios Kotsakis. Effect of anti-PD-1 therapy on immune cells in the peripheral blood of non-small cell lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 619. doi:10.1158/1538-7445.AM2017-619

58 Background: One of the tumour escape mechanisms is the expression of programmed cell death-1 (PD-1) receptor on immune cells. Clinical trials have demonstrated that antibodies against PD-L1 or PD-1 molecules induce objective clinical responses in pre-treated patients with NSCLC. In this study, we evaluated the levels of PD-1+ and PD-L1+expressing- immune cells and their association with the clinical outcome in NSCLC patients. Methods: Peripheral blood was collected from 32 advanced/metastatic pre-treated NSCLC patients before anti-PD-1 therapy (Nivolumab). Flow cytometry was performed to identify and quantify PD-1 and PD-L1 expression on circulating immune cells with anti-tumor function (CD4+ and CD8+ T cells, B cells, Dendritic cells) , as well as on immunosuppressivecells [(CD4+ and CD8+ Treg cells, Bregs, Myeloid-derived Suppressor cells (MDSC)]. Correlation between the levels of PD-1+ and PD-L1+-expressing immune cells, as well as their association with overall (OS) and progression-free survival (PFS) was evaluated; high expression of immune cells was defined as the percentage of the cells above the mean value. Results: PD-1 and PD-L1 expression was detected on all tested immune cells with anti-tumor activity. PD-1 expression was found on all immunosuppressive cells, whereas only CD4+ and CD8+ Treg cells and Granulocytic -MDSCs expressed PD-L1. No PD-L1 expression was observed on Bregs and monocytic-MDSCs. There was no correlation of PD-1 or PD-L1-expressing cells with response to anti-PD1 treatment. A significantly decreased PFS was observed in the low CD4+ PD-L1+ T cells group compared with the high CD4+ PD-L1+ group (3.4 months vs. 5.2 months, p=0.03). Univariate analysis for PFS revealed that the low percentages of CD4+ PDL-1+ T cells were prognostic for shorter PFS (HR= 3.1, p=0.04). On the multivariate analysis, low PD-L1+ CD4+T cells were independently associated with decreased PFS (HR: 3.3, p=0.03). Conclusions: These data provide evidence that PD-L1+ expression on peripheral CD4+ T cells was a significant predictor of better PFS in NSCLC patients. Therefore, PD-L1 expression could be used for the selection of patients who might benefit from PD-1/PD-L1 inhibitors.

Background: The determination of Ki67 in the primary tumor has prognostic value in early breast cancer (BC). We evaluated Ki67 expression in circulating tumor cells (CTCs) from patients with early BC undergoing adjuvant chemotherapy and correlated Ki67 positivity with patient outcome. Methods: Ki67 expression in CTCs was evaluated by immunofluorescent analysis in paired blood samples of patients with early BC (n=166) obtained before and after adjuvant chemotherapy. Ki67 expression was also evaluated in CTC-positive patients at 6 - 24 months after the end of chemotherapy (n=31). Cytospins of peripheral blood mononuclear cells were double stained with A45-B/B3 cytokeratin and Ki67 antibodies. The proliferation index (PI) of CTCs was defined as the ratio of Ki67-positive CTCs/total CTCs. Results: CTCs were detected in 53 (32%) patients before and/or after chemotherapy. Ki67-positive [Ki67(+)] CTCs were identified in 79% of CTC-positive patients, 25% presenting exclusively Ki67(+) CTCs and 21%, exclusively Ki67(-) CTCs. The mean value of Ki67(+) CTCs/patient remained unchanged pre- and post-chemotherapy [(mean±SE): pre- vs post-chemotherapy 2.5±0.7 vs 4.2±2, respectively; p= 0.900]. Similarly, the PI among the total CTCs detected pre- and post-chemotherapy was 59% and 60%, respectively. Ten (19%) of 53 CTC-positive and 9 (8%) of 113 CTC-negative patients relapsed (p = 0.039). In addition, all CTC-positive patients who relapsed harbored Ki67(+) CTCs before and/or after chemotherapy. Interestingly, 70% of them experienced early disease recurrence, ranging from 6-29 months after the initiation of adjuvant chemotherapy. Furthermore, 38.5% of patients with exclusively Ki67(+) CTCs relapsed compared to none among patients with exclusively Ki67(-) CTCs (p = 0.041). Of the 31 CTC-positive patients evaluated during follow-up, 39% remained CTC-positive. However, only 33.3% of them harbored Ki67(+) CTCs, 8.3% had exclusively Ki67(+) CTCs and 66.7% exclusively Ki67(-) CTCs. The mean value of Ki67(+) CTCs/patient was significantly reduced on the follow-up samples [(mean±SE): follow-up vs pre-chemotherapy, 1.35±1.3 vs 2.5±0.7, respectively; p=0.014 and follow-up vs post-chemotherapy, 1.35±1.3 vs 4.2±2, respectively; p= 0.026]. Conclusions: Ki67 expression on CTCs is predictive of early relapse in patients with early BC. Ki67 expression is not decreased by adjuvant chemotherapy, whereas it is reduced early during follow-up, possibly due to adjuvant hormone therapy and/or anti-HER2 therapy. The above results suggest that additional therapy is needed for patients with early BC and Ki67(+) CTCs to prevent early disease recurrence. Citation Format: Agelaki S, Spiliotaki M, Politaki E, Spanaki A, Kassiou L, Koinis F, Georgoulias V, Mavroudis D. Ki67-positive CTCs are associated with early disease relapse in patients with early breast cancer undergoing adjuvant chemotherapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-01-06.

To evaluate the safety and antitumor activity of docetaxel (DOC) and pegylated liposomal doxorubicin (PLD) combination in patients with platinum- and taxane-sensitive ovarian cancer.Twenty-three patients were enrolled. DOC was administered at the dose of 40 mg/m(2) intravenously (i.v.) and PLD at 20 mg/m(2) i.v. on days 1 and 15 in cycles of 28 days. The study was closed prematurely due to slow accrual.Seven (30.4 %) patients achieved objective response (three complete, four partial), while five (21.7 %) others experienced stable disease (overall disease control rate 52.1 %). The median progression-free survival was 4.8 months and the median overall survival 18.8 months. Grade 3-4 neutropenia occurred in two (8.7 %) and one (4.3 %) patients, respectively. Febrile neutropenia occurred in two patients. The most common non-hematological grade 3 toxicity was hand-foot syndrome (13 % of patients). There was no treatment-related death.The combination of pegylated liposomal doxorubicin and docetaxel is a well tolerated and a relatively active regimen in pretreated patients with platinum- and taxane-sensitive advanced ovarian cancer.

8562Background: To investigate the effect of 2nd line PZN on the number and phenotype of CTCs in patients with SCLC. Methods: CTCs were detected in58 pts using the CelleSearch assay (CS) and double...

8561Background: Pazopanib (PZB) is a small anti-angiogenic molecule inhibiting the tyrosine kinase of VEGFR-1, VEGFR-2, VEGFR-3, PDGF, and c-kit. Several studies have shown that angiogenesis is of ...

Background: The assessment of Ki67 in the primary tumor represents a prognostic marker with potential predictive implications in early BC. We evaluated Ki67 expression in CTCs from patients with early BC and assessed the effect of adjuvant chemotherapy as well as Ki67 expression in the primary tumor. Methods: Ki67 was evaluated in CTCs of 97 patients with early BC pre- and post- adjuvant chemotherapy by the use of immunofluorescence analysis. Cytospins of peripheral blood mononuclear cells were double stained with A45-B/B3 cytokeratin mouse antibody and a Ki67 rabbit antibody. Ki67 staining of the primary tumor was also performed for 13 CTC-positive patients. A proliferation index (PI) in CTCs was considered as the ratio of Ki67-positive CTCs/total CTCs. A PI of up to 14% was defined as 'low' whereas a PI above 14% was defined as 'high'. Results: CTCs were detected in 26 (26.8%) patients before and/or after chemotherapy. Seven (27%) of 26 CTC-positive and 8 (11%) of 74 CTC-negative patients relapsed (p = 0.047). Ki67-positive CTCs were identified in 20 (76.9%) of 26 patients, whereas in 1 (3.9%) and 5 (19.2%) patients, exclusively Ki67-positive and Ki67-negative CTCs, respectively, were detected. Seven (33%) of 21 Ki67-positive patients relapsed in contrast to none among the exclusively Ki67-negative patients (p = 0.13). A total of 154 and 161 CTCs were detected pre- and post-chemotherapy, respectively; the PI in CTCs was 56% and 55%, respectively. In 8 patients with detectable CTCs at both time points, the PI was 65% and 49% pre- and post-chemotherapy, respectively. In 5 (62.5%) out of 8 patients, the PI remained high, in 2 (25%) increased and in 1 patient no Ki67–positive CTCs were detected post-chemotherapy. Seventeen patients were CTC-positive at baseline [HER2 positive, n=5; triple negative, n=1; hormone receptor positive, n=11]. A concordance in Ki67 staining between the primary tumor and CTCs was recorded in 10 (77%) out of 13 patients. Moreover, in 2 (67%) of 3 patients with exclusively Ki67-negative CTCs, low Ki67 expression was also observed in the primary tumor. Interestingly, 2 out of 5 patients with HER2 positive primary relapsed and both had high PI in their CTCs, whereas 2 out the 3 HER2 positive patients that did not relapse had low CTC proliferation index. Similarly, the triple negative patient had low PI in her CTCs and has not relapsed after 4 years of follow up. Conclusions: Adjuvant chemotherapy fails to decrease the proliferation index in CTCs. Ki67 expression in CTCs seems to reflect Ki67 expression in the primary tumor and could be predictive of patient outcome. Citation Format: Agelaki S, Spiliotaki M, Spanaki A, Kassiou L, Tzardi M, Koinis F, Kafousi M, Georgoulias V, Mavroudis D. The proliferation index of circulating tumor cells (CTCs) is not influenced by the administration of adjuvant chemotherapy in early breast cancer (BC) and seems to reflect Ki67 expression of the primary tumor. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-16.

e19044 Background: Platinum-based chemotherapy is the standard front-line treatment for patients with advanced Non Small Cell Lung Cancer (NSCLC). However, third generation non-platinum combination...

In our previous study, high levels of one granulocytic (G-MDSC) and two monocytic (M-MDSCs) subpopulations of immunosuppressive MDSCs were found and their overexpression was correlated with worse prognosis in NSCLC patients. Using flow cytometry, the impact of chemotherapy on the percentages and functionality of M-MDSC (CD14+CD15-CD11b+CD33+HLA-DR-Lin- and CD14+CD15+CD11b+ CD33+HLA-DR-Lin-) and G-MDSC (CD14-CD15+CD11b+CD33+HLA-DR-Lin-) was evaluated in the peripheral blood of patients (n=141) prior to chemotherapy and after the 3rd and 6th cycle of treatment. The M-MDSC (CD14+CD15-CD11b+CD33+HLA-DR-Lin-) percentages were found significantly decreased post chemotherapy compared to baseline, whereas chemotherapy had no effect on CD14+CD15+CD11b+CD33+HLA-DR-Lin- M-MDSCs. In contrast, the production of iNOS by M-MDSCs was significantly increased compared to the baseline. Both G-MDSC levels and their ROS expression were not affected by chemotherapy. In addition, both subtypes of MDSCs, when co-cultured with CD3+ T cells, were able to significantly suppress IFN-γ secretion by T cells. Finally, the M-MDSC (CD14+CD15-CD11b+CD33+HLA-DR-Lin-) percentages were found significantly decreased in patients that did not develop progressive disease during or after treatment completion, compared to patients with disease progression. Chemotherapy seems to have an impact on MDSC expression and functionality, hence targeting these cells may lead to a better clinical outcome in NSCLC patients.

Background: The immune system can either prevent and control the tumor growth or promote tumor escape. Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous population of immature cells with immune suppressive properties and their overexpression seems to confer a worse prognosis in cancer patients. Objective: The aim of the study was to investigate the presence of new phenotypically immature subpopulations of MDSCs which could be associated with advanced/metastatic NSCLC patients' clinical outcome. Materials & Methods: Circulating subtypes of MDSCs (monocytic and granulocytic), as well as the CD4+ , CD8+ , dendritic (DC), monocytes and B cells were assessed in peripheral blood of of chemotherapy-naive patients with advanced/metastatic NSCLC (n=134) and healthy controls (n=28) were analyzed using flow cytometry. The phenotypic characterization of MDSCs subpopulations was determined in strictly immature myeloid cells. A correlation between the levels of MDSCs and other tested immune cells as well as their association with overall (OS) and progression- free survival (PFS) was evaluated; high expression of MDSCs was defined as the percentage of the cells above the 90% percentile of the controls. Results: Two monocytic [M-MDSC: CD14+CD15-CD11b+CD33+HLA-DR-Lin- and CD14+CD15+CD11b+CD33+HLA-DR-Lin-] and a granulocytic [G-MDSC: CD14-CD15+CD11b+CD33+HLA-DR-Lin-] subpopulation of MDSCs were significantly increased (p Conclusion: The data provide evidence that the increased frequency of two new M-MDSC subpopulations in patients with advanced/metastatic NSCLC is associated with an unfavorable clinical outcome. Citation Format: Eleni Kyriaki Vetsika, Filippos Koinis, Marianthi Gioulmpasani, Despoina Aggouraki, Anna Koutoulaki, Eirini Skalidaki, Dimitris Mavroudis, Vassilis Georgoulias, Athanasios Kotsakis. High frequency of a circulating monocytic subpopulation of myeloid-derived suppressor cells predicts worst clinical outcome in untreated non-small lung cancer patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3664. doi:10.1158/1538-7445.AM2014-3664

Defining therapeutically “vulnerable” genes that modulate anti-cancer drug response is of paramount importance in precision cancer treatment. The success of such a task largely depends on the ability to develop computational resources that integrate big “omic” data into effective drug-response models. Herein, based on the pharmacogenomic profile of 1,001 cancer cell lines we constructed a novel in silico screening process based on Association Rule Mining for identifying genes as candidate drivers of drug response. Our computational pipeline explores with high efficiency large sample-spaces, is able to detect low frequency events and evaluate statistical significance even in the multidimensional space, presenting the results in the form of easily interpretable rules. The selection algorithm was validated by in silico and experimental means. Within this context, we identified experimentally novel targets related with responsiveness to: i) Doxorubicin treatment, and ii) MAPK and PI3K inhibitor administration. The presented data mining scheme provides evidence for potential practical applications and a proof-of-concept for the implementation of precision medicine in everyday clinical practice.