Colorectal cancer ranks third in global incidence and second in cancer mortality. Patient-derived models are irreplaceable for studying tumor biology. We established a human epithelial cell line from a rectal adenocarcinoma overexpressing cancer stem cell marker ALDH1A1, and we investigated the effect of ALDH1A1 knockout on tumor cell traits. The cell line and its CRISPR-Cas9 ALDH1A1 knockouts were characterized by genomic and cytogenetic methods (CNV, WES, RNAseq, karyotype), in vitro (proliferation, response to chemotherapy, migration, invasion, apoptosis), and in vivo methods. We identified the landscape of somatic mutations and copy number alterations in the original tumor and the derived cell line. Genetic attenuation of ALDH1A1 was characterized by an increase in migratory potential and extensive metastatic ability, accompanied by reduced growth of subcutaneous xenografts and alterations in gene expression associated with inhibited proliferation and promoted invasion and metastasis, ultimately resulting in dysregulation of the Wnt signaling pathway. Increased metastatic potential was also confirmed in HT-29 cells after ALDH1A1 genetic attenuation. CRISPR-Cas9-mediated editing led to functional, cellular, and molecular changes confirming the role of ALDH1A1 in colorectal cancer carcinogenesis.

Breast cancer remains a leading cause of cancer-related mortality, particularly due to its metastatic potential. Circulating tumor cells (CTCs) have emerged as critical players in metastasis, offering potential as prognostic and predictive markers. Among CTC populations, those undergoing epithelial-to-mesenchymal transition (EMT) exhibit enhanced invasiveness, motility, and resistance to therapy. EMT-CTCs, often associated with cancer stem cell-like traits, contribute significantly to tumor progression and treatment failure. However, their detection is challenging due to their heterogeneous nature and partial EMT states. This chapter explores advanced methodologies for detecting EMT-CTCs, their molecular characteristics, and their clinical relevance in breast cancer. Biomarkers such as TWIST1, vimentin, and PLS3 are highlighted for their roles in identifying EMT-CTCs and tracking their transition states. The prognostic implications of EMT-CTCs, particularly their correlation with poor outcomes and resistance to therapy, underscore their potential utility in personalized medicine. Further research into standardizing detection techniques and understanding the complex interplay between EMT-CTCs and the tumor microenvironment is essential for integrating these insights into clinical practice.

To achieve an R0 resection margin in patients with locally advanced pancreatic ductal adenocarcinoma, high-volume pancreatic centers standardly incorporate portal vein or superior mesenteric vein resection. However, there is currently no consensus on the optimal reconstructive approach. Postoperative venous thrombosis or stenosis can significantly increase patient morbidity or mortality. The objective of this study was to report the long-term patency rate of portal/superior mesenteric vein reconstruction, as well as to identify potential predictors of postoperative venous thrombosis/stenosis. A single-center retrospective cohort analysis was conducted on patients undergoing pancreatic resection due to pancreatic tumor. The patency of the vascular reconstruction was assessed by routine surveillance using computed tomographic imaging at 3, 6, 9, and 12 months after surgery. A total of 297 pancreatic resections were performed with 53 patients undergoing concomitant venous resection. Among these, 26.4% (N = 14) had primary closure, 22.7% (N = 12) underwent an end-to-end anastomosis, and 50.9% (N = 27) received an interposition graft reconstruction. At the 1-year follow up, 90.2% (N = 37) of patients with venous reconstruction had a fully patent vein. The analysis did not reveal any statistically significant perioperative or postoperative factors associated with an increased risk of reconstruction thrombosis. While our study confirms a high long-term patency rate of 90.2% at 1 year, it underscores the necessity for a randomized controlled trial to determine the optimal method of venous reconstruction in pancreatic surgery.

e17017 Background: Teratomas are unique neoplastic growths that encompass a diverse array of tissue types derived from multiple germ layers, often exhibiting varying degrees of differentiation. Among the phenomena associated with teratomas, the growing teratoma syndrome (GTS) stands out as a rare yet clinically significant occurrence. GTS, characterized by the persistence or regrowth of teratomatous elements despite initial treatment, poses challenges for both diagnosis and management. In this abstract, we present the results of our expression array analysis of teratomas, aiming to uncover novel insights into their molecular composition, heterogeneity, and potential implications for clinical management. Methods: This study included 53 patients with retroperitoneal teratoma (7 chemotherapy naïve and 46 with postchemotherapy teratoma) and 20 patients with viable postchemotherapy germ cell tumor from retroperitoneum that had surgery at National Cancer Institute in Slovakia and for whom formalin-fixed paraffin-embedded (FFPE) tumor tissue was available. Study also includes samples from 5 patients with normal testis as control group. Ten patients (18.9%) in this cohort had growing teratoma syndrome. Analysis was performed by HTG EdgeSeq Oncology Biomarker panel (HTG Molecular Diagnostics, Inc., Tucson, USA). Identified candidate genes associated with GTS were further validated by immunohistochemistry on FFPE. Results: Molecular profiling indicates no differences in expression profile in retroperitoneal teratomas regardless of previous chemotherapy. Expression analysis indicates 1586 genes being differently expressed with high significance ( p < 0.05) in teratomas compared to normal testis and 1571 genes differentially expressed compared postchemotherapy viable tumors. We identified 14 genes being differently expressed in growing teratoma syndrome compared to teratoma without growth (CYP4A22, IGFBP1, CXCL6, LTF, CYP2C8, CFTR, CCL20, PFKFB3, SLC2A3, LIPA, HMOX1, GPNMB, CCL18, DLK1. Pathway analysis revealed MAPK and PI3K−Akt signaling pathways are mostly dysregulated in GTS. Conclusions: This molecular profiling identify genes differentially expressed in teratomas that are potential biomarkers for prediction of teratoma element in postchemotherapy residues in testicular germ cell tumor patients. Moreover, inhibition of identified signaling pathways associated with GTS could represent potentially novel therapeutic targets in case of unresectable disease.

Although advances in diagnostic techniques, new therapeutic strategies and personalization of breast cancer (BC) care have improved the survival for a number of patients, BC remains a major cause of morbidity and mortality for women. The study of circulating tumor cells (CTCs) has significant potential in translational oncology since these cells represent promising biomarkers throughout the entire course of BC in patients. CTCs also have notable prognostic value in early BC as well as metastatic BC. Based on current knowledge, it seems that the dynamics of CTCs that change during therapy reflect therapy response, and CTCs could serve as a tool for risk stratification and real-time monitoring of treatment in patients with BC. The question of how to use this information in everyday clinical practice and how this information can guide or change therapy to affect the clinical outcome of patients with BC remains unanswered. The present review aims to discuss current completed and ongoing trials that have been designed to demonstrate the clinical significance of CTCs, offer insights into treatment efficacy and assess CTC utility, facilitating their implementation in the routine management of patients with BC.

BackgroundTesticular cancer is the most common malignancy among young men. Vitamin D has pluripotent effects on cancer pathogenesis and plays a role in the metastatic cascade. The aim of this study is to analyze plasma vitamin D in association with clinico-pathological findings and prognosis in patients with germ-cell tumors (GCTs).MethodsThis study included 120 newly diagnosed and/or relapsed GCT patients treated from April 2013 to July 2020, for whom plasma was available in the biobank. Blood samples were drawn the 1st chemotherapy cycle as well as before the 2nd cycle. Plasma vitamin D was measured using ELISA and correlated with disease characteristics and the outcome. For survival analysis, the cohort was dichotomized into “low” and “high” based on median vitamin D.ResultsThere was no significant difference in vitamin D plasma levels between healthy donors and GCT patients (p = 0.71). Vitamin D level was not associated with disease characteristics except for brain metastases, where patients with brain metastases had a vitamin D level that was 32% lower compared to patients without brain metastases, p = 0.03. Vitamin D was also associated with response to chemotherapy, with an approximately 32% lower value in patients with an unfavorable response compared to a favorable response, p = 0.02. Moreover, low plasma levels of vitamin D were significantly associated with disease recurrence and inferior progression-free survival (PFS), but not with overall survival (OS) (HR = 3.02, 95% CI 1.36–6.71, p = 0.01 for PFS and HR = 2.06, 95% CI 0.84–5.06, p = 0.14 for OS, respectively).ConclusionOur study suggests the prognostic value of pretreatment vitamin D concentrations in GCT patients. Low plasma vitamin D was associated with an unfavorable response to therapy and disease recurrence. However, it remains to be determined whether the biology of the disease confirms a causative role for low vitamin D and whether its supplementation affects the outcome.

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest cancers worldwide, primarily due to its robust desmoplastic stroma and immunosuppressive tumor microenvironment (TME), which facilitate tumor progression and metastasis. In addition, fibrous tissue leads to sparse vasculature, high interstitial fluid pressure, and hypoxia, thereby hindering effective systemic drug delivery and immune cell infiltration. Thus, remodeling the TME to enhance tumor perfusion, increase drug retention, and reverse immunosuppression has become a key therapeutic strategy. In recent years, targeting epigenetic pathways has emerged as a promising approach to overcome tumor immunosuppression and cancer progression. Moreover, the progress in nanotechnology has provided new opportunities for enhancing the efficacy of conventional and epigenetic drugs. Nano-based drug delivery systems (NDDSs) offer several advantages, including improved drug pharmacokinetics, enhanced tumor penetration, and reduced systemic toxicity. Smart NDDSs enable precise targeting of stromal components and augment the effectiveness of immunotherapy through multiple drug delivery options. This review offers an overview of the latest nano-based approaches developed to achieve superior therapeutic efficacy and overcome drug resistance. We specifically focus on the TME and epigenetic-targeted therapies in the context of PDAC, discussing the advantages and limitations of current strategies while highlighting promising new developments. By emphasizing the immense potential of NDDSs in improving therapeutic outcomes in PDAC, our review paves the way for future research in this rapidly evolving field.

Background: Circulating tumor cells (CTC) with phenotype of epithelial-mesenchymal transition (CTC_EMT) represent novel subpopulation of CTC associated with inferior outcome in primary breast cancer (PBC). However, molecular characterization of primary tumors associated with this CTC subpopulation is lacking. The aim of this study was to identify signaling pathways associated with presence of CTC_EMT in PBC patients using a comprehensive genomics approach. Methods: This translational study included 17 patients with PBC and 5 donors of normal breast tissue. CTC_EMT were detected before surgery by quantitative RT-PCR assay for expression of epithelial-mesenchymal transition (EMT) genes (TWIST1, SNAIL1, SLUG, ZEB1). Total RNA was extracted, in parallel, from fresh frozen primary tumor and whole-trancriptome profiles were obtained using RNA sequencing and additionally mRNAs profiles by microarray. Genes expressions were further validated by qRT-PCR. Results: Analyzing RNA sequencing and microarray data, we found set of genes differentially expressed in absence or presence of CTC_EMT in PBC. We identified 157 genes differentially expressed in CTC_EMT phenotype compared to patients with non-detectable CTC. Namely, keratin family is represented by genes KRT5, KRT14, KRT17. Gene ontologies related to membrane structure or communication and immunology appears to be involved in CTC-related processes, pathways related to cell junction and various signaling pathways including PI3K and Ras-signaling appear to be significant in processes leading to CTC EMT presence. Conclusions: We suspect multiple genes of having a role in primary tumour processes leading to CTC EMT production in breast cancer patients. Data suggest, that PI3K & Ras-signalling and pathways related to cell junction are the key pathways for changes inside of primary tumour tissue between CTC EMT and CTC- phenotype of breast cancer patients. We propose, additional study with single-cell resolution is needed for better understanding of the processes. Citation Format: Michal Mego, Dominik Hadzega, Gabriel Minarik, Andrea Soltysova, Petra Nemcova, Katarina Kalavska, Marian Karaba, Juraj Benca, Tatiana Sedlackova, Daniel Pindak, Lubos Klucar. Differentially expressed genes and their pathways in breast cancer patients with mesenchymal CTC [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-11-04.

BACKGROUND:Pericardial effusions with its potential life threatening progression towards cardiac tamponade have to be often managed with surgical intervention. In our case study we describe a complication after a common surgical procedure which has only scarce literature mentions.CASE PRESENTATION:We present a case of a 22-year-old male patient who underwent subxiphoidal pericardial fenestration, due to symptomatic pericardial effusion with the Chamberlain procedure and biopsy of enlarged mediastinal lymph nodes. The histology report confirmed classical Hodgkin lymphoma and subsequently the patient underwent oncological treatment. Later on he was admitted to the hospital with dyspnoea and chest pain. The initial examinations stated a suspicion for intrathoracic tumour arising from the pericardium or liver. Further investigation revealed symptomatic intrathoracic liver herniation for which the patient underwent laparoscopic surgery with the mobilisation of liver and placement of a perforated Parietene™ composite mesh.CONCLUSION:The purpose of this case report is to describe a rare complication after pericardial fenestration with its potential clinical implications.

Branislav Bezak MD | Daniel Pindak MD, PhD | Peter Svajdler MD | Ivo Gasparovic MD, PhD | Panagiotis Artemiou MD, PhD | Michal Hulman MD, PhD Clinic of Cardiac Surgery, Medical Faculty of the Comenious University, National Institute of Cardiovascular Diseases, Bratislava, Slovakia Medical Faculty of the Slovak Medical University, Bratislava, Slovakia Department of Surgical Oncology, Medical Faculty of Slovak Medical University, National Cancer Institute, Bratislava, Slovakia Cytopathos sro, Bratislava, Slovakia

BackgroundCirculating tumor cells (CTCs) contribute to the metastatic cascade and represent an independent survival predictor in breast cancer (BC) patients. Vitamin D has pleiotropic effects, and its low concentrations are associated with breast cancer and metastasis. The aim of this study was to assess plasma vitamin D in primary BC patients in relation to CTCs.MethodsThis study included 91 non-metastatic BC patients (stage I–III) and 24 healthy donors. Blood samples for the analyses were drawn at the time of surgery. CTCs were assessed using a quantitative RT-PCR assay for expression of epithelial (CK19) or epithelial-to-mesenchymal transition (EMT) genes (TWIST1, SNAIL1, SLUG, and ZEB1). Total 25-OH vitamin D was measured in plasma using ELISA. Plasma cytokines and angiogenic factors were measured by enzyme-linked immunoassay.ResultsCTCs were detected in 30 (33%) patients. Patients with detectable CTCs in peripheral blood had significantly lower vitamin D concentrations in comparison to patients without detectable CTCs ((mean ± SD) 8.50 ± 3.89 µg/L for CTC-positive vs 9.69 ± 3.49 µg/L for CTC-negative patients, p = 0.03). The mean ( ± SD) vitamin D plasma level was 9.3 ± 3.65 µg/L for breast cancer patients compared to 18.6 ± 6.8 for healthy donors (p < 0.000001). There was no association between plasma vitamin D and other patient/tumor characteristics. Plasma vitamin D levels are inversely correlated with plasma TGF-β1, TGF-β2, IL β, IL-5, and eotaxin (all p < 0.05). Patients with vitamin D above the median had a better overall survival (hazard ratio (HR) = 0.36, 95% CI 0.16–0.80, p = 0.017), and combined analysis showed the best survival for CTC-negative patients with vitamin D levels above the median as compared to patients with opposite characteristics (HR = 0.18, 95% CI 0.05–0.63, p = 0.004).ConclusionsLow vitamin D could be a consequence and hence a biomarker of a more invasive disease. Alternatively, vitamin D could be associated with survival because of its role in tumor dissemination. Whether its supplementation affects the metastatic cascade should be tested in animal experiments and interventional studies.

Abstract Background: Matrix metalloproteinase 9 (MMP9) is involved in the extracellular matrix degradation during physiological and pathological conditions including tumorigenesis. This translational study was aimed to evaluate the prognostic role of the intratumoral MMP9 expression and correlate it with presence of CTCs in early breast cancer. Methods: A total of 318 primary breast cancer (PBC) patients were enrolled into this study. Surgical specimens were processed by the tissue microarray method and subjected to immunohistochemistry using the MMP9 monoclonal antibody. The MMP9 expression was evaluated in tumor cell as well as in tumor associated stroma. Quantitative real-time polymerase chain reaction -based assays was applied for identification of CTCs. Results: Significantly increased expression of MMP9 was found in breast cancer cells when compared to tumor associated stroma. A positive correlation was determined between MMP9 expression and hormone positive status as well as low proliferation index of analysed breast cancer tumour cells. Additionally, in tumor associated stroma was confirmed only the association with hormone receptor status. The univariate survival analysis of whole tested population detected no prognostic role of MMP9 expression neither in tumor cells (HR = 0.96, 95% CI 0.58-1.59, P = 0.864) nor in tumor associated stroma (HR = 1.29, 95% CI 0.60-2.78, P = 0.547). However, the subgroup of in hormone receptor negative and triple negative patients with absence of MMP9 expression in tumor cells and stroma had significantly better disease-free survival (DFS) (HR = 0.33, 95% CI 0.12-0.93, P = 0.025, and (HR = 0.14, 95% CI 0.00-4.81, P = 0.002, respectively) and (HR = 0.17, 95% CI 0.05-0.57, P = 0.003); (HR = 0.12, 95% CI 0.00-4.89, P = 0.001) compared with patients with presence of MMP9. Moreover, while tumor MMP9 was prognostic in CTC_EMT positive subgroup (HR = 0.40, 95% CI 0.16-0.95, P = 0.047), absence of stromal MMP9 had protective role in CTC_EP positive patients (HR = 0.18, 95% CI 0.01-2.75, P = 0.053). Conclusions: Our data suggest that the increased expression of MMP9 in PBC was related with favorable tumor characteristics. However, it´s prognostic value was limited only to hormone receptor negative, triple negative, CTC_EMT and CTC_EP positive subgroups. Therefore, we can suppose that evaluating of MMP9 tumor expression could help identify patients with increased risk of disease recurrence in these subgroups of patients. Citation Format: Michal Mego, Zuzana Cierna, Marian Karaba, Gabriel Minarik, Juraj Benca, Tatiana Sedlackova, Ivana Mrvova, Daniel Pindak, Katarina Rejlekova, Jozef Mardiak, Katarina Kalavska. The prognostic role of MMP 9 in early breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS16-26.

Recent research studies are showing breast tissues as a place where various species of microorganisms can thrive and cannot be considered sterile, as previously thought. We analysed the microbial composition of primary tumour tissue and normal breast tissue and found differences between them and between multiple breast cancer phenotypes. We sequenced the transcriptome of breast tumours and normal tissues (from cancer-free women) of 23 individuals from Slovakia and used bioinformatics tools to uncover differences in the microbial composition of tissues. To analyse our RNA-seq data (rRNA depleted), we used and tested Kraken2 and Metaphlan3 tools. Kraken2 has shown higher reliability for our data. Additionally, we analysed 91 samples obtained from SRA database, originated in China and submitted by Sichuan University. In breast tissue, the most enriched group were Proteobacteria, then Firmicutes and Actinobacteria for both datasets, in Slovak samples also Bacteroides, while in Chinese samples Cyanobacteria were more frequent. We have observed changes in the microbiome between cancerous and healthy tissues and also different phenotypes of diseases, based on the presence of circulating tumour cells and few other markers.

Background: Germ cell tumors represent highly curable disease even in metastatic stage. However, poor-risk patients with an unfavorable serum tumor marker (STM) decline after the first cycle of chemotherapy represent a subgroup with dismal prognosis, with approximately 50% cure rate using bleomycin, etoposide, and cisplatin (BEP). Objective: The aim of this study was to determine the efficacy and safety of paclitaxel, ifosfamide, and cisplatin (TIP) in this patient population. Design, setting, and participants: This was an open-labeled, nonrandomized, single center phase II trial to study the efficacy and toxicity of TIP in the first-line treatment of germ cell tumor patients with an unfavorable decline of STMs. Nineteen patients with a poor prognosis according to the International Germ Cell Cancer Collaboration Group classification and an unfavorable STM decline after the first cycle of chemotherapy were included in this phase II study (NCT02414685). The treatment regimen consisted of paclitaxel 250 mg/m(2) on day 1, ifosfamide 1200 mg/m2 on days 1-5, and cisplatin 20 mg/m(2) on days 1-5, totally for four cycles. Outcome measurements and statistical analysis: The primary endpoint was com- plete response (CR) rate. An optimal Simon two-stage design was used with a type I error of 5% and study power of 80%. If fewer than six CRs to study therapy have been observed among the first 19 patients, the study was to be terminated. Results and limitations: A CR was achieved in four (21.1%) patients; therefore, the study was terminated in the first stage. A favorable response rate (CR or partial remission with negative tumor markers) was observed in 14 (78.9%) patients. At a median follow-up period of 35.2 mo (range, 5.6-62.1 mo), ten (52.6%) patients experienced disease progression and eight patients (42.1%) died. The 2-yr progres- sion-free and overall survival was 41.2% (95% confidence interval [CI] 16.8-65.7) and 72.7% (95% CI 48.9-96.4), respectively. TIP was well tolerated, and no unex- pected toxicity was observed. No informative biomarkers, including miR-371a-3p was identified. Conclusions: Treatment modification from the BEP to the TIP regimen in patients with an unfavorable STM decline after the first cycle of chemotherapy was not associated with improved outcome, and four cycles of BEP remain the standard treatment option in this patient population. Patient summary: Poor-risk patients with an unfavorable serum tumor marker decline after the first cycle of chemotherapy represent a subgroup with dismal prognosis, with an approximately 50% cure rate using bleomycin, etoposide, and cisplatin (BEP). Treatment modification from the BEP regimen to the paclitaxel, ifosfamide, and cisplatin regimen in patients with an unfavorable serum tumor marker decline after the first cycle of chemotherapy was not associated with improved outcome, and four cycles of BEP remain the standard treatment option in this patient population. (C) 2021 The Author(s). Published by Elsevier B.V. on behalf of European Association of Urology.

Breast tissues were considered to be sterile in the past, but the recent years of research showed, that microorganisms can be found in both healthy breast tissue and breast tumours. Overrepresented or underrepresented microbes have been reported in one or another. There are multiple ways to uncover microbial composition inside of human tissues. In our study, we were studying the presence of microbes in breast cancer primary tumours of patients with different cancer phenotypes and also in samples from healthy tissues (23 patients from Slovakia in total). We were using Illumina RNA-seq data (transcriptomic, rRNA depleted) and we analysed them by Kraken2 tool in Galaxy. We have observed changes in the microbiome between disease and healthy tissues and also different phenotypes of diseases, based on circulating tumour cells presence. To compare data to similar RNA-sequencing projects we used data from SRA database, containing healthy breast tissues of 18 patients and primary breast tumour tissue of 19 patients from China. In breast tissue, the most enriched group were Proteobacteria , then Firmicutes and Actinobacteria for both datasets, in Slovak samples also Bacteroides , while in Chinese samples Cyanobacteria were more frequent. Healthy tissues were richer in microbes and multiple taxonomic groups were overrepresented or underrepresented compared to tumour tissues. Furthermore, there were changes observed between breast cancer phenotypes.

MMP9 is involved in extracellular matrix degradation during various physiological and pathological conditions, including tumorigenesis. The present study aimed to assess the prognostic role of intratumoral MMP9 and to determine its association with circulating tumor cells (CTCs) in patients with early breast cancer. A total of 318 patients with primary breast cancer (PBC) were enrolled into the present study. Specimens were subjected to immunohistochemistry analysis, using the MMP9 monoclonal antibody. MMP9 expression was scored using a weighted histoscore (WH). The results demonstrated that the mean WH ± SEM for MMP9 expression was significantly higher in breast tumor cells compared with tumor associated stromas (132.0±5.2 vs. 50.8±3.7; P<0.00001). Furthermore, a positive association was observed between MMP9 expression, the hormone positive status and proliferation index of analysed breast cancer tumour cells. Notably, the prognostic role of MMP9 was not observed in tumor cells [hazard ratio (HR) =0.96; 95% confidence interval (CI), 0.58-1.59; P=0.864] or tumor associated stroma (HR=1.29; 95% CI, 0.60-2.78; P=0.547). Subgroup analysis demonstrated that patients that were HR negative or triple negative, with low MMP9 expression in tumor cells and stroma had a significantly improved disease-free survival than patients with high MMP9 expression. Taken together, the results of the present study demonstrated that high MMP9 expression in PBC was associated with favorable tumor characteristics. However, the prognostic value of MMP9 was limited to only the HR negative and CTC epithelial-to-mesenchymal transition positive subgroups. Thus, analyzing MMP9 tumor expression may help identify patients with increased risk of disease recurrence in these subgroups.

Aim: Different types of chronic medication may affect breast cancer prognosis. Circulating tumor cells (CTCs) play an important role in cancer metastasis formation. There is no evidence of how chronic medication affects CTCs and breast cancer prognosis. The aim of this study was to evaluate association between chronic medication and CTCs in patients with primary breast cancer. Methods: This study involved 414 patients with stage I-III primary breast cancer. Chronic drug history was collected from patients' medical records and included all drugs that were prescribed for patients over at least the last 6 months prior to CTCs evaluation. CTCs were detected using a quantitative real-time polymerase chain reaction (qRT-PCR)-based method at the time of breast surgery. Results: There was no association between CTCs, including their different subpopulations and chronic medication. Chronic medication using angiotensin-converting-enzyme inhibitors (ACEi), metformin, and insulin were associated with inferior disease-free survival (HR = 0.49, 95%CI 0.26-0.94, P = 0.007 for ACEi; HR = 0.27, 95%CI 0.08-0.91, P < 0.001 for metformin; and HR = 0.12, 95%CI 0.01-2.91, P < 0.001 for insulin) and this was most pronounced in patients with epithelial to mesenchymal transition (CTC_EMT) phenotype. In multivariate analysis, chronic administration of metformin and/or insulin was an independent predictor of inferior outcome. Conclusion: Our findings show that there was no association between chronically used medication and CTCs in primary breast cancer patients. However, administration of ACEi, metformin, and/or insulin could negatively affect prognosis of patients with CTC_EMT.

e12553 Background: Nucleosomes are composed of DNA wound around histone proteins and represent the basic structural unit of chromatin in the nucleus. When cells die, nucleosomes get out of the cell and end eventually in the circulation. Plasma nucleosomes might serve as a non-specific biomarker of cell death, which might be of particular interest for non-invasive tumor monitoring. The aim of this study was to assess the prognostic value of circulating nucleosomes in primary breast cancer. Methods: This study included 92 primary breast cancer patients treated with surgery from March 2012 to February 2015, for whom plasma isolated on the day before surgery was available in the biobank. Plasma nucleosomes were detected using Cell Death Detection ELISA kit with anti-histone and anti-DNA antibodies. Results: Circulating nucleosomes were associated with the systemic inflammatory index (0.17 vs. 0.27, P = 0.02) and with aldehyde-dehydrogenase expression (0.22 vs. 0.15, P = 0.03). Patients with lower than mean nucleosomes had significantly better disease-free survival (HR = 0.46, P = 0.05). The prognostic value was most pronounced in lymph node positive disease with high proliferation rate and in patients with detectable circulating tumor cells with epithelial-to-mesenchymal transition, but negative for epithelial circulating tumor cells. In a multivariate analysis, nucleosomes, hormone receptor status, HER2 status, lymph node involvement and tumor grade were independent predictors of disease-free survival. Conclusions: Our data suggest prognostic value of plasma nucleosomes in primary breast cancer and their association with metastatic ability and stem-cell ness characteristics. Their quantification could be added to the established prognostic markers.