Extracellular Vesicles-A Source of RNA Biomarkers for the Detection of Breast Cancer in Liquid Biopsies.

Over the past decade, extracellular vesicles (EVs) have emerged as a promising source of cancer-derived RNAs for liquid biopsies. However, blood contains a pool of heterogeneous EVs released by a variety of cell types, making the identification of cancer RNA biomarkers challenging. Here, we performed deep sequencing of plasma EV RNA cargo in 32 patients with locally advanced breast cancer (BC) at diagnosis and 7 days after breast surgery and in 30 cancer-free healthy controls (HCs). To identify BC-derived RNA biomarkers, we searched for RNAs that had higher levels in BC EVs at the time of diagnosis compared with HCs and decreased after surgery. Data analysis showed that the fractions of miRNAs, snRNAs, snoRNAs, and tRFs were increased, but the fraction of lncRNAs was decreased in BC EVs as compared to HCs. BC-derived biomarker candidates were identified across various RNA biotypes. Considered individually, they had very high specificity but moderate sensitivity for the detection of BC, whereas a biomarker model composed of eight RNAs: SNORD3H, SNORD1C, SNORA74D, miR-224-5p, piR-32949, lnc-IFT-122-2, lnc-C9orf50-4, and lnc-FAM122C-3 was able to distinguish BC from HC EVs with an AUC of 0.902 (95% CI = 0.872-0.931, p = 3.4 × 10-9) in leave-one-out cross-validation. Furthermore, a number of RNA biomarkers were correlated with the ER and HER2 expression and additional biomarker models were created to predict hormone receptor and HER2 status. Overall, this study demonstrated that the RNA composition of plasma EVs is altered in BC patients and that they contain cancer-derived RNA biomarkers that can be used for BC detection and monitoring using liquid biopsies.

Comprehensive characterization of RNA cargo of extracellular vesicles in breast cancer patients undergoing neoadjuvant chemotherapy.

Extracellular vesicles (EVs) are g7aining increased attention as carriers of cancer-derived molecules for liquid biopsies. Here, we studied the dynamics of EV levels in the plasma of breast cancer (BC) patients undergoing neoadjuvant chemotherapy (NAC) and explored the relevance of their RNA cargo for the prediction of patients' response to the therapy. EVs were isolated from serial blood samples collected at the time of diagnosis, at the end of NAC, and 7 days, 6, and 12 months after the surgery from 32 patients with locally advanced BC, and 30 cancer-free healthy controls (HCs) and quantified by nanoparticle tracking analysis. The pre-treatment levels of EVs in BC patients were higher than in HCs, significantly increased during the NAC and surgery, and decreased to the levels found in HCs 6 months after surgery, thus showing that a substantial fraction of plasma EVs in BC patients are produced due to the disease processes and treatment. RNA sequencing analysis revealed that the changes in the EV levels were associated with the alterations in the proportions of various RNA biotypes in EVs. To search for RNA biomarkers that predict response to the NAC, patients were dichotomized as responders and non-responders based on Miller-Payne grades and differential expression analyses were carried out between responders and non-responders, and HCs. This resulted in the identification of 6 miRNAs, 4 lncRNAs, and 1 snoRNA that had significantly higher levels in EVs from non-responders than responders at the time of diagnosis and throughout the NAC, and significantly lower levels in HCs, thus representing biomarkers for the prediction of response to NAC at the time of diagnosis. In addition, we found 14 RNAs representing piRNA, miRNA, lncRNA, snoRNA, and snRNA biotypes that were induced by NAC in non-responders and 2 snoRNAs and 1 piRNA that were induced by NAC in patients with early disease progression, thus warranting further functional studies on their role in chemoresistance and metastasis.

Clinicopathological Significance of Exosomal Proteins CD9 and CD63 and DNA Mismatch Repair Proteins in Prostate Adenocarcinoma and Benign Hyperplasia.

INTRODUCTION: Recently, it has been shown that exosomal biomarkers and DNA mismatch repair proteins (MMR) could play an important role in cancer risk stratification and prognosis assessment. The gold standard for prostate carcinoma (PCa) diagnosis is biopsy and histopathological examination. Thus, the complex evaluation of exosomal and MMR proteins could be beneficial for prostate cancer risk stratification and diagnostics. The aim of the current study was to evaluate and compare the expression of exosomal proteins CD9 and CD63 and MMR proteins in the tissue of patients with prostate benign hyperplasia (BPH) and PCa. METHODS: The study was retrospective. Altogether, 92 patients with PCa and 20 patients with BPH (control group) were enrolled in the study. Exosomal and MMR protein expression was analyzed by immunohistochemistry (IHC). The follow-up for each PCa patient in our study lasted till disease progression and/or a maximum of 5 years. RESULTS: Low-grade PCa was observed in 56 patients and high-grade PCa in 36 patients. CD63 expression was significantly higher in patients with high-grade PCa compared to those with low-grade PCa. CD9 expression was significantly downregulated in PCa patients compared to the control group. MMR protein expression deficiency was observed in 10 PCa patients. MMR proteins were maintained in all cases of BPH. The study found a negative correlation between MMR protein loss and PCa ISUP grade groups. Progression-free survival (PFS) in patients with MMR deficiency was significantly shorter than in patients with maintained MMR expression. CONCLUSIONS: CD9 protein expression was downregulated in PCa, compared to BPH, while CD63 protein expression was upregulated in high-grade PCa but downregulated in low-grade PCa. CD63 protein upregulation, CD9 downregulation, and loss of MMR protein characterized the shorter PFS of high-grade PCa patients. CD9, CD63, and MMR could be the routine immunohistochemical biomarkers for the diagnosis and risk stratification of PCa.

Patients-centered SurvivorShIp care plan after Cancer treatments based on Big Data and Artificial Intelligence technologies (PERSIST): a multicenter study protocol to evaluate efficacy of digital tools supporting cancer survivors.

BACKGROUND: It is encouraging to see a substantial increase in individuals surviving cancer. Even more so since most of them will have a positive effect on society by returning to work. However, many cancer survivors have unmet needs, especially when it comes to improving their quality of life (QoL). Only few survivors are able to meet all of the recommendations regarding well-being and there is a body of evidence that cancer survivors' needs often remain neglected from health policy and national cancer control plans. This increases the impact of inequalities in cancer care and adds a dangerous component to it. The inequalities affect the individual survivor, their career, along with their relatives and society as a whole. The current study will evaluate the impact of the use of big data analytics and artificial intelligence on the self-efficacy of participants following intervention supported by digital tools. The secondary endpoints include evaluation of the impact of patient trajectories (from retrospective data) and patient gathered health data on prediction and improved intervention against possible secondary disease or negative outcomes (e.g. late toxicities, fatal events). METHODS/DESIGN: The study is designed as a single-case experimental prospective study where each individual serves as its own control group with basal measurements obtained at the recruitment and subsequent measurements performed every 6 months during follow ups. The measurement will involve CASE-cancer, Patient Activation Measure and System Usability Scale. The study will involve 160 survivors (80 survivors of Breast Cancer and 80 survivors of Colorectal Cancer) from four countries, Belgium, Latvia, Slovenia, and Spain. The intervention will be implemented via a digital tool (mHealthApplication), collecting objective biomarkers (vital signs) and subjective biomarkers (PROs) with the support of a (embodied) conversational agent. Additionally, the Clinical Decision Support system (CDSS), including visualization of cohorts and trajectories will enable oncologists to personalize treatment for an efficient care plan and follow-up management. DISCUSSION: We expect that cancer survivors will significantly increase their self-efficacy following the personalized intervention supported by the m-HealthApplication compared to control measurements at recruitment. We expect to observe improvement in healthy habits, disease self-management and self-perceived QoL. Trial registration ISRCTN97617326. https://doi.org/10.1186/ISRCTN97617326 . Original Registration Date: 26/03/2021.

Water safety plan enhancements with improved drinking water quality detection techniques.

Drinking water quality has been regulated in most European countries for nearly two decades by the drinking water directive 98/83/EC. The directive is now under revision with the goal of meeting stricter demands for safe water for all citizens, as safe water has been recognized as a human right by the United Nations. An important change to the directive is the implementation of a risk-based approach in all regulated water supplies. The European Union Framework Seventh Programme Aquavalens project has developed several new detection technologies for pathogens and indicators and tested them in water supplies in seven European countries. One of the tasks of the project was to evaluate the impact of these new techniques on water safety and on water safety management. Data were collected on risk factors to water safety for five large supplies in Denmark, Germany, Spain and the UK, and for fifteen small water supplies in Scotland, Portugal and Serbia, via a questionnaire aiming to ascertain risk factors and the stage of implementation of Water Safety Plans, and via site-specific surveys known as Sanitary Site Inspection. Samples were collected from the water supplies from all stages of water production to delivery. Pathogens were detected in around 23% of the 470 samples tested. Fecal contamination was high in raw water and even in treated water at the small supplies. Old infrastructure was considered a challenge at all the water supplies. The results showed that some of the technique, if implemented as part of the water safety management, can detect rapidly the most common waterborne pathogens and fecal pollution indicators and therefore have a great early warning potential; can improve water safety for the consumer; can validate whether mitigation methods are working as intended; and can confirm the quality of the water at source and at the tap.

Heavy Resistance Training in Breast Cancer Patients Undergoing Adjuvant Therapy.

BACKGROUND AND PURPOSE: Adjuvant breast cancer therapy may reduce maximal muscle strength, muscle mass, and functional performance. Although maximal strength training (MST) has the potential to counteract this debilitating outcome and is shown to be superior to low- and moderate-intensity strength training, it is unknown if it can elicit effective adaptations in patients suffering treatment-induced adverse side effects. METHODS: Fifty-five newly diagnosed stage I to III breast cancer patients (49 ± 7 yr) scheduled for adjuvant therapy were randomized to MST or a control group. The MST group performed 4 × 4 repetitions of dynamic leg press at approximately 90% of one-repetition maximum (1RM) twice a week for 12 wk. RESULTS: In the MST group, improvements in 1RM (20% ± 8%; P < 0.001) were accompanied by improved walking economy (9% ± 8%) and increased time to exhaustion during incremental walking (9% ± 8%; both P < 0.01). Moreover, the MST group increased 6-min walking distance (6MWD; 10% ± 7%), and chair rising (30% ± 20%) and stair climbing performance (12% ± 7%; all P < 0.001). All MST-induced improvements were different from the control group (P < 0.01) which reduced their 1RM (9% ± 5%), walking economy (4% ± 4%), time to exhaustion (10% ± 8%), 6MWD (5% ± 5%), chair rising performance (12% ± 12%), and stair climbing performance (6% ± 8%; all P < 0.01). Finally, although MST maintained estimated quadriceps femoris muscle mass, a decrease was observed in the control group (7% ± 10%; P < 0.001). The change in 1RM correlated with the change in walking economy (r = 0.754), time to exhaustion (r = 0.793), 6MWD (r = 0.807), chair rising performance (r = 0.808), and stair climbing performance (r = 0.754; all P < 0.001). CONCLUSIONS: Lower-extremity MST effectively increases lower-extremity maximal muscle strength in breast cancer patients undergoing adjuvant therapy and results in improved work economy, functional performance, and maintenance of muscle mass. These results advocate that MST should be considered in breast cancer treatment.

Extracellular Vesicles as Biomarkers and Therapeutic Targets in Breast Cancer.

Cancer-derived extracellular vesicles (EVs) contain various cancer-associated molecules, such as mutated or overexpressed oncoproteins, glycoproteins, mRNAs, various non-coding RNAs and DNA fragments. They have been shown to propagate phenotypic traits, such as drug resistance, increased proliferation rate, invasiveness and stemness across cancer cells and to mediate cancer-induced immunosuppression. Therefore, cancer-derived EVs have gained increasing attention as cancer biomarkers and therapeutic targets. Unlike circulating tumor cells they are highly abundant in biofluids and, on the contrary to single-molecule circulating biomarkers, they protect their molecular cargo against degradation and may carry molecular signatures associated with specific phenotypes. Herein, we summarize studies investigating EVs as biomarkers in breast cancer and propose scenarios for various clinical applications of EV-based biomarkers in the management of breast cancer. Furthermore, we provide an overview of recent findings regarding the cancer-promoting effects of breast cancer-derived EVs and discuss opportunities for blocking EV-mediated signaling as a therapeutic strategy for breast cancer.

Prognostic relevance of carbonic anhydrase IX expression is distinct in various subtypes of breast cancer and its silencing suppresses self-renewal capacity of breast cancer cells.

PURPOSE: Carbonic anhydrase IX (CAIX) is a hypoxia-inducible enzyme with extracellular catalytic domain that is overexpressed in a variety of cancers including breast cancer and plays a crucial role in maintaining favourable intracellular pH and reducing extracellular pH. The purpose of the current study was to elucidate the prognostic significance of CAIX in the intrinsic subtypes of breast cancer and to characterise CAIX as a drug target in breast cancer. METHODS: The prognostic significance of CAIX mRNA expression was interrogated in a cohort of 3,455 breast tumours by using an online tool, Kaplan-Meier plotter. The functional effects of stable CAIX depletion by shRNA in three breast cancer cell lines­MDA-MB-231, MCF7 and SKBR-3, representing basal-like, luminal A and HER2+ subtypes, respectively­were studied by proliferation, invasion, clonal spheroid formation and chemosensitivity assays under normoxia and hypoxia. Finally, the effect of pharmacological CA inhibition alone or in the combination with doxorubicin on self-renewal was assessed by spheroid-forming assay. RESULTS: High CAIX mRNA expression was significantly associated with poor survival in patients with basal-like, luminal B and triple-negative breast cancer, but not luminal A and HER+ subtypes. Silencing of CAIX expression had no significant effect on the cell proliferation or viability upon treatment with doxorubicin in any of the cell lines studied, while it inhibited spheroid formation in hypoxic conditions. Furthermore, pharmacological inhibition of CAs using acetazolamide had a synergistic effect with doxorubicin on decreasing the spheroid-forming efficiency in MDA-MB-231 cells. CONCLUSIONS: Inhibition of CAIX reduces the self-renewal capacity of breast cancer cells, and the combination of doxorubicin and CAIX inhibition is an attractive therapeutic strategy in basal-like and triple-negative breast cancer, which warrants further investigations.

BRCA1 gene-related hereditary susceptibility to breast and ovarian cancer in Latvia.

PURPOSE: In this report, we summarise data on BRCA1 gene analysis in Latvia to characterise criteria of genetic testing for breast and ovarian cancer susceptibility. MATERIAL/METHODS: Analysis by SSCP/HD, MALDI-TOF mass spectrometry or DNA sequencing was used for mutation detection. Mutations identified were confirmed by direct DNA sequencing. RESULTS: Out of 1068 breast and 231 ovarian cancer patients from different families: 58 carried the c.5266dupC and 43 carried the c.4035delA mutations. Every 4th patient in our study did not report cancer in the family. The breast cancer was diagnosed earlier in carriers of the c.5266dupC than in carriers of the c.4035delA (p=0.003). The incidence of breast or ovarian cancer does not differ among the 2 mutation carriers in our patient group. The nature of the c.5266dupC mutation might be more deleterious. CONCLUSIONS: We recommend the screening of 4 founder BRCA1 mutations in all breast and ovarian cancer patients in Latvia at diagnosis of disease regardless of family history or age. The BRCA1 screening can be carried out efficiently using the MALDI-TOF mass spectrometry mutation detection method developed in the Biomedical Research and Study Centre (Riga, Latvia).

Delays in diagnosis and treatment of breast cancer: a multinational analysis.

BACKGROUND: Reducing treatment delay improves outcomes in breast cancer. The aim of this study was to determine factors influencing patient- and system-related delays in commencing breast cancer treatment in different countries. METHODS: A total of 6588 female breast cancer patients from 12 countries were surveyed. Total delay time was determined as the sum of the patient-related delay time (time between onset of the first symptoms and the first medical visit) and system-related delay time (time between the first medical visit and the start of therapy). RESULTS: The average patient-related delay time and total delay time were 4.7 (range: 3.4-6.2) weeks and 14.4 (range: 11.5-29.4) weeks, respectively. Longer patient-related delay times were associated with distrust and disregard, and shorter patient-related delay times were associated with fear of breast cancer, practicing self-examination, higher education level, being employed, having support from friends and family and living in big cities. The average system-related delay time was 11.1 (range: 8.3-24.7) weeks. Cancer diagnosis made by an oncologist versus another physician, higher education level, older age, family history of female cancers and having a breast lump as the first cancer sign were associated with shorter system-related delay times. Longer patient-related delay times and higher levels of distrust and disregard were predictors of longer system-related delay times. CONCLUSIONS: The delay in diagnosis and treatment of breast cancer remains a serious problem. Several psychological and behavioural patient attributes strongly determine both patient-related delay time and system-related delay time, but their strength is different in particular countries.

Evaluation of the pharmacodynamics and pharmacokinetics of the PARP inhibitor olaparib: a phase I multicentre trial in patients scheduled for elective breast cancer surgery.

Olaparib (AZD2281) is an oral poly(ADP-ribose) polymerase (PARP) inhibitor with antitumour activity in cancer patients with BRCA1/2 germline mutations and in patients with homologous recombination deficiency. In this dose-finding study, patients were randomized to olaparib 10, 30, 100, 200 or 400 mg (capsule formulation) twice daily for the 4-5 days preceding breast cancer surgery. The primary objective was to identify an effective biological dose of olaparib for future trials. Secondary endpoints included evaluation of PARP-1 inhibition dose/exposure-response, and safety. Olaparib plasma pharmacokinetics (PK) and the pharmacodynamics (PD) in tumour and peripheral blood mononuclear cells (PBMCs) were evaluated. Population PK/PD modelling was performed on pooled data from this study and a previously reported study. Sixty patients were randomized (n = 12, each dose). Dose-dependent increases in exposure to olaparib were observed, but at ~50 % lower plasma exposure levels than seen in advanced disease studies. The mean maximal extent of PARP inhibition in PBMCs and tumour tissue was 50.6 % and 70.0 %, respectively, and was similar to inhibitory levels reported previously. No PARP inhibition-dose relationship was observed. Due to the unexpectedly low olaparib exposure, we were unable to determine an effective biological dose. Common adverse events included procedural pain (n = 31 patients), nausea, asthenia, malaise and increased blood creatinine (n = 6, each); these were of mild-to-moderate intensity, and all were manageable. Despite low olaparib exposure, PARP inhibition was consistent with previous reports. Reasons for the inter-study differences in exposure are unclear. The tolerability profile of olaparib was consistent with previous studies.

Prevalence of Helicobacter pylori infection and atrophic gastritis in Latvia.

OBJECTIVES: Helicobacter pylori infection and atrophic gastritis are related to an increased risk for gastric cancer. There is a decrease in global H. pylori prevalence. We analyzed the prevalence of H. pylori infection in Latvia by the plasma IgG test and the presence of atrophy by means of pepsinogen testing. METHODS: This subanalysis was carried out on a randomly selected cross-sectional sample of a general population of adults to access cardiovascular risk factors. Plasma samples were screened for H. pylori IgG (cutoff value 24 U/ml), and pepsinogens (Pg) I and II. Pg cutoff values of PgI/PgII ≤ 3 and PgI ≤ 70 ng/ml were used to assess the prevalence of atrophy of any grade and PgI/PgII ≤ 2 and PgI ≤ 30 ng/ml for advanced atrophy. RESULTS: Altogether, 3564 serum samples were available for the study (2346 women, 1218 men; median age 54 years). Of the tested individuals, 79.21% were H. pylori positive, with no difference between sexes. The prevalence increased with age (P<0.001). Atrophy of any grade was identified in 1444 individuals (40.52%) and advanced atrophy in 475 individuals (13.33%). Linear association with age was present in both response types (P<0.001). The prevalence of atrophy of any grade was higher in women (41.73%) than in men (38.18%; P=0.04); this difference was lost for advanced atrophy (women 13.98%, men 12.07%; P=0.1). CONCLUSION: The prevalence of H. pylori infection or atrophy remains high in Latvia. Determining the right cutoff value is critically important for pepsinogen-based atrophy detection in Europe in order to objectively stratify gastric cancer risk.

High prevalence of two BRCA1 mutations, 4154delA and 5382insC, in Latvia.

Our aim was to characterise the germline BRCA1 mutation profile in Latvian breast cancer and ovarian cancer patients, to develop an effective BRCA1 gene mutation detection strategy, and to document genotype-phenotype correlations in mutation carriers. The entire BRCA1 gene was analysed in 75 breast cancer and 30 ovarian cancer patients. Screening for three mutations (5382insC, 4154delA and 300T>G) was carried out in 55 breast cancer and 66 ovarian cancer patients, and for two mutations, 5382insC and 4154delA, in 376 unselected patients with any cancer (including 51 breast cancer and 29 ovarian cancers) and 215 women with any gynaecological tumour. Mutation detection techniques used were SSCP/HD analysis or F-SSCP (ABI PRISM 310). Five different deleterious mutations were detected by analysis of the entire BRCA1 gene. The proportion of cases with mutations amongst 50 breast cancer patients diagnosed before 48 years was 26.0% (95% CI: 14.6-40.3%). Two mutations (5382insC and 4154delA) made up more than 80% of all mutations identified by the analysis of the entire BRCA1 gene in Latvia, at present. Further screening for only the prevalent mutations in different cancer patient groups resulted in the identification of 53 more mutation carriers. We conclude that breast cancer diagnosed before the age of 48 years and ovarian cancer before 65 years are criteria for DNA testing to be offered to women in Latvia, regardless of cancer history in the family. The observed associations of specific prevalent mutations with cancer site and age at onset of disease are discussed.