Browsing by Author "Miklaševičs, Edvins"

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    Challenges in the management of a patient with Cowden syndrome : Case report and literature review
    (2012-04-14) Melbarde-Gorkuša, Inga; Irmejs, Arvids; Berziņa, Dace; Štrumfa, Ilze; Aboliņš, Arnis; Gardovskis, Andris; Subatniece, Signe; Trofimovičs, Genadijs; Gardovskis, Janis; Miklaševičs, Edvins; Pārmantotā vēža pētniecības nodaļa
    We would like to present a patient with a classical phenotype of a rare disorder - Cowden syndrome, its diagnostics and management challenges. A breast surgeon has to be aware of this rare condition when treating a patient with breast manifestations of Cowden syndrome and has to refer the patient to a clinical geneticist for further evaluation. Sequencing of the PTEN gene showed the Asp24Gly mutation. According to the latest literature data, the lifetime risk of breast cancer for Cowden syndrome patients is 81% and surgery is a justified option to reduce the risk of breast cancer. Bilateral risk-reducing mastectomy with immediate reconstruction was performed to eliminate further risk of breast cancer. 3 years after the risk-reducing breast surgery the patient is satisfied with the outcome. This is to our best knowledge the first reported Cowden syndrome case with follow-up data after risk-reducing measures have been taken.
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    Cumulative Small Effect Genetic Markers and the Risk of Colorectal Cancer in Poland, Estonia, Lithuania, and Latvia
    (2015) Serrano-Fernandez, Pablo; Dymerska, Dagmara; Kurzawski, Grzegorz; Derkacz, Róza; Sobieszczańska, Tatiana; Banaszkiewicz, Zbigniew; Roomere, Hanno; Oitmaa, Eneli; Metspalu, Andres; Janavičius, Ramunas; Elsakov, Pavel; Razumas, Mindaugas; Petrulis, Kestutis; Irmejs, Arvids; Miklaševičs, Edvins; Scott, Rodney J.; Lubiński, Jan; Rīga Stradiņš University
    The continued identification of new low-penetrance genetic variants for colorectal cancer (CRC) raises the question of their potential cumulative effect among compound carriers. We focused on 6 SNPs (rs380284, rs4464148, rs4779584, rs4939827, rs6983267, and rs10795668), already described as risk markers, and tested their possible independent and combined contribution to CRC predisposition. Material and Methods. DNA was collected and genotyped from 2330 unselected consecutive CRC cases and controls from Estonia (166 cases and controls), Latvia (81 cases and controls), Lithuania (123 cases and controls), and Poland (795 cases and controls). Results. Beyond individual effects, the analysis revealed statistically significant linear cumulative effects for these 6 markers for all samples except of the Latvian one (corrected P value = 0.018 for the Estonian, corrected P value = 0.0034 for the Lithuanian, and corrected P value = 0.0076 for the Polish sample). Conclusions. The significant linear cumulative effects demonstrated here support the idea of using sets of low-risk markers for delimiting new groups with high-risk of CRC in clinical practice that are not carriers of the usual CRC high-risk markers.
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    Effectiveness of Secondary Risk–Reducing Strategies in Patients with Unilateral Breast Cancer with Pathogenic Variants of BRCA1 and BRCA2 Subjected to Breast-Conserving Surgery : Evidence-Based Simulation Study
    (2022-12) Maksimenko, Jelena; Rodrigues, Pedro Pereira; Nakazawa-Miklaševiča, Miki; Pinto, David; Miklaševičs, Edvins; Trofimovičs, Genadijs; Gardovskis, Jānis; Cardoso, Fatima; Cardoso, Maria João; Department of Surgery; Onkoloģijas institūts; Faculty of Medicine
    Background: Approximately 62% of patients with breast cancer with a pathogenic variant (BRCA1 or BRCA2) undergo primary breast-conserving therapy. Objective: The study aims to develop a personalized risk management decision support tool for carriers of a pathogenic variant (BRCA1 or BRCA2) who underwent breast-conserving therapy for unilateral early-stage breast cancer. Methods: We developed a Bayesian network model of a hypothetical cohort of carriers of BRCA1 or BRCA2 diagnosed with stage I/II unilateral breast cancer and treated with breast-conserving treatment who underwent subsequent second primary cancer risk–reducing strategies. Using event dependencies structured according to expert knowledge and conditional probabilities obtained from published evidence, we predicted the 40-year overall survival rate of different risk-reducing strategies for 144 cohorts of women defined by the type of pathogenic variants (BRCA1 or BRCA2), age at primary breast cancer diagnosis, breast cancer subtype, stage of primary breast cancer, and presence or absence of adjuvant chemotherapy. Results: Absence of adjuvant chemotherapy was the most powerful factor that was linked to a dramatic decline in survival. There was a negligible decline in the mortality in patients with triple-negative breast cancer, who received no chemotherapy and underwent any secondary risk–reducing strategy, compared with surveillance. The potential survival benefit from any risk-reducing strategy was more modest in patients with triple-negative breast cancer who received chemotherapy compared with patients with luminal breast cancer. However, most patients with triple-negative breast cancer in stage I benefited from bilateral risk-reducing mastectomy and risk-reducing salpingo-oophorectomy or just risk-reducing salpingo-oophorectomy. Most patients with luminal stage I/II unilateral breast cancer benefited from bilateral risk-reducing mastectomy and risk-reducing salpingo-oophorectomy. The impact of risk-reducing salpingo-oophorectomy in patients with luminal breast cancer in stage I/II increased with age. Most older patients with the BRCA1 and BRCA2 pathogenic variants in exons 12-24/25 with luminal breast cancer may gain a similar survival benefit from other risk-reducing strategies or surveillance. Conclusions: Our study showed that it is mandatory to consider the complex interplay between the types of BRCA1 and BRCA2 pathogenic variants, age at primary breast cancer diagnosis, breast cancer subtype and stage, and received systemic treatment. As no prospective study results are available at the moment, our simulation model, which will integrate a decision support system in the near future, could facilitate the conversation between the health care provider and patient and help to weigh all the options for risk-reducing strategies leading to a more balanced decision.
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    Epidemiologic, clinical, and molecular characteristics of hereditary prostate cancer in Latvia
    (2011) Abele, Andris; Vjaters, Egils; Irmejs, Arvids; Trofimovičs, Genadijs; Miklaševičs, Edvins; Gardovskis, Janis; Onkoloģijas institūts
    Background and Objective. Prostate cancer is one of the most commonly diagnosed malignancy affecting men in Latvia. The aim of this study was to evaluate the epidemiological features and molecular basis of hereditary prostate cancer in Latvia. Material and Methods. A total of 1217 newly diagnosed prostate cancer patients were recruited in our study. Data were analyzed according to clinical diagnostic criteria for hereditary prostate cancer. Molecular testing for the founder mutation 657del5 of the NBS1 gene was performed for the first 280 prostate cancer patients and 173 control cases, and for the founder mutations 300T/G, 4153delA, and 5382insC of the BRCA1 gene for 112 prostate cancer patients with a history of breast or ovarian cancer in their families. Results. Of the 1217 families, 14 (1.2%; 95% CI, 0.7%-1.9%) matched clinical diagnostic criteria for definitive hereditary prostate cancer, and of the 1217 families, 196 (16.1%; 95% CI, 14.1%-18.3%) for suspected hereditary prostate cancer. The founder mutation of the NBS1 gene was detected in 1 (0.4%, 95% CI, 0.1%-2.0%) of the 280 cases in the prostate cancer group and in 1 (0.6%; 95% CI, 0.1%-3.2%) of the 173 cases in the control group. The mutation 5382insC of the BRCA1 gene was detected in 2 (1.8%; 95% CI, 0.5%-6.3%) of the 112 cases analyzed in the prostate cancer group. No other BRCA1 founder mutations were detected. Conclusions. Our study did not reveal predisposition genes for hereditary prostate cancer as the founder mutations of the BRCA1 and NBS1 genes are rarely detected in Latvia, but showed the importance of evaluation risk individually as a positive family history of cancer was associated with the earlier onset of prostate cancer.
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    High expression of miR-214 is associated with a worse disease-specific survival of the triple-negative breast cancer patients
    (2015-02-08) Kalniete, Dagnija; Nakazawa-Miklaševiča, Miki; Štrumfa, Ilze; Abolinš, Arnis; Irmejs, Arvids; Gardovskis, Janis; Miklaševičs, Edvins; Onkoloģijas institūts; Rīga Stradiņš University
    Background: Hereditary triple-negative breast cancer patients have better recurrence-free survival than triple-negative sporadic ones. High expression of some of the miRNAs is related to worse overall and disease-free survival of triple-negative breast cancer patients. The attempt to associate expression level of some miRNA in triple-negative hereditary and sporadic breast cancers to disease specific survival was performed in this study. Material and methods: Study group was made of 18 triple-negative breast cancer patients harboring the BRCA1 gene mutations and 32 triple-negative sporadic breast cancer patients. Quantitative amount of mir-10b, mir-21, mir-29a, mir-31, and mir-214 by real-time PCR was assessed. The disease-specific survival in relation of high and low levels of some of the miRNAs was analyzed using Log-rank (Mantel-Cox) test. Results: MiR-214 showed significantly higher expression level in sporadic tissues than in hereditary ones (p=0.0005). Triple-negative breast cancer patients with high level of miR-214 showed significantly worse disease-specific survival than patients with low level (p=0.0314). Conclusions: Our finding suggests that miR-214 possibly could be used as a potential prognostic biomarker for triple-negative breast cancer patients.
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    Population screening for hereditary and familial cancer syndromes in Valka district of Latvia
    (2010-10-29) Vanags, Andrejs; Štrumfa, Ilze; Gardovskis, Andris; Borošenko, Viktors; Aboliņš, Arnis; Teibe, Uldis; Trofimovičs, Genadijs; Miklaševičs, Edvins; Gardovskis, Janis; Pārmantotā vēža pētniecības nodaļa
    Background: The growing possibilities of cancer prevention and treatment as well as the increasing knowledge about hereditary cancers require proper identification of the persons at risk. The aim of this study was to test the outcome of population screening in the scientific and practical evaluation of hereditary cancer.Methods: Population screening for hereditary cancer was carried out retrospectively in a geographic area of Latvia. Family cancer histories were collected from 18642 adults representing 76.6% of the population of this area. Hereditary cancer syndromes were diagnosed clinically. Molecular testing for BRCA1 founder mutations 300 T/G, 4153delA and 5382insC was conducted in 588 persons who reported at least one case of breast or ovary cancer among blood relatives.Results: Clinically, 74 (0.40%; 95% confidence interval (CI): 0.32 - 0.50%) high-risk and 548 (2.94%, 95% CI: 2.71 - 3.19) moderate-risk hereditary cancer syndromes were detected covering wide cancer spectrum. All syndromes were characterised by high cancer frequency among blood relatives ranging 8.6 - 46.2% in contrast to spouse correlation of 2.5 - 3.6%. The mean age of cancer onset ranged 38.0 - 72.0 years in different syndromes. The BRCA1 gene mutations were identified in 10 (1.7%; 95% CI: 0.9 - 3.1%) probands. Families with established BRCA1 gene founder mutations were identified with the frequency 1:2663 clinically screened persons.Conclusions: Population screening is a useful practical tool for the identification of persons belonging to families with high frequency of malignant tumours. The whole hereditary and familial cancer spectrum along with the age structure was identified adjusting follow-up guidelines. Another benefit of the population screening is the possibility to identify oncologically healthy persons belonging to hereditary and familial cancer families so that appropriate surveillance can be offered. Clinical diagnostics is appropriate for population screening purposes; molecular investigation provides additional information. In collaboration with family doctors, the screening is technically manageable as characterised by high compliance.
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    Presence of methicillin-resistant Staphylococcus aureus in slaughterhouse environment, pigs, carcasses, and workers
    (2017-09) Ivbule, Meldra; Miklaševičs, Edvins; Čupane, Liene; Berziņa, Laima; Balinš, Andris; Valdovska, Anda; Onkoloģijas institūts
    Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is a highly resistant and difficult to cure zoonotic microorganism, which makes up a large part of food toxic infections and has shown high prevalence among pig population all over the world. The aim of the study was to establish the occurrence of MRSA in slaughterhouses, evaluate its antimicrobial resistance, and verify whether there are any differences or similarities with reference to other European countries. Material and Methods: A total of 100 pigs, 105 carcasses, 19 workers, and 24 samples from the environment of several slaughterhouses were examined by conventional microbial and molecular methods. Results: In total, 78 MRSA isolates were found. MRSA prevalence in slaughtered pigs varied from 8.0% to 88.6% depending on the slaughterhouse, reaching higher prevalence in slaughterhouses with higher slaughter capacity. In total, 21.1% of all workers were carriers of MRSA and 6.7% of carcasses were contaminated with MRSA. The 98.2% of MRSA isolates were resistant to penicillin, 89.1% to tetracycline, 60.1% to erythromycin, 65.5% to gentamycin, and 15 different spa types were found, among which spa type t01333 was most widespread. Conclusion: The study indicated that MRSA prevalence and spa types differed according to slaughterhouse slaughter capacity and good hygiene practices. Quite high MRSA occurrence among slaughterhouse workers is one of the main factors which increase pork contamination risk.