Search Results (4)

This study aimed at analyzing the DNA methylation pattern and TP53 mutation status of intrinsic breast cancer (BC) subtypes for improved characterization and survival prediction. DNA methylation of 17 genes was tested by methylation-specific PCR in 116 non-familial BRCA mutation-negative BC and 29 control noncancerous cases. At least one gene methylation was detected in all BC specimens and a 10-gene panel statistically significantly separated tumors from noncancerous breast tissues. Methylation of FILIP1L and MT1E was predominant in triple-negative (TN) BC, while other BC subtypes were characterized by RASSF1, PRKCB, MT1G, APC, and RUNX3 hypermethylation. TP53 mutation (TP53-mut) was found in 38% of sequenced samples and mainly affected TN BC cases (87%). Cox analysis revealed that TN status, age at diagnosis, and RUNX3 methylation are independent prognostic factors for overall survival (OS) in BC. The combinations of methylated biomarkers, RUNX3 with MT1E or FILIP1L, were also predictive for shorter OS, whereas methylated FILIP1L was predictive of a poor outcome in the TP53-mut subgroup. Therefore, DNA methylation patterns of specific genes significantly separate BC from noncancerous breast tissues and distinguishes TN cases from non-TN BC, whereas the combination of two-to-three epigenetic biomarkers can be an informative tool for BC outcome predictions. Full article

The pandemic spread of the COVID-19 virus significantly affected daily life, but the highest pressure was piled on the health care system. Our aim was to evaluate an impact of COVID-19 pandemic management measures on cancer services at the National Cancer Institute (NCI) of Lithuania. We assessed the time period from 1 February 2020 to 31 December 2020 and compared it to the same period of 2019. Data for our analysis were extracted from the NCI Hospital Information System (HIS) and the National Health Insurance Fund (NHIF). Contingency table analysis and ANOVA were performed. The COVID-19 pandemic negatively affected the cancer services provided by NCI. Reductions in diagnostic radiology (−16%) and endoscopy (−29%) procedures were accompanied by a decreased number of patients with ongoing medical (−30%), radiation (−6%) or surgical (−10%) treatment. The changes in the number of newly diagnosed cancer patients were dependent on tumor type and disease stage, showing a rise in advanced disease at diagnosis already during the early period of the first lockdown. The extent of out-patient consultations (−14%) and disease follow-up visits (−16%) was also affected by the pandemic, and only referrals to psychological/psychiatric counselling were increased. Additionally, the COVID-19 pandemic had an impact on the structure of cancer services by fostering the application of modified systemic anticancer therapy or hypofractionated radiotherapy. The most dramatic drop occurred in the number of patients participating in cancer prevention programs; the loss was 25% for colon cancer and 62% for breast cancer screening. Marked restriction in access to preventive cancer screening and overall reduction of the whole spectrum of cancer services may negatively affect cancer survival measures in the nearest future. Full article

Background and Objectives: The purpose of this study is to evaluate the level of oxidative stress before and after breast cancer surgery. Materials and Methods: Malondialdehyde (MDA) level was tested using a thiobarbituric acid (TBA) assay based on the release of a color complex due to TBA reaction with MDA. The glutathione S-transferase (GST) activity was evaluated by enzymatic conjugation of reduced glutathione (GSH) with 1-chloro-2,4-dinitrobenzene. The level of total glutathione (reduced GSH and oxidized GSSG) was detected using a recycling system by 5,5-dithiobis(2-nitrobenzoic acid). The levels of the indices were determined in the serum of 52 patients before surgery, two hours and five days after surgery, and in 42 healthy women. Results: In the patients over 50 years old the level of MDA was higher after surgery in comparison with before surgery, and GST activity was lower in comparison with the control. The GSH + GSSG level in both ages groups after surgery was lower than in the control. Significant differences of MDA level were detected in patients with stage III after surgery compared to the control. The level of GSH + GSSG was significantly lower in the patients with I–III stages compared to the control. Conclusion: The most expressed changes demonstrate the significance of MDA as a marker to evaluate oxidative stress in breast cancer patients. The degree of oxidative stress depends on the patient’s age and stage of disease. (1) Malondialdehyde can be used as an oxidative stress marker; (2) A higher stage of the disease and older age correspond to a higher rise of malondialdehyde, suggesting more intensive oxidative stress. Full article

Background and Objective. Breast cancer is the leading cause of death from cancer among women worldwide. The aberrant promoter methylation of tumor suppressor genes is a typical epigenetic alteration for breast cancer and can be detected in early carcinogenesis. High-throughput and cost-effective methods are needed for the early and sensitive detection of epigenetic changes in clinical material. The main purpose of our study was to optimize a high-resolution melting (HRM) assay for the reliable and quantitative assessment of RASSF1 gene methylation, which is considered one of the earliest epigenetic alterations in breast cancer.
Material and Methods. A total of 76 breast carcinomas and 10 noncancerous breast tissues were studied by means of HRM and compared with the results obtained by means of quantitative methylation-specific polymerase chain reaction (QMSP) and methylation-specific polymerase chain reaction (MSP).
Results. Both quantitative methods, HRM and QMSP, showed a similar specificity and sensitivity for the detection of RASSF1 methylation in breast cancer (about 80% and 70%, respectively). In breast cancer, the mean methylation intensity of RASSF1 was 42.5% and 48.6% according to HRM and QMSP, respectively. Both methods detected low levels of methylation (less than 5%) in noncancerous breast tissues. In comparison with quantitative methods, MSP showed a lower sensitivity (70%), but a higher specificity (80%) for the detection of RASSF1 methylation in breast cancer.
Conclusions. HRM is as a simple, cost-effective method for the reliable high-throughput quantification of DNA methylation in clinical material. Full article