Abstract 417P
Background
Emerging evidence highlights the key role of microRNA (miR)-21 in cell-to-cell communication and tumorigenesis. Limited knowledge exists on the expression and clinical meaning of miR-21 in extracellular vesicles (EVs) of breast cancer (BC) patients. Thus, the aim of this study has been to assess EV-derived miR-21 expression in different BC subsets.
Methods
One hundred women were enrolled: 30 with early BC, 30 with metastatic BC on treatment progression, 30 cancer survivors on follow up and 10 healthy controls matched for age and BMI. EVs, isolated from serum samples, were characterized by nanoparticle tracking analyzer (NTA), scanning electron microscopy (SEM) and atomic force microscopy (AFM) to detect their concentration, size and structure. The miR-21 in EVs was evaluated by Real Time PCR. The expression of miR-21 was compared between groups by calculating the ΔΔCt statistic and the fold change, considering miR-16 as the housekeeping gene. The ΔΔCt was calculated using a linear mixed model approach with gene x group interaction as the parameter of interest, adjusting for age, BMI and menopausal status, and considering random intercept and random slope terms to account for individual variability.
Results
No differences in EVs size and concentration among the four groups were detected. Considering the early BC group, the clinical stage at diagnosis and tumor subtype did not influence miR-21 expression. Higher expression of miR-21 has been found in metastatic versus healthy controls (p= 0.029 95% CI -1.549 to -0.079), mainly in HER2+ and hormone receptor positive patients (p 0.0005 and 0.036, respectively). In particular, in HER2+ miR-21 was significantly higher in patients with active BC (early and metastatic) (p 0.002 95% CI -1,707 to -0,376) compared to control group.
Conclusions
While further investigations shall be requested, our data on serum EV suggest that miR-21 may become a promising biomarker for early diagnosis and tumor activity, mainly in HER2+ BC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Claudia Omarini.
Funding
MIUR Dipartimenti Eccellenti 2022.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
383P - Clinical experience with TTX-MC138: A first-in-class therapy against metastatic cancer
Presenter: Andreas Varkaris
Session: Poster session 15
385P - A phase II study of nivolumab, ipilimumab plus bicalutamide in metastatic breast cancer
Presenter: David Page
Session: Poster session 15
388P - Anlotinib or bevacizumab combined with chemotherapy for the second-line HER-2 negative metastatic breast cancer: A retrospective cohort study
Presenter: jin xiang
Session: Poster session 15
390P - SARELIFE: An Italian, multicentric real-world study of sacituzumab govitecan (SG) in pretreated metastatic triple-negative breast cancer (mTNBC)
Presenter: Maria Cona
Session: Poster session 15
391P - Real-world activity of sacituzumab govitecan for metastatic breast cancer
Presenter: Stefania Morganti
Session: Poster session 15
392P - Quality-adjusted time without symptoms of disease progression or toxicity of treatment (Q-TWiST) analysis to assess benefit-risk of sacituzumab govitecan (SG) in previously treated patients (pts) with metastatic triple-negative breast cancer (mTNBC)
Presenter: Adam Brufsky
Session: Poster session 15