Elevated Circulating Extracellular Vesicles as Prognostic Biomarkers in Cervical Cancer Progression

Introduction: Cervical cancer ranks among the leading cancers in women worldwide, with mortality disproportionately affecting low- and middle-income countries. Traditional diagnostic and prognostic tools have limited sensitivity and specificity, and accessibility challenges, underscoring the need for innovative biomarkers. Recent findings suggest that extracellular vesicles (EVs), released by both tumor and immune cells, may reflect the disease state and serve as minimally invasive biomarkers. This study investigates circulating EVs and their potential role as biomarkers in cervical cancer. Objective: To evaluate the levels and cellular origins of circulating EVs in cervical cancer patients across different clinical stages and outcomes, assessing their potential as diagnostic and prognostic biomarkers. Methods: In this study, we analyzed 96 cervical cancer patients and 31 healthy controls. Peripheral blood samples were processed to isolate and quantify EVs, followed by immunophenotyping using flow cytometry. Specific markers identified EVs originating from neutrophils, lymphocytes, platelets, and endothelial cells. Comparative analyses were conducted to assess EV profiles in relation to clinical stages and patient outcomes. Statistical significance was set at p < 0.05. Machine learning approaches were employed to assess EV performance. Results: Circulating EV levels were significantly elevated in cervical cancer patients compared to healthy controls (p < 0.01). Immunophenotyping revealed marked increases in EVs derived from neutrophils (CD66⁺, CD16⁺), T lymphocytes (CD3⁺), leukocytes (CD45⁺), platelets (CD41a⁺), and endothelial cells (CD51/CD61⁺), all of which were highly significant (p < 0.0001). Monocyte-derived EVs (CD14⁺) and erythrocyte-derived EVs (CD235a⁺) were also significantly elevated (p < 0.01 and p < 0.001, respectively). When stratified by survival outcomes at 8 months post-treatment, responders exhibited a more pronounced elevation in erythrocyte-derived EVs compared to non-responders and deceased patients (p = 0.0002), suggesting a potential association with improved outcomes. Total EV levels were significantly higher in advanced-stage patients (Stages III and IV) than in controls (p < 0.05), but not in early-stage patients (Stages I and II). However, EVs derived from specific cell types were significantly increased in both early and advanced stages (all p < 0.05), with no significant differences between the stages, indicating a consistent elevation regardless of disease progression. Regarding histopathological grades, total EV levels were significantly elevated in patients with Grade I and Grade III tumors (both p < 0.05) but not in those with Grade II tumors. Cell-specific EV elevations were observed across all grades, though with some variations; for instance, monocyte-derived EVs were significantly elevated in Grades I and III (both p < 0.05) but not in Grade II. These findings highlight that while elevated EV levels are a hallmark of cervical cancer, specific EV subtypes may have distinct associations with clinical stages, histopathological grades, and patient outcomes. This underscores their potential utility as diagnostic and prognostic biomarkers. Conclusions: This study highlights the potential of circulating EVs as non-invasive biomarkers for cervical cancer, with distinct EV profiles associated with disease severity and prognosis. These findings suggest that EV analysis could aid in stratifying patients by risk, enhancing personalized treatment strategies. Future research should explore the molecular cargo within EVs to further elucidate their role in tumor biology and as therapeutic targets.