PRISMA 2020 checklist.

<div><p>Background</p><p>Osteosarcoma (OSC) is considered one of the most common malignant bone tumours in adolescents. Due to OSC’s poor prognosis, a comprehensive approach to exploring these aspects is highly needed to improve the survival probability of OSC. In this study, we tried to explore the significance of miRNA-encoded PTEN for clinical-pathological features and prognostic value in OSC.</p><p>Method</p><p>We performed this systematic review and meta-analysis using articles and sources published between 2013 and 2023 from six databases (Scopus, PubMed, ProQuest, Science Direct, Sage Pub, and Cochrane). Included studies were clinical cross-sectional studies. Other study designs, articles not written in English, without full text, and not relevant—were excluded. Then, ROBINS-I is used to evaluate the distance. The results are constructed according to the PICOS criteria in a table. The expression of miRNA related to OSC is assessed in the meta-analysis as the main outcome to determine its ability as a diagnostic and prognostic agent for OSC. This systematic review followed the PRISMA guidelines.</p><p>Results</p><p>A total of 17 studies were included in the final screening. The meta-analysis showed significantly increased (p < 0.00001) miRNA expression in patients with OSC compared to healthy controlled with pooled md (2.85) (95% CI: 2.69, 3.02; I<sup>2</sup> = 22%, p = 0.20), the high inverse correlation (p < 0.001) between miRNA and PTEN expression was shown as mean effect size (-0.681) (95% CI: -0.787, -0.536; I<sup>2</sup> = 75%, p < 0.0001), and the prognostic evaluation of OS was significantly increased in low expression miRNA (p < 0.00001) with pooled OR.</p><p>Conclusion</p><p>Fifteen miRNAs from 17 studies were found, and together with PTEN expression, they may serve as potential prognostic biomarkers for OSC. High-level levels of miRNA expression are correlated with low PTEN expression, leading to a bad prognosis for OSC.</p></div>