Abstract
BACKGROUND: Genomic techniques and the evaluation of epigenetic and proteomic alterations are increasingly used to predict breast tumors' behavior and histopathological patterns. While some studies have linked PTEN and HES1 gene expression to tumor aggressiveness and metastatic behavior, others have not confirmed these associations. This study aimed to assess PTEN and HES1 gene expression in breast cancer lesions and explore their relationship with tumor morphological features and behavior. METHODS: This cross-sectional study involved 50 women with breast cancer. Tumor and adjacent normal breast tissue (50 each) were collected to assess PTEN and HES1 gene expression using Real-Time PCR. RNA extraction was performed using the Trizol method, followed by cDNA synthesis. Gene expression changes were quantified using the ΔΔCT method. Statistical analysis was conducted using SPSS version 23.0, with significance set at p ≤ 0.05. RESULTS: PTEN down-regulation was observed in 70.0%, and HES1 up-regulation in 98.0% of cases. No significant association was found between PTEN down-regulation and tumor-related characteristics, except for a significantly higher mean age in patients with down-regulated PTEN (p = 0.003). HES1 expression intensity, with a mean fold change of 6.193 (median: 4.560, SD: 5.116), showed no significant relationship with any histopathological features or invasive behavior. CONCLUSION: Older patients showed reduced PTEN expression. Additionally, elevated HES1 was identified in 98% of patients and lower PTEN in 70%. However, these gene alterations do not seem to reliably predict aggressive tumor behavior in our population, possibly due to the limited sample size. Further studies with long-term follow-up are needed to fully evaluate the prognostic significance of these markers.