Sex Hormones and Iron-Related Biomarkers Associate with EMT Features and Tumor Stage in Colorectal Cancer: A Serum- and Tissue-Based Analysis

Sex steroid hormones and systemic iron metabolism are emerging as modulators of colorectal cancer (CRC) development and progression. However, information linking systemic factors to tumor characteristics and epithelial–mesenchymal transition (EMT) is limited, particularly in a sex-specific context. We measured serum levels of sex hormones [testosterone, estradiol, progesterone, Luteinizing Hormone (LH), Follicle-Stimulating Hormone (FSH), Carcinoembryonic antigen (CEA)] and iron-related biomarkers (iron, transferrin, ferritin, % transferrin saturation, ceruloplasmin, and the ceruloplasmin/transferrin ratio) in 82 CRC patients and 31 healthy controls. EMT-related proteins [mediator of ErbB2-driven cell motility 1 (MEMO1), E-cadherin, fibronectin, vimentin, and vinculin] were quantified by Western blotting in tumor and adjacent normal mucosa. Non-parametric tests and Spearman correlations were applied, stratified by sex and corrected for age and anemia where appropriate. Progesterone levels were significantly lower in male CRC patients (median 0.17 ng/mL vs. 0.20 ng/mL, p = 0.04) and higher in female patients (0.17 ng/mL vs. 0.10 ng/mL, p = 0.0077) compared with controls. The iron-related biomarkers indicated a pattern of iron deficiency, including in non-anemic patients, with reduced % transferrin saturation (p < 0.01) and an elevated ceruloplasmin/transferrin ratio (p = 0.02). Correlations were found between iron status, tumor stage, and hormonal levels. Progesterone correlated with EMT protein expression in healthy mucosa (e.g., fibronectin in females: ρ = 0.567, p = 0.014; vimentin in males: ρ = −0.446, p = 0.007), but not in tumor tissue. In the healthy mucosa of male patients, ceruloplasmin/transferrin correlated with MEMO1 (ρ = 0.419, p = 0.04), vinculin (ρ = 0.299, p = 0.041), and vimentin (ρ = 0.394, p = 0.07); transferrin levels inversely correlated with MEMO1 expression (ρ = −0.392, p = 0.032), and vimentin showed a positive correlation with serum iron (ρ = 0.350, p = 0.043). Furthermore, fibronectin expression inversely correlated with iron in the sole tumor tissue of female patients (ρ = −0.366, p = 0.040). These findings support the role of sex hormones and iron metabolism in CRC biology, suggesting that EMT might be accompanied by altered iron uptake and redox remodeling, which can enhance cellular motility and the metastatic potential.