Circulating tumor cells as key biomarkers for risk assessment and diagnosis of malignant salivary gland tumors

Malignant salivary gland tumors are rare but aggressive cancers with high rates of recurrence and metastasis. Early detection of circulating tumor cells (CTC) offers a promising approach to monitor tumor progression and metastasis. The purpose of this study was to evaluate the clinical significance of detecting circulating tumor cells in patients with malignant salivary gland tumors and to investigate the correlation between the presence of CTC and tumor histology and key molecular markers such as Ki67, CK7, CK5/6, and P63. Peripheral blood samples were obtained from 171 participants and CTCs were isolated using negative immunomagnetic enrichment and detected by fluorescence in situ hybridization (FISH). CTCs were identified in 63.8% of patients with malignant tumors, 22.9% of those with benign tumors, and none of the healthy controls. In addition, the presence of CTCs showed a significant correlation with high expression levels of Ki67, CK7, and P63, particularly in carcinoma ex pleomorphic adenoma (CXPA) and mucoepidermoid carcinoma (MEC). These findings indicate that CTC detection is a valuable tool for evaluating the aggressiveness and metastatic potential of malignant salivary gland tumors, underlining its potential clinical application as a prognostic biomarker. • Detect circulating tumor cells (CTCs) in 63.8% of malignant salivary tumors. • Identify CXPA and MEC as subtypes with the highest CTC detection rates. • Correlate CTC positivity with high Ki67, CK7, and P63 expression levels. • Demonstrate Ki67 as the most significant marker associated with CTCs. • Establish CTC detection as an indicator of tumor aggressiveness and metastasis.