Circulating tumor cells: a valuable indicator for locally advanced nasopharyngeal carcinoma

Background Advancements in nasopharyngeal carcinoma (NPC) treatment have led to a focus on personalized treatment. Circulating tumor cells (CTCs) are important for liquid biopsies and personalized treatment but are not being fully utilized. This study examined how pre- and post-treatment CTC counts, EMT subtypes, clinical characteristics, and patient prognosis are related in order to support the use of liquid biopsy in managing NPC. Methods This retrospective study included 141 patients with locally advanced NPC. All patients underwent CanPatrol (TM) CTC detection pre- and post-treatment and were categorized into EMT subtypes: epithelial type, mixed type, and mesenchymal type. This study analyzed CTC enumeration, EMT subtypes, and their associations with clinical characteristics and survival outcomes. Results The results indicated a positive correlation between the pre-treatment detection rate of CTCs and N stage (P < 0.01), alongside a positive correlation with the TNM clinical stage (P = 0.02). Additionally, the detection rate of mesenchymal CTCs post-treatment is positively associated with the N stage (P = 0.02). The enumeration of CTCs pre- and post-treatment is negatively correlated with prognosis and has statistical significance. Additionally, an investigation into the EMT subtypes of CTCs revealed a significant association between the presence of mesenchymal CTCs pre- and post-treatment and decreased overall survival (OS) (P < 0.05). Furthermore, T stage, N stage, TNM clinical stage, and Epstein-Barr virus (EBV) DNA were also significantly correlated with OS. Conclusion The study found that mesenchymal CTCs pre- and post-treatment, as well as the number of CTCs, were linked to a poor prognosis.