Tracking tumor biology in real time: circulating tumor cells in laryngopharyngeal carcinoma

Background Laryngopharyngeal squamous cell carcinoma (LPSCC), a subset of head and neck malignancies, reveals different clinical outcomes despite similar staging. Circulating tumor cells (CTCs) have emerged as one of the important and promising minimally invasive biomarkers for disease management; however, their clinical utility in LPSCC remains unclear, particularly in resource-limited settings. Methods This prospective observational study was conducted at the State Cancer Institute, a part of a tertiary cancer hospital center in the northernmost region of India, from June 2021 to March 2026. Peripheral blood samples were collected at baseline (n=30) and at 3-month follow-up. The 3-month interval was chosen to assess short-term changes in the study parameters. All enrolled subjects continue to remain under follow-up beyond this period, and data collection is ongoing to capture longer-term outcomes. CTCs were detected and quantified using an EpCAM-based enrichment method with immunofluorescence markers. Associations between CTC counts, clinicopathological variables, treatment response, and disease outcomes were analyzed. Results Baseline CTCs were detected in 53% of patients, with the majority of the demographic and clinical variables showing insignificant associations with CTC positivity (all P >0.05). At 3 months, 94% of evaluable patients achieved a complete response, while CTC progression was noted in 56% (9/16). P = 0.049). CTC dynamics did not correlate significantly with treatment response or survival outcomes. Nodal involvement, rather than CTC burden, emerged as a stronger predictor of prognosis. At 3 years, overall survival (OS) was 69.0% for the cohort, with no significant difference by CTC status (76.9% vs. 62.5%, P = 0.507); however, nodal involvement was strongly associated with poorer OS (90.0% vs. 22.2%, P = 0.0001). Cancer-specific OS at 3 years was 81.2%, with significantly worse outcomes in patients with CTCs, 68.8% vs. 100% ( P = 0.049). Conclusion CTCs were detectable across both early and locally advanced LPSCC. Although dynamic changes in CTCs were noted, their prognostic significance remains unclear. Larger longitudinal studies are required to validate CTCs as biomarkers and to explore their role in personalized management of LPSCC.