Measurement of circulating tumor cells in squamous cell carcinoma of the head and neck and patient outcomes

Objectives: We report the outcomes of patients with squamous cell carcinoma of the head and neck (HNSCC) whose circulating tumor cells (CTCs) were quantified using surface-enhanced Raman scattering (SERS) nanotechnology. Methods: SERS tagged with EGF was used to directly measure targeted CTCs. Patient charts were retrospectively reviewed. An optimal cut point for CTCs in 7.5 ml of peripheral blood predictive of for distant metastasis-free survival (DMFS) was identified by maximizing the log-rank statistic. An ROC analysis was also performed. Results: Of 82 patients, 13 experienced metastatic progression. The optimal cut point for DMFS was 675 CTCs (p = 0.047). For those with distant recurrence (n = 13) versus those without distant recurrence (n = 69), the CTC cut point which results in the largest combined sensitivity and specificity values is also 675 (sensitivity = 69%, specificity = 68%). Conclusion: Liquid biopsy techniques in HNSCC show promise as a means of identifying patients at greater risk of disease progression.