Abstract 479: Detection and clinical significance of circulating tumor cells in squamous cell carcinoma of the head and neck

Abstract

Abstract Background: With a developing tumor, tumor cells shed a variety of substances into the blood stream, such as tumor cells, tumor DNA, or exosomes, and these are considered to be as attractive circulating biomarkers to monitor disease progression in cancer patients. However, impact of circulating tumor cells (CTCs) in squamous cell carcinoma of the head and neck (SCCHN) is still not fully understood. In this study, we show that CTCs are present in the peripheral blood of patients with SCCHN, and then investigate the correlation with clinicopathological factors. Materials and Methods: 7.5mL of peripheral blood was obtained from 32 patients with pathologically and clinically confirmed SCCHN. Samples were run with a CellSieve™ Microfiltration Assay (Creatv MicroTech, Inc., Rockville, MD) using a low-pressure vacuum system. The CTCs captured by the filter were stained with an antibody mixture of FITC-conjugated anti-CK 8, 18, and 19, PE-conjugated anti-EpCAM, and Cyanine 5-conjugated anti-CD45. Cells that stained positive for DAPI and CK but negative for CD45, were identified as CTCs. Results: The CTCs were found in 29 (90.6%) of 32 patients. Although there was no association between the number of CTCs and tumor sites, the number of CTCs in patients with advanced disease (stage III/IV) was significantly increased, as compared with those with early disease (stage I/II) (p<0.05). Furthermore, patients with T3/4 had higher number of CTCs compared to patients with T1/2 (p<0.01). Meanwhile, nodal status was not significantly associated with the number of CTCs. In 12 of 32 patients tested, the number of CTCs after treatments was also evaluated. As expected, the number of CTCs was significantly decreased after treatments, regardless of the treatment modalities. Conclusion: Our results suggest that microfiltration is very efficient in capturing CTCs from SCCHN patients. Moreover, CTCs analysis in SCCHN may provide useful information for assessment of treatment efficacy. Citation Format: Kazuaki Chikamatsu, Hideyuki Takahashi, Koichi Sakakura, Minoru Toyoda. Detection and clinical significance of circulating tumor cells in squamous cell carcinoma of the head and neck. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 479.