Clinical significance of circulating tumor cells in radical radiotherapy for esophageal cancer

Objective To explore the correlations of circulating tumor cells (CTCs) with clinical features and prognosis in patients with esophageal cancer.

Methods A total of 114 patients with esophageal squamous cell carcinoma in Tongzhou District People's Hospital of Nantong City from August 11, 2019 to March 4, 2021 were selected as research objects, and CTCs were detected by immunomagnetic bead negative enrichment combined with immunofluorescence in situ hybridization. The clinical data of patients were collected and statistically analyzed in combination with clinical features such as TNM staging, gender, age and tumor location; the level of CTCs before and after radiotherapy was compared in 50 patients with radical radiotherapy, and the correlations of CTCs level with short-term remission rate and progression free survival (PFS) were analyzed.

Results In 114 patients with esophageal squamous cell carcinoma, positive rate of CTCs had no correlations with age, gender and tumor location (P > 0.05), but was correlated with T staging, N staging, M staging and clinical stages (P < 0.05 or P < 0.01). The positive rate of CTCs in 50 patients was 62.00% (31/50) before radiotherapy and 52.00% (26/50) after radiotherapy, and there was no significant difference before and after radiotherapy (χ²=1.020, P=0.313). The survival curve drawn by Kaplan-Meier method showed that the PFS of patients negative for CTCs before radiotherapywas 18.62 months (95%CI, 15.24 to 21.99), which was significantly higher than 13.84 months (95%CI, 10.01 to 17.68) of patients positive for CTCs before radiotherapy(P=0.048). After radiotherapy, the PFS of patients negative for CTCs was 19.58 months (95%CI, 16.51 to 22.67), which was significantly higher than 12.13 months (95%CI, 7.94 to 16.32) of patients positive for CTCs (P=0.003). Multivariate Cox regression analysis showed that tumor clinical stages and CTCs after radiotherapy were the independent prognostic factors of patients with esophageal squamous cell carcinoma (P < 0.05).

Conclusion CTCs i s an important index in evaluating the progress of disease and prognostic assessment after radiotherapyin patients with esophageal squamous cell carcinoma.