Long-term prognostic impact of circulating tumour cells in gastric cancer patients

AIM: To analyse the long-term prognostic impact of circulating tumour cells (CTCs) in gastric cancer patients who underwent surgery. METHODS: A 7.5-mL peripheral vein blood sample was obtained from each patient with treatment-negative gastric adenocarcinoma before surgery. OBP-401, a telomerase-specific, replication-selective, oncolytic adenoviral agent carrying the green fluorescent protein gene, was used to label CTCs. Correlations between the number of CTCs and clinical end points were evaluated. RESULTS: The median follow-up period of the surviving patients with gastric cancer was 60 mo. The CTC number tended to increase concomitantly with disease progression. The overall survival of patients with more than five CTCs in 7.5-mL of peripheral blood was lower than that of patients with five or less CTCs, although the difference was not significant (P = 0.183). A significant difference in relapse-free survival was found between patients with more than five and those with five or less CTCs (P = 0.034). CONCLUSION: A lower number of CTCs was correlated with higher relapse-free survival rates in patients. Detection of CTCs using OBP-401 may be useful for predicting prognosis in gastric cancer.