Detection of folate receptor-positive circulating tumor cells as a biomarker for diagnosis, prognostication, and therapeutic monitoring in breast cancer.

OBJECTIVES: This study is to explore the clinical significance of folate receptor-positive circulating tumor cells (FR+ CTC) in the early diagnosis and disease progress in patients with breast cancer. METHODS: Folate receptor-positive circulating tumor cells was enriched from peripheral blood of the patients with immunomagnetic separation method and quantitated by folate receptor on the CTC with the ligand-targeted PCR. RESULTS: The levels of FR+ CTC were significantly higher in breast cancer patients compared with healthy controls. Detective rate of FR+ CTC was decreased in 19 of 27 patients underwent the surgery in 2 weeks post-operation compared with pre-operation; statistical analysis showed the difference was significant. We also found that the combination of FR+ CTC, CEA, CA125, and CA153 can significantly improve the diagnostic efficiency for breast cancer. CONCLUSIONS: This study showed the detective rate of FR+ CTC is significantly increased in the patients with breast cancer, and the detective level is associated with disease progress.