IDH1 and central nervous system cancer: Recurred glioma = 7/836/42 had detectable CTC.CTCs higher in astrocytomas compared to oligodendrogliomas.Large number of CTC-WBC clusters detected and could help monitor. Recurrence. No difference noted in glioma subtype.CTC level related to P53 mutation, IDH1 status and poor outcome. Resection may promote CTCs in gliomas.