No currently reliable method, but blood test may help classify patients
An ongoing study showed women who had cancer cells detected in their blood 5 years after a breast cancer diagnosis were 13 times more likely to have their cancer return than women who did not.
Most women who are diagnosed with hormone receptor–positive breast cancer that has not spread will not have a recurrence. Among those who do have a recurrence, more than half have a late recurrence, meaning their disease will return five or more years after diagnosis.
Doctors do not currently have a reliable method to predict who is likely to have a late recurrence and is a candidate for therapies that might prevent or delay it. According to the study findings, a blood test—a type of liquid biopsy—may help classify patients according to their recurrence risk.
“This [finding] is not something that should change practice now,” said lead investigator Kathy Miller, M.D., of Indiana University Melvin and Bren Simon Cancer Center. “But it gives us the potential for future clinical trials that identify patients at higher risk [of late recurrence] and study whether having that information could change treatment and improve outcomes,” she added.
Though there are limitations, “this is a really well-conducted study,” said Lyndsay Harris, M.D., of NCI’s Division of Cancer Treatment and Diagnosis, who has conducted similar research but was not involved in the study. “It’s part of a clinical trial and therefore was carefully controlled.”
The finding that detection of tumor cells in blood is associated with late recurrence of breast cancer “is a really important observation that had not been clearly shown in the setting of a large clinical trial,” she added.
The study, funded in part by NCI, was reported in JAMA Oncology on July 26.