A blood test may be able to save lives by helping doctors determine whether or not a patient with early breast cancer has a high risk of death or relapse, the AFP reported Wednesday.

Tumor cells in the blood sample – at an early stage of cancer -- are an accurate predictor of how likely the patient is to survive, the researchers said.  This could help doctors identify which patients would benefit from additional treatment such as chemotherapy.

"The presence of one or more circulating tumor cells (CTCs, in the blood) predicted early recurrence and decreased overall survival," the researchers from the University of Texas' MD Anderson Cancer Center told the AFP.  In other words, the more CTCs there were in the blood, the higher the patient’s risk of death.

According to the AFP, CTC blood tests are not used on cancer patients because cancer typically is thought to spread through the lymphatic system instead of the blood stream.

The study, which was published in Lancet Oncology, was conducted among 302 patients treated between February 2005 and December 2010.  One quarter were found to have CTCs in their blood.

The researchers said further studies were needed to confirm their findings.

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