How blood test can detect traces of cancer DNA

Doctors say a simple blood test called a liquid biopsy is able to identify women who are more likely to have a recurrence of breast cancer.

A large US study shows the tests may someday reveal which women need longer preventive therapy, and those who don't.

How does it work?

Tumors are made up of cancer cells that change, reproduce and die over time.

Sometimes tumors shed cells that can get into the bloodstream.

And when cancer cells die, they release DNA and other fragments that can get into blood, too.

Tests called liquid biopsies can analyze a blood sample for traces of cancer DNA, to see what genes and mutations are most active.

This can suggest what treatment might help a patient.

These tests also might give an early warning that cancer is present, or has recurred after treatment.

Source(s): AP