Blood Test ‘Powerful Predictor’ for Metastatic Breast Cancer
August 4, 2011 – Researchers at Georgetown Lombardi Comprehensive Cancer Center say the number of circulating tumor cells (CTCs) in the blood is a “powerful predictor” for physicians to more reliably assess treatment benefit for patients with metastatic breast cancer.
The findings from a large analysis using pooled data from international cancer centers were presented at the 2011 annual meeting of the American Society of Clinical Oncology in Chicago.
“The current standard of care for monitoring patients with metastatic breast cancer involves the use of radiology studies such as CT scans, ultrasounds and the like to determine whether or not patients are deriving benefit from their current therapies,” says Dr. Minetta Liu, lead analysis investigator. “These tests can be expensive and invasive, and can negatively impact a patient’s quality of life."
Liu is also director of translational breast cancer research at Georgetown Lombardi, part of Georgetown University Medical Center.
She says the new analysis validates the test, which counts the number of CTCs in the blood.
Results at or above the threshold of five are reliably associated with clinical and/or radiographic evidence of worsening disease, the researchers say, which suggests a change in therapy with the goal of improving long-term patient outcomes.
Quality of Life
Teams from institutions around the world contributed blind data to create a pooled dataset of 841 patients.
The large sample size enabled Liu to confirm findings from other studies that indicate a CTC count of five or more is associated with disease progression.
“Using a blood test to count CTCs in addition to our existing tools for disease monitoring might improve our ability to appropriately treat patients and maximize their quality of life,” Liu explains. “When a patient with metastatic breast cancer feels well and looks well, has had normal recent scans and CTC results that are consistently less than five, we feel more confident in her current treatment plan and may delay repeat imaging studies in favor of the less-invasive CTC blood test.”