Wandering Tumor Cells Predict Poor Outcome
Circulating Tumor Cells Linked to Higher Risk of Recurrence, Death in Breast Cancer
Doctors Divided on Usefulness of CTC Testing
Still, doctors appear divided on whether CTC testing is useful.
Alison T. Stopeck, MD, director of the Clinical Breast Cancer Program at the Arizona Cancer Center in Tucson, says she doesn't use the CTC test at all.
"More often than not, I know which of my patients with metastatic breast cancer are progressing just by examining them," she tells WebMD.
Plus a high CTC count doesn't provide any information about what treatment might help, Stopeck says.
Minetta Liu, MD, director of translational breast cancer research at Georgetown Lombardi Comprehensive Cancer Center in Washington D.C., says the test is very useful.
"I use every tool I have," she tells WebMD. In some cases, knowing a woman has no CTCs allows her to delay much more expensive imaging tests to track the progress of the cancer, Liu says.
Early Breast Cancer
Also at the meeting, U.S. researchers reported that having even one CTC in the blood increases the risk of recurrence and death in women with early-stage breast cancer.
The study involved about 2,000 women with early cancer, nearly one-fourth of whom had CTCs in their blood.
After three years, about 5% of those with no CTCs relapsed vs. about 85% of those with CTCs. About 96% of those with no CTCs and 93% of those with CTCs were alive, says researcher Brigitte Rack, MD, head of the department of gynecological oncology at the Women’s Hospital at the University of Munich, Germany.
"We don't have markers for prognosis or to tell us if a treatment is working," Rack tells WebMD. "If we had an early marker, it could help us to see if a different treatment might be better."
Still, CTC testing is not ready for prime time in women with early breast cancer, Rack and Liu say.
"We don't know what options to offer if a woman does have CTCs," Rack says.
Several studies looking at whether CTC testing can improve survival in early breast cancer are ongoing in Europe and the United States, she says.
This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.