A new technology that counts cancer cells in the blood helps predict the success of breast cancer treatments more quickly and more reliably than established methods, researchers reported Wednesday.
A study published in Thursday's edition of The New England Journal of Medicine said the new technique allows doctors to determine within weeks, not months, whether a breast cancer patient's treatment is working.
The study -- funded by a company that helped develop the technique -- could lead to more tailored treatments that would spare some women from the most potent chemotherapy or recognize which patients need more aggressive therapy at the start of treatment, said lead author Massimo Cristofanilli.
"It makes a huge difference in case you have to decide how aggressive you want to be with a woman with breast cancer," Cristofanilli, of the University of Texas M.D. Anderson Cancer Center in Houston, told Reuters.
However, he noted that the system was only tested on breast cancer that had spread. Further research will be needed to see if the technique helps against less aggressive breast cancer or other types of tumors where cancer cells are less likely to be shed into the blood.
Improved care
More than 1.2 million people are expected to be diagnosed with breast cancer this year worldwide, and the disease will kill 40,000 in the United States alone.
Cells of a tumor sometimes break off and circulate in the blood. When those nomadic cells find a new home and start to grow -- a process known as metastasis -- cancers become much harder to treat.
The technique to count such cells, known as the CellSearch System, was developed by Veridex LLC, a Johnson & Johnson company, in conjunction with Immunicon Corp., which funded the study. Each test is expected to cost $300 to $400.
In an editorial in the Journal, Stephan Braun and Christian Marth of Innsbruck Medical University predicted that the CellSearch technique will become widespread and thereby improve care for patients with metastatic breast cancer.
"Measurement of circulating tumor cells predicts a response to treatment much more quickly than our usual clinical practice, which in the best of circumstances permits a treatment evaluation after two to three months," Braun and Marth said.
Currently, doctors use a variety of methods -- such as tumor size, tumor type, the patient's age, whether cancer cells have spread to adjacent lymph nodes, and the tumor's sensitivity to estrogen -- to try to predict which treatment will be most effective.
The new technique, tested at 20 locations in the United States, involved 177 volunteers with advanced breast cancer.
The Cristofanilli team found that women with high levels of cancer cells in their blood survived for an average of 10.1 months, while those with low levels survived for more than 18 months.
Cristofanilli said plans are under way to test the technique against other forms of cancer, and to see if it will predict which women are more likely to have a recurrence of breast cancer.
"One day, we may be able to suggest to a patient, based on personal risk, a more aggressive treatment, a less aggressive treatment, or no treatment at all," he told Reuters. "But this is going to take a few years."