Researchers have made a breakthrough in one of the most difficult aspects of treating cancer.
Usually it takes two to three months to determine whether a cancer patient is responding to treatment, but now a simple blood test lets doctors know immediately if the treatment is working or not. This allows doctors to change the strategy before it's too late.
"What this study means is we now have the capability of getting an early look at whether a treatment is being effective for that individual patient. As a consequence of that we might be able to change to a more effective treatment, which would benefit the patient," says Dr. Thomas Budd, an oncologist.
The test measures the number of tumor cells circulating in the blood of cancer patients. Researchers at the University of Michigan say that test in 177 women with advanced breast cancer accurately predicted the prognosis in each woman and told doctors whether or not the treatment was working. Of course that's important for the patient who needs to switch gears and find another treatment that will work.
Researchers say if this test becomes available, it could also be of value to the patient who ultimately will not be saved by medicine so they can be spared difficult treatments. Researchers say women who had five or more circulating tumor cells had much worse prognosis than women with fewer than five circulating tumor cells. Women with five or more CTC's had an average progression free survival of 2.7 months compared to seven months in the group with more than five CTC's. For overall survival prognosis, women with high circulating tumor cell counts had an average of ten months, compared to more than 18 months in women with fewer than five CTC's. A small study in the past found as many as 30% of newly diagnosed breast cancer patients have circulating tumor cells.
The study was led by researchers at MD Anderson Cancer Center. Patients were enrolled at 20 sites across the U.S. The study is published in the New England Journal of Medicine.