Test Pinpoints Aggressive Prostate Tumors
Goal of New Test Is to Determine Which Men Will and Will Not Need Treatment for Prostate Cancer
Test May Predict Prostate Cancer Spread
Also at the meeting, researchers reported using a microchip to detect
circulating tumor cells in the blood of people with prostate cancer.
The presence of circulating tumor cells, or CTCs, in the blood is an
indication of cancer spread, says Sunitha Nagrath, PhD, an instructor of
surgery and bioengineering at Harvard Medical School.
CTCs also carry molecular signatures that can be used to guide targeted drug
therapy, she says. The problem: There are only a few CTCs in millions of cells,
she tells WebMD. "It’s like looking for a needle in a haystack."
The CTC-chip can capture about 200 circulating tumor cells from a teaspoon
of blood, she says.
In a small pilot study, the researchers found CTCs in nearly half of 20
people with early-stage prostate cancer and in two-thirds of people with
"We think that's an indicator they are more prone to metastasis (cancer
spread), but that remains to be proven," Nagrath says.
The test is not commercially available.
"Eventually we hope that when a patient walks in, we can take a simple blood
test that tells us if a cancer will spread and also about its molecular
signature," she says.
Massimo Cristofanilli, MD, chairman of the department of medical oncology at
Fox Chase Cancer Center, is cautiously enthusiastic, saying that a lot more
work is needed before either test can be integrated into patient care.
With the CTC chip, he says, one of the issues to be worked out is when to
give the test: at the time of diagnosis, surgery, or a few weeks afterward.
There's also the issue of who will pay for new tests, he says. "Insurance
will not cover every test for very patient," Cristofanilli tells WebMD.