Test Pinpoints Aggressive Prostate Tumors
Goal of New Test Is to Determine Which Men Will and Will Not Need Treatment for Prostate Cancer
New Prostate Cancer Test Shows Promise continued...
The federally funded study involved 71 men who were diagnosed as having small, low-grade, and low-stage prostate cancer based on their PSA results. At the time of their diagnosis, their blood had been banked.
By an average of nearly four years later, 39 had unfavorable biopsy results that signaled a need for treatment.
The PHI test was performed on blood samples from all 71 men.
"When we combined the [biopsy results] and the serum Prostate Health Index, we were able to predict seven in 10 men that might progress," Veltri says.
Veltri says the PHI test won't replace biopsies but will hopefully allow men to have them every other year instead of year.
His lab is now conducting an expanded study to look for other biomarkers that may predict aggressive cancers.
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 advanced cancer.
"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.