Most men would agree that prostate cancer screening isn’t anywhere near the top of their to-do lists. That’s unfortunate because prostate cancer is highly curable when caught early, and screening is still the best way to find it before it spreads.
But a new development may make screening easier to take.
Scientists in City of Hope’s Division of Urology and Urologic Oncology have found a potential new prostate cancer screening method that could not only make diagnosis more accurate, but also may dramatically reduce the number of unnecessary biopsies.
|Steven Smith, left, discusses study data with Laura Crocitto. (Photo by Darrin S. Joy)|
Physicians today screen for prostate cancer by using a digital rectal examination to feel for tumors and by measuring levels of prostate specific antigen, or PSA, in a man’s blood. If these noninvasive tests hint that a man might have prostate cancer, the physician follows up by taking a biopsy.
In a prostate biopsy, doctors surgically remove small samples of prostate tissue from the area of a suspected tumor and check them for cancer cells. Pathologists then examine the sampled cells and, if they’re cancerous, determine the cancer’s aggressiveness.
One third of these biopsies taken after screening confirm the presence of cancer, making them critical for early detection. But two thirds show no cancer. City of Hope researchers believe their new, advanced test in development will sharpen the accuracy of noninvasive screening — and cut down the number of unnecessary biopsies.
“Our combined test provides a considerable improvement over current noninvasive tests,” said Steven Smith, Ph.D., professor of molecular science and principal investigator on the National Cancer Institute-funded project. “The clinical value lies in the possibility that unnecessary and sometimes painful biopsies could be avoided.”
The new test involves massaging the prostate gland to push fluid from it, then testing the fluid for DNA biomarkers that point to the presence of cancer.
DNA biomarkers are altered forms of DNA that appear in cancer but not in normal tissue.
For their study, the researchers collected prostatic fluid from patients and compared three different biomarkers in each patient’s fluid. They wanted to see if the biomarkers could predict whether the biopsy would show that cancer was present.
They found that all three biomarkers could predict the outcome of the biopsy with some level of accuracy, but one test clearly stood out: a biomarker called TMPRSS2:ERG, used together with the digital rectal exam and PSA results.
This combination also most accurately predicted the aggressiveness of the cancer for those patients who had the disease, according to the study results.
Noted Timothy Wilson, M.D., Pauline and Martin Collins Family Chair in Urology and chief of the division: “By adding this third component to the current prostate cancer screening standards, we could potentially save the health-care system a great deal of money, not to mention the pain, inconvenience and worry men go through.”
The researchers continue to study the new screening test to further validate their findings.