A prostate biopsy is a common method of detecting prostate cancer. The procedure, however, can be painful and stressful, and it does not always result in an accurate diagnosis. According to a validation study involving over 1,500 patients, a urine test could have saved one-third of unnecessary prostate cancer biopsies while missing only a small number of cancers.
According to a validation study involving more than 1,500 patients, a urine test based on University of Michigan Rogel Cancer Center research could have saved one-third of unnecessary prostate cancer biopsies while missing only a small number of cancers. The findings appear in the Journal of Urology.
Despite this, over a million people in the United States have prostate biopsies each year. Only 200,000 of these people are diagnosed with prostate cancer. While prostate biopsies can be medically beneficial, they can also cause unnecessary anxiety and prompt treatment for prostate cancer when it is not required. For early signs of prostate cancer, many people do not require active treatment.
A urine test could have avoided one-third of unnecessary prostate cancer biopsies while failing to detect only a small number of cancers.
LynxDX, a U-M startup company, is commercializing the MyProstateScore test, which measures levels of cancer-specific genes in a patient’s urine. It is based on research from the University of Michigan that discovered that half of all prostate tumors have a genetic anomaly in which the genes TMPRSS2 and ERG relocate on a chromosome and fuse together, creating an on-switch for prostate cancer development.
A blood test for prostate-specific antigen, also known as the PSA test, is currently one of the best methods available to doctors for detecting prostate cancer. Although elevated PSA levels may indicate cancer, the vast majority of men with elevated PSA levels do not have prostate cancer.
Men with an elevated PSA test undergo an invasive procedure called a transrectal biopsy to determine who has cancer and who does not. Patients experience discomfort during prostate biopsies, and there is a small risk of complications. MRI scans are also used to detect prostate cancer, but they can miss cancerous lesions and are much more expensive and scarce.
“Our ultimate goal was to see if the MyProstateScore test could be a practical, reliable test that could eliminate the need for more expensive or invasive testing in men referred for a prostate biopsy,” says study lead author Jeffrey Tosoian, M.D., M.P.H., a clinical lecturer in urology at Michigan Medicine.
Tosoian and two of his co-authors founded LynxDX and have a stake in the company. Not all prostate cancers are the same level of concern. Many appear later in life and grow so slowly that the best course of action is simply to keep an eye on them. Patients with slow-growing cancers or no cancer, despite elevated PSA levels, could be spared from more invasive or expensive procedures, according to the researchers.
Patients seen at academic health centers and community health settings were included in the validation study. Among the 1,525 patients, 338 (22%) had cancers detected on biopsy that were group grade 2 or higher, indicating that they were serious enough to require immediate treatment.
The study discovered that if the MyProstateScore test had been available to patients in the study, 387 biopsies that revealed no cancer or slow-growing cancer could have been avoided. Meanwhile, the test would have missed only ten clinically significant cancers that required immediate treatment.
“The data show that this simple, secondary testing approach could reduce the use of more expensive and invasive procedures after a PSA test,” Tosoian says. The prostate-specific antigen (PSA) test is a common prostate cancer screening test. PSA is a protein produced by the prostate gland. The PSA level in your blood is measured by the test. It’s a simple blood test, but for some men, it’s a lifesaver.
A high PSA score will almost always lead to a doctor recommending a prostate biopsy. Other health issues, however, can contribute to an elevated PSA score. A PSA score tends to rise with age as well. Waiting and re-testing PSA levels can be beneficial. If a person’s PSA level remains high but has not changed since the previous test, he or she may not have prostate cancer.
