A Simple Urine Test Can Determine Prostate Cancer Severity

A Simple Urine Test Can Determine Prostate Cancer Severity
By Alice Carver
14:00, February 17th 2009 2

A new urine test that tracks a certain substance produced by prostate cancer cells may help doctors distinguish between aggressive forms of prostate cancer and non-aggressive ones.

Prostate cancer is the second leading form of cancer among men after skin cancer in the United States. There are two types of prostate cancer, aggressive, also called tiger and non-aggressive, called pussycat. Usually, men with pussycat cancer can have a healthy life, but those with tiger cancer (who make up 1/3 of total cases) regularly don’t live more than a year and a half. That is why the test could prove pivotal in doctors’ efforts to identify the severity of the condition.

The test is also necessary as it is a known fact that men with early stage prostate cancer typically don’t present symptoms of the disease. Their cancer might spread without knowing, as it can’t be detected by such methods as PSA and DRE. Prostate-Specific Antigen (PSA) or digital rectal examination (DRE) are not 100% accurate in revealing the presence of prostate cancer, studies note.
At the same type, the method of prostate cancer biopsy is considered more accurate, but researchers hope that one day this method will be replaced by more accurate and easier tests.

For the study published in the journal Nature, a team of researchers at the University of Michigan analyzed a total of 1,126 molecules produced by the body in 262 samples of tissue, blood or urine taken from men who were healthy or were diagnosed with early stage prostate cancer or more advanced forms of prostate cancer.

By comparing these samples, the team found that a compound called sarcosine appeared to be the crucial element of the test as it indicated if a patient had slow-growing prostate cancer, or a form of cancer that was likely to spread and become lethal. The substance, which could be easily detected in a simple urine test, proved to be a better indicator of aggressive forms of prostate cancer than testing for prostate-specific antigen (PSA), according to the study. PSA is a protein that is produced by the cells of the prostate gland and physicians can detect prostate cancer by measuring the level of PSA in the blood stream.
But recent studies have shown that the level of PSA in the blood may be influenced by pain relievers like aspirin and ibuprofen. It appears that men who regularly take these medications have a lower serum PSA level, which makes it hard for doctors to identify it they are at risk for prostate cancer or not.

“One of the biggest challenges we face in prostate cancer is determining if the cancer is aggressive. We end up over-treating our patients because physicians don't know which tumors will be slow-growing,” Dr. Arul M. Chinnaiyan, MD, PhD., professor of pathology and urology at University of Michigan, Ann Arbor said in a statement. “With this research, we have identified a potential marker for the aggressive tumors,” he added. The discovery could lead to new ways of preventing the spread of tumours and to better treatments, Chinnaiyan said.