Gene test may help guide prostate cancer treatment

A new genetic test to gauge the aggressiveness of prostate cancer may help tens of thousands of men each year decide whether they need to treat their cancer right away or can safely monitor it.

The new test, which goes on sale Wednesday, joins another one that recently came on the market. Both analyze multiple genes in a biopsy sample and give a score for aggressiveness, similar to tests used now for certain breast and colon cancers.

Doctors say tests like these have the potential to curb a major problem in cancer care - overtreatment. Prostate tumors usually grow so slowly they will never threaten a man's life, but some prove fatal and there is no reliable way now to tell which ones will. Treatment with surgery, radiation or hormone blockers isn't needed in most cases and can cause impotence or incontinence, yet most men are afraid to skip it.

"We're not giving patients enough information to make their decision," said Dr. Peter Carroll, chairman of urology at the University of California, San Francisco. "You can shop for a toaster" better than for prostate treatment, he said.

A study he led of the newest test - the Oncotype DX Genomic Prostate Score - is set for discussion Wednesday at an American Urological Association meeting in San Diego.

The results suggest the test could triple the number of men thought to be at such low risk for aggressive disease that monitoring is a clearly safe option. Conversely, the test also suggested some tumors were more aggressive than doctors had believed.

Prostate cancer is found mainly in older men. As men age, the prostate may get bigger and block the urethra or bladder. This may cause trouble urinating or sexual problems. The condition is called benign prostatic hyperplasia (BPH), and although it is not cancer, surgery may be needed to correct it. The symptoms of benign prostatic hyperplasia or of other problems in the prostate may be like symptoms of prostate cancer. Possible signs of prostate cancer include a weak flow of urine or frequent urination.

These and other symptoms may be caused by prostate cancer. Other conditions may cause the same symptoms. Check with your doctor if you have any of the following problems:

Weak or interrupted flow of urine.
Frequent urination (especially at night).
Trouble urinating.
Pain or burning during urination.
Blood in the urine or semen.
A pain in the back, hips, or pelvis that doesn't go away.
Painful ejaculation.

Independent experts say such a test is desperately needed but that it's unclear how much information this one adds or whether it will be enough to persuade men with low-risk tumors to forgo treatment, and treat it only if it gets worse. Only 10 percent who are candidates for monitoring choose it now.