More than half of men with lower-risk prostate cancer received surgery or radiation treatment, when a wait-and-see approach might have been a better option, according to a new study.

For men with less aggressive prostate cancers, it is not always easy to calculate the risks and benefits of immediate treatment with surgery or radiation. Research has shown that most older men with lower-risk prostate cancer who choose so-called watchful waiting will die from another cause during the 20 years after being diagnosed with cancer. Meanwhile, aggressive treatment — surgery or radiation — can lead to erectile dysfunction, urinary incontinence and bowel difficulties.

Research has shown that most older men with lower-risk prostate cancer who choose so-called watchful waiting will die from another cause during the 20 years after being diagnosed with cancer.

"Just as a failure to treat a potentially lethal prostate cancer is generally considered inappropriate from a quality-of-care perspective, overtreatment of lower-risk cancers is also not in the patient's best interest. For some men with early stage prostate cancer, surgery or radiation therapy may result in substantial negative effects without a survival benefit," says study author John T. Wei, M.D., M.S., associate professor of urology at the U-M Medical School.

Researchers looked at 64,112 men diagnosed with early stage prostate cancer. Men were divided into high-risk or low-risk categories. Among the 24,835 men with lower-risk cancers, 55 percent were treated with initial surgery or radiation, raising the question of whether they are being treated over-aggressively.

The study appears in the Aug. 16 issue of the Journal of the National Cancer Institute.

"There are many men with prostate cancer who will benefit from early treatment with surgery or radiation therapy. However, prostate cancer is not a one-size-fits-all condition and we now know that many men are diagnosed with slowly growing cancers that are unlikely to cause symptoms or be fatal," says lead study author David C Miller, M.D., MPH, adjunct lecturer at U-M and now a health services research and urological oncology fellow at the David Geffen School of Medicine at UCLA.

"Based on data from this study, it is clear that the number of lower-risk patients who receive initial aggressive therapy is not trivial and we have to ask the question whether this is too much treatment for some of these men," Miller continues.

The authors report that for many men with lower-risk cancers the best treatment option may be what is known as active surveillance. This involves frequent monitoring of the tumor without immediate active treatment; it can help distinguish between more-aggressive and less-aggressive cancers, thereby improving doctors' ability to identify who is most likely to benefit from surgery or radiation.

Some 234,000 men will be diagnosed with prostate cancer this year and 27,350 will die from it, according to the American Cancer Society.