Prostate cancer trial finds similar long-term outcomes from surgery, radiation

Veteran John Kane of Iowa City, seen here in a 2009 photo with nurse researcher Dr. Karen Clark Griffith, received an experimental treatment for prostate cancer that had spread beyond the prostate gland. All the men in the study had initially received surgery or radiation but required further treatment. (Photo by Michael Stenerson)

Treatment tribulations— Veteran John Kane of Iowa City, seen here in a 2009 photo with nurse researcher Dr. Karen Clark Griffith, received an experimental treatment for prostate cancer that had spread beyond the prostate gland. All the men in the study had initially received surgery or radiation but required further treatment. (Photo by Michael Stenerson)

An enlarged cancerous prostate is shown on a CT scan. As part of a large NIH-sponsored study, VA researchers and colleagues have reported the 15-year follow-up results on more than 1,600 men treated for the disease. (Photo: iStockphoto)

Cancer chronicles— An enlarged cancerous prostate is shown on a CT scan. As part of a large NIH-sponsored study, VA researchers and colleagues have reported the 15-year follow-up results on more than 1,600 men treated for the disease. (Photo: iStockphoto)

The latest report from a nationwide study of prostate cancer treatment confirms that surgery and radiation both entail serious side effects.

The National Cancer Institute-funded Prostate Cancer Outcomes Study started in 1994. About 3,500 men have taken part, all with a diagnosis of prostate cancer. Researchers conducting the study included a team at the Nashville VA Medical Center and Vanderbilt University.

The latest findings, published Jan. 31 in the New England Journal of Medicine, reflect 15 years of follow-up on more than 1,164 men who were treated with surgery—removal of the walnut-shaped prostate gland—and 491 who received radiation. Most of the men were in their 60s when they were first treated.

The surgery group was more likely to have loss of bladder control and erectile dysfunction at two years and five years post-diagnosis. At two years, 9.6 percent of surgery-treated men had urinary incontinence, vs. 3.2 percent of the radiation group. At five years, the figures were 13.4 percent vs. 4.4 percent.

At two years, 78.8 percent of the surgery group had erectile difficulty, compared with 60.8 percent of the radiation group. After five years, the gap closed somewhat: about 76 percent vs. 72 percent.

Bowel urgency was worse among the radiation group both at two and five years: 7.9 vs. 2.9 percent, and 5.8 vs. 4.4 percent.

By the 15-year follow-up, however, the differences in side effects between the groups had evened out. The researchers suspect part of that trend was due simply to the passing of time: Some men eventually developed these health problems as a result of aging and not the treatment.

At 15 years, about 28 percent of the surgery group had died, compared with 50 percent of the radiation group. The study did not analyze how many of those men died from the prostate cancer versus other causes.

Also, the study did not analyze outcomes for those men who were in the initial study group but opted to get no treatment—neither surgery nor radiation. A debate has raged in the medical community as to the best course of action for men who have localized prostate cancer that appears to be slow-growing and not likely to spread. Many of these men will eventually die from other causes without ever suffering effects of the cancer.

Senior author David Penson, MD, MPH, of the Nashville VA and Vanderbilt, told NBC News that "so many of these men have low-risk disease that probably doesn’t need to be treated."

Experts say that many men opt for treatment after a diagnosis because of the worry associated with knowing they have cancer, even if they are assured by their doctors that waiting and watching is a sensible strategy.

Researchers continue to look for protein markers and other ways to distinguish slow-growing prostate tumors from more aggressive ones that are likely to be life-threatening. With such tests, doctors will be able to offer better guidance to men after their diagnosis.

Lead author on the study, Matthew Resnick, MD, also of the Nashville VA and Vanderbilt University, told dailyrx.com that he would like to see future studies compare outcomes among men who undergo some of the newer, emerging treatments for prostate cancer, such as robotic surgery, intensity modulated radiation therapy, or proton therapy.

(New England Journal of Medicine, Jan. 31, 2013)