Studies have shown that patients with localized prostate cancer have favorable long-term overall survival rates and cancer-specific survival regardless of the treatment that is selected. Few prospective, randomized trials have looked at differences in survival outcomes between radical prostatectomy and external-beam radiation therapy. As a result, the decision-making process for clinicians and patients shifts. Treatment decisions become more about predicting functional outcome than about survival.

Investigations with short-term and intermediate follow-up have identified incremental differences in functional outcome between patients undergoing prostatectomy and those receiving radiotherapy. While much is known about what happens the first several years after treatment, less is known about outcomes extending beyond 5 years. “Most patients live 10 to 20 years after treatment,” says David F. Penson, MD, MPH. “A careful evaluation of long-term functional outcomes can help us better understand the experience of men living with a diagnosis of prostate cancer.”

Long-Term Function of Prostatectomy Vs Radiotherapy

In a study published in the New England Journal of Medicine, Dr. Penson and colleagues prospectively compared urinary, sexual, and bowel function in 1,655 men with clinically localized prostate cancer, 1,164 of whom underwent prostatectomy, while 491 received radiotherapy. The study team also examined the extent to which men were bothered by declines in function at 15 years after prostatectomy or radiotherapy. Most of the men were in their 60s when they first received treatment.

According to the results, men receiving prostatectomy were significantly more likely than those in the radiotherapy group to report urinary leakage and erectile dysfunction at 2 and 5 years after treatment. However, these problems increased in both groups over time, including 15 years after treatment (Figures 1 and 2). The likelihood of having these side effects was similar between the groups.


At 15 years, 87.0% of men reported having erection problems after undergoing prostatectomy, while 93.9% of the radiotherapy group reported these problems. However, only 43.5% of men in the prostatectomy group and 37.7% of those in the radiotherapy group reported being bothered with respect to sexual symptoms. Dr. Penson notes that there may be several possible reasons for these findings, including declines in sexual interest with age, acceptance of sexual dysfunction over time, or both.

“Disease-specific health-related quality of life outcomes are essential components of decision making for any man with prostate cancer.”

In addition, bowel urgency increased in both groups over time until the extent of the problem was fairly similar between the prostatectomy and radiotherapy groups (Figure 3). At 2 and 5 years after treatment, men in the radiation group were significantly more likely to report bowel urgency than those in the prostatectomy group. However, no statistically significant differences were observed between groups at 15 years.

Implications for Decision Making for Prostate Cancer

According to Dr. Penson, the findings from his study team’s analysis may be useful when choosing a treatment plan after a diagnosis of prostate cancer. “Disease-specific, health-related quality of life outcomes are essential components of decision making for any man with prostate cancer,” he says. “Men typically live for many years after prostate cancer treatment. With this new longer-term prospective data, clinicians can help their patients understand the likelihood of these important side effects, which in turn can play a role in how decisions are made on treatment.”

Many men who have low-risk prostate cancer may be good candidates for active surveillance, in which the cancer is monitored closely and surgery or radiotherapy is delayed until signs suggest that it is needed. “Regardless of treatment, our study demonstrates that declines in urinary, sexual, and bowel function are likely to occur,” Dr. Penson says. These declines are probably due to advancing age and additional cancer treatments, but more research is needed.

Gathering data on functional changes from 5 to 15 years in men without prostate cancer can also be beneficial, according to Dr. Penson. “This information can be compared with that of men who have prostate cancer to further inform decision making. A better understanding of the longitudinal evolution of function after prostate cancer treatments will be of great help when caring for these patients.”

Dr. Penson recommends that clinicians discuss all treatment options when treating prostate cancer patients. “This includes goals and possible side effects with treatment,” he says. “The key is to determine which therapies will best fit the needs of patients as they adjust to living as survivors of the disease and treatment side effects.”