A long-term study of men diagnosed with early-stage prostate cancer has confirmed that patients who forgo immediate surgery have the same odds of living another decade or two as patients who have their tumors surgically removed.
The results, published in Thursday's edition of the New England Journal of Medicine, show that while each approach offers a different mix of benefits and risks, neither is likely to result in death due to prostate cancer.
"Surgery did not reduce mortality in men with localized prostate cancer," said Dr. Timothy Wilt of the Minneapolis VA Center for Chronic Disease Outcomes Research, who led the study with Dr. Michael Brawer of Myriad Genetics. "We are particularly confident of this in men with low-risk disease, men who are 65 or older, or younger men with serious health conditions."
Over the last decade — and especially within the last five years — doctors have increasingly recommended observation for men with early-stage localized prostate cancer instead of immediate surgery or radiation treatment.
Since prostate cancer tends to be a fairly slow-moving disease, the pain and side effects of surgery may end up causing more problems than the disease itself. But would surgery, despite these risks, ultimately lead to a longer life?
To find out, Wilt and his colleagues enrolled 731 men in a clinical trial starting in November 1994. After being diagnosed with localized prostate cancer, 364 of the men were randomly assigned to have their prostates and some of the surrounding tissue surgically removed. The other 367 men were assigned to the observation group.
The average age of the patients when they joined the study was 67. All of them were tracked until their death or through August 2014, whichever came first.
During that time, 7.4% of the men in the surgery group died of prostate cancer, as did 11.4% of the men in the observation group, according to the study. That difference was too small to be statistically significant, meaning that it could have been due to chance.
In addition, 61% of the men in the surgery group and 67% of the men in the observation group died for any reason over the course of the study. That difference was also too small to be statistically significant.
Wilt and his team also compared the quality of life for patients in the two groups. During the follow-up period, which ranged between 12 years and 19.5 years depending on the patient, the men who had surgery tended to experience more physical discomfort, limitations in day-to-day activities and general inconvenience arising from their cancer or its treatment.
In the first five years after surgery, they were more likely to suffer erectile and sexual dysfunction than their counterparts who avoided surgery. They also reported more urinary incontinence for up to 10 years after surgery.
Meanwhile, the men assigned to observation were more likely to need additional treatment as their prostate cancers progressed, such as prostatectomy, radiation or cryotherapy.
As the longest and largest study of its kind, the results provide powerful information for doctors and their patients, Wilt said. In fact, he added, the study findings have prompted him to recommend observation over surgery to most of his early-stage prostate cancer patients.
There are certain cases, however, in which he might recommend surgery, such as in young men with a life expectancy of at least 20 years. Even then, he said, he would make sure his patients understood the trade-offs.
"Some men will take that trade," he said.
Dr. Christopher Saigal, a urologist at UCLA's David Geffen School of Medicine who was not involved in the study, said surgical techniques for removing prostates have improved a great deal since the study began. That means patients contemplating surgery today might face a lower risk of side effects such as incontinence and sexual dysfunction than did the patients in the study.
Even so, both Saigal and Dr. Sumanta Pal, an oncologist at City of Hope Comprehensive Cancer Center in Duarte who was not involved with the study, said the results are in line with the way doctors currently treat prostate cancer.
Encouraging observation for low-risk patients is supported in practice as long as they seek treatment when necessary, Saigal said.
The study hinted at a possible exception, Hilt said: patients whose cancers were judged to be of intermediate risk.
Men in the low-risk category typically don't die from the disease, so observation is usually sufficient. At the other end of the spectrum, men with high-risk cancers usually need treatment beyond surgery.
The patients in the middle might be at the point where their disease is aggressive enough to benefit from surgical intervention, but not so aggressive that surgery alone can't solve the problem, Wilt said. However, he noted, this finding in intermediate-risk patients fell just short of being statistically significant.