Active surveillance in select patients with early prostate cancer is a safe option, a new trial shows
Men with early prostate cancer have the same mortality rate at 10 years whether they undergo watchful waiting, radical prostatectomy or radiotherapy, a major trial confirms, but the surveillance group were more likely to develop metastases over the same period.
Over 10-years, death from prostate cancer in these men remained low at approximately 1%, the authors of the study published in the NEJM said.
In the trial, more than 1600 men with localised cancer were randomised into one of the three groups and followed from 1999 to 2009.
In absolute numbers, eight died in the active-monitoring group compared with five and four in surgery and radiotherapy groups – an insignificant difference.
An Australian expert said the trial demonstrated the safety of active surveillance in select patients.
Professor Mark Frydenberg, president of the Urological Society of Australia and New Zealand, said while rates of metastasis were twice as high in the monitoring group, this was not necessarily a reason to abandon watchful waiting.
“Our ability to watch people was very different in 1999,” Professor Frydenberg told TMR.
“We now have MRIs that provide much better insights into what’s going on in the prostate, we now have different biopsy techniques which are much more thorough, and the reality is that our ability to watch people is a lot better now than it was then.”
“So if we were replicating the study today, we may well find that we don’t have the increased risk of metastatic spread that did in this trial.”
An accompanying editorial said men over 65 in the study were more likely to die from prostate cancer if assigned to active monitoring than treatment, “a near-significant interaction”.
Should this interaction become significant as men were followed for longer, it would support the recommendation that otherwise healthy older men should be offered treatment, it said.
But Professor Frydenberg said many men in his own practice had been under observation with no treatment for close to two decades, and had had no ill-effects.
Instead, the study showed that men with a low risk of prostate cancer did not need to rush to make a decision about their treatment, he said.
“When you’ve got nearly 99% of the men surviving and not dying of prostate cancer at the ten-year mark, that’s obviously a very good way to manage low-risk prostate cancer,” he said.
Emeritus Professor Bruce Armstrong, at the School of Public Health at Sydney University, said the study supported the Australian guidelines released earlier this year, and reinforced the merits of each relative therapy.
While surgery and radiation plus androgen therapy had similar mortality outcomes at 10 years, surgery was associated with poorer sexual and urological function, whereas bowel function was worse after radiotherapy.
NEJM; online 14 September