Prostatectomy ‘Cures’ Disputed in Absence of Plateau of Patients With Undetectable PSA

Oncology NEWS International Vol 6 No 9, Volume 6, Issue 9

CHICAGO-Radical prostatectomy as treatment for men with localized prostate cancer came under attack by Kent E. Wallner, MD, at the Prostate Cancer Shootout II conference.

CHICAGO—Radical prostatectomy as treatment for men with localized prostate cancer came under attack by Kent E. Wallner, MD, at the Prostate Cancer Shootout II conference.

According to Dr. Wallner, associate professor of radiation oncology, University of Washington Medical Center, Seattle, “the men who do well after surgery are the ones who probably didn’t need to be treated in the first place.”

He also questioned whether so-called nerve-sparing radical prostatectomy preserves potency as well as many of its proponents claim, and argued that this surgery may not be eradicating cancer in men with localized prostate cancer.

The Prostate Cancer Shootout was sponsored by the Chicago Urological Society, Chicago Radiological Society, and Chicago Medical Society. For the second year, the conference presented debates on today’s methods of treating prostate cancer. (See the August 1997 issue for reports on the debates on brachytherapy, watchful waiting, and cryosurgery.)

Dr. Wallner used what he calls a simple definition of cancer “cure” to explain his concerns about the use of prostatec-tomy. Assuming that men with no evidence of rising levels of prostate-specific antigen (PSA) have been “cured” after treatment, Dr. Wallner looked for a point in time at which the percent of men with undetectable PSA levels plateaued following radical prostatectomy.

He cited a 1992 study of 230 men who had been followed for 144 months (J Urol 147:942, 1992), but he could not identify a time when the proportion of men with undetectable PSA leveled off.

One of the most widely quoted studies, of 894 men who underwent radical prostatectomy at Johns Hopkins Medical Center (Urol Clin North Am 28:713, 1994), also did not provide an obvious plateau in the time to PSA failure, in Dr. Wallner’s view. “The percent of men with undetectable PSA declines slowly over time because patients have slowly progressing disease,” he said.

Finally, Dr. Wallner pointed to a review of pooled data from eight institutions (JAMA 276:615, 1997) showing that 80% of patients with well-differentiated prostate cancer were free of metastasis at 10 years. However, the percent of these patients with undetectable PSA continued to decline. “Maybe at 15 or 20 years we will see a more convincing plateau, but right now we don’t see it,” he said.

“I’m not sure why some studies continue to show a progressive decline in the number of men with undetectable PSA after prostatectomy,” David F. Paulson, MD, chief of urologic surgery, Duke University Medical Center, said in response to Dr. Wallner’s presentation.

However, Dr Paulson noted, “if you look at the data on margin-positive disease, by 22 months after radical prostatectomy, 80% of patients have PSA failure and 20% do not. This would suggest that some patients with pathologic margin-positive disease are biochemical cures."

In addition, Dr. Paulson said, the only randomized comparison of radical prostatectomy and external beam radiation showed a clear advantage for surgery. Only 12% of men who underwent radical prostatectomy had clinically detectable recurrence of prostate cancer at five years, as opposed to 34% of men who received radiotherapy.

Both physicians agreed that the number of men who remain potent after even nerve-sparing radical prostatectomy is not very high. “In the community, the ability to preserve potency is probably around 10% to 12%, maybe 15% in a highly selective patient population,” Dr. Paulson said.

He insisted that the desire to preserve potency should not take precedence over the opportunity to remove prostate cancer. “My philosophy is that it is never reasonable to sacrifice an attempt for cancer control for potency-preserving surgery, particularly when drugs are available that can turn a 60-year-old back to a 35-year-old in terms of potency,” Dr. Paulson said.

However, Dr. Wallner pointed out that at least 50% of men stop administering the injections to promote erections within a few years.

“As with all quality-of-life issues, you can’t just tell patients what will happen in the next two years but also what will happen in the next few years,” he commented. “And over time, the quality-of-life issues are much less favorable following surgery than radiotherapy.”