CHICAGO--Despite strong evidence of the effectiveness of watchful waiting for men with localized prostate cancer in a Swedish study, participants at the Prostate Cancer Shootout II conference remained unconvinced.
Expert panelists and members of the audience worried in particular about the age at which watchful waiting might be offered and the pathologic stage of the disease that might be best suited to conservative management.
In his presentation on watchful waiting, Jan-Erik Johansson, MD, assistant professor and chair of the Department of Urology, Orebro Medical Center, Orebro, Sweden, described a prospective cohort of 642 men who had been diagnosed with prostate cancer between 1977 and 1984. This group included 300 men with localized disease, 223 of whom were placed on watchful waiting.
The 81% survival rate at 15 years for these men was identical to the rate achieved in the 77 men who had initial radical prostatec-tomy or radiotherapy. "Survival seems to be better than expected," Dr. Johansson said, "and patients avoid the risks and side effects associated with initial prostate cancer treatment."
David F. Paulson, M.D., chief of urologic surgery, Duke University Medical Center, took the stand against watchful waiting. Dr. Johansson's hypothesis, he said, is that "prostate cancer is a benevolent malignancy with little risk of death from progressive disease, and if you look at his data--the population he constructed and the outcomes--you reach that conclusion."
Dr. Paulson pointed out that the average age of the men first diagnosed with prostate cancer in the Johansson study was 72 years, which is seven years older than the average age of men treated with radical prostatectomy in the United States. "The population of patients in the Swedish study was older and therefore at increased risk for dying from causes other than prostate cancer," he said.
Most of the men in the Swedish study (66%) had grade 1 prostate cancer, which is equivalent to Gleason scores of 2 to 4. "Grade 1 or Gleason 2 to 4 has little biologic potential to produce death in a surgical series and is never associated with margin-positive residual disease," Dr. Paulson said. "This population is not representative of the overall population that presents for curative treatment in the United States."
The Johansson study consequently did not resolve the nagging question of when men should be offered conservative management, Dr. Paulson said. Because prostate cancer progresses with respect to tumor volume and Gleason score, he said he would not offer watchful waiting to men in their 40s or 50s with Gleason scores of 2 to 4.
"For elderly patients with low Gleason scores, watchful waiting is the best form of therapy, but it is not for the totality of patients with prostate cancer," Dr. Paulson said.
Dr. Johansson, however, would consider watchful waiting for men with grade 1 tumors because, according to his study, they tend to have good outcomes. He also would offer conservative management to men with grade 2 tumors if their life expectancy was less than 10 years and to those with grade 3 tumors if life expectancy was less than five years.
Watchful Waiting Rejected
After listening to the debate, only 9% of the audience agreed that a hypothetical 72-year-old man with Gleason score of 2 to 3 should be placed on watchful waiting; 37% opted for external beam radiotherapy, 36% for interstitial radiotherapy (brachytherapy), and 18% for radical prostatectomy.