Active Surveillance Is No Threat to Prostate Cancer Cure-So Far

Stacy Loeb, MD

Prostate cancer patients who chose active surveillance did not compromise their chances of a cure by waiting before they underwent radical prostatectomy, data from a Swedish registry showed.

Men who tried active surveillance before surgery had more high-grade disease when they had surgery. However, rates of biochemical recurrence, secondary therapy, and cancer-specific mortality did not differ significantly from those of men who had prostatectomy immediately after diagnosis, a researcher said in a presentation during the 2014 Annual Meeting of the American Urological Association in Orlando, Florida.

“Active surveillance followed by delayed radical prostatectomy does not compromise the opportunity for cure in the intermediate follow-up period,” said the researcher, Stacy Loeb, MD, assistant professor of Urology at NYU Langone Medical Center.

Commonplace in Canada and Europe, active surveillance for early prostate cancer has yet to win widespread support from physicians or patients in the United States. One possible explanation is that men and perhaps clinicians fear missing a window of opportunity to cure the disease, Loeb said. However, scant long-term data have accumulated to either validate or dispel the concern.

To provide missing data, Loeb and colleagues analyzed information from Sweden’s National Prostate Cancer Registry, which includes records for nearly all men diagnosed with prostate cancer in that country since 1998. The query identified 634 men who opted for active surveillance and subsequently underwent delayed prostatectomy. The cases were matched with 634 men who had surgery shortly after prostate cancer diagnosis. The men were matched by year of diagnosis, age, PSA, clinical stage, and biopsy Gleason grade at diagnosis.

Investigators compared outcomes for the two groups of men with respect to prostatectomy pathology, biochemical recurrence, secondary therapy, and cancer-specific mortality.

The patients were a median age of 62, and the delayed and immediate prostatectomy groups had a similar distribution of PSA levels, proportion with stage T2 disease, and biopsy Gleason grade 7. The principal difference between the groups was median time to prostatectomy, which was 0.3 year in the immediate group and 2.2 years in the delayed-prostatectomy group.

After adjustment for comorbidity burden, education, and marital status, members of the delayed-prostatectomy group did not differ significantly from those in the immediate group with respect to their odds of extraprostatic extension (odds ratio [OR] 1.1), biochemical recurrence (hazard ratio 1.2), or secondary therapy (subdistribution hazard ratio 1.3).

The delayed group did have a significantly greater risk of high-grade disease at the time of surgery (OR 1.8 versus the control group).

“Even though the delayed group did have a higher risk of upgrading at prostatectomy, that could have been the reason for the prostatectomy, that they were found to have upgrading during follow-up in surveillance,” Loeb said.

During a median follow-up of 7.1 years, overall mortality did not differ significantly between the two groups, and prostate-specific mortality was <1% in each group.

“Patients in both groups were much more likely to die of causes other than prostate cancer,” Loeb said.

Commenting on the difference in high-grade disease at surgery, Laurence Klotz, MD, a professor of Surgery at the University of Toronto, said that upgrading is not uncommon among men on active surveillance. The nature of the upgrade is what matters.

“Most of the upgrading is to Gleason 3+4,” said Klotz, who has been a principal investigator in one of the longest-running studies of active surveillance in North America, the Sunnybrook Active Surveillance Program at Sunnybrook Medical Center in Toronto. “To be upgraded to Gleason 8 or 9 is not very common.”

Reference

Loeb emphasized that the 7.1-year median follow-up is fairly brief for slow-growing prostate cancer. A median of 10 years or more, she said, would provide more assurance that delaying definitive treatment for early prostate cancer does not deprive patients of a chance for cure.Loeb S, Folkvaljon Y, Robinson D, Makarov D, Stattin P. Does active surveillance miss the window for cure? Matched comparison of immediate versus delayed prostatectomy in a nationwide population-based cohort. Presented at: the Annual Meeting of the American Urological Association; May 16-21, 2014; Orlando, Florida.

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