An independent panel convened by the U.S. National Institutes of Health has endorsed the use of active surveillance and delay of treatment for men with localized, low-risk prostate cancer.
"Our panel found that many men with localized, low-risk prostate cancer should be closely monitored, permitting their treatment to be delayed until disease progression warrants it. Some of the men affected by prostate cancer will benefit from immediate treatment and others will benefit from observation," panel and conference chairperson Dr. Patricia A. Ganz said in a telebriefing.
Dr. Patricia A. Ganz
However, monitoring or observational strategies, sometimes referred to as "watchful waiting" or "active surveillance," have not been uniformly studied, and available data do not yet point to clear follow-up protocols, said Dr. Ganz, director of the division of cancer prevention and control research at the Jonsson Comprehensive Cancer Center, University of California, Los Angeles.
The panel identified the combination of a prostate-specific antigen (PSA) level less than 10 ng/dL and a Gleason score of 6 or lower as the emerging consensus definition of "low-risk" disease. "Using this definition, we estimate that more than 100,000 men diagnosed with prostate cancer each year in the United States would be candidates for active monitoring rather than immediate treatment," she said.
Additional research will be needed to determine the point at which treatment might ultimately be needed for men who are being closely monitored. The panel recommended that such studies receiving federal funding should not be done at a single site, but rather should be multicenter studies with large patient populations.
The consensus about active surveillance came from increasing evidence that outcomes for men with low-risk disease are not better for those who undergo surgery or radiation therapy. Among the evidence considered was the newly reported findings of the Prostate Cancer Intervention Versus Observation Trial (PIVOT), the only randomized controlled trial conducted on men identified via PSA screening that compared watchful waiting with radical prostatectomy.
With a median follow-up of 10 years, there were no statistically significant differences in prostate cancer mortality or all-cause mortality. "Supporting data from additional cohort studies give us confidence that the risk of death is minimal in a low risk population," the panel wrote.
According to the document, only about 10% of men eligible for observational strategies choose this approach. The reasons for this are probably due both to physician communication that favors treatment and to patient expectations. "When men are given a diagnosis of cancer, it’s very difficult to decline the standard therapy for this disease, which is either surgery or radiation therapy," Dr. Ganz noted.
For this reason, the panel also endorsed consideration of a name change to remove the anxiety-provoking term cancer to describe this low-risk condition, much as was done with cervical intraepithelial neoplasia for early-stage cervical neoplasms and ductal carcinoma in situ for lower-risk breast lesions.
"Some of the men affected by prostate cancer will benefit from immediate treatment and others will benefit from observation."
They also discussed ways in which urologists and primary care physicians ordering PSA tests could be educated to counsel patients about the potential benefits of active surveillance and delaying treatment, Dr. Ganz said.
"Anything we can do to bring this into the consultation room so that the patient feels comfortable raising this issue with his physician ... [Stakeholders] now have an NIH-vetted document that describes this as a reasonable approach to the management of prostate cancer and for those reasons it can be very powerful," she said.
The 14-member state-of-the-science panel included experts in the fields of cancer prevention and control, urology, pathology, epidemiology, genetics, transplantation, bioethics, economics, health services research, shared decision-making, health communication, and community engagement.
Panel members were compensated for travel to the conference, but were not otherwise paid and have no additional conflicts of interest. The statement does not constitute federal policy.
The draft statement is posted online, and the final version will be posted by mid to late January 2012.