Active surveillance may not be the best option for patients diagnosed with intermediate-risk prostate cancer, results of a prospective study suggest.
Among 945 men managed with active surveillance, the risk of dying from prostate cancer within 15 years of diagnosis was nearly fourfold higher for those with an initial diagnosis of intermediate-risk disease than for those with low-risk disease.
Dr. Andrew Loblaw
“What surprised us was that their actually seemed to be a greater risk of dying of prostate cancer for patients diagnosed with intermediate risk disease and placed on surveillance,” said Dr. Andrew Loblaw, a radiation oncologist at Sunnybrook Health Sciences Centre in Toronto.
“When we actually stratify it by patients in the low-risk category, we see that [active surveillance] is a very safe and reasonable approach, and appropriate in our minds for low-risk patients, in line with the guideline recommendations. But despite the selection factors that we use in our clinic for intermediate-risk patients, we’re still seeing, at least in this analysis, greater risk of dying from prostate cancer, and we think that more research is needed to better identify the group of patients that may be watched conservatively,” he said in a media briefing held covering studies to be presented later at the 2015 Genitourinary Cancers Symposium, jointly sponsored by the American Society of Clinical Oncology (ASCO), American Society of Clinical Radiology (ASTRO), and Society of Urologic Oncology (SUO).
Dr. Charles J. Ryan, who moderated the briefing but was not involved in the study said that the findings are provocative.
Dr. Charles J. Ryan
“There are a number of things that we don’t know from these data. For example, did some of these patients who were on active surveillance go on to receive local therapy later, what were the subsequent therapies they received for metastatic disease, et cetera. But it is an important point to state the fact that some patients with intermediate risk do in fact die of prostate cancer,” said Dr. Ryan, an ASCO Expert with the departments of medicine and urology at the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center.
Ontario guidelines: ‘Preferred strategy’
Cancer Care Ontario guidelines for the management of low-risk prostate cancer state that “for patients with low-risk (Gleason score ≤ 6) localized prostate cancer, active surveillance is the preferred disease management strategy.”
In the United States, the National Comprehensive Cancer Network (NCCN) recommends active surveillance as an alternative to radiation or surgery in the management of men with low-risk prostate cancer and a life expectancy of 10 years or more. Active surveillance is not, however, recommended for men with intermediate-risk disease.