The Role of Active Surveillance in Managing Localized Prostate Cancer
An independent panel convened recently by the National Institutes of Health has concluded that many men with localized, low-risk prostate cancer should be closely monitored, permitting treatment to be delayed until warranted by disease progression. However, monitoring strategies – such as active surveillance – have not been uniformly studied, and available data do not yet point to clear follow-up protocols. The panel recommended standardizing definitions and conducting additional studies to clarify which monitoring strategies are most likely to optimize people’s outcomes.
“It’s clear that many men would benefit from delaying treatment, but there is no consensus on what constitutes observational strategies and what criteria should be used to determine when treatment might ultimately be needed among closely-monitored men,” says Dr. Patricia A. Ganz, conference panel chairperson and director of the Division of Cancer Prevention and Control Research at the Jonsson Comprehensive Cancer Center at the University of California in Los Angeles.
Identifying appropriate management strategies for different subgroups of people is critical to improving survival.
More than half of prostate cancers are localized (confined to the prostate), not aggressive at diagnosis, and unlikely to become life-threatening. However, approximately 90 percent of men receive immediate treatment, such as surgery or radiation therapy. For many of these men, treatment has substantial short- and long-term side effects, such as diminished sexual function and loss of urinary control, without clear benefits, such as improved survival. Identifying appropriate management strategies for different subgroups of people is critical to improving survival and reducing the burden of adverse effects.
Currently, clinicians often describe two alternatives to immediate treatment of low-risk prostate cancer: observation with and without the intent to cure. Observation without intent to cure, sometimes referred to as watchful waiting, is a passive approach, with treatment provided to alleviate symptoms if they develop. Observation with intent to cure, often referred to as active surveillance, involves proactive follow-up in which blood samples, digital rectal exams, and repeat prostate biopsies are conducted on a regular schedule, and curative treatment is initiated if the cancer progresses.
The panel identified emerging consensus in the medical community on a definition for low-risk prostate cancer: a prostate-specific antigen (PSA) level less than 10 ng/mL and a Gleason score of 6 or less. Using this definition, the panel estimated that more than 100,000 men diagnosed with prostate cancer each year would be candidates for active monitoring rather than immediate treatment. Importantly, however, the panel found that protocols to manage active monitoring still vary widely, hampering the evaluation and comparison of research findings.
“Prostate cancer affects some 30 to 40 percent of men over the age of 50. Some of these men will benefit from immediate treatment, others will benefit from observation. We need to standardize definitions, group patients by their risks, and conduct additional research to determine the best protocols for managing low-risk disease,” states Dr. Ganz.
The panel further recommended that disease terminology should be refined as a result of changes in the population of people with prostate cancer due to prostate-specific antigen (PSA) testing. Because of the very favorable prognosis of PSA-detected, low-risk prostate cancer, the panel recommended that strong consideration be given to removing the anxiety-provoking term “cancer” for this condition.
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