Active surveillance — in which prostate cancer is regularly monitored for signs of progression — spares men whose tumors may never progress from potential treatment-associated adverse effects, such as sexual dysfunction or incontinence.
This approach is especially common among men who are older and have limited life expectancies, as well as among younger men who want to ensure they maintain a high quality of life until treatment becomes necessary.
“Active surveillance does not mean ‘don’t treat,’” Matthew R. Cooperberg, MD, MPH, associate professor of urology and epidemiology & biostatistics at University of California, San Francisco, told HemOnc Today. “It means, ‘Don’t treat now and follow carefully with every intention of cure if there is progression.’”
The strategy has gained considerable acceptance. In community-based practices, the percentage of men with low-risk disease who underwent active surveillance climbed steadily from 6.7% in 1990 to 14.3% in 2009, a study by Cooperberg and colleagues showed. Between 2010 and 2013, the figure exceeded 40%.
Proponents contend active surveillance is a viable option because mortality rates among men whose tumors are limited to the prostate are low, and many of these men never experience symptoms from their disease.
However, some urologic oncologists question active surveillance as a standard management strategy and contend its use should be limited.
They emphasize repeat biopsies — necessary to monitor for disease progression during active surveillance — can still negatively affect quality of life. Questions also remain about whether risk stratification is an appropriate guide for active surveillance.
The debate about whether active surveillance is suitable for patients with intermediate-risk disease — who may sacrifice the chance to have their cancer treated at its most curable stage — is particularly contentious.
“By definition, the number of men who die because they went on surveillance is very low but cannot be zero — that’s the law of nature in cancer,” Cooperberg said. “If you have thousands of men on active surveillance, a few of them are going to miss the window. But, this number is likely much smaller than the number of men seriously harmed by avoidable surgery or radiation therapy.”
HemOnc Today spoke with oncologists and urologists about the benefits and risks of active surveillance, the factors that most affect risk stratification, the differences between active surveillance and “watchful waiting,” and how disparities among black patients may affect their outcomes in this setting.
An established approach
Monitoring disease rather than immediately commencing treatment is not a new concept. Active surveillance is a new way to describe — with modifications — what used to be known as watchful waiting.
Chodak and colleagues published data in 1994 in The New England Journal of Medicine that showed men with grade 1 or grade 2 prostate cancer could safely undergo conservative management and delayed hormone therapy without significantly affecting DFS.
Watchful waiting became common among men with well-differentiated and moderately well-differentiated cancers.
Today, these categories would refer to men with Gleason scores between 2 and 7. Because tumor grade can vary within a biopsy, Gleason scores are calculated by adding the most common Gleason grade in the sample with the highest grade to predict the likelihood of disease progression.
The concept of active surveillance involves more intense monitoring than watchful waiting, usually through frequent tests such as annual or biennial biopsies.
“Since we believed in watchful waiting in the past, it makes sense we can continue a more focused surveillance approach for men who are unlikely to progress,” Daniel B. Rukstalis, MD, urologic oncologist and professor of urology at Wake Forest University School of Medicine, told HemOnc Today. “Active surveillance is an evolutionary step from what we knew worked for most men — simply watchful waiting. The word ‘active’ implies that we are going to do more than simply the first biopsy. We know more about the cancer now and, therefore, we can make a better guess as to which patient is going to progress in his healthy lifetime.”