Active Surveillance Continues to Rise in Low- to Intermediate-Risk Prostate Cancer

William J. Catalona, MD

Across major guidelines, active surveillance is a recommended strategy for disease management in patients with low-risk prostate cancer. However, in clinical practice, there is still variability in whether oncologists choose to surveil or treat their patients.

New research based on AQUA Registry data shows a rapid increase in active surveillance for patients with low-risk prostate cancer in the past 10 years, but the variability in adoption still exists. The cohort evaluated included 84,596 men with newly-diagnosed prostate cancer who were treated between 2014 and 2019.

The patient population had a median age of 66 (61-72), and was 79.6% White, 15.9% Black, 1.8% Asian/Pacific Islander, 0.3% Native American, and 2.5% Other. Overall, 20.3% of the population was classified as low-risk.

Results from the study showed that active surveillance rates in the low-risk prostate cancer population increased from 29.6% in 2014 to 49.5% in 2019. In the intermediate-risk population, active surveillance rates rose from 10.4% in 2014 to 20.4% in 2019.

In an interview with Targeted Oncology™, William J. Catalona, MD, professor of Urology at Northwestern Medicine, Feinberg School of Medicine, reviewed the history of active surveillance in the prostate cancer space and how the practice has become more widespread in the United States.

TARGETED ONCOLOGY: How has active surveillance of patients with prostate cancer evolved over the years?

Catalona: Looking back, active surveillance was coined in England around 1990. At that time, almost all prostate cancers were detected in very advanced stages, and PSA screening had not been developed. But with the advent of PSA screening around 1990, they began to identify very low-risk prostate cancer in some very old and sick men. At that time, all these men were treated with radiation therapy, because surgery for prostate cancer had not really developed in England either. They thought to themselves, why should we put these elderly men who have a short life expectancy through radiation, and why don't we just watch them and see how they do. So, they did, and they called that active surveillance.

What they learned was that a lot of them live longer than anticipated. Some of them did very well for a long time, and their disease didn't progress. The concept of active surveillance then began came to the United States and Canada, and around the world, and younger men and healthier men became eligible, and it's still evolving at the present time.

What challenges do oncologists sometimes face when choosing surveillance over treatment?

When surveilling patients, it really must be acknowledged that we are rolling the dice to some extent, because we know from experience that 30% to 50% of them harbor worse cancer than we thought based mostly on sampling error in their biopsies. These men have to be watched. About half of them will do well long term, and the other half of them will be reclassified as having more aggressive disease and will need to go on to treatment. The challenge is really to be able to identify those who are harboring the more aggressive disease and treating them within the window of opportunity to cure them.

For a recent study, you and your fellow investigators utilized the AQUA Registry to look at active surveillance rates in the low-risk prostate cancer population. What can you tell us about this registry?

The AQUA Registry was really started by the AUA as a means for practicing urologists to report their outcomes to the Center for Medicare and Medicaid. It's mandated that doctors, in order to get compensated for taking care of Medicare and Medicaid patients, to report their outcomes. This became a big burden for individual practices and the AUA organized the AQUA Registry to provide this as a service to practice practicing urologists.

What was discovered through your analysis of the AQUA Registry data?

The results were presented at the AUA Annual Meeting by Matthew Cooperberg. It is sort of the latest update on active surveillance within the AQUA Registry, which now represents a large number of practices across the entire United States. A few years ago, maybe 10% or 15% of patients who had low-risk prostate cancer and would be considered reasonable candidates for active surveillance were adopting active surveillance. Then a few years ago, it was up to 30%. Now, what he is showing is that it's approximately 50%, so, it's increasing.

But there's tremendous variability in terms of individual practitioner and practices. So, yes, some practitioners will recommend doctors for active surveillance for 0% of their patients and some recommended for 100% of their appropriate patients. In large practices with multiple doctors, some doctors don't recommend active surveillance for any appropriate patients and some recommended for all. There's tremendous variability that needs to be taken care of.

How should future studies be conducted to confirm these findings?

These findings really need to be confirmed and in very large segments of the population. The studies would have to be national or international types of studies that represent all different socioeconomic groups and large enough patients to have robust data.

For community oncologists, what is your key advice on utilizing the active surveillance strategy?

Approximately 50% of patients who have low-risk prostate cancer really do not need immediate treatment, and the unlucky 50% will be classified as having more aggressive disease. The fault is probably in their genes and their environment. The real challenge is to be able to surveil the patients carefully to detect the cancer in time. The real stumbling block to this is it requires surveillance biopsies, and the biopsies are not pleasant, and they carry a risk for bleeding, infection, and also continued misclassification.

Many patients after having had 2 or 3 biopsies say, I'm not going to do biopsies anymore, so oncologists don’t have a good way to surveil them. Some think that the MRI scan, or some of the genomic markers would be a good substitute for the biopsies, but they're not adequate. That's really the main challenge for community oncologists is to keep the patients engaged and compliant with their surveillance regimen.

_REFERENCE:

_{Cooperberg M, Meeks W, Fang R, et al. MP43-03: Active surveillance for low-risk prostate cancer: time trends and variation in the AUA Quality (AQUA) Registry. J Urol. 2022;207(5): e740. doi: 10.1097/JU.0000000000002609.03}