Weighing in on Active Surveillance
Advocates of active surveillance say it’s effective because mortality rates are low among men whose tumors are limited to the prostate, and many of these men do not have symptoms from the disease. The main advantage of active surveillance is that men whose tumors may never progress to a life-threatening state avoid potential adverse effects associated with treatment, such as sexual dysfunction or incontinence.
HemOnc Today interviewed a number of oncologists and urologists about the benefits and risks of active surveillance for an in-depth article published in September, “Active surveillance redefines paradigm for prostate cancer management.” Dr. Catalona is one of the experts cited extensively in the article.
Dr. Catalona cautioned that weighing the harms and benefits of active surveillance versus early treatment is complex. He said, “If somebody is incontinent or has erectile dysfunction after a radical prostatectomy, he can be treated for those conditions and can live a pretty normal life. But if you have metastatic prostate cancer or die of prostate cancer, that’s a pretty terrible outcome.”
Risks of cancer of spreading
Dr. Catalona told HemOnc Today that 40% of men who fulfill the criteria for active surveillance and undergo radical prostatectomy have higher Gleason-grade cancer in their prostate or have cancer that has spread to the margins of the prostate or beyond. “These patients who seem to be good candidates for active surveillance really are not. In studies that have good long-term follow-up, only about half of patients who enrolled in active surveillance but later had to undergo radiation or surgery had curable disease,” he said.
Downsides of frequent biopsies
Dr. Catalona also said that the frequency with which patients on active surveillance need to undergo biopsies to monitor their disease is problematic. The procedures can be painful and expensive, and some lead to sepsis or other adverse effects. “After biopsies, patients can get scarring around their prostate, and if they are found to need a nerve-sparing prostatectomy, it can be a lot more difficult because they had several biopsies,” he said.
Stratifying patients by risk
Low-risk prostate cancer is generally defined as a Gleason score of 6 or lower. Intermediate-risk is generally considered to have a Gleason score of 7 or a PSA between 10 and 20.
Some organizations, including the National Comprehensive Cancer Network and the American Urological Association, recommend active surveillance for lowrisk disease. However, many physicians feel active surveillance is underused because not all patients with low-risk disease are interested delaying treatment.
Research offers conflicting data on the effectiveness of active surveillance for men with intermediate disease. A 2014 study found that 94.3% of patients with intermediate-risk prostate cancer were still alive at 15 years, and 55% of these men were still being treated with active surveillance. However, a 2015 Canadian study showed that men with intermediaterisk prostate cancer on active surveillance were 3.75 times more likely to die from prostate cancer than patients with low-risk disease.
Clinicians may also need to take ethnicity into account when offering active surveillance. African American patients are diagnosed with prostate cancer more frequently than Caucasian men, and African American men are more likely to have high-grade disease. Current diagnostic approaches do not necessarily account for this.
There is a critical need for scientific research to find biomarkers of aggressive disease in patients with prostate cancer. This will help identify which patients can be safely managed with active surveillance, and which need immediate treatment.
Dr. Catalona’s SPORE research project is involved in these research efforts. The project’s goal is to identify genetic variants that lead to the failure of active surveillance for prostate cancer.