Posted: Tuesday, August 30, 2022
Active surveillance of patients with clinically localized very low–risk, low-risk, or intermediate-risk prostate cancer is the recommended best practice treatment, according to the National Comprehensive Cancer Network Guidelines in Clinical Practice in Oncology. However, few studies are evaluating pharmacologic treatments to slow disease progression in patients under active surveillance. According to Scott A. Tomlins, MD, of Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, and colleagues, treatment with enzalutamide monotherapy demonstrated a 46% reduction in pathologic or therapeutic prostate cancer progression in patients with low-risk or intermediate-risk localized prostate cancer compared with active surveillance alone.
“Results suggest that enzalutamide may offer an alternative short-term treatment option for this patient population, potentially reducing the need for more aggressive treatment approaches,” the researchers concluded.
The phase II, open-label, randomized trial evaluated 227 patients with low-risk or intermediate-risk localized prostate cancer within 6 months of diagnosis. All patients were undergoing active surveillance. A cohort of 114 patients were treated for 1 year with 160 mg of enzalutamide plus active surveillance. A second cohort of 113 patients did not receive the study drug but continued active surveillance. Patients were monitored for 24 months after treatment.
The time to pathologic or therapeutic prostate cancer progression was observed in 32 patients (28.1%) in the treatment arm and in 42 patients (37.2%) in the active surveillance arm. Prostate cancer progression risk was reduced by 46% in the enzalutamide treatment arm versus the active surveillance arm (95% confidence interval [CI] = 0.33–0.89; P = .02). The 1-year incidence of pathologic or therapeutic prostate cancer progression was 7.9% with enzalutamide versus 23% with active surveillance. The 2-year incidence was 16.0% versus 16.4%, respectively (95% CI = 0.36–2.24; P = .81). Negative biopsy results at the 1-year follow-up were significantly lower in patients treated with enzalutamide versus active surveillance (95% CI = 1.76–6.92; P < .001).
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.