Herein,we discuss 18-year follow-up data from the Scandinavian Prostate Cancer Group-4 (SPCG-4) trial,a randomized study comparing observation and radical prostatectomy (RP) in patients with localized prostate cancer.The results of this study are contrasted with another study employing a similar randomization,the Prostate Cancer Intervention Versus Observation Trial (PIVOT).We highlight several key differences in study eligibility and enrollment that may account for distinct results,and describe how these datasets impact the complex landscape of therapy for localized prostate cancer.