Presentation Authors: Eugenio Ventimiglia*, Milan, Italy, Mieke Van Hemelrijck, London, United Kingdom, Lars Lindhagen, Pär Stattin, Uppsala, Sweden, Hans Garmo, London, United Kingdom
Introduction: Due to limited follow-up time of active surveillance (AS) series, the safety of AS is still questioned. We present a state-transition model of men with prostate cancer (PCa) primarily managed with AS with a 30-year follow-up.
Methods: We created and applied a state-transition model for treatment trajectories with estimated states, state transitions, and transition probabilities in Prostate Cancer data Base of Sweden (PCBaSeTraject), using nationwide population-based data from 23,649 men diagnosed with PCa and managed with deferred treatment. Discrete time steps of four weeks were used to capture all transitions (PCBaSeSim) until death from PCa or other causes. We then simulated 100,000 men per each combination of age at diagnosis, range: 55-70 years, Charlson comorbidity index (CCI) 0, 1, and 2, modified NCCN PCa risk classification, very low-risk, low-risk, intermediate-risk with Gleason grade group 2, and PSA levels (range 1-10 ng/ml) with a follow-up of 30 years. PCa and other causes for death at age 85 were estimated for every combination, as well as the proportion of time without active PCa treatment (i.e. time on AS and post-AS watchful waiting/remaining lifetime). We then assessed trade-offs in terms of time without active PCa treatment from date of diagnosis until date of death or age 85 vs risk of PCa death.
Results: Among healthy men (CCI=0), the proportion who died of PCa death at age 85 among men diagnosed at age 70 was 4% for very low-risk PCa, 6% for low-risk and 7% for intermediate-risk. For men diagnosed at age 55, the corresponding percentages were 11%, 14%, and 16%. The mean proportion of time spent without active PCa treatment for men diagnosed at age 55 was 13/25 years (51%) for very low-risk PCa, 10/25 years (41%) for low-risk PCa, and 9/25 (35%) for intermediate-risk PCa; for men at age 70, the corresponding percentages were 10/13 years (78%), 9/13 years (70%), and 8/13 years (63%). Men with intermediate-risk PCa diagnosed below 60 years had little benefit in terms of time without active PCa treatment (35-39%) considering their high risk of PCa death (13-16%), whereas men older than 65 years with low-risk PCa had a larger benefit in terms of both longer time without active PCa treatment (53-70%) and lower risk of PCa death (6-8%).
Conclusions: In our state transition model with 30-year follow-up, AS was a safe treatment strategy in healthy men above 65 years with low-risk PCa.