Survival Trend in Individuals With De Novo Metastatic Prostate Cancer After the Introduction of Doublet Therapy

Abstract

ImportanceRecently, life-prolonging treatments for patients with advanced prostate cancer have been introduced in clinical practice.ObjectiveTo investigate if the introduction of doublet therapy is associated with changes in survival on a population-basis.Design, Setting, and ParticipantsThis nationwide population-based cohort study used data from the Prostate Cancer data Base Sweden from 2008 to 2020. Men registered with de novo metastatic castration-sensitive prostate cancer (mCSPC) were included.ExposureThe proportion of men with mCSPC who received doublet therapy, ie, androgen deprivation therapy plus androgen receptor pathway inhibitor drugs or chemotherapy was assessed.Main Outcomes and MeasuresStandardized overall survival, taking age, comorbidity, and cancer characteristics into consideration, was estimated by use of a parametric survival model.ResultsA total of 11 382 men were included in this study (median [IQR] age, 74.0 [68-81] years). There was a shift toward less advanced prostate cancer during the study period with a decrease in median (IQR) prostate-specific antigen at diagnosis in men with mCSPC from 145 (39-571) ng/mL to 107 (27-426) ng/mL. Upfront treatment with doublet therapy in these men simultaneously increased from 1% (7 of 991) in 2016 to 44% (402 of 922) in 2020. The adjusted 5-year overall survival increased from 26% (95% CI, 25%-28%) from 2008 to 2012 to 35% (95% CI, 31%-40%) from 2017 to 2020. During the first 5 years after diagnosis, there was an increase in mean survival of 6 months, from 2.7 (95% CI, 2.6-2.8) years from 2008 to 2012 to 3.2 (95% CI, 3.1-3.1) years from 2017 to 2020.Conclusions and RelevanceIn parallel with improvements in treatment of advanced prostate cancer, a clinically meaningful increase in mean survival was observed in men with de novo mCSPC in Sweden between 2008 and 2020 in this study.