Epidemiology of men with synchronous metastatic prostate cancer diagnosis - A nationwide 26-year temporal analysis.

Background: Evolving imaging modalities, increased awareness, and prostate-specific antigen testing in men with synchronous metastatic prostate cancer (mHSPC) are expected to have prolonged survival. Here we analyze trends in survival among men diagnosed with synchronous metastatic prostate cancer in Denmark.

Methods: Here, we included all men diagnosed with mHSPC (N = 12,017) in Denmark between January 1st, 1995, and December 31st, 2021. Men were followed until December 31st, 2022. Median time to death was calculated by the Kaplan Meier method and the 3-year risk of prostate cancer death per calendar year was estimated by the Aalen-Johansen estimator from time of diagnosis.

Findings: Median follow-up was 9 years (IQR: 4-15), from 2015 59 % of the men with mHSPC had treatment beyond androgen depletion therapy. Median survival increased from 1.7 years (IQR: 1·3-2·0) to 3.8 years (IQR: 3·3-4·2) in men diagnosed in 1995 and 2018, respectively (p < 0·001), after which median survival was not reached. The prostate cancer-specific mortality three years after diagnosis decreased from 66 % (95 %CI: 60-72) in 1995 to 28 % (95 %CI: 25-32) in 2019 (p < 0·001). From the period 1995-1999 to 2015-2021 median overall survival increased from 1·7 years (IQR: 0·8-3·7) to 4·5 years (IQR: 2·4-not reached; p < 0·001) in men age < 65 years and from 1·5 years (IQR: 0·7-2·9) to 3·1 years (IQR: 1·6-5·7; p < 0.001) in men older than 74 years at diagnosis.

Interpretation: The improved survival suggests that, among other contributing factors, implementing novel therapies has likely been efficacious outside the clinical trial setting. Still, most men diagnosed with synchronous metastatic prostate cancer will die of prostate cancer. As such the need for life-prolonging and age-tailored treatment trials remains evident.