Real-world Treatment Selection and Shared Decision-making in De Novo Metastatic Castration-sensitive Prostate Cancer...

This study aimed to describe the selection of first-line treatment and early outcomes in patients with de novo metastatic castration-sensitive prostate cancer (mCSPC) after the introduction of triplet therapy in Japan.

We retrospectively investigated 46 patients with de novo mCSPC treated at a specialist Japanese cancer center between March 2023 and August 2025. The patients were grouped according to whether they received androgen deprivation therapy (ADT) alone (the monotherapy group), doublet therapy consisting of ADT and an androgen receptor signaling inhibitor (the doublet group), or triplet therapy consisting of ADT with docetaxel 70 mg/m² and darolutamide (the triplet group).

The median patient age was 73 years, and most patients had LATITUDE high-risk disease and CHAARTED high-volume disease. Patients in the monotherapy group were significantly older than those in the doublet group and triplet group (80 vs. 74 and 69 years, respectively, p<0.001). A prostate-specific antigen level of <0.2 ng/ml was detected in 27% of patients in the monotherapy group, 67% of those in the doublet group, and 63% of those in the triplet group, with ≥90% declines in 80%, 92% and 100%, respectively. In the triplet group, febrile neutropenia occurred in 5.3% of patients, interstitial pneumonitis in 5.3%, and peripheral neuropathy in 10.5%.

In Japan, treatment intensity in patients with de novo mCSPC is determined mainly by age rather than by metastatic burden.