Four factors recorded at diagnosis identify men with low-volume de novo metastatic hormone- sensitive prostate cancer whose survival is worse than high-volume disease

Abstract Treatment intensification in metastatic castration-sensitive prostate cancer is guided largely by CHAARTED disease volume, yet low-volume disease is not homogeneous and some men die early. We analysed 16,530 men with de novo metastatic prostate cancer diagnosed in 2018–2023 in SEER Research Plus, restricted to biopsy-confirmed adenocarcinoma with a recorded PSA. Of every variable recorded at diagnosis, four separated clearly from the rest in a multivariable Cox model: age 80 years or over, PSA 100 ng/mL or above, liver or brain metastasis, and Gleason score 9 or above. Overall survival fell steadily with the number of factors present, by 1.67 (95% CI 1.62–1.73) per additional factor. Among 14,904 men without visceral metastasis, a group containing every low-volume man, those with two factors still did better than men with visceral metastasis, who are high volume whatever the bone count (hazard ratio 0.86, 0.79–0.94), whereas men with all three did worse (1.40, 1.24–1.59; median survival 25.7 versus 33.9 months). These 758 men were 5.1% of the non-visceral group, and 5.7% received chemotherapy against 32.0% of men with visceral metastasis. Four factors recorded at diagnosis therefore identify low-volume men whose survival is worse than high-volume disease, and who are least often treated. Clinical trial number: not applicable.