Patient and treatment stratification for metastatic hormone-sensitive prostate cancer (mHSPC) is usually based on metastatic burden according to CHAARTED criteria, classifying high-volume disease as at least 4 bone metastases, one outside the axial skeleton, or one visceral metastasis. We aimed to examine the impact of the number of bone metastases independently of CHAARTED criteria.
Using the FRAMCAP (FRAnkfurt Metastatic Cancer database of the Prostate), time to castration resistant prostate cancer (ttCRPC) and overall survival (OS) were analyzed in patients with mHSPC stratified into 1 to 3 vs. 4 to 7 vs. ≥8 bone metastases, irrespective of axial skeletal location. Comparisons were made against CHAARTED low- and high-volume mHSPC outcomes.
Of 398 patients with mHSPC, 43% harbored 1 to 3, 19% 4 to 7 and 38% ≥8 bone metastases. CHAARTED high-volume mHSPC was diagnosed in 52%. Median ttCRPC was lowest for ≥8 bone metastases (16.2 months), followed by 4 to 7 (17.3 months) and 1 to 3 bone metastases (28.4 months; P < 0.01). Similar ttCRPC outcomes were observed when stratification was made into CHAARTED low- (28.4 months) vs. high-volume mHSPC (17.2 months). Median OS was also significantly shorter for ≥8 bone metastases (34.5 months), followed by 4 to 7 (53.3 months), and 1 to 3 (56.4 months; P < 0.001). Comparable OS outcomes were observed in CHAARTED low- (58.3 months) vs. high-volume mHSPC (43.4 months).
The number of bone metastases, regardless of their localization in the axial skeleton, has a significant influence on cancer-control outcomes. Especially, patients with ≥4 bone metastases have comparable outcomes to CHAARTED high-volume patients with mHSPC with at least one metastasis outside the axial skeleton.
Urologic oncology. 2026 Jul 12 [Epub ahead of print]
Mike Wenzel, Lena Theissen, Carolin Siech, Benedikt Lauer, Sophia Winkler, Maximilian Filzmayer, Chi Le, Clara Humke, Maximilian Kriegmair, Thomas Steuber, Felix K H Chun, Philipp Mandel
Department of Urology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Frankfurt, Germany. Electronic address: ., Department of Urology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Frankfurt, Germany., Urological Clinic Munich-Planegg, Planegg, Germany; Department of Urology and Urosurgery, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany., Martini-Klinik Prostate Cancer Center, University Hospital Hamburg-Eppendorf, Hamburg, Germany., Department of Urology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Frankfurt, Germany; Martini-Klinik Prostate Cancer Center, University Hospital Hamburg-Eppendorf, Hamburg, Germany.