To best employ radium-223 dichloride (Ra-223) for patients with castration-resistant prostate cancer (CRPC) and bone metastasis, we investigated the bone-predominant status in patients treated with Ra-223.
We retrospectively evaluated 127 CRPC patients who underwent treatment with Ra-223. The patients were divided into three groups based on the types of dynamic changes of bone metastasis between diagnosis and just before Ra-223: (a) only known lesions; (b) de novo lesions; (c) new progressive lesions. We developed the risk assessment using predictive factors based on progression-free survival (PFS).
During the median follow-up period of 10.4 months, the median PFS in the only known lesions group was 11.3 months compared to 8.1 months in the de novo lesions group and 5.1 months in the new progressive lesions group (P < .001). In multivariate analysis, the type of the new progressive lesions in bone metastasis (HR 1.45, 95% CI 1.13-1.66, P = .003), performance status of >1 (HR 1.74, 95% CI 1.04-2.89, P = .034), PSA value of >100 ng/mL (HR 1.59, 95% CI 1.02-2.50, P = .043), and PSA doubling time (PSADT) of <3 months (HR 1.53, 95% CI 1.11-2.03, P = .007) were independent unfavorable predictive factors for PFS. The risk assessment for PFS was highlighted when the type of dynamic changes of bone metastasis was combined with PSADT just before Ra-223 treatment. This was associated with non-bone metastasis progression, especially visceral metastasis, and overall survival.
Risk assessment in combination with dynamic changes of bone metastasis and PSADT determines the bone-predominant metastasis type to benefit from Ra-223.
Cancer medicine. 2020 Sep 22 [Epub ahead of print]
Kohei Hashimoto, Yasuhide Miyoshi, Tetsuya Shindo, Masakazu Hori, Yasumasa Tsuboi, Ko Kobayashi, Fumimasa Fukuta, Toshiaki Tanaka, Shintaro Miyamoto, Takeshi Maehana, Manabu Okada, Naotaka Nishiyama, Masahiro Yanase, Ryuichi Kato, Hiroshi Hotta, Yasuharu Kunishima, Atsushi Takahashi, Shiro Hinotsu, Koh-Ichi Sakata, Hiroshi Kitamura, Hiroji Uemura, Naoya Masumori
Department of Urology, Sapporo Medical University School of Medicine, Sapporo, Japan., Department of Urology and Renal Transplantation, Yokohama City University Medical Center, Yokohama, Japan., Department of Radiology, Sapporo Medical University School of Medicine, Sapporo, Japan., Department of Urology, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Toyama, Japan., Department of Urology, Sunagawa City Medical Center, Sunagawa, Japan., Department of Urology, Muroran City General Hospital, Muroran, Japan., Department of Urology, Asahikawa Redcross Hospital, Asahikawa, Japan., Department of Urology, Hakodate Goryoukaku Hospital, Hakodate, Japan., Department of Biostatistics, Sapporo Medical University School of Medicine, Sapporo, Japan.