Nobuaki Matsubara1, Yoko Yamada2, Ken-Ichi Tabata3, Takefumi Satoh3, Naoto Kamiya4, Hiroyoshi Suzuki4, Takashi Kawahara5, Hiroji Uemura5, Akihiro Yano6, Satoru Kawakami6, Masafumi Otsuka7, Satoshi Fukasawa7. 1. Department of Breast and Medical Oncology, National Cancer Center Hospital East, Chiba, Japan. Electronic address: nmatsuba@east.ncc.go.jp. 2. Department of Breast and Medical Oncology, National Cancer Center Hospital East, Chiba, Japan. 3. Department of Urology, Kitasato University School of Medicine, Kanagawa, Japan. 4. Department of Urology, Toho University Sakura Medical Center, Chiba, Japan. 5. Departments of Urology and Renal Transplantation, Yokohama City University Medical Center, Kanagawa, Japan. 6. Department of Urology, Saitama Medical Center, Saitama Medical University, Saitama, Japan. 7. Department of Urology, Chiba Cancer Center Hospital, Chiba, Japan.
Abstract
BACKGROUND: An important clinical question of great interest to clinicians is how to best sequence androgen receptor targeted agents (ARTAs) and chemotherapy for metastatic castration-resistant prostate cancer (mCRPC), but the answer is still unclear. MATERIALS AND METHODS: To evaluate and compare the clinical outcomes of ARTA and docetaxel (DTX) as second-line treatment in the post first-line ARTA, we conducted a retrospective analysis of chemotherapy-naive mCRPC patients who had received sequential treatment with ARTA followed by another ARTA (ARTA-ARTA) or ARTA followed by DTX (ARTA-DTX). RESULTS: A total of 97 patients were treated with the ARTA-ARTA sequence and 42 with the ARTA-DTX sequence. A prostate-specific antigen (PSA) response to the second-line treatment was observed in 18.6% in the ARTA-ARTA and in 33.3% in the ARTA-DTX sequence, but the difference in PSA response was not statistically significant (P = .057). The median progression-free survival (PFS) was significantly different between ARTA and DTX in the second-line treatment (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.24-0.59; P < .001). The favorable outcome in the ARTA-DTX sequence compared with the ARTA-ARTA sequence remained (HR, 0.51, 95% CI, 0.33-0.80; P = .004) in the combined PFS (first-line PFS + second-line PFS). However, no statistically significant difference in overall survival (OS) between the 2 groups was observed (HR, 0.60; 95% CI, 0.34-1.09; P = .095). In multivariate analysis, the ARTA-DTX sequence was identified as an independent prognostic factor for combined PFS, but not OS. CONCLUSION: ARTA-DTX might improve clinical outcomes in terms of second-line PFS and combined PFS, compared with the ARTA-ARTA sequence. However, this significance was not observed for OS.
BACKGROUND: An important clinical question of great interest to clinicians is how to best sequence androgen receptor targeted agents (ARTAs) and chemotherapy for metastatic castration-resistant prostate cancer (mCRPC), but the answer is still unclear. MATERIALS AND METHODS: To evaluate and compare the clinical outcomes of ARTA and docetaxel (DTX) as second-line treatment in the post first-line ARTA, we conducted a retrospective analysis of chemotherapy-naive mCRPC patients who had received sequential treatment with ARTA followed by another ARTA (ARTA-ARTA) or ARTA followed by DTX (ARTA-DTX). RESULTS: A total of 97 patients were treated with the ARTA-ARTA sequence and 42 with the ARTA-DTX sequence. A prostate-specific antigen (PSA) response to the second-line treatment was observed in 18.6% in the ARTA-ARTA and in 33.3% in the ARTA-DTX sequence, but the difference in PSA response was not statistically significant (P = .057). The median progression-free survival (PFS) was significantly different between ARTA and DTX in the second-line treatment (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.24-0.59; P < .001). The favorable outcome in the ARTA-DTX sequence compared with the ARTA-ARTA sequence remained (HR, 0.51, 95% CI, 0.33-0.80; P = .004) in the combined PFS (first-line PFS + second-line PFS). However, no statistically significant difference in overall survival (OS) between the 2 groups was observed (HR, 0.60; 95% CI, 0.34-1.09; P = .095). In multivariate analysis, the ARTA-DTX sequence was identified as an independent prognostic factor for combined PFS, but not OS. CONCLUSION:ARTA-DTX might improve clinical outcomes in terms of second-line PFS and combined PFS, compared with the ARTA-ARTA sequence. However, this significance was not observed for OS.