Shared decision making, physicians' explanations, and treatment satisfaction: a cross-sectional survey of prostate cancer patients.

BACKGROUND: Hormone therapy is one option for some types of prostate cancer. Shared decision making (SDM) is important in the decision making process, but SDM between prostate cancer patients receiving hormone therapy and physicians is not fully understood. This study tested hypotheses: "Patients' perception of SDM is associated with treatment satisfaction, mediated by satisfaction with physicians' explanations and perceived effective decision making" and "The amount of information provided to patients by physicians on diseases and treatment is associated with treatment satisfaction mediated by patients' perceived SDM and satisfaction with physicians' explanations." METHODS: This cross-sectional study was conducted using an online panel via a private research company in Japan. The participants in this study were patients registered with the panel who had received or were currently receiving hormone therapy for prostate cancer and physicians registered with the panel who were treating patients with prostate cancer. Measures used in this study included a nine-item Shared Decision Making Questionnaire, levels of satisfaction with physicians' explanations and treatment satisfaction, and effective decision making for patients (feeling the choice is informed, value-based, likely to be implemented and expressing satisfaction with the choice), and a Shared Decision Making Questionnaire for Doctors. The hypotheses were examined using path analysis. RESULTS: In total, 124 patients and 150 physicians were included in the analyses. In keeping with our hypotheses, perceived SDM significantly correlated with the physicians' explanations and perceived effective decision making for patients, and satisfaction with physicians' explanations and perceived effective decision making for patients were both related to treatment satisfaction. Although the amount of information provided to patients was correlated with the perceived SDM, it was indirectly related to their satisfaction with physicians' explanations. CONCLUSIONS: When physicians encourage patients to be actively involved in making decisions about treatment through the SDM process while presenting a wide range of information at the start of hormone therapy, patients' effective decision making and physicians' explanations may be improved; consequently, the patients' overall treatment satisfaction may be improved. Physicians who treat patients with prostate cancer may have underestimated the importance of SDM before starting hormone therapy, even greater extent than patients.

Efficacy and safety of abiraterone acetate plus prednisone in Japanese patients with newly diagnosed, metastatic hormone-naive prostate cancer: final subgroup analysis of LATITUDE, a randomized, double-blind, placebo-controlled, phase 3 study.

BACKGROUND: LATITUDE was a randomized, double-blind, international and phase 3 study of abiraterone acetate plus prednisone in patients with high-risk metastatic hormone-naïve prostate cancer. In the first interim analysis of LATITUDE (clinical cutoff date: 31 October 2016), significant prolongation in overall survival and radiographic progression-free survival (co-primary endpoints) was observed when compared with placebo. The results of the Japanese subgroup analysis of LATITUDE first interim analysis were consistent with those of the overall population. In this study, overall survival and safety results from the final analysis of the Japanese subgroup of the LATITUDE study are presented (clinical cutoff date: 15 August 2018). METHODS: Abiraterone acetate (1000 mg/day) and prednisone (5 mg/day) were administered orally in the abiraterone acetate plus prednisone group, and matching placebos in the placebo group. RESULTS: Of the 1199 patients included in LATITUDE, 70 constituted the Japanese subgroup (abiraterone acetate plus prednisone: n = 35, placebo: n = 35). Following a median (range) follow-up of 56.6 (2.5, 64.2) months, the median overall survival was not reached in both the treatment arms of the Japanese subgroup (hazard ratio: 0.61; 95% confidence interval: 0.27-1.42; nominal P = 0.2502). A total of 23 deaths (abiraterone acetate plus prednisone: 9 [25.7%], placebo group: 14 [40.0%]) were reported in Japanese subgroup. Grade 3/4 adverse events were reported in 24 (68.6%) and 9 (25.7%) patients in the abiraterone acetate plus prednisone and placebo groups, respectively. CONCLUSIONS: In this Japanese subgroup analysis, addition of abiraterone acetate plus prednisone to androgen-deprivation therapy demonstrated favorable efficacy and safety outcomes in patients with newly diagnosed, high-risk metastatic hormone-naïve prostate cancer. Survival benefits observed in the Japanese subgroup first interim analysis were sustained long-term and were consistent with the overall population.