Characteristics of the Study PopulationPhysicians

The study participation request was sent to 682 urologists and 65 oncologists through the physician panel; 177 urologists and 5 oncologists who consented to participate in the study were recruited with a response rate of 24.4% (Fig. S1). Of these, 177 physicians who met the selection criteria proceeded to the main survey; 173 (97.7%) were urologists with an average experience of 22.3 years in clinical practice (Table 1, Table S4). The remaining four physicians (2.3%) were oncologists, with an average experience of 18.5 years. Overall, 42.4% (n = 75) of the physicians worked at a general hospital, 22.6% (n = 40) at a university hospital, and 20.3% (n = 36) at national and public hospitals. The average number of patients with PC seen by a physician per month was 52.4 (range 10–300).

Table 1 Physicians’ characteristicsPatients

Multiple consumer panels were used to send a request regarding study participation to 2,121,472 patients, of which 412,116 consented to participate in the study (response rate: 19.4%). Upon screening, 381 patients who met the selection criteria were eligible for the study, but 67 of them did not complete the survey, while the remaining 314 patients (mCSPC: 102; CRPC: 212) did. Data cleaning according to quality check criteria prescribed in the protocol resulted in 292 patients (mCSPC: 94; CRPC: 198) being analyzed (Table 2, Fig. S2). Overall, most resided in the Kanto region (42.5%), followed by Kansai (17.8%) and Chubu-Shinetsu (16.4%). The average age of the patients was 67.5 years, and 51.4% were not working at the time of the study (unemployed [retired]: 44.5%; unemployed [student, full-time homemaker, etc.]: 4.8%; leave of absence: 2.1%). Almost half the patients (49.3%) had an annual household income of < 5 million Japanese yen (JPY). Patients were first diagnosed with PC and metastatic PC at an average age of 63.0 years and 65.1 years, respectively. The average time since PC diagnosis was 4.6 years and that from metastatic PC diagnosis was 2.9 years. Most patients with mCSPC (86.2%) reported having bone metastasis. Among patients with CRPC, metastases were self-reported in 27.8% cases (bone or visceral organs, 20.2%; lymph nodes only, 7.6%). The mean prostate-specific antigen (PSA) level was 47.0 ng/ml in patients with mCSPC, and 22.7 ng/ml in those with CRPC.

Table 2 Patients’ characteristicsMedical Treatment

More than 90% of physicians had experience with prescribing conventional hormone therapies (androgen-deprivation therapy and combined androgen blockade or maximal androgen blockade) in mCSPC settings (Table S5). Overall, 72.9% of physicians had experience in prescribing docetaxel. Further, 88.1% and 83.1% of physicians prescribed enzalutamide and abiraterone, respectively.

In nmCRPC settings, more than half of the physicians had experience with prescribing enzalutamide (82.5%), abiraterone (68.4%), apalutamide (63.3%), and darolutamide (54.8%) (Table S5). In mCRPC settings, 87.6% and 76.8% of physicians had experience with prescribing chemotherapeutic agents such as docetaxel and cabazitaxel, respectively. Enzalutamide and abiraterone were prescribed by 93.8% and 89.8% of physicians, respectively.

Among patients with mCSPC, 17.0% had previously undergone bilateral orchiectomy (Table S6). The most common therapies that patients were receiving for mCSPC at the time of the study were bicalutamide (25.5%), abiraterone (24.5%), and denosumab (23.4%). About 22.3% of patients with mCSPC were receiving leuprorelin. Among patients with CRPC, leuprorelin (34.3%) and bicalutamide (22.2%) were the most common treatments. About 8.6% of patients with CRPC were receiving enzalutamide, and 7.1% were receiving abiraterone; 23.7% of patients with CRPC were not receiving any treatment at the time of the study.

Physician and Patient Preferences for the Treatment of mCSPCPhysicians

Physicians placed maximum importance on efficacy, with “Efficacy: 70 of 100 patients can survive for 5 years” being rated the most important (11.1%), followed by “Efficacy: Prevention of PSA elevation for 2 years in 90 of 100 patients” (10.8%) and “Efficacy: Spreading of metastases after 1 year can be prevented in 80 of 100 patients” (10.8%) (Fig. 1). After efficacy, physicians placed the most importance on “Target patients: Can be used for patients with cardiovascular disorders” (4.8%) and “Safety: Possible side effect of skin or body rash” (3.4%).

Fig. 1

Comparison of relative importance of items between patients and physicians in mCSPC settings. JPY Japanese yen, mCSPC metastatic castration-sensitive prostate cancer

Patients

Patients with mCSPC also placed maximum importance on efficacy, with “Efficacy: Spreading of metastases after 1 year can be prevented in 80 of 100 patients” (9.7%) being rated the most important, followed by “Efficacy: Prevention of PSA elevation for 2 years in 90 of 100 patients” (9.3%) (Fig. 1). The two were close enough to be ranked interchangeably in the results by utility values, suggesting that patients placed equal importance on preventing the spread of metastases and an increase in PSA (Fig. S3). After efficacy items, patients placed the highest importance on “Safety: Falls or fractures may occur as a side effect of the drug” (5.6%), and they were also sensitive to an increase in medical expenditures (difference of 3.35 points between levels, with “Medical expenditures: Increase of 10,000 JPY/month” being rated at 2.1% and “Medical expenditures: Increase of 35,000 JPY/month” rated at 5.4%).

Comparison of Relative Importance Between Patients and Physicians

Both physicians and patients placed maximum importance on efficacy (Fig. 1, Fig. S3). Physicians focused more on items directly related to survival, whereas maintaining good clinical conditions, including preventing the spread of metastases and PSA elevation, were more important for patients. After efficacy, physicians considered items related to target patients to be more important than other attributes. Patients, however, focused on safety and medical expenditures and were more sensitive to the increase in costs than physicians. Among items related to safety, patients considered falls or fractures to be most important in contrast to physicians, who focused on skin or body rash. For both patients and physicians, “Target patients: Can be used for patients with cardiovascular disorders” was the most important item related to target patients.

Physician and Patient Preferences for the Treatment of CRPCPhysicians

For the treatment of CRPC, physicians placed the maximum importance on efficacy, with “Efficacy: Development or spreading of metastases after 2 years can be prevented in 70 of 100 patients” being rated the most important (9.6%), followed by “Efficacy: PSA levels can be prevented from rising for 2 years in 70 of 100 patients” (9.3%) (Fig. 2). After efficacy, physicians placed the highest importance on “Target patients: Can be used for patients with cardiovascular disorders” (3.4%).

Fig. 2

Comparison of relative importance of items between patients and physicians in CRPC settings. CRPC castration-resistant prostate cancer, JPY Japanese yen

Patients

Similar to physicians, patients with CRPC placed the maximum importance on efficacy, with “Efficacy: Development or spread of metastases after 2 years can be prevented in 70 of 100 patients” being rated the most important (8.3%), followed by “Efficacy: PSA levels can be prevented from rising for 2 years in 70 of 100 patients” (7.9%) (Fig. 2). After efficacy, patients placed the highest importance on “Safety: Liver dysfunction may occur as a side effect of the drug” (4.7%).

Comparison of Relative Importance Between Patients and Physicians

Both physicians and patients placed the most importance on efficacy (Fig. 2, Fig. S4). Among items related to efficacy, physicians and patients considered preventing the development or spread of metastasis and PSA elevation to be most important. After efficacy, patients placed more importance on items related to safety and medical expenditures, whereas physicians were more concerned with target patients. Among items related to safety, patients focused on liver dysfunction, whereas for physicians, skin or body rash was more important. For both physicians and patients, the most important item related to target patients was “Target patients: Can be used for patients with cardiovascular disorders.”