Patients with high-risk localized prostate cancer (HR LPC) are at significant risk of developing systemic or local recurrence as well as symptoms and/or death from the disease.¹ While there is a range of treatment options available, including radical prostatectomy (RP), radiation therapy with or without androgen deprivation therapy (ADT), and chemotherapy, there is currently no consensus on the optimal treatment for these patients.¹ The role and benefits of using neoadjuvant or adjuvant ADT in HR LPC patients are also inconclusive, especially among Asia-Pacific patients treated with RP and perioperative hormonal therapy (HT).¹ As such, this retrospective observational study was performed to describe the real-world clinical characteristics and treatment patterns of HR LRPC patients in Japan, South Korea and Taiwan.¹

In this study, clinical characteristics and treatment data from chart review at five sites in Japan and data from electronic medical records of three medical centers in Korea and a multi-hospital system in Taiwan were utilized.¹ Newly diagnosed prostate cancer patients ≥18 years of age who had exactly one high-risk feature as per National Comprehensive Cancer Network (NCCN) prostate cancer guidelines (cT3a, Gleason Grade Group 4 or 5, or Prostate-specific antigen [PSA] >20ng/mL) were eligible.¹ These patients also received RP and had ≥3 months neoadjuvant HT (last dose given within 2 months before RP), and/or ≥6 months adjuvant HT (first dose given within 6 months after RP).¹ Considering differences in data collection methodology and clinical practice, data for Japan were reported separately from Korea and Taiwan.¹

Across sites in Japan and those in Korea and Taiwan, similar proportions of newly diagnosed HR LPC patients received RP (Japan: 72.6% [257 of 354 patients], Korea and Taiwan: 72.4% [490 of 677 patients]).¹ These rates are higher compared to previously published rates in the United States in 2013 (42.0%).¹ Moreover, a higher proportion of patients in Japan (20.3%) received RP + perioperative HT and were eligible for inclusion in the study, compared to 4.9% (n=33) of patients in Korea and Taiwan.¹ However, this observed lower percentage of patients in the Korea and Taiwan cohort may be because patients who received intermittent HT were not included in this study.¹

Robot-assisted RP was also the most common type of RP performed on HR LPC patients in both cohorts (Japan: 94.4%, Korea and Taiwan: 66.7%), followed by laparoscopic RP for the Japan cohort (5.6%), whereas open radical RP was more common in Korea and Taiwan (21.2%) compared to laparoscopic RP (12.1%).¹ In the Japan cohort, the majority of patients receiving perioperative HT received neoadjuvant HT (95.8%) for a median duration of 7.1 months, among which the most frequently used was LH-RH antagonist (75.4%), followed by the combination of first-generation anti-androgen with ADT (14.5%).¹ On the other hand, the majority of HR LPC patients receiving perioperative HT in the Korea and Taiwan cohort received adjuvant HT (93.9%) for a median duration of 11.2 months.¹ The most common adjuvant HT used in this cohort was the combination of first-generation anti-androgen with ADT (71.0%), followed by LH-RH agonist (16.1%), and first-generation anti-androgen only (12.9%).¹

The patient and clinical characteristics across the two cohorts were also compared.¹ The median age of patients was 73.5 (Q1-Q3: 68.0-78.0) years in the Japan cohort and 67.8 (65.1-71.5) years in the Korea and Taiwan cohort.¹ In both cohorts, the majority of patients had cT3a (Japan: 44.4%, Korea and Taiwan: 42.4%) and one-third of patients had Gleason grade group 4 or 5 at LPC diagnosis.¹ The median PSA at LPC diagnosis was also lower in the Japan cohort (9.3 [6.7-17.0] ng/mL) compared with the Korea and Taiwan cohort (11.1 [8.5-23.5] ng/mL).¹ Additionally, the majority (87.5%) of HR LPC patients in the Japan cohort had negative tumor margin after RP, compared with slightly less than half (45.5%) of the patients in the Korea and Taiwan cohort.¹ The lower rate of positive margin observed in the Japan cohort is likely due to the high prevalence of neoadjuvant HT combined with chemotherapy used in this cohort.¹ Lastly, while the median duration of follow-up was 71.8 (64.3-75.7) months in the Korea and Taiwan cohort, this was only 11.7 (9.0-60.2) months in the Japan cohort due to a large number of patients being transferred back to their referring institution after receiving RP from sites included in this study.¹

In summary, while the proportion of HR LPC patients receiving RP was similar within the Asia-Pacific region, clinical practice on the use of perioperative HT differed, with a higher frequency of neoadjuvant HT being used in Japan while adjuvant HT was more common in Korea and Taiwan.¹