The analysis of active surveillance for Japanese young early-stage prostate cancer patients: From the PRIAS-JAPAN study.
Authors: Takuma Kato, Takahiro Kimura, Ryuji Matsumoto, Akira Yokomizo, Takuma Sato, Yoichiro Tohi, Haruki Kume, Koji Inoue, Hidefumi Kinoshita, Shinichi Sakamoto, Isao Hara, Hiroshi Fukuhara, Mikio Sugimoto
Journal: Journal of Clinical Oncology (2025)

351 Background: The current status of active surveillance (AS) for early-stage young Japanese patients is unknown. We examined it from the data of PRIAS-JAPAN, a multicenter prospective collaborative study of AS in Japan. Methods: Initially, low-risk patients with a PSA density (PSAD) &lt;0.2 and 2 or fewer positive cores were eligible. The eligibility criteria have since been revised accordingly, and from 2021, when MRI imaging was performed, the inclusion criteria allowed a PSAD of up to 0.25, no upper limit on the number of positive cores for Gleason score (GS) 3+3 cases, and up to half of the total number of positive cores for intermediate-risk GS 3+4 cases. PSA test every 3 months, rectal examination every 6 months, biopsy at 1, 4, 7, and 10 years, and every 5 years after that, and recommendation for secondary treatment after confirming pathological deterioration. The AS results and clinical outcomes were compared between the patients aged 60 years and younger (Young group: Y-group, n=165) and those over 60 years old (elderly group: E-group; n=1,109). Results: In the Y-group, the median age was 57 years, the median PSA at diagnosis was 4.8 ng/ml, the median prostate volume was 33.4 cm3, the median PSAD was 0.15 ng/ml/c m3,T1c was 149. At diagnosis, the Y-group had significantly smaller prostate volumes and a higher proportion of GS 3+3 cases than the E-group. The biopsy acceptance rate decreased with increasing (1 st , 2 nd , 3 rd, and 4th year: 81.8%, 70.3%, 34.4%, and 13.3%). The reclassification rate increased over time (1 st , 2 nd , 3 rd and 4th year: 28.7%, 30.8%, 27.3%, and 50.0%). The persistence rate of the Y-group decreased over time, with a 10-year persistence rate of 19.2%, with no significant difference between the two groups. The 10-year metastasis-free survival (MFS), 10-year overall survival (VS), and 10-year cancer-specific survival (CSS) rates of the Y-group were 98.8%, 98.9%, and 100%, respectively. Although OS was lower in the Y-group (p=0.051, HR=2.29. 95%CI 1.004-5.21), MFS and CSS did not significantly differ between the two groups. The Y-group was more likely than the E-group to choose prostatectomy (38.3%) as the next treatment, while they did not want hormone therapy (4,7%) or watchful waiting (6.5%). Conclusions: Although the Y-group was superior to the E-group in OS, there was no significant difference in MFS and CSS between the two groups. AS persistence rate Metastasis-free survival 3 year 5 year 10 year 13 year 3 year 5 year 10 year 13 year ≤60y.o 55.7% 39.9% 19.2% 17.1% ≤60y.o 100% 100% 99% 99% 60y.o&lt; 58.2% 38.5% 16.3% 12.0% 60y.o&lt; 100% 100% 99% 98% Overall survival Cancer-specific survival 3 year 5 year 10 year 13 year 3 year 5 year 10 year 13 year ≤60y.o 100.0% 100.0% 98.9% 95.3% ≤60y.o 100.0% 100.0% 100.0% 100.0% 60y.o&lt; 97.9% 97.0% 92.2% 88.7% 60y.o&lt; 99.9% 99.9% 99.9% 99.9%