Purpose This study proposed the optimal definition of biochemical recurrence (BCR) after salvage radiotherapy (SRT) following radical prostatectomy for prostate cancer. Materials and Methods Among 1,117 patients who had received SRT, data from 205 hormone-naïve patients who experienced postSRT prostate-specific antigen (PSA) elevation were included in a multi-institutional database. The primary endpoint was to determine the PSA parameters predictive of distant metastasis (DM). Absolute serum PSA levels and the prostate-specific antigen doubling time (PSA-DT) were adopted as PSA parameters. Results When BCR was defined based on serum PSA levels ranging from 0.4 ng/mL to nadir+2.0 ng/mL, the 5-year probability of DM was 27.6%-33.7%. The difference in the 5-year probability of DM became significant when BCR was defined as a serum PSA level of 0.8 ng/ml or higher (1.0-2.0 ng/mL). Application of a serum PSA level of ≥ 0.8 ng/mL yielded a c-index value of 0.589. When BCR was defined based on the PSA-DT, the 5-year probability was 22.7%-39.4%. The difference was significant when BCR was defined as a PSA-DT ≤ 3 months and ≤ 6 months. Application of a PSA-DT ≤ 6 months yielded the highest c-index (0.660). These two parameters complemented each other; for patients meeting both PSA parameters, the probability of DM was 39.5%-44.5%; for those not meeting either parameter, the probability was 0.0%-3.1%. Conclusion A serum PSA level > 0.8 ng/mL was a reasonable threshold for the definition of BCR after SRT. In addition, a PSA-DT ≤ 6 months was significantly predictive of subsequent DM, and combined application of both parameters enhanced predictability.
|Number of pages||9|
|Journal||Cancer Research and Treatment|
|Publication status||Published - 2022 Oct|
Bibliographical noteFunding Information:
The au hor thank D in ee im at eimng niesit ong san M dical Cente,r D nang im at Chngnam ational ni versity College of Medicine, . DrJi oY ng Jang at Chosun University H spital, .D S J g S im at E j H spital, D oY ng im at Jeju National University Medical Cente r . Dr Dong Soo Lee at Uijeongbu St. Mary’s Hospital, and . Dr Ah Ram Chang at Soon chunhyang University Hospital for patient accrual. This study was supported by a National Cancer Center Grant (NCC 1910300-3) and the Korean Radiation Oncology Group. The funding source had no role in the study design, data curation, or analy - sis and interpretation of data.
© 2022 Korean Cancer Association. All rights reserved.
All Science Journal Classification (ASJC) codes
- Cancer Research