Postprostatectomy prostate cancer treated with radiation therapy: adverse features and androgen deprivation therapy use in a statewide consortium.

[BACKGROUND] The 2024 American Urological Association, American Society for Radiation Oncology, and Society of Urologic Oncology practice guidelines recommend early salvage radiation therapy (RT) for biochemical recurrence after radical prostatectomy and androgen deprivation therapy for high-risk features. Increasingly, men with high-risk disease are undergoing radical prostatectomy. We therefore characterized contemporary RT and androgen deprivation therapy practices within the Michigan Radiation Oncology Quality Consortium and Michigan Urological Surgery Improvement Collaborative.

[METHODS] Patients receiving postprostatectomy RT from June 9, 2020, to June 9, 2024, were eligible. Prospectively collected data included surgical pathology, RT, and androgen deprivation therapy details. RT was adjuvant (pre-RT prostate-specific antigen [PSA] <0.1 ng/mL), consolidative (persistent PSA ≥0.1), or salvage (all others). Multivariable analyses evaluated associations between clinicopathologic features and androgen deprivation therapy use.

[RESULTS] Among 345 patients across 26 centers, 56% had at least 1 high-risk feature: pT3b/T4 (24%), pN1 (6%), grade group 4/5 (30%), pre-RT PSA greater than 0.5 ng/mL (27%). RT was adjuvant (10%), consolidative (28%), or salvage (62%), initiated at median PSA of 0.07 ng/mL (interquartile range [IQR] = 0.03-0.09 ng/mL), 0.5 ng/mL (IQR = 0.3-1.5 ng/mL), and 0.3 ng/mL (IQR = 0.2-0.5 ng/mL), respectively. Median time to RT was 8, 6, and 29 months. A minority were recommended 24 months of androgen deprivation therapy (17%), and very few were recommended intensification with AR-pathway inhibitors (5%). On multivariate analysis, androgen deprivation therapy was associated with pT3b/T4 (odds ratio [OR] = 2.77, 95% confidence interval [CI] = 1.34 to 5.93), pN1 (OR = 6.22, 95% CI = 1.35 to 47.57), grade group 4/5 (OR = 2.87, 95% CI = 1.51 to 5.56), and pre-RT PSA more than 0.5 (OR = 2.11, 95% CI = 1.17 to 3.91).

[CONCLUSIONS] Within the Michigan Radiation Oncology Quality Consortium, more than half who received postprostatectomy RT had high-risk features; nearly 30% required consolidation for persistently positive PSA. Androgen deprivation therapy was associated with high-risk features, but few received androgen deprivation therapy prolongation or intensification. Studies are needed to personalize androgen deprivation therapy, especially for those with persistent PSA, who are frequently treated yet underrepresented in trials.