"The presenting T stage was borderline significant, while PSA at presentation, Gleason Score and age were not... the use of ADT for 12 months and time-to-nadir PSA remained significant."
https://pmc.ncbi.nlm.nih.gov/articles/PMC9743609/
(In the interest of a quicker read, I omitted some details from the excerpt below.)

Abstract
A nadir Prostate-Specific Antigen (nPSA) of 0.06 ng/mL has been shown to be a strong independent predictor of biochemical recurrence-free survival (bRFS) in patients with intermediate or high-risk (HR) prostate cancer treated with definitive external beam radiation therapy (RT) and androgen deprivation therapy (ADT). We aimed to examine the association between the duration of ADT and bRFS in HR localized prostate cancer, based on nPSA.

Methods
Between 1998 and 2015, 204 patients with HR localized prostate cancer were identified. Of them, 157 patients (77.0%) reached the desired nPSA of < 0.06 ng/mL (favorable group), while 47 (23.0%) did not (unfavorable group). Duration of ADT varied among patients depending on physician preference, patient tolerance, and/or compliance.

Results
In the favorable group, ADT for at least 12 months lead to superior bRFS compared to ≤ 9 months of ADT (P = 0.036). However, no significant difference was seen when examining the value of receiving ADT beyond 12, 18, or 24 months, respectively... analysis for bRFS, the use of ADT for at least 12 months was significant as well as time to nadir PSA (tnPSA), (≤ 6 vs > 6 months). The presenting T stage was borderline significant, while PSA at presentation, Gleason Score and age were not... the use of ADT for 12 months and tnPSA remained significant. In the unfavorable group, receiving ADT beyond 9 and 12 months was associated with improved bRFS. However, beyond 18 months, there was no significant difference.