Short call.

Top Line: Do age and comorbidity influence the benefit of short course ADT for prostate cancer?

The Study: Prostate cancer treated with radiation almost always benefits from ADT. The problem is that the absolute benefit depends on the relative risk of developing distant metastatic disease or prostate cancer mortality. At ASTRO 2021, the results of RTOG 0815 showed that the addition of 6 months of ADT to dose-escalated prostate radiation for intermediate risk disease reduced biochemical recurrence risk (10% v 21%) but not overall survival (~90%) at 5 years. But we’ve also seen studies that show prostate cancer of any risk stratification derives benefit from concurrent and adjuvant ADT independent of dose. Finally, genomic classifiers are being explored as a way to identify disease that derives a greater benefit from ADT. What about the patient, though? This study took a second look at the RTOG 9408 trial to determine if patient-related competing risks of mortality influenced the benefit of short course ADT. As a reminder, 9408 showed improved OS at 10 years (but not 18) with the addition of 4 months ADT to non-dose escalated RT. Characteristics associated with distant metastasis and prostate cancer death included T2b disease, increasing grade, and increasing PSA. Increasing age and comorbidities were associated with a higher risk of non-cancer mortality. Among patients with low or favorable intermediate risk disease, 28.7% actually had a higher relative risk of prostate cancer mortality than non-cancer mortality. Those patients had improved event free survival with ADT. In contrast, 22.8% with unfavorable intermediate risk disease had a higher relative risk of non-cancer mortality than their risk of prostate cancer mortality.

TBL: Patients with favorable prostate cancer and a low risk of non-cancer mortality may derive a greater benefit from short course ADT with definitive radiation. | Mell, Eur Urol 2023