Willingness of patients with biochemically recurrent prostate cancer (BCR) with positive 18F-dcfpyl PET/CT PSMA to monitor without treatment.

5104 Background: For patients that have a rising PSA and negative CT and bone scan after surgery or radiation, there are no therapies that have been shown to improve survival. This fact has not been changed by the approval of DCFPyL PET/CT PSMA, which can now define subclinical disease in patients with bone and CT scans that are otherwise negative. Treatment and outcome data in BCR is not equivalent to metastatic castration sensitive prostate cancer (mCSPC). Despite the lack of data for the optimal management for prostate cancer that is PSMA positive (ppBCR), many providers feel they must treat patients because patients are unwilling to monitor ppBCR over time. Methods: The NCI is currently accruing to a study (NCT05588128; goal n=250) designed to monitor patients with BCR to understand the evolution of PSMA imaging over time. Eligible patients have BCR and underwent definitive treatment (surgery and/or radiation therapy) > 6 months prior to enrollment. Required PSA minimum 0.5 ng/mL; Testosterone minimum 100 ng/dL. Baseline CT and Tc-99m bone scans must be negative. Initial PSMA assessments occur within 8 weeks of confirmed eligibility. Positive PSMAs will be repeated every 6 months and negative PSMAs are repeated every 12 months for up to 5 years. PSAs are collected every 3 months. Following each PSMA scan, patients are counseled on the results. Radiation and intermittent systemic therapies (for 6 months or less) are allowed on this trial. Results: 57 patients have enrolled on the study and have been evaluated with PSMA PET thus far. Median PSA value at enrollment is 3.65 ng/mL (range, 0.5-71.6 ng/mL). Median PSA doubling time is 11.3 months (range, 1.2-132.4 months). Median patient age is 71 years (range, 54-92 years old). Self-reported race/ethnicity as follows: 75% White, non-Hispanic, 12% Black, non-Hispanic, 3.5% White, Hispanic, 3.5% Other, Hispanic, 2% Asian, 4% Unknown. Of the first 57 patients enrolled who have had PSMA PET scans, 52 patients (91%) were found to have positive findings. Among these, 49 patients (94%) with ppBCR elected to monitor their disease until the next scan. Conclusions: This study (NCT05588128) is the first prospective trial to monitor ppBCR patients to better define the natural history of BCR in the PSMA era. This preliminary data from the ongoing study thus far suggests that with appropriate counseling and a follow-up plan, the majority of patients are willing to monitor ppBCR. Given that no data has demonstrated a survival advantage for BCR or ppBCR, it is important for providers to have balanced conversations with patients about the implications of ppBCR, which often results in an indolent disease course. Clinical trial information: NCT05588128 .