(UroToday.com) The 2024 American Society of Clinical Oncology (ASCO) annual meeting featured a session on prostate cancer, and a presentation by Monique Williams discussing the willingness of patients with biochemically recurrent prostate cancer with positive 18F-DCFPyL PET/CT PSMA to monitor without treatment. 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 remains the case despite the approval of 18F-DCFPyL PET/CT PSMA, which can now define subclinical disease in patients with bone and CT scans that are otherwise negative or equivocal. Despite the lack of data for the optimal management for prostate cancer that is PSMA-positive biochemical recurrence, many providers feel they must treat patients because patients are unwilling to monitor PSMA-positive biochemical recurrence over time.
The NCI is currently accruing to a study (goal n = 250) designed to monitor patients with biochemical recurrence to understand the evolution of PSMA imaging over time. Eligible patients have biochemical recurrence and underwent definitive treatment (surgery and/or radiation therapy) > 6 months prior to enrollment. Required PSA minimum is 0.5 ng/mL and testosterone minimum is 100 ng/dL. Baseline CT and Tc-99m bone scans must be negative. Initial PSMA assessments occur within 8 weeks of confirmed eligibility, and 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 and 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. The trial design is as follows:
Thus far, 86 patients have enrolled on the study and have been evaluated with PSMA PET. The median PSA value at enrollment is 2.55 ng/mL (range, 0.5-71.6 ng/mL), median PSA doubling time is 11 months (range, 1.2-132.4 months), and the median patient age is 71 years (range, 54-92 years old). Self-reported race/ethnicity as follows:
- 81.4% White, non-Hispanic
- 13.9% Black, non-Hispanic
- 8% White, Hispanic
- 3.5% Other, Hispanic
- 1.2% Asian
Among the first 86 patients enrolled who have had PSMA PET scans, 77 patients (89.5%) were found to have positive findings. Among these, 67 patients (87%) with PSMA-positive biochemical recurrence elected to monitor their disease until the next scan.
Monique Williams concluded her presentation discussing the willingness of patients with biochemically recurrent prostate cancer with positive 18F-DCFPyL PET/CT PSMA to monitor without treatment with the following take-home messages:
- This study is the first prospective trial to monitor PSMA-positive biochemical recurrence patients to better define the natural history of biochemical recurrence 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 PSMA-positive biochemical recurrence
- Given that no data has demonstrated a survival advantage for biochemical recurrence or PSMA-positive biochemical recurrence, it is important for providers to have balanced conversations with patients about the implications of PSMA-positive biochemical recurrence, which often results in an indolent disease course
Presented by: Monique Williams, MS, PMP, National Cancer Institute, National Institutes of Health, Bethesda, MD
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, Wellstar MCG Health, @zklaassen_md on Twitter during the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting, Chicago, IL, Fri, May 31 – Tues, June 4, 2024.