(UroToday.com) The 2024 European Association of Urology (EAU) annual congress held in Paris, France between April 5th and 8th was host to an abstract session on treatment intensification to improve prostate cancer outcomes. Dr. Lotte Zuur presented the results of an analysis evaluating oncological outcomes following radical prostatectomy for patients with prostate-specific membrane antigen (PSMA) positron emission tomography computed tomography (PET/CT)–positive pelvic lymph node disease on staging work-up.
The potential benefits of radical prostatectomy for patients with PSMA PET/CT-positive pelvic lymph node prostate cancer have not been fully explored. The objective of this study was to assess the early oncological outcomes of patients with pelvic lymph node-positive prostate cancer at preoperative PSMA PET/CT who subsequently underwent a radical prostatectomy with extended pelvic lymph node dissection.
This was a single center retrospective analysis of patients who were staged as miN1M0, as per pre-operative PSMA PET/CT, between 2015 and 2022, and subsequently treated with radical prostatectomy + extended pelvic lymph node dissection. Patients who had received neoadjuvant treatment were excluded. Pathological characteristics and clinical data related to oncologic outcomes, such as persistent prostate-specific antigen (PSA), defined as PSA ≥ 0.05 ng/ml, biochemical recurrence (defined as PSA ≥ 0.2 ng/ml), and post-operative PSMA PET/CT scans, were retrospectively collected from electronic medical records.
This analysis included 64 patients staged as miN1M0, with a median follow-up of 27 months (IQR: 8 – 55 months). The mean patient age was 66 years (SD: 6.7 years). The median amount of positive lymph nodes on pre-operative PSMA PET/CT was 1 (IQR: 1–2). The median lymph node yield was 19 nodes (IQR: 16–25), and the median number of pathologically involved lymph nodes was 2 (IQR: 1–3). In total, 58 (91%) patients were staged as pN1, and 6 (9%) were staged as pN0. Accordingly, the positive predictive value of PSMA PET/CT in this setting was 91%. The median size of the positive lymph nodes was 5.4 mm (IQR: 3.0–9.0).
Among the 64 included patients, 35 (55%) had persistent PSA measurements post-operatively, and 46 (72%) developed early biochemical recurrence. The median time to biochemical recurrence was 8 months (IQR: 3–17 months).
All patients with biochemical recurrence underwent a PSMA PET/CT post-operatively. PSMA PET/CT demonstrated PSMA positive disease in 34/46 (74%) patients, with pelvic-only disease in 21/46 (46%) and outside the pelvic area (M1 disease) in 14/46 (30%) patients.
Based on these results, the investigators concluded that >70% of patients with pelvic lymph node-positive disease on pre-operative PSMA PET/CT developed biochemical recurrence within one year of undergoing a radical prostatectomy with an extended pelvic lymph node dissection. Additionally, a high proportion of patients demonstrated evidence of PSMA PET/CT-positive disease outside the pelvis at the first post-operative PSMA PET/CT. This suggests that patients with pelvic lymph node-positive prostate cancer on pre-operative PSMA PET/CT remain at high risk of underlying systemic disease and should be considered for multimodal approaches, including neoadjuvant therapy within the context of clinical trials.
Presented by: Lotte Zuur, MD, Netherlands Cancer Institute, Department of Urology, Amsterdam, The Netherlands
Written by: Rashid Sayyid, MD, MSc – Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @rksayyid on Twitter during the 2024 European Association of Urology (EAU) annual congress, Paris, France, April 5th – April 8th, 2024