(UroToday.com) The 2023 European Association of Urology (EAU) annual congress held in Milan, Italy between March 10th and 13th, 2023 was host to an abstract session of studies addressing long-term prostate cancer control outcomes. Dr. Antony Pellegrino presented the results of a study evaluating the effect of metastasis-directed therapy (MDT) on progression patterns of prostate cancer patients with evidence of biochemical recurrence and 68Ga-PSMA-PET/CT positive findings.
Dr. Pellegrino began by noting that in men with PSMA-PET/CT positive lesions for biochemical recurrence after radical prostatectomy, MDT is emerging as a popular treatment option that has been shown in a pooled analysis of ORIOLE and STOMP to improve progression-free survival from 6 to 12 months months (HR: 0.44, p<0.001).1 However, data regarding recurrence patterns post-MDT remain unclear. As such, this study aimed to explore MDT's effect on progression and biochemical recurrence outcomes in patients with positive PSMA-PET/CT scans.
To this end, the authors identified 226 patients who had biochemical recurrence post-radical prostatectomy and had positive 68Ga-PSMA-PET/CT findings, between 2016 and 2022. MDT consisted of stereotactic ablative radiotherapy (SBRT) to PSMA-positive lesions (node, bone, or visceral lesions). Clinical recurrence was defined as new metastases detected on imaging performed subsequent to the first PSMA-PET/CT. Patients were stratified into MDT (n=109) and no MDT groups (n=117).
Time to clinical recurrence was evaluated using Kaplan Meier curves. Per-lesion analysis using Pearson’s Chi square testing was performed to assess impact of MDT on location of clinical recurrence. The variation of recurrence sites compared to the location of positive spots at first PSMA-PET/CT (pelvic versus non-pelvic distant) were tested and represented using alluvial plots.
At a median follow-up of 24 months after the first PSMA-PET/CT, 73/226 patients had clinical recurrence. The three-year clinical recurrence-free survival rates were 51% for MDT versus 28% for no MDT.
The distribution of positive spots location at first PSMA-PET/CT did not differ significantly between men receiving and not receiving MDT (p=0.6). Similarly, in men with clinical recurrence after a positive PSMA-PET/CT (n=73), no statistically significant differences in terms of clinical recurrence and MDT use were detected (p=0.4).
A significant increase in the rate of distant metastases at clinical recurrence was reported in men not receiving MDT when results were compared to those at their first PSMA-PET/CT scan (from 77% to 86%). A reduction in the proportion of distant metastases at clinical recurrence was observed in patients receiving MDT (from 76% to 67%).
Dr. Pellegrino concluded that the use of MDT represents a protective factor for metastases during follow-up. Interestingly, the pattern of recurrence was influenced by the use of MDT, with a lower rate of clinical recurrence to non-pelvic distant sites. As such, salvage therapies might alter patterns of prostate cancer dissemination.
Presented by: Dr. Antony Pellegrino, MD, Division of Oncology – Unit of Urology IRCCS Ospedale San Raffaele Vita-Salute San Raffaele University, Milan, Italy
Written by: Rashid K. Sayyid, MD, MSc – Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @rksayyid on Twitter during the 2023 European Association of Urology (EAU) Annual Meeting, Milan, IT, Fri, Mar 10 – Mon, Mar 13, 2023.
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