EAU 2021: Salvage Therapies for PSMA PET/CT-Positive Nodal-Only Recurrent Prostate Cancer: Impact on Survival, Functional Outcomes and Health-Related Quality of Life

(UroToday.com) At the metastatic prostate cancer session at the European Association of Urology 2021 annual meeting, Dr. Alexander Kretschmer presented data assessing salvage therapies for PSMA PET/CT-positive node-only recurrent prostate cancer. The role of salvage lymph node dissection in the management of nodal-only recurrent prostate cancer remains controversial. While unfavorable long-term oncological outcomes have cast doubt on the value of salvage lymph node dissection as monotherapy in this clinical setting, comparative data with salvage lymph node radiation therapy as a therapeutic alternative is rare. In addition, the impact on health-related quality of life (HRQOL) has not been adequately evaluated yet. In the current study, Dr. Kretschmer and colleagues analyzed oncological, as well as functional, outcomes of patients with nodal-only recurrent prostate cancer treated with salvage lymph node dissection or salvage lymph node radiation therapy in a single academic tertiary care center.

           
Analysis was limited to patients that were diagnosed with nodal-only recurrent prostate cancer via PSMA-PET/CT. Salvage lymph node dissection was performed via open approach, and for salvage lymph node radiation therapy, radiotherapy dose regimens were normo- or slightly hypo-fractionated, with a boost to the PSMA PET-positive local recurrences within prostatic fossa and lymph nodes applied simultaneously. Questionnaires were sent to obtain functional and oncological outcomes, and EORTC QLQ-C30 and PR-25 questionnaires were used to assess HRQOL. Continence status was assessed using daily pad usage and the validated ICIQ-SF questionnaire. Cox regression models were used for multivariable analysis (p<0.05).

There were 138 patients included in the current analysis, including 71 in the salvage lymph node dissection arm and 67 in the salvage lymph node radiation therapy arm:

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The median follow-up was 47 months for salvage lymph node radiation therapy patients (IQR 40 – 61), and 33 months for salvage lymph node dissection patients (IQR 20–49; p<0.001). Peri-interventional androgen deprivation therapy (ADT) was administered to 89.6% in the salvage lymph node radiation therapy subgroup and only 5.6% among patients undergoing salvage lymph node dissection (p<0.001). Median ADT duration for salvage lymph node radiation therapy patients was 9 months (IQR 3–21), and 43 patients (65.2%) in the salvage lymph node dissection cohort underwent ADT during follow-up. The biochemical recurrence rate was 40.3% for the salvage lymph node radiation therapy group and 86.4% for the salvage lymph node dissection group (p<0.001). In multivariable analysis, salvage lymph node radiation therapy was confirmed as an independent predictor for increased biochemical recurrence-free survival (RFS; HR 0.08, 95% CI 0.04–0.14, p<0.001). Estimated mean metastasis-free survival (MFS) was 57.6 months (95% CI 51.4 – 63.8) for salvage lymph node radiation therapy patients and 39.5 months (33.4–45.6) for salvage lymph node dissection patients (HR 0.64, 95% CI 0.32-1.31, p=0.222):

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There were no significant differences regarding general HRQOL (QLQ-C30 global health status), daily pad usage, and ICIQ-SF scores between both subgroups:

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Dr. Kretschmer concluded his presentation with the following take-home messages:

  • In a large contemporary series of patients with nodal-only recurrent prostate cancer based on PSMA-PET/CT staging, there was a significantly increased biochemical RFS in patients undergoing salvage lymph node radiation therapy
  • There were no significant differences observed in MFS, and functional outcomes, including HRQOL

Presented By: Alexander Kretschmer, MD, LMU Munich, Dept. of Urology, Munich, Germany

Written By: Zachary Klaassen, MD, MSc – Urologic Oncologist, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2021 European Association of Urology, EAU 2021- Virtual Meeting, July 8-12, 2021.