Biochemical recurrence (BCR) after radical prostatectomy, as Dr. Tilki highlighted from her institution’s experience, is not infrequent as 20.3% of men in a sample of 14,532 patients experienced BCR at a median follow-up of 50.8 months.1 SLND represents a 4th treatment possibility for patients with lymph node specific metastasis in this setting, along with androgen deprivation therapy, radiotherapy, and observation. However, the EAU guidelines currently list SLND as a Grade C treatment recommendation, largely based on expert opinion. Dr. Tilki notes that among current retrospective studies (all <100 patients) of patients undergoing SLND, 22-59% of patients achieve complete biochemical response, although BCR occurs after SLND in the majority of patients. These studies suffer from a heterogeneous surgical approach, heterogeneous patient population and limited follow-up. Certainly, a positive 11C-choline and 18F-choline PET/CT correctly predicts the presence of lymph node metastasis in the majority of patients with BCR, however Dr. Tilki mentions that imaging likely underestimates the extent of nodal recurrence and is unable to detect micro-metastatic disease. At her institution, Dr. Tilki notes that even with PSMA-PET/CT, the PPV was 73.1% and NPV 88.7%, thus advocating for extended SLND.
Hopefully PSMA-radioguided surgery for detection of prostate cancer recurrence continues to advance and improve estimation of disease burden. However, as Dr. Tilki concludes, we do not know whether improved imaging modalities improves survival, or is possibly another source for over-diagnosis and over-treatment.
- Tilki D, Mandel P, Schlomm T, et al. External validation of the CAPRA-S score to predict biochemical recurrence, metastasis and mortality after radical prostatectomy in a European cohort. J Urol 2015;193(6):1970-1975.
Speaker: D. Tilki, Martini-Klinik, Hamburg, Germany
Written By: Zachary Klaassen, MD. Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre, at #EAU17 London UK, March 24 - 28, 2017.