Methods: The authors report on an ongoing clinical trial (NCT02430480) at a single institution recruiting treatment-naïve patients with intermediate risk (IR) (Gleason score [GS] 7, PSA 10-20, or stage T2b on magnetic resonance imaging [MRI]) or high risk (HR) (GS 8, PSA >20, or stage T3) PCa. Patients with distant metastases detected on imaging were excluded. All patients underwent MRI-transrectal ultrasound (TRUS)-guided fusion biopsy (Fbx), a six-month course of enzalutamide and goserelin, followed by MRI and RP. Evidence of BCR was monitored with PSA measurements.
Results: Up to this time point, 20 enrolled patients completed neoadjuvant treatment, MRIs, and robotically-assisted RP. Mean tumor volume decreased by 80.7% and 9/19 cases down-staged from clinical T3/T4 disease on pre-neoadjuvant MRI to pT2 disease on final pathology. 3 cases demonstrated pathological complete response. Post neoadjuvant MRI correctly staged 15/20 cases and 1 case was upstaged. Mean estimated blood loss was 355 (+/- 205) and a mean of 25 lymph nodes were dissected (17-37). Nerve-sparing was achieved in 15 cases with no complications noted.
Conclusion: mpMRI is an effective measure of treatment response and down-staging confirmed on final pathology after neoadjuvant therapy. Treatment response can be dramatic, but the degree of response varies between lesions from minimal response to complete response.
Speaker: Samuel Alexander Gold
Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, @GoldbergHanan, at the 18th Annual Meeting of the Society of Urologic Oncology, November 29-December 1, 2017 – Washington, DC