Presentation Authors: Mohit Gupta*, Arnav Srivastava, Hiten Patel, Diane Reyes, Bruce Trock, Phuoc Tran, Mohamed Allaf, Trinity Bivalacqua, Herbert Carter, Ashley Ross, Alan Partin, Edward Schaeffer, Kenneth Pienta, Christian Pavlovich, Baltimore, MD
Introduction: Although men with newly-diagnosed oligometastatic prostate cancer have historically been treated with androgen deprivation therapy (ADT), emerging evidence suggests local treatment of the primary tumor may improve survival. Recent randomized trials have also demonstrated benefit from combination docetaxel with ADT for men with naive metastatic cancer. The use neoadjuvant chemo-hormonal therapy in conjunction with local consolidative treatment in this setting, however, has not previously been described. We present the initial surgical outcomes of a novel protocol.
Methods: A phase II study conducted at our institution began accruing patients in 2016. Men with newly diagnosed oligometastatic prostate cancer (T1-4, N0-1, M1a-b) consisting of â‰¤5 metastatic lesions were treated with the following: (1st) systemic therapy with up to 6 months of neoadjuvant ADT and 6 cycles of docetaxel+ADT, (2nd) consolidation with radical prostatectomy (RP) Â± adjuvant radiation therapy (XRT), and (3rd) Â± stereotactic radiation (SBRT) to oligometastatic lesions.
Results: To date, 18 patients have enrolled in the study: 17 have undergone RP and 1 is currently receiving neoadjuvant systemic therapy. For men undergoing surgery, median age was 58.0 years (IQR 55.0-64.0) with median follow-up of 10.1 months (IQR 4.1-13.2). Patients had a median 2 sites of metastases (IQR 1.0-3.0) and PSA 15.9 (IQR 7.2-66; range, 3.6-953) at diagnosis. Patients received a median of 12 months of ADT and 4 cycles of Docetaxel; median PSA after systemic therapy was 0.6 (IQR 0.2-1.6). Median operative time, blood loss, and length of hospitalization were 177.5 min (IQR 153.0-194.5), 200 ml (IQR 137.5-450.0), and 1 day (IQR 1.0-1.3), respectively. Six patients underwent open and 11 underwent robot-assisted RP with a 23.6% perioperative transfusion rate overall - 2 patients in the open group and 2 in the robot group. One patient (5.9%) experienced a Clavien grade II complication (hematuria with UTI); the other three experienced Clavien grade III complications (hematuria in 1 patient, bladder neck contractures requiring dilation in 2 patients). The majority (13 patients, 76.5%) had â‰¥ypT3a disease and 5 (47.1%) had positive surgical margins. Lymph node dissection yielded a median 13.5 nodes (IQR 9.8-22.3), and 7 (41.1%) men had lymph node metastases. Seven patients (41.1%) have undergone adjuvant XRT and 9 (52.9%) have completed SBRT, to date. All 17 patients thus far have obtained post-RP PSA levels, all of which are undetectable.
Conclusions: The combination of neoadjuvant chemo-hormonal therapy with definitive local therapy and SBRT for patients with oligometastatic prostate cancer appears feasible based on initial surgical outcomes. This management paradigm presents a possible future option for the treatment of men with oligometastatic prostate cancer. Longer-term safety, survival, and functional outcomes from this study are forthcoming.