1
|
Glicksman RM, Ramotar M, Metser U, Chung PW, Liu Z, Vines D, Finelli A, Hamilton R, Fleshner NE, Perlis N, Zlotta AR, Bayley A, Helou J, Raman S, Kulkarni G, Catton C, Lam T, Chan R, Warde P, Gospodarowicz M, Jaffray DA, Berlin A. Extended Results and Independent Validation of a Phase 2 Trial of Metastasis Directed Therapy for Molecularly Defined Oligometastatic Prostate Cancer. Int J Radiat Oncol Biol Phys 2022; 114:693-704. [PMID: 36031465 DOI: 10.1016/j.ijrobp.2022.06.080] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/23/2022] [Accepted: 06/21/2022] [Indexed: 12/30/2022]
Abstract
PURPOSE The role of metastasis-directed therapy (MDT) in molecularly defined oligorecurrent prostate cancer (PCa) remains irresolute. We present extended follow-up and an independent validation cohort of a prospective trial. METHODS AND MATERIALS This study consists of 2 sequential single-arm phase-2 trials of patients with biochemical recurrence (prostate specific antigen [PSA] 0.4-3.0 ng/mL) and negative conventional imaging after radical prostatectomy and postoperative radiation therapy. All patients underwent [18F]DCFPyL positron emission tomography/computed tomography. Patients with molecularly defined oligorecurrent prostate cancer underwent MDT with stereotactic body radiation therapy or surgery, without androgen deprivation therapy (ADT). The primary end point was biochemical response (≥50% PSA decline from baseline). Secondary end points included PSA progression-free survival and ADT-free survival. The sample size of 37 MDT patients was determined based on a Simon's 2-stage design with biochemical response rate >20%, and this design was also applied for the subsequent independent validation cohort. RESULTS Seventy-four patients underwent MDT: 37 each in the initial and validation cohorts. Both cohorts met the prespecified biochemical response rate and completed the planned 2-stages of accrual. For the pooled cohort, the median number of prostate specific membrane antigen positron emission tomography avid lesions was 2 and most (87%) recurrences were nodal. Sixty-four (87%) had stereotactic body radiation therapy and 10 (13%) had surgery. Median follow-up (interquartile range [IQR]) for the initial, validation and combined cohorts were 41 (35-46) months, 14 months (7-21), and 24 months (14-41), respectively. The biochemical response rates for the initial, validation and combined cohorts were 59%, 43%, and 51%, respectively. For the combined cohort, median biochemical progression-free survival was 21 months (95% confidence interval, 13-not reached), and median ADT-free survival was 45 months (95% confidence interval, 31-not reached). CONCLUSIONS Half of patients treated with MDT for molecularly defined-only oligorecurrent prostate cancer exhibited a biochemical response. This study provides necessary and validated evidence to support randomized trials aiming to determine whether MDT (alone or with systemic therapy) can affect clinically meaningful end points.
Collapse
Affiliation(s)
- Rachel M Glicksman
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Matthew Ramotar
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Ur Metser
- Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital and Women's College Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Peter W Chung
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Zhihui Liu
- Department of Biostatistics, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Douglass Vines
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Antonio Finelli
- Department of Surgical Oncology, Division of Urology, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Robert Hamilton
- Department of Surgical Oncology, Division of Urology, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Neil E Fleshner
- Department of Surgical Oncology, Division of Urology, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Nathan Perlis
- Department of Surgical Oncology, Division of Urology, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Alexandre R Zlotta
- Department of Surgical Oncology, Division of Urology, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Bayley
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Joelle Helou
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Srinivas Raman
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Girish Kulkarni
- Department of Surgical Oncology, Division of Urology, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Charles Catton
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Tony Lam
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Rosanna Chan
- Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital and Women's College Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Padraig Warde
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Mary Gospodarowicz
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - David A Jaffray
- TECHNA Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada; Divisions of Radiation Oncology and Diagnostic Radiology, MD Anderson Cancer Centre, Houston, Texas
| | - Alejandro Berlin
- Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada; TECHNA Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|