title: Identifying optimal candidates for local treatment of the primary tumor among patients diagnosed with metastatic prostate cancer: a SEER-based study.
abstract: A recent study observed a survival benefit in men diagnosed with metastatic prostate cancer (mPCa) and managed with local treatment of the primary tumor (LT; either radical prostatectomy plus pelvic lymph node dissection or radiation therapy). We tested the hypothesis that only specific mPCa patients would benefit from LT and that the potential benefit would vary based on primary tumor characteristics. A total of 8197 mPCa patients at diagnosis (M1a, M1b, and M1c) were identified using the Surveillance Epidemiology and End Results database (2004-2011) and were divided according to treatment type: LT versus nonlocal treatment of the primary tumor (NLT; either androgen deprivation therapy or observation). Multivariable Cox regression analysis was used to predict cancer-specific mortality (CSM) in patients that received NLT. To assess whether the benefit of LT was different by baseline risk, we tested an interaction with CSM risk and LT. At multivariable analysis, all predictors were significantly associated with CSM, and the interaction test was statistically significant (p<0.0001). Local treatment of the primary tumor, compared with NLT, conferred a higher CSM-free survival rate in patients with a predicted CSM risk <40%. The number needed to treat according to the predicted CSM risk at 3 yr after diagnosis remained substantially constant from 10% to 30%, whereas it exponentially increased for predicted CSM risk >40%. These results should serve as a foundation for future prospective trials.
  
  
  RESULTS
  Among metastatic prostate cancer patients, the potential benefit of local treatment to the primary tumor depends greatly on tumor characteristics, and patient selection is essential to avoid either over- or undertreatment.
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA; Division of Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Fossati
authors.affiliation: Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Quoc-Dien
authors.initials: QD
authors.lastname: Trinh
authors.affiliation: Vattikuti Urology Institute and VUI Center for Outcomes Research Analytics and Evaluation, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Jesse
authors.initials: J
authors.lastname: Sammon
authors.affiliation: Vattikuti Urology Institute and VUI Center for Outcomes Research Analytics and Evaluation, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Akshay
authors.initials: A
authors.lastname: Sood
authors.affiliation: Division of Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy; Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Quebec, Canada.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Larcher
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Quebec, Canada.
authors.forename: Maxine
authors.initials: M
authors.lastname: Sun
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Quebec, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Karakiewicz
authors.affiliation: Division of Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Guazzoni
authors.affiliation: Division of Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
authors.affiliation: Division of Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Briganti
authors.affiliation: Vattikuti Urology Institute and VUI Center for Outcomes Research Analytics and Evaluation, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Mani
authors.initials: M
authors.lastname: Menon
authors.affiliation: Vattikuti Urology Institute and VUI Center for Outcomes Research Analytics and Evaluation, Henry Ford Hospital, Detroit, MI, USA. Electronic address: firas.abdollah@gmail.com.
authors.forename: Firas
authors.initials: F
authors.lastname: Abdollah
mesh_terms: D000367:Age Factors; D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D001918:Brachytherapy; D006801:Humans; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D061366:Numbers Needed To Treat; D018579:Patient Selection; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D018426:SEER Program; D015996:Survival Rate; D057832:Watchful Waiting
chemical_list: D000726:Androgen Antagonists
keywords: Cancer-specific survival; Metastasis; Primary tumor treatment; Prostate cancer; Radiation therapy; Radical prostatectomy