title: The association between radiographic response and overall survival in men with metastatic castration-resistant prostate cancer receiving chemotherapy.
abstract: BACKGROUND
  In men with metastatic castration-resistant prostate cancer (CRPC), the association of measurable tumor responses with overall survival (OS) is unknown. The authors retrospectively evaluated the TAX327 phase 3 trial to study this relation.
  
  
  METHODS
  Eligible patients for this analysis included those with World Health Organization (WHO)-defined measurable metastatic disease randomized to receive either docetaxel or mitoxantrone. OS was estimated by using the Kaplan-Meier method, and the prognostic relation of WHO-defined radiologic response with OS was performed by using Cox proportional hazards regression. Landmark analyses evaluated survival from baseline and at 2, 3, 4, and 6 months after baseline.
  
  
  RESULTS
  Four hundred twelve patients enrolled on the TAX327 trial had measurable tumors. Thirty-seven patients exhibited a complete or partial objective response (CR/PR, 9.0%), 116 had stable disease (SD, 28.2%), 99 had progressive disease (PD, 24%) and 160 (38.8%) did not have a after-baseline objective assessment. Partial responders demonstrated longer median OS (29.0 months) than patients with SD (22.1 months) or those with PD (10.8 months) or those who were not assessed (12.7 months). These results remained after landmark analysis. The authors found a significant association between ≥ 30% prostate-specific antigen (PSA) declines and radiologic response, with ≥ 30% PSA declines occurring in all patients with CR/PR, 79.8% of patients with SD, and 34.4% with PD. Radiologic response remained a significant but modest post-treatment prognostic factor for OS after adjusting for treatment, pain response, and ≥ 30% PSA decline (P = .009).
  
  
  CONCLUSIONS
  In men with metastatic CRPC and measurable disease receiving chemotherapy, objective tumor response was prognostic for OS and appeared to complement PSA assessment.
authors.affiliation: Texas Oncology and Department of Medicine, Section of Medical Oncology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Guru
authors.initials: G
authors.lastname: Sonpavde
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Pond
authors.forename: William R
authors.initials: WR
authors.lastname: Berry
authors.forename: Ronald
authors.initials: R
authors.lastname: de Wit
authors.forename: Mario A
authors.initials: MA
authors.lastname: Eisenberger
authors.forename: Ian F
authors.initials: IF
authors.lastname: Tannock
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Armstrong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002369:Castration; D017326:Clinical Trials, Phase III as Topic; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000401:mortality* / Q000473:pathology; D011859:Radiography; D016032:Randomized Controlled Trials as Topic; D017211:Treatment Failure; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D017430:Prostate-Specific Antigen