Postradiotherapy 2-year prostate-specific antigen nadir as a predictor of long-term prostate cancer mortality Journal Article

Authors: Zelefsky, M. J.; Shi, W.; Yamada, Y.; Kollmeier, M. A.; Cox, B.; Park, J.; Seshan, V. E.
Article Title: Postradiotherapy 2-year prostate-specific antigen nadir as a predictor of long-term prostate cancer mortality
Abstract: Purpose: To report the influence of posttreatment prostate-specific antigen (PSA) nadir response at 2 years after external beam radiotherapy (RT) on distant metastases (DM) and cause-specific mortality (CSM). Methods and Materials: Eight hundred forty-four patients with localized prostate cancer were treated with conformal RT. The median duration of follow-up was 9.1 years. A fixed landmark time point at 2 years was used to assess the influence of nadir PSA value as a time-dependent variable on long-term outcomes. Results: Multivariate analysis demonstrated that nadir PSA ≤1.5 ng/mL at the landmark was an independent predictor of progression-free survival after adjusting for T stage, Gleason score, pre-RT PSA value, and RT dose (p = 0.03). The 5- and 10-year cumulative incidences of DM were 2.4% and 7.9%, respectively, in those with nadir PSA levels ≤1.5 ng/mL at the 2-year landmark, and were 10.3% and 17.5%, respectively, in patients with higher nadir values. Multivariate analysis showed that the higher nadir PSA value at the 2-year landmark (p = 0.002), higher Gleason scores (p < 0.001), and increasing T stage (p = 0.03) were predictors of DM after adjusting for pre-RT PSA values and RT dose. Multivariate analysis also showed that higher Gleason scores (p = 0.002), and higher nadir PSA values at the 2-year landmark (p = 0.03) were risk factors associated with CSM after adjusting for T stage and pre-RT PSA value. Conclusions: Nadir PSA values of ≤1.5 ng/mL at 2 years after RT for prostate cancer predict for long-term DM and CSM outcomes. Patients with higher absolute nadir levels at 2 years after treatment should be evaluated for the presence of nonresponding disease, and earlier salvage treatment interventions should be considered. © 2009 Elsevier Inc. All rights reserved.
Keywords: adult; cancer survival; treatment outcome; treatment response; aged; aged, 80 and over; disease-free survival; middle aged; major clinical study; cancer patient; disease free survival; radiation dose; cancer staging; follow up; follow-up studies; cancer diagnosis; neoplasm staging; prostate specific antigen; progression free survival; radiotherapy dosage; radiotherapy; risk factors; patient monitoring; pathology; risk factor; cancer mortality; distant metastasis; time factors; prostate cancer; gleason score; prostate-specific antigen; prostatic neoplasms; cause of death; antigens; radiotherapy, intensity-modulated; gleason scores; predictor variable; radiotherapy, conformal; external beam radiotherapy; computer assisted radiotherapy; decision making; multi variate analysis; multivariant analysis; analysis of variance; prostate cancers; peeling; risk analysis; diseases; time points; blood level; cause-specific survival; distant metastases; psa nadir; after-treatment; cumulative incidence; independent predictors; localized prostate cancer; long-term outcome; post treatment; salvage treatment; time-dependent variables; prostate specific antigen blood level
Journal Title: International Journal of Radiation Oncology, Biology, Physics
Volume: 75
Issue: 5
ISSN: 0360-3016
Publisher: Elsevier Inc.  
Date Published: 2009-12-01
Start Page: 1350
End Page: 1356
Language: English
DOI: 10.1016/j.ijrobp.2008.12.067
PUBMED: 19515504
PROVIDER: scopus
Notes: --- - "Cited By (since 1996): 3" - "Export Date: 30 November 2010" - "CODEN: IOBPD" - "Source: Scopus"
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MSK Authors
  1. Brett Wayne Cox
    62 Cox
  2. Michael J Zelefsky
    615 Zelefsky
  3. Weiji Shi
    111 Shi
  4. Yoshiya Yamada
    357 Yamada
  5. Marisa A Kollmeier
    144 Kollmeier
  6. Jessica Park
    11 Park