Department of Radiation Oncology, Centre hospitalier de l'Université de Montréal (CHUM), Montréal, Québec, Canada.
Service de consultation en biostatistique du Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Canada.
To study the influence of an exponential prostate-specific antigen (PSA) decline on biochemical failure after external-beam radiotherapy (EBRT).
We analyzed 114 patients with intermediate risk prostate cancer (Gleason≤ 6 and PSA 10-20 or Gleason 7 and PSA < 10). Patients were randomized between EBRT doses of either 70.2Gy or 79.2Gy (1.8Gy per day). All patients had a follow up of at least six PSA measurements post-EBRT. Exponential decline and PSA half life were included in a Cox regression analysis for factors associated with biochemical failure.
A total of 80/114 (70.2%) patterns were classified as having an exponential PSA decline. Both exponential decline (HR 0.115, 95%CI 0.03-0.44, p=0.0016) and PSA half life ratio were statistically significant predictors (HR 1.03 (95% CI 1.01-1.06)) of biochemical failure. In the model predicting for exponential decline, none of the factors were significant.
Patients with an exponential PSA decline show a better biochemical outcome in the long term.
Written by:
Delouya G, Kaufman G, Sylvestre MP, Nguyen TV, Bahary JP, Taussky D, Després P. Are you the author?
Reference: Cancer Epidemiol. 2011 Nov 15. Epub ahead of print.
doi: 10.1016/j.canep.2011.10.007
PubMed Abstract
PMID: 22094327
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