Pretreatment prostate specific antigen (PSA) and 2-year PSA dynamics: Early predictors of prostate cancer prognosis with external radiation therapy

Abstract

IntroductionThe dynamics of prostate specific antigen (PSA) in patients who have prostate cancer and receive radiotherapy is a very interesting but complicated topic. We tried to plot the sequential changes of PSA with and without hormone therapy and tried to find out the predictors for the high-risk patients for prostate cancer recurrence. MethodsWe reviewed the medical records of 164 prostate cancer patients who underwent intensity-modulated radiation therapy (IMRT) as the primary treatment. We recorded the patients' age, initial PSA, cancer grading at diagnostic biopsies (Gleason's score), clinical stage, the IMRT dosage, neoadjuvant, concomitant, and prolonged hormone therapy, follow-up PSA levels, biochemical progression, and distant metastasis. ResultsOf the 84 patients undergoing radiotherapy for prostate cancer with complete data for analysis, the biochemical failure-free survival (BFFS) rate was 88.09%. The patients with an initial PSA of less than 10 ng/mL had the best BFFS. Of the patients receiving neoadjuvant hormone therapy (NHT), serum PSA levels were significantly higher in those with biochemical failure than those without biochemical failure in the 3 months after radiation therapy. As for the patients free of biochemical failure, the mean PSA fell below 1 ng/mL immediately after IMRT for the NHT(+) group and at 9 months after IMRT for the NHT(–) group. ConclusionFor the patients with localized prostate cancer who underwent IMRT, initial PSA could predict clinical stage, 1-year BFFS, and 2-year BFFS. The follow-up PSA, as early as 3 months, was of clinical predictive value.