A biochemical definition of cure after brachytherapy for prostate cancer

Juanita M. Crook, Chad Tang, Howard Thames, Pierre Blanchard, Jeremiah Sanders, Jay Ciezki, Mira Keyes, W. James Morris, Gregory Merrick, Charles Catton, Hamid Raziee, Richard Stock, Frank Sullivan, Mitch Anscher, Jeremy Millar, Steven Frank

Research output: Contribution to journalArticle

Abstract

Background and purpose: To identify a PSA threshold value at an intermediate follow-up time after low dose rate (LDR) prostate brachytherapy associated with cure, defined as long-term (10–15 year) freedom from prostate cancer. Materials and methods: Data from 7 institutions for 14,220 patients with localized prostate cancer treated with LDR brachytherapy, either alone (8552) or with external beam radiotherapy (n = 1175), androgen deprivation (n = 3165), or both (n = 1328), were analyzed. Risk distribution was 42.4% favorable, 49.2% intermediate, and 8.4% high-risk. Patients with clinical failure before 3.5 years were excluded. Kaplan-Meier analysis was used with clinical failure (local, distant, regional or biochemical triggering salvage) as an endpoint for each of four PSA categories: PSA ≤ 0.2, >0.2 to ≤0.5, >0.5 to ≤1.0, and >1.0 ng/mL. PSA levels at 4 years (±6 months) in 8746 patients without clinical failure were correlated with disease status at 10–15 years. Results: For the 77.1% of patients with 4-year PSA ≤ 0.2, the freedom-from-recurrence (FFR) rates were 98.7% (95% CI 98.3–99.0) at 10 years and 96.1% (95% CI 94.8–97.2) at 15 years. Three independent validation cohorts confirmed 97–99% 10-year FFR rates with 4-year PSA ≤ 0.2. Successive PSA categories were associated with diminished disease-free rates at 10 and 15 years. PSA category was strongly associated with treatment success (p < 0.0005). Conclusions: Since 98.7% of patients with PSA ≤ 0.2 ng/mL at 4 years after LDR prostate brachytherapy were disease-free beyond 10 years, we suggest adopting this biochemical definition of cure for patients with ≥4 years’ follow-up after LDR brachytherapy.

Original languageEnglish (US)
Pages (from-to)64-69
Number of pages6
JournalRadiotherapy and Oncology
Volume149
DOIs
StatePublished - Aug 2020

Keywords

  • Adenocarcinoma of prostate
  • Brachytherapy
  • Low dose rate brachytherapy
  • Prostate specific antigen
  • PSA definition of cure

ASJC Scopus subject areas

  • Hematology
  • Oncology
  • Radiology Nuclear Medicine and imaging

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  • Cite this

    Crook, J. M., Tang, C., Thames, H., Blanchard, P., Sanders, J., Ciezki, J., Keyes, M., Morris, W. J., Merrick, G., Catton, C., Raziee, H., Stock, R., Sullivan, F., Anscher, M., Millar, J., & Frank, S. (2020). A biochemical definition of cure after brachytherapy for prostate cancer. Radiotherapy and Oncology, 149, 64-69. https://doi.org/10.1016/j.radonc.2020.04.038