Androgen Suppression Combined with Elective Nodal and Dose Escalated Radiation Therapy (the ASCENDE-RT Trial): An Analysis of Survival Endpoints for a Randomized Trial Comparing a Low-Dose-Rate Brachytherapy Boost to a Dose-Escalated External Beam Boost for High- and Intermediate-risk Prostate Cancer

Int J Radiat Oncol Biol Phys. 2017 Jun 1;98(2):275-285. doi: 10.1016/j.ijrobp.2016.11.026. Epub 2016 Nov 24.


Purpose: To report the primary endpoint of biochemical progression-free survival (b-PFS) and secondary survival endpoints from ASCENDE-RT, a randomized trial comparing 2 methods of dose escalation for intermediate- and high-risk prostate cancer.

Methods and materials: ASCENDE-RT enrolled 398 men, with a median age of 68 years; 69% (n=276) had high-risk disease. After stratification by risk group, the subjects were randomized to a standard arm with 12 months of androgen deprivation therapy, pelvic irradiation to 46 Gy, followed by a dose-escalated external beam radiation therapy (DE-EBRT) boost to 78 Gy, or an experimental arm that substituted a low-dose-rate prostate brachytherapy (LDR-PB) boost. Of the 398 trial subjects, 200 were assigned to DE-EBRT boost and 198 to LDR-PB boost. The median follow-up was 6.5 years.

Results: In an intent-to-treat analysis, men randomized to DE-EBRT were twice as likely to experience biochemical failure (multivariable analysis [MVA] hazard ratio [HR] 2.04; P=.004). The 5-, 7-, and 9-year Kaplan-Meier b-PFS estimates were 89%, 86%, and 83% for the LDR-PB boost versus 84%, 75%, and 62% for the DE-EBRT boost (log-rank P<.001). The LDR-PB boost benefited both intermediate- and high-risk patients. Because the b-PFS curves for the treatment arms diverge sharply after 4 years, the relative advantage of the LDR-PB should increase with longer follow-up. On MVA, the only variables correlated with reduced overall survival were age (MVA HR 1.06/y; P=.004) and biochemical failure (MVA HR 6.30; P<.001). Although biochemical failure was associated with increased mortality and randomization to DE-EBRT doubled the rate of biochemical failure, no significant overall survival difference was observed between the treatment arms (MVA HR 1.13; P=.62).

Conclusions: Compared with 78 Gy EBRT, men randomized to the LDR-PB boost were twice as likely to be free of biochemical failure at a median follow-up of 6.5 years.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Androgen Antagonists / therapeutic use*
  • Brachytherapy / methods*
  • Combined Modality Therapy / methods
  • Disease-Free Survival
  • Follow-Up Studies
  • Gonadotropin-Releasing Hormone / therapeutic use
  • Humans
  • Intention to Treat Analysis
  • Iodine Radioisotopes / therapeutic use
  • Kaplan-Meier Estimate
  • Lymphatic Irradiation / methods*
  • Male
  • Middle Aged
  • Pelvis
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / drug therapy*
  • Prostatic Neoplasms / mortality*
  • Prostatic Neoplasms / radiotherapy*
  • Radiotherapy Dosage
  • Re-Irradiation / methods
  • Re-Irradiation / statistics & numerical data
  • Time Factors


  • Androgen Antagonists
  • Iodine Radioisotopes
  • Gonadotropin-Releasing Hormone
  • Prostate-Specific Antigen