Effect of Pelvic External Beam Radiation Therapy on Bone Mineral Density: A Secondary Analysis of a Phase 3 Randomized Controlled Trial
Abstract
Purpose: Pelvic radiation therapy may lead to decreased bone mineral density (BMD) and increased risk of fracture that could be of particular concern in patients with prostate cancer who also receive androgen deprivation therapy (ADT). We performed an exploratory analysis of a randomized, double-masked, placebo-controlled trial to determine whether exposure to prior pelvic external beam radiation therapy (XRT) affects BMD and risk of fracture in patients with prostate cancer treated with ADT.
Methods and materials: Patients with nonmetastatic prostate cancer aged ≥70 years or <70 years with low BMD (T-score < -1) or osteoporotic fracture who had been receiving ADT for ≥12 months were randomly assigned to receive densoumab or placebo every 6 months for 3 years. BMD was measured at baseline and at months 1, 3, 6, 12, 24, and 36. We applied multivariable linear mixed-effects models with an interaction term between the treatment arm and exposure to prior pelvic XRT to evaluate differential XRT effect on percent BMD change between the 2 treatment arms.
Results: Among 1407 eligible patients, 31% (n = 447) received prior pelvic XRT. There was no significant difference in any clinical fractures among patients with (5.8%, 26 of 447) or without (5.2%, 50 of 960) prior pelvic XRT (P = .42). Prior pelvic XRT was associated with a significant (0.54%) improvement in BMD (95% CI, 0.05-1.02) in the placebo group and a nonsignificant (0.04%) decline in BMD (95% CI, -0.47 to -0.35) in the…
How strong is the evidence?
Evidence Hub reads this as a secondary / pooled analysis, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 1,407 participants or records.
Read the paper
Related studies
- Effectiveness of Bisphosphonates and Denosumab on Risk of Vertebral Fractures in Prostate Cancer Patients Under Androgen Deprivation Therapies: A Real-World Prospective Study
- Osteoporosis-related fractures after spinal cord injury: a retrospective study from Brazil
- Serum 25-hydroxyvitamin D, parathyroid hormone, and mortality in older men
- Lack of Association between Vitamin D Insufficiency and Cardiovascular or Fracture Risk: A UK Biobank Study
- Muscle strength and body composition are clinical indicators of osteoporosis
- Incidence of bone protection and associated fragility injuries in patients with proximal femur fractures
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.