Radiation therapy dose and androgen deprivation therapy in localized prostate cancer: a meta-regression of 5-year outcomes in phase III randomized controlled trials

• Published in: Prostate cancer and prostatic diseases 2022-03, Vol.25 (1), p.126-128
• Main Authors: Jiang, Tommy, Markovic, Daniela, Patel, Jay, Juarez, Jesus E., Ma, Ting Martin, Shabsovich, David, Nickols, Nicholas G., Reiter, Robert E., Elashoff, David, Rettig, Matthew B., Zaorsky, Nicholas G., Spratt, Daniel E., Kishan, Amar U.
• Format: Article
• Language: English
• Subjects: 692/308/409; 692/699/2768/1753/466; 692/699/67/1059; Amplification; Androgen Antagonists - therapeutic use; Androgens; Androgens - therapeutic use; Biomedical and Life Sciences; Biomedicine; Brief Communication; Cancer Research; Cancer therapies; Clinical trials; Clinical Trials, Phase III as Topic; Confidence intervals; Deprivation; Heterogeneity; Hormone Replacement Therapy; Humans; Male; Metastases; Patients; Prolongation; Prostate cancer; Prostatic Neoplasms - drug therapy; Prostatic Neoplasms - radiotherapy; Radiation; Radiation dosage; Radiation therapy; Randomized Controlled Trials as Topic; Reproductive Medicine; Statistical analysis
• ISSN: 1365-7852; 1476-5608
• DOI: 10.1038/s41391-021-00432-2

Background While multiple randomized trials have evaluated the benefit of radiation therapy (RT) dose escalation and the use and prolongation of androgen deprivation therapy (ADT) in the treatment of prostate cancer, few studies have evaluated the relative benefit of either form of treatment intensification with each other. Many trials have included treatment strategies that incorporate either high or low dose RT, or short-term or long-term ADT (STADT or LTADT), in one or more trial arms. We sought to compare different forms of treatment intensification of RT in the context of localized prostate cancer. Methods Using preferred reporting items for systemic reviews and meta-analyses (PRISMA) guidelines, we collected over 40 phases III clinical trials comparing different forms of RT for localized prostate cancer. We performed a meta-regression of 40 individual trials with 21,429 total patients to allow a comparison of the rates and cumulative proportions of 5-year overall survival (OS), prostate cancer-specific mortality (PCSM), and distant metastasis (DM) for each treatment arm of every trial. Results Dose-escalation either in the absence or presence of STADT failed to significantly improve any 5-year outcome. In contrast, adding LTADT to low dose RT significantly improved 5-year PCSM (Odds ratio [OR] 0.34, 95% confidence interval [CI] 0.22–0.54, p