Radiotherapy for elder patients aged ≥80 with clinically localized prostate cancer – Brachytherapy enhanced late GU toxicity especially in elderly

• Main Authors: Hideya Yamazaki, Koji Masui, Gen Suzuki, Daisuke Shimizu, Norihiro Aibe, Kei Yamada, Atsuko Fujihara, Takumi Shiraishi, Koji Okihara, Osamu Ukimura, Ken Yoshida, Satoaki Nakamura, Haruumi Okabe
• Format: Article
• Language: English
• Published: Elsevier 2020-11-01
• Series: Clinical and Translational Radiation Oncology
• Subjects: Prostate cancer; Radiotherapy; Brachytherapy; Elderly; Late GU toxicity
• Online Access: http://www.sciencedirect.com/science/article/pii/S240563082030080X

Background and purpose: Elongation of life expectancy had led to marked increase in number of elderly patients with localized prostate cancer. However, the standard treatment for such patients is not well determined because of a high prevalence of comorbidities and slow growth of prostate cancer. The aim of this study is to examine the feasibility of radiotherapy for elderly patients aged ≥80 years. Materials and methods: We compared 96 patients aged ≥80 years and 2333 younger patients (aged 60–79 years) using multi-institutional data included cT1-T4N0M0 prostate cancer treated with 902 external beam radiotherapy (EBRT) and 1527 brachytherapy (BT). Results: The 5-year biochemical failure-free survival rate was similar between elderly ≥80 years and younger control (91.3% vs. 85.9%, p = 0.6171) (100%, 92.9%, 82.4% and 96.3%, 93.7%, 89% for low, intermediate and high risk group), and for the prostate cancer-specific survival rate (100% and 99.3%, p = 0.6171). The accumulated incidence of late gastrointestinal (GI) at 5 years was also similar between elderly and younger patients (3.5% vs. 2.5%, p = 0.6857). Brachytherapy improved biochemical control rate and reduced GI toxicity compared with EBRT, however, enhanced late genitourinary (GU) toxicity, especially in elderly patients. Elderly received brachytherapy showed highest rate of late GU toxicity grade ≥2 of 22.1% than the younger counterparts of 12.7% at 5 years, whereas younger patients treated with EBRT had 2.4% and elderly EBRT had 2.7% (p < 0.0001). Conclusion: Elderly patients aged ≥80 years showed equivalent biochemical control, prostate cancer-related survival, and gastrointestinal toxicity profiles to younger patients. Meticulous care should be required for brachytherapy enhanced late GU toxicity, especially in elderly patients aged ≥80 years.