Radiotherapy of the oldest old - feasibility and institutional analysis

Little is known about efficacy and toxicity of radiation therapy in the elderly, as the vast majority of prospective trials excluded patients aged over 70 years. The aim of this study was to investigate the outcome of radiation therapy in a group of so-called oldest old cancer patients (≥85 years). We retrospectively reviewed data from patients aged ≥85 years, treated between 2010 and 2015 for any tumor histology at the University Hospital Zurich, Switzerland. Overall survival (OS), relapse-free survival (RFS), performance status (ECOG), Charlson comorbidity index (CCI) and treatment tolerance were assessed. We identified and included 100 patients with a mean age of 88 years (range: 85–102 years). Most patients received a curative-intent treatment (n = 64, 64%). About one third received palliative radiation therapy for symptomatic metastatic disease (n = 36, 36%). Curative treatment was well tolerated, with no high-grade acute toxicities (≥grade 4). Median OS was 52.6 and 13.1 months for the curative and palliative treated patient groups, respectively. 5‑year OS for all patients was 39.5% (95% CI: 23.6–54.5%). The Charlson comorbidity index (CCI) had a predictive value for overall survival (CCI > 10, p = 0.0001) in the curative group. The number of older cancer patients will increase considerably in the next decades because of demographic changes. Our analysis supports the notion that radiation therapy for this patient group of oldest old cancer patients is feasible in general. Treatment decisions should not be based on chronological age but rather on comorbidities and functional status.