Health-related quality of life in men with oligometastatic prostate cancer following metastases-directed stereotactic body radiotherapy: Real-world data from the E2-RADIatE OligoCare cohort

Objective: To evaluate the impact of metastases -directed stereotactic body radiotherapy (SBRT) on health -related quality of life (HRQoL) in men with oligometastatic prostate cancer (PCa) using real -world data from the OligoCare cohort. Materials and methods: OligoCare is a pragmatic, observational cohort designed to assess the impact of metastases -directed SBRT on patients with oligometastatic disease (OMD). We report an interim analyses of the secondary endpoint HRQoL, assessed using the EORTC QLQ-C30, within six months of metastases -directed SBRT for oligometastatic disease in men with PCa among the first 1600 registered patients. HRQoL data collection was optional within the OligoCare cohort. To compare HRQoL between baseline and first follow-up assessment, a Wilcoxon signed -rank test was used. A multiple linear regression model was used to explore the HRQoL associations with predefined factors. Results: Out of the 1600 registered patients, 658 were treated for oligometastatic PCa, of which 233 had baseline QoL data and 132 patients had both baseline and follow-up HRQoL data. At baseline, most patients had a WHO performance status of 0 or 1 (87 %), were de-novo oligometastatic (79 %), had one metastasis (90 %), and had a good overall global health status (mean 80.81, SD16.11, IQR 75-92). 51 % received hormonal therapy as concomitant systemic treatment. Patients with comorbidities as assessed by the Charlson Comorbidity index had a worse global health status at baseline (-4.88, 95 % CI: -9.35, -0.42). No clinically meaningful significant difference in global health status was observed at first assessment following SBRT (median 3.0 months) compared with baseline (mean difference 2.27, 95 % CI: -1.54, 6.08). Upon evaluating the proportions, meaningful clinically important differences (a 10 -point or more difference) was observed in, 17 % and 11 % of the patients reporting deterioration and improvement of global health status, respectively. Conclusion: Metastases -directed stereotactic body radiotherapy had no negative impact on global HRQoL within the first six months after treatment.