Quality of Life after Palliative Radiotherapy for Bone Metastases: Analysis of the PRESENT-cohort

Purpose or Objective
Symptomatic bone metastases are a frequent and serious problem for patients with advanced cancer, as painful lesions negatively impact overall quality of life (QoL). Improving or maintaining the different domains of QoL in patients with a limited life expectancy is a priority form patient, patients' carers, and research perspectives. The aim of this study is to evaluate the course of Quality of Life (QoL) in patients with painful bone metastases treated with palliative radiotherapy and to analyze whether the course of QoL differs between patients who do and do not experience pain relief after treatment.

Materials and Methods
This study is nested within the prospective PRESENT cohort on bone metastases. All patients treated with conventional radiotherapy for painful symptomatic bone metastases originating from solid tumors were selected. Patient reported outcomes were collected before start of radiotherapy, and at 4, 8, 12 weeks, 3 and 6 months thereafter. Response was defined as a 2-point decrease in pain score without increase in analgesic use according to the international consensus. Linear mixed models were used to assess QoL by comparing differences in domain scores of the EORTC QLQ-C15-PAL and EORTC QLQ-BM22 QoL questionnaires between responding and non-responding patients. We adjusted for baseline QoL and potential confounding factors.

Results
Responding patients (n=275, 58%) showed significantly better overall QoL scores over time compared to non-responders (n=197, 42%). Responders performed better on functional and symptom scales. A significantly higher percentage of patients with a response to radiotherapy improved at any time during follow-up in all QLQ-BM22 domains and in half of the QLQ-C15-PAL domains.

Conclusion
Patients responding to palliative radiotherapy for pain have better QoL compared to non-responding patients, independently of other confounding factors. As the improvements in QoL are small, further analysis of potential associations between clinical pain response and patient reported outcomes is needed to maintain or even improve QoL in patients with bone metastases.