Frequency of Complicated Symptomatic Bone Metastasis Over a Breadth of Operational Definitions

Incidence and radiotherapy treatment patterns of complicated bone metastases

Background

Despite the encouraging results of the SCORAD trial, single fraction radiotherapy (SFRT) remains underused for patients with complicated bone metastases with rates as low as 18-39%. We aimed to evaluate the incidence and treatment patterns of these metastases in patients being referred to a tertiary centre for palliative radiotherapy.

Materials and methods

We performed a retrospective review of all bone metastases treated at our centre from January 2013 until December 2017. Lesions were classified as uncomplicated or complicated. Complicated was defined as associated with (impending) fracture, existing spinal cord or cauda equina compression. Our protocol suggests using SFRT for all patients with complicated bone metastases, except for those with symptomatic neuraxial compression and a life expectancy of ≥28 weeks.

Results

Overall, 37 % of all bone metastases were classified as complicated. Most often as a result of an (impending) fracture (56 %) or spinal cord compression (44 %). In 93 % of cases, complicated lesions were located in the spine, most commonly originating from prostate, breast and lung cancer (60 %). Median survival of patients with complicated bone metastases was 4 months. The use of SFRT for complicated bone metastases increased from 51 % to 85 % over the study period, reaching 100 % for patients with the poorest prognosis.

Conclusions

Approximately 37 % of bone metastases are classified as complicated with the majority related to (impending) fracture. Patients with complicated bone metastases have a median survival of 4 months and were mostly treated with SFRT.

A Randomized Placebo-Controlled Trial of the Anti-Nerve Growth Factor Antibody Tanezumab in Subjects With Cancer Pain Due to Bone Metastasis

BACKGROUND

This phase III, randomized, double-blind, placebo-controlled, parallel-group study assessed the efficacy and safety of tanezumab in subjects with cancer pain predominantly due to bone metastasis receiving background opioid therapy.

METHODS

Subjects were randomized (stratified by (1) tumor aggressiveness and (2) presence/absence of concomitant anticancer treatment) to placebo or tanezumab 20 mg. Treatment was administered by subcutaneous injection every 8 weeks for 24 weeks (3 doses) followed by a 24-week safety follow-up period. The primary outcome was change in daily average pain in the index bone metastasis cancer pain site (from 0 = no pain to 10 = worst possible pain) from baseline to week 8.

RESULTS

LS mean (SE) change in pain at week 8 was -1.25 (0.35) for placebo (n = 73) and -2.03 (0.35) for tanezumab 20 mg (n = 72). LS mean (SE) [95% CI] difference from placebo was -0.78 (0.37) [-1.52, -0.04]; P = .0381 with α = 0.0478. The number of subjects with a treatment-emergent adverse event during the treatment period was 50 (68.5%) for placebo and 53 (73.6%) for tanezumab 20 mg. The number of subjects with a prespecified joint safety event was 0 for placebo and 2 (2.8%) for tanezumab 20 mg (pathologic fracture; n = 2).

CONCLUSION

Tanezumab 20 mg met the primary efficacy endpoint at week 8. Conclusions on longer-term efficacy are limited since the study was not designed to evaluate the durability of the effect beyond 8 weeks. Safety findings were consistent with adverse events expected in subjects with cancer pain due to bone metastasis and the known safety profile of tanezumab. Clinicaltrials.gov identifier: NCT02609828.

Radiation Therapy for Painful Bone Metastases: Fractionation, Recalcification, and Symptom Control

Bone is a common site for metastases, which may cause pain and other skeletal-related events (SRE) in patients with advanced cancer. Since the 1980s, prospective clinical trials have demonstrated the high efficacy of external beam radiotherapy (EBRT) for pain relief from focal, symptomatic lesions. In uncomplicated bone metastases, which include those without pathologic fracture, evidence of cord compression, or prior surgical intervention, improvement or complete pain relief with radiotherapy is as high as 60%, with no difference in efficacy when radiotherapy is delivered in a single or multiple fractions. The ability to treat with a single fraction makes EBRT an attractive therapy even for patients with poor performance status and/or life expectancy. Even in patients with complicated bone metastases (eg cord compression), several randomized trials have demonstrated similar rates of pain relief in addition to improved functional outcomes such as ambulation. In this review, we summarize the role of EBRT for alleviating painful bone metastases and explore its role for other endpoints including functional outcomes, recalcification, and prevention of SREs.

Evaluation of the Clinical Utility of the Bone Metastases Ensemble Trees for Survival Decision Support Platform (BMETS-DSP): A Case-Based Pilot Assessment

PURPOSE

The Bone Metastases Ensemble Trees for Survival Decision Support Platform (BMETS-DSP) provides patient-specific survival predictions and evidence-based recommendations to guide multidisciplinary management for symptomatic bone metastases. We assessed the clinical utility of the BMETS-DSP through a pilot prepost design in a simulated clinical environment.

METHODS

Ten Radiation Oncology physicians reviewed 55 patient cases at two time points: without and then with the use of BMETS-DSP. Assessment included 12-month survival estimate, confidence in and likelihood of sharing estimates with patients, and recommendations for open surgery, systemic therapy, hospice referral, and radiotherapy (RT) regimen. Paired statistics compared pre- versus post-DSP outcomes. Reported statistical significance is P < .05.

RESULTS

Pre- versus post-DSP, overestimation of true minus estimated survival time was significantly reduced (mean difference -2.1 [standard deviation 4.1] v -1 month [standard deviation 3.5]). Prediction accuracy was significantly improved at cut points of < 3 (72 v 79%), ≤ 6 (64 v 71%), and ≥ 12 months (70 v 81%). Median ratings of confidence in and likelihood of sharing prognosis significantly increased. Significantly greater concordance was seen in matching use of 1-fraction RT with the true survival < 3 months (70 v 76%) and < 10-fraction RT with the true survival < 12 months (55 v 62%) and appropriate use of open surgery (47% v 53%), without significant changes in selection of hospice referral or systemic therapy.

CONCLUSION

This pilot study demonstrates that BMETS-DSP significantly improved physician survival estimation accuracy, prognostic confidence, likelihood of sharing prognosis, and use of prognosis-appropriate RT regimens in the care of symptomatic bone metastases, supporting future multi-institutional validation of the platform.

Improving providers' survival estimates and selection of prognosis- and guidelines-appropriate treatment for patients with symptomatic bone metastases: Development of the Bone Metastases Ensemble Trees for Survival Decision Support Platform

RATIONALE, AIMS AND OBJECTIVES

In the management of symptomatic bone metastases, current practice guidelines do not provide clear methodology for selecting palliative radiotherapy (RT) regimens based on specific patient and disease features. Decision support aids may offer an effective means for translating the complex data needed to render individualised treatment decisions, yet no such tools are available for use in this setting. Thus, we describe the development of the Bone Metastases Ensemble Trees for Survival-Decision Support Platform (BMETS-DSP), which aims to optimise selection of evidence-based, individualised palliative RT regimens.

METHOD

The Ottawa Decision Support Framework was used as the theoretical basis for development of BMETS-DSP. First, we utilised stakeholder input and review of the literature to assess determinants underlying the provider decision. Based on this assessment and iterative stakeholder feedback, we developed the web-based, provider-facing BMETS-DSP. Consistent with the underlying theoretical framework, our design also included assessment of decision quality using the International Patient Decision Aids Standards (IPDAS) certification checklist.

RESULTS

Stakeholder input and review of 54 evidence-based publications identified the following determinants of the provider decision: estimated prognosis, characteristics of the target symptomatic lesion and the primary cancer type, consideration of alternative interventions, access to patient-specific recommendations, and patient preferences. Based on these determinants, we developed the BMETS-DSP that (1) collects patient-specific data, (2) displays an individualised predicted survival curve, and (3) provides case-specific, evidence-based recommendations regarding RT, open surgery, systemic therapy, and hospice referral to aid in the decision-making process. The finalised tool met IPDAS quality requirements. Preliminary results of a pilot assessment suggest impact of clinical outcomes.

CONCLUSIONS

We describe the successful development of a provider-facing decision support platform to aid in the provision of palliative RT in better alignment with patient and disease features. Impact of the BMETS-DSP on decision outcomes will be further assessed in a randomised, controlled study.

Advances in radiotherapy in bone metastases in the context of new target therapies and ablative alternatives: A critical review

In patients with bone metastases (BM), radiotherapy (RT) is used to alleviate symptoms, reduce the risk of fracture, and improve quality of life (QoL). However, with the emergence of concepts like oligometastases, minimal invasive surgery, ablative therapies such as stereotactic ablative RT (SABR), radiosurgery (SRS), thermal ablation, and new systemic anticancer therapies, there have been a paradigm shift in the multidisciplinary approach to BM with the aim of preserving mobility and function survival. Despite guidelines on using single-dose RT in uncomplicated BM, its use remains relatively low. In uncomplicated BM, single-fraction RT produces similar overall and complete response rates to RT with multiple fractions, although it is associated with a higher retreatment rate of 20% versus 8%. Complicated BM can be characterised as the presence of impending or existing pathologic fracture, a major soft tissue component, existing spinal cord or cauda equina compression and neuropathic pain. The rate of complicated BM is around 35%. Unfortunately, there is a lack of prospective trials on RT in complicated BM and the best dose/fractionation regimen is not yet established. There are contradictory outcomes in studies reporting BM pain control rates and time to pain reduction when comparing SABR with Conventional RT. While some studies showed that SABR produces a faster reduction in pain and higher pain control rates than conventional RT, other studies did not show differences. Moreover, the local control rate for BM treated with SABR is higher than 80% in most studies, and the rate of grade 3 or 4 toxicity is very low. The use of SABR may be preferred in three circumstances: reirradiation, oligometastatic disease, and radioresistant tumours. Local ablative therapies like SABR can delay change or use of systemic therapy, preserve patients' Qol, and improve disease-free survival, progression-free survival and overall survival. Moreover, despite the potential benefit of SABR in oligometastatic disease, there is a need to establish the optial indication, RT dose fractionation, prognostic factors and optimal timing in combination with systemic therapies for SABR. This review evaluates the role of RT in BM considering these recent treatment advances. We consider the definition of complicated BM, use of single and multiple fractions RT for both complicated and uncomplicated BM, reirradiation, new treatment paradigms including local ablative treatments, oligometastatic disease, systemic therapy, physical activity and rehabilitation.