Real-world associations between bone-targeted agents and palliative bone radiotherapy in prostate cancer decedents: A province-wide population study.
Bibliographic record
Abstract
e17043 Background: Palliative bone radiation is the predominant skeletal-related event (SRE) reported in advanced prostate cancer. Bone targeted agents (BTA), such as denosumab and zoledronic acid, are shown to both prevent and delay SREs including bone radiation. This study evaluated real-world use of BTA in a large provincial database in relation to palliative bone radiotherapy prior to prostate-cancer related death. Methods: Linked, province-wide administrative databases from Ontario, Canada identified patients with prostate cancer (2007-2018, n = 98646), who received continuous androgen deprivation therapy (n = 29453), died between 2013-2018 (n = 4184), and qualified for Ontario Drug Benefits (OBD; 65 years or older, n = 3788). Patients receiving novel life prolonging therapy (LPT) for metastatic castration-resistant prostate cancer (mCRPC; abiraterone, enzalutamide, docetaxel, cabazitaxel and radium-223) were selected, and use of BTA (denosumab, zoledronic acid) was identified. Demographic, health, and treatment characteristics were collected over a 2-year observation window looking back from the date of death. Multivariable analyses were conducted to identify factors important in use of palliative bone radiation. Results: 1769 patients received LPT for mCRPC, including abiraterone (n = 1094, 62%), docetaxel (n = 881, 60%), enzalutamide (n = 480, 27%), radium-223 (n = 250, 14%) and cabazitaxel (n = 108, 6%). Amongst patients receiving LPT, 57% received BTA and 60% received palliative radiation to bone. Factors associated with palliative bone radiation were receipt of BTA (OR 1.46; 95% confidence interval [CI] 1.13-1.91), metastatic disease at diagnosis (OR 1.48; CI: 1.11-1.97), radiation oncologist involvement (OR 103.11; CI: 47.03-226.25), whereas patients with fewer chronic diseases (OR 0.73; CI: 0.54-0.98) and who had prior prostatectomy (OR 0.54; CI: 0.36-0.84) were less likely to receive radiation. This relationship was maintained for both zoledronic acid (OR 1.68; CI: 1.09-2.58) and denosumab (OR 1.35, CI: 1.03-1.77). No specific LPT was associated with use of palliative bone radiation. Conclusions: Despite clinicians prescribing BTAs to prevent SREs, in this cohort, radiotherapy to bone was more likely in patients receiving BTAs. This suggests that clinicians are prescribing BTAs to patients at greater risk of SREs, but that patients dying of prostate cancer continue to have significant bone-related morbidity despite contemporary prostate cancer treatment. An analysis of primary (before bone radiotherapy) versus secondary (after bone radiotherapy) BTA prescriptions will be presented, as well as timing of BTA initiation in relation to death.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.006 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".