Bone-Modifying Agents Underutilized in Some Patients With mCRPC

Patients with metastatic castration-resistant prostate cancer (mCRPC) who are older, Black, or have more comorbidities are less likely to receive guideline concordant care to prevent skeletal-related events (SREs), according to study findings published in JCO Oncology Practice. 

Clinical guidelines recommend bone-modifying agents (BMAs) in patients with mCRPC and bone metastases, but real world use often does not live up to the recommendations. As such, a group of researchers sought to learn more about utilization of BMAs, which are used to decrease SREs, in this patient population. 

The researchers conducted a retrospective cohort study to report on factors associated with BMA use. A cohort of patients were identified from the Veteran Affairs Corporate Data Warehouse who received at least 1 mCRPC therapy that included ketoconazole, docetaxel, abiraterone, or enzalutamide. 

Of 3980 men with mCRPC, 47% had received a BMA. Mean age was 73.5 years; 29% were Black; 55% had a Charlson comorbidity index (CCI) of 0, 22% had a CCI of 1, and 23% had a CCI of 2 or higher; estimated glomerular filtration rate (eGFR) was ≥60 mL/minutes in 69%, 30-59 mL/minutes in 26%, and 0-29 mL/minutes in 4%. The median time from the start of their mCRPC treatment to BMA was 102 days. 

The following factors were associated with BMA use:

• previous BMA use (adjusted odds ratio [aOR], 7.81; 95% CI, 6.48-9.47), 
• a diagnosis code for bone metastases (aOR, 1.26; 95% CI, 1.08-1.46), 
• concomitant corticosteroid use (aOR, 1.53; 95% CI, 1.29-1.82). 

Decreased BMA use was associated with:

• advancing age (aOR, 0.85 per 10 years; 95% CI, 0.78-0.92), 
• CCI of 2 or higher (aOR, 0.76; 95% CI, 0.63-0.93), 
• Black race (aOR, 0.83; 95% CI, 0.70-0.98), 
• decreased eGFR: 0-29 mL/minutes (aOR, 0.19; 95% CI, 0.11-0.32) or 30-59 mL/minutes (aOR, 0.76; 95% CI, 0.64-0.91).

These findings “highlight the unique needs of the older mCRPC population” the researchers noted.

“Although treatment decisions in older patients with cancer require a comprehensive evaluation of comorbidities, life expectancy, and patient goals, age and underlying comorbidities should not factor into the decision to receive BMA therapy, especially as the goal of BMA therapy is to maintain quality of life,” they wrote in conclusion. 

“Black patients were also less likely to receive a BMA, which underscores the persistent racial disparities with BMA use in solid tumors. Future work should identify barriers to BMA use and interventions to enhance guideline-concordant care.”

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures. 

Reference

Nguyen CB, Kobe C, Kumbier KE, et al. Determinants of bone-modifying agent prescribing for metastatic castration-resistant prostate cancer in a national health care delivery system. JCO Oncology Practice. Published online November 2, 2023. doi:10.1200/OP.23.00258