Real-World Use of Bone Modifying Agents in Metastatic Castration-Sensitive Prostate Cancer

Commercial Versus Medicaid Insurance and Use of High-Priced Anticancer Treatments

BACKGROUND

Because the markups on cancer drugs vary by payor, providers' financial incentive to use high-price drugs is differential according to each patient's insurance type. We evaluated the association between patient insurer (commercial vs Medicaid) and the use of high-priced cancer treatments.

MATERIALS AND METHODS

We linked cancer registry, administrative claims, and demographic data for individuals diagnosed with cancer in North Carolina from 2004 to 2011, with either commercial or Medicaid insurance. We selected cancers with multiple FDA-approved, guideline-recommended chemotherapy options and large price differences between treatment options: advanced colorectal, lung, and head and neck cancer. The outcome was a receipt of a higher-priced option, and the exposure was insurer: commercial versus Medicaid. We estimated risk ratios (RRs) for the association between insurer and higher-priced treatment using log-binomial models with inverse probability of exposure weights.

RESULTS

Of 812 patients, 209 (26%) had Medicaid. The unadjusted risk of receiving higher-priced treatment was 36% (215/603) for commercially insured and 27% (57/209) for Medicaid insured (RR: 1.31, 95% CI: 1.02-1.67). After adjustment for confounders the association was attenuated (RR: 1.15, 95% CI: 0.81-1.65). Exploratory subgroup analysis suggested that commercial insurance was associated with increased receipt of higher-priced treatment among patients treated by non-NCI-designated providers (RR: 1.53, 95% CI: 1.14-2.04).

CONCLUSIONS

Individuals with Medicaid and commercial insurance received high-priced treatments in similar proportion, after accounting for differences in case mix. However, modification by provider characteristics suggests that insurance type may influence treatment selection for some patient groups. Further work is needed to determine the relationship between insurance status and newer, high-price drugs such as immune-oncology agents.

Real-World Evidence of Triplet Therapy in Metastatic Hormone-Sensitive Prostate Cancer: An Austrian Multicenter Study

INTRODUCTION

Two randomized trials demonstrated a survival benefit of triplet therapy (androgen deprivation therapy [ADT]) plus androgen receptor pathway inhibitor [ARPI] plus docetaxel) over doublet therapy (ADT plus docetaxel), thus changing treatment strategies in metastatic hormonesensitive prostate cancer (mHSPC).

PATIENTS AND METHODS

We conducted the first real-world analysis comprising 97 mHSPC patients from 16 Austrian medical centers, among them 79.4% of patients received abiraterone and 17.5% darolutamide treatment. Baseline characteristics and clinical parameters during triplet therapy were documented. Mann-Whitney U test for continuous or X²-test for categorical variables was used. Variables on progression were tested using logistic regression analysis and tabulated as hazard ratios (HR), 95% confidence interval (CI).

RESULTS

Of 83.5% patients with synchronous and 16.5% with metachronous disease were included. 83.5% had high-volume disease diagnosed by conventional imaging (48.9%) or PSMA PET-CT (51.1%). While docetaxel and ARPI were administered consistent with pivotal trials, prednisolone, prophylactic gCSF and osteoprotective agents were not applied guideline conform in 32.5%, 37%, and 24.3% of patients, respectively. Importantly, a nonsimultaneous onset of chemotherapy and ARPI, performed in 44.3% of patients, was associated with significantly worse treatment response (P = .015, HR 0.245). Starting ARPI before chemotherapy was associated with significantly higher probability for progression (P = .023, HR 15.781) than vice versa. Strikingly, 15.6% (abiraterone) and 25.5% (darolutamide) low-volume patients as well as 14.4% (abiraterone) and 17.6% (darolutamide) metachronous patients received triplet therapy. Adverse events (AE) occurred in 61.9% with grade 3 to 5 in 15% of patient without age-related differences. All patients achieved a PSA decline of 99% and imaging response was confirmed in 88% of abiraterone and 75% of darolutamide patients.

CONCLUSIONS

Triplet therapy arrived in clinical practice primarily for synchronous high-volume mHSPC. Regardless of selected therapy regimen, treatment is highly effective and tolerable. Preferably therapy should be administered simultaneously, however if not possible, chemotherapy should be started first.

Paraneoplastic Syndromes in Neuroendocrine Prostate Cancer: A Systematic Review

Neuroendocrine prostate cancer (NEPC) is a rare subtype of prostate cancer (PCa) that usually results in poor clinical outcomes and may be accompanied by paraneoplastic syndromes (PNS). NEPC is becoming more frequent. It can initially manifest as PNS, complicating diagnosis. Therefore, we reviewed the literature on the different PNS associated with NEPC. We systematically reviewed English-language articles from January 2017 to September 2023, identifying 17 studies meeting PRISMA guidelines for NEPC and associated PNS. A total of 17 articles were included in the review. Among these, Cushing's Syndrome (CS) due to ectopic Adrenocorticotropic hormone (ACTH) secretion was the most commonly reported PNS. Other PNS included syndrome of inappropriate Anti-Diuretic Hormone secretion (SIADH), Anti-Hu-mediated chronic intestinal pseudo-obstruction (CIPO), limbic encephalitis, Evans Syndrome, hypercalcemia, dermatomyositis, and polycythemia. Many patients had a history of prostate adenocarcinoma treated with androgen deprivation therapy (ADT) before neuroendocrine features developed. The mean age was 65.5 years, with a maximum survival of 9 months post-diagnosis. NEPC is becoming an increasingly more common subtype of PCa that can result in various PNS. This makes the diagnosis and treatment of NEPC challenging. Further research is crucial to understanding these syndromes and developing standardized, targeted treatments to improve patient survival.

Bone-Modifying Agents in Patients With High-Risk Metastatic Castration-Sensitive Prostate Cancer Treated With Abiraterone Acetate

Importance

The association between the use of bone-modifying agents (BMAs) and the outcomes among patients with metastatic castration-sensitive prostate cancer (mCSPC) treated with abiraterone acetate plus prednisone (AAP) remains unclear.

Objective

To investigate the association between BMA use and the outcomes of patients with mCSPC receiving AAP.

Design, Setting, and Participants

In this cohort study, a post hoc analysis of individual participant data from the LATITUDE trial was performed. The LATITUDE trial, a phase 3 randomized clinical trial, aimed to assess the efficacy of AAP and androgen deprivation therapy (ADT) vs dual-placebo and ADT in patients with high-risk mCSPC (data cutoff, August 15, 2018). Eligible patients had newly diagnosed prostate cancer with metastases and at least 2 of 3 high-risk factors (Gleason score ≥8, presence of ≥3 lesions on bone scan, or presence of measurable visceral metastasis). The trial was conducted at 235 sites in 34 countries. Data for the present study were evaluated from July 18 to September 23, 2023.

Exposures

Use of BMAs was defined as the administration of bisphosphonates and denosumab within 90 days before and after randomization.

Main Outcomes and Measures

The primary outcomes were time to skeletal-related events (SREs) and overall survival (OS). An SRE was defined as a clinical or pathological fracture, spinal cord compression, palliative radiation to bone, or surgery involving bone. Differences in these outcomes were examined using the restricted mean survival time from inverse probability of treatment weighting-adjusted Kaplan-Meier curves, estimated until the last event was observed (longest time observed, 63.9 months). Treatment × covariate interactions were analyzed using weighted Cox proportional hazards regression models for the total cohort.

Results

In the total cohort of 1199 patients (956 [79.7%] younger than 75 years), 597 (49.8%) received AAP and ADT, including 474 (79.4%) younger than 75 years and 384 (64.3%) with more than 10 bone metastases (AAP cohort); 602 (50.2%) were treated with dual placebo and ADT, including 482 (80.1%) younger than 75 years and 377 (62.6%) with more than 10 bone metastases (ADT cohort). In the AAP cohort, 132 patients (22.1%) received BMAs, while in the ADT cohort, 131 (21.8%) did. Zoledronic acid was the most frequently administered BMA in both the AAP (93 [70.5%]) and the ADT (88 [67.2%]) cohorts. During the median follow-up of 51.8 (IQR, 47.2-57.0) months in the AAP cohort, BMA use was associated with a longer time to SRE (difference, 7.8 [95% CI, 4.2-11.3] months) but not with OS (difference, 1.6 [95% CI, -2.5 to 5.8] months). In the ADT cohort, BMA use was associated with both time to SRE (difference, 9.3 [95% CI, 5.2-13.3] months) and OS (difference, 5.5 [95% CI, 3.2-9.8] months). No evidence was found that the outcomes of BMA varied by AAP or ADT (hazard ratio for time to SRE, 0.99 [95% CI, 0.48-2.08]; P = .99 for interaction; hazard ratio for OS, 1.31 [95% CI, 0.88-1.96]; P = .18 for interaction).

Conclusions and Relevance

The findings of this cohort study suggest that use of BMAs was associated with a longer time to SRE in patients with high-risk mCSPC treated with ADT, with or without AAP, suggesting that BMA use might provide benefits to this population.

Costs to Medicare of Nonrecommended Bone-Modifying Agent Use for Castration-Sensitive Prostate Cancer

PURPOSE

Bone-modifying agents (BMAs) do not prevent skeletal-related events among patients with castration-sensitive prostate cancer (CSPC), but many patients receive BMAs unnecessarily. The costs to Medicare from overuse have not been assessed.

METHODS

We used linked SEER-Medicare data 2011-2015 to measure the frequency and number of doses of zoledronic acid (ZA) and denosumab received during CSPC (between diagnosis and initiation of metastatic, castration resistant prostate cancer therapy). We estimated excess BMA among patients who received BMA therapy for CSPC and did not have an indication for osteoporosis fracture prevention. We used the Medicare fee schedule for drug prices and peer-reviewed sources to estimate adverse event frequencies and costs.

RESULTS

Median CSPC duration was 387 days (IQR, 253-573), during which time 42% of patients received ≥one dose of denosumab (mean doses, 7) and 18% received ≥one dose of ZA (mean doses, 7). Thirty-eight percent of those receiving denosumab and 47% of those receiving ZA had a history of osteoporosis, osteopenia, spine or hip fracture, or hypercalcemia. The estimated, annual excess BMA cost to Medicare was $44,105,041 in US dollars (USD), composed of $43,303,078 USD and $45,512 USD in drug costs for denosumab and ZA, respectively, and $682,865 USD and $75,585 USD in adverse event costs, respectively. In one-way sensitivity analysis, the estimate was most sensitive to denosumab dosing frequency (estimate range, $28,469,237 USD-$98,830,351 USD) and duration of CSPC (estimate range, $36,823,311 USD-$99,015,908 USD).

CONCLUSION

BMA overuse in CSPC incurs substantial cost to Medicare, largely because of denosumab drug costs. Excess costs may be reduced by greater adherence to guideline-concordant BMA use.

Physician knowledge, practice patterns, and barriers encountered regarding guideline-concordant use of bone modifying agents for prostate cancer

BACKGROUND

Guidelines recommend bone-modifying agents (BMAs) for patients with castrate-resistant prostate cancer (CRPC) and bone metastasis, but not for castrate-sensitive prostate cancer (CSPC). Physicians beliefs and practices regarding BMA therapy are poorly understood.

METHODS

This was a qualitative interview study with embedded Likert-scale elements. Study participants were physicians who treat prostate cancer, located within an academic cancer center or an affiliated community-based network. Participants were asked about their experiences and practice patterns regarding BMA therapy. Participants used Likert-scale items to identify the most common barriers to guideline-concordant BMA use and the most effective potential interventions. Participants were subsequently asked to rank the three most common barriers and the three most effective interventions to reduce underuse (for CRPC) and overuse (for CSPC).

RESULTS

Nineteen physicians were invited and 15 participated; one physician did not answer some questions as outside of their practice scope. All were aware of the recommendation for BMAs in CRPC. 14% (2/14) were unaware of the recommendation against BMA use for CSPC; an additional 29% (4/14) believed that BMA use could be appropriate for CSPC depending on the metastatic disease burden. 36% (5/14) were unaware of recommendations for screening and treatment of low bone mineral density. The most common barriers (occurring "often" or "sometimes") were obtaining dental clearance (11/15) and insufficient clinic time (6/15). The interventions identified as most effective to reduce underuse were dental navigation (11/15) and electronic medical record (EMR)-based guidance (9/15). The interventions identified as most effective to reduce overuse were peer-to-peer education (14/15) and EMR-based guidance (13/15).

CONCLUSIONS

Awareness of guideline recommendations for screening and treatment of low bone mineral density and against BMA use for CSPC was good, but not complete. Dental navigation, peer-to-peer education, and EMR-based guidance were preferred intervention strategies to improve guideline-concordant use.

Determinants of Bone-Modifying Agent Prescribing for Metastatic Castration-Resistant Prostate Cancer in a National Health Care Delivery System

PURPOSE

Despite guidelines recommending bone-modifying agents (BMAs) to decrease skeletal-related events (SREs) in men with metastatic castration-resistant prostate cancer (mCRPC), BMAs are underutilized. In this retrospective cohort study, we report the factors associated with BMA use in a national health care delivery system.

METHODS

We used the Veterans Affairs Corporate Data Warehouse to identify men with mCRPC between 2010 and 2017. BMA prescribing frequency was evaluated, and the association between patient- and disease-specific factors with BMA use was assessed using multivariable logistic regression.

RESULTS

Among 3,980 men identified with mCRPC (mean age 73.5 years, 29% Black), 47% received a BMA; median time to BMA from start of mCRPC treatment was 102 days. Factors associated with BMA use included previous BMA use (adjusted odds ratio [aOR], 7.81 [95% CI, 6.48 to 9.47]), diagnosis code for bone metastases (aOR, 1.26 [95% CI, 1.08 to 1.46]), and concomitant corticosteroid use (aOR, 1.53 [95% CI, 1.29 to 1.82]). Decreased BMA use was associated with advancing age (aOR, 0.85 per 10 years [95% CI, 0.78 to 0.92]), Charlson comorbidity index ≥2 (aOR, 0.76 [95% CI, 0.63 to 0.93]), Black race (aOR, 0.83 [95% CI, 0.70 to 0.98]), and decreased estimated glomerular filtration rate (eGFR; aOR, 0.19 [95% CI, 0.11 to 0.32] for eGFR 0-29 mL/minutes; aOR, 0.76 [95% CI, 0.64 to 0.91] for 30-59 mL/minutes).

CONCLUSION

Patients who are older, Black, or have more comorbidities are less likely to receive guideline concordant care to prevent SREs. These observations highlight the unique challenges of caring for patients with mCRPC and the need for future studies to increase BMA use in these populations.

Prophylactic Radiation Therapy Versus Standard of Care for Patients With High-Risk Asymptomatic Bone Metastases: A Multicenter, Randomized Phase II Clinical Trial

PURPOSE

External-beam radiation therapy (RT) is standard of care (SOC) for pain relief of symptomatic bone metastases. We aimed to evaluate the efficacy of radiation to asymptomatic bone metastases in preventing skeletal-related events (SRE).

METHODS

In a multicenter randomized controlled trial, adult patients with widely metastatic solid tumor malignancies were stratified by histology and planned SOC (systemic therapy or observation) and randomly assigned in a 1:1 ratio to receive RT to asymptomatic high-risk bone metastases or SOC alone. The primary outcome of the trial was SRE. Secondary outcomes included hospitalizations for SRE and overall survival (OS).

RESULTS

A total of 78 patients with 122 high-risk bone metastases were enrolled between May 8, 2018, and August 9, 2021, at three institutions across an affiliated cancer network in the United States. Seventy-three patients were evaluable for the primary end point. The most common primary cancer types were lung (27%), breast (24%), and prostate (22%). At 1 year, SRE occurred in one of 62 bone metastases (1.6%) in the RT arm and 14 of 49 bone metastases (29%) in the SOC arm (P < .001). There were significantly fewer patients hospitalized for SRE in the RT arm compared with the SOC arm (0 v 4, P = .045). At a median follow-up of 2.5 years, OS was significantly longer in the RT arm (hazard ratio [HR], 0.49; 95% CI, 0.27 to 0.89; P = .018), which persisted on multivariable Cox regression analysis (HR, 0.46; 95% CI, 0.23 to 0.85; P = .01).

CONCLUSION

Radiation delivered prophylactically to asymptomatic, high-risk bone metastases reduced SRE and hospitalizations. We also observed an improvement in OS with prophylactic radiation, although a confirmatory phase III trial is warranted.

Management of Prostate Cancer in Older Adults

The majority of men with prostate cancer are diagnosed when they are older than 65 years; however, clinical trial participants are disproportionately younger and more fit than the real-world population treated in typical clinical practices. It is, therefore, unknown whether the optimal approach to prostate cancer treatment is the same for older men as it is for younger and/or more fit men. Short screening tools can be used to efficiently assess frailty, functional status, life expectancy, and treatment toxicity risk. These risk assessment tools allow for targeted interventions to increase a patient's reserve and improve treatment tolerance, potentially allowing more men to experience the benefit of the significant recent treatment advances in prostate cancer. Treatment plans should also take into consideration each patient's individual goals and values considered within their overall health and social context to reduce barriers to care. In this review, we will discuss evidence-based risk assessment and decision tools for older men with prostate cancer, highlight intervention strategies to improve treatment tolerance, and contextualize these tools within the current treatment landscape for prostate cancer.

Vertical integration of oncologists and cancer outcomes and costs in metastatic castration-resistant prostate cancer

BACKGROUND

The share of oncology practices owned by hospitals (ie, vertically integrated) nearly doubled from 2007 to 2017. We examined how integration between hospitals and oncologists affected care quality, outcomes, and spending among metastatic castration-resistant prostate cancer (mCRPC) patients.

METHODS

Using Surveillance, Epidemiology, and End Results-Medicare linked data and the Medicare Data on Provider Practice and Specialty, we identified Medicare beneficiaries who initiated systemic therapy for mCRPC between 2008 and 2017 (n = 9172). Primary outcomes included 1) bone-modifying agents (BMA) use, 2) time on systemic therapy, 3) survival, and 4) Medicare spending for the first 3 months following therapy initiation. We used a differences-in-differences approach to estimate the impact of vertical integration on outcomes, adjusting for patient and provider characteristics.

RESULTS

The proportion of patients treated by integrated oncologists increased from 28% to 55% from 2008 to 2017. Vertical integration was associated with an 11.7 percentage point (95% confidence interval [CI] = 4.2 to 19.1) increased likelihood of BMA use. There were no satistically significant changes in time on systemic therapy, survival, or total per-patient Medicare spending. Further decomposition showed an increase in outpatient payment ($5190, 95% CI = $1451 to $8930) and decrease in professional service payment (-$4757, 95% CI = -$7644 to -$1870) but no statistically significant changes for other service types (eg, inpatient and prescription drugs).

CONCLUSIONS

Vertical integration was associated with statistically significant increased BMA use but not with other cancer outcomes among mCRPC patients. For oncologists who switched service billing from physician offices to outpatient departments, there was no statistically significant change in overall Medicare spending in the first 3 months of therapy initiation. Future studies should extend the investigation to other cancer types and patient outcomes.

Real-world use of bone modifying agents in metastatic, castration-resistant prostate cancer

BACKGROUND

Bone modifying agents (BMAs) prevent skeletal related events among patients with metastatic, castration-resistant prostate cancer (mCRPC) involving bone and prevent osteoporotic fractures among patients at high risk. BMA utilization for patients with mCRPC has not been well quantified.

METHODS

We used linked SEER registry and Medicare claims data. We included men diagnosed with stage IV prostate adenocarcinoma during 2007-2015, aged > = 66 at diagnosis, with sufficient continuous enrollment in Medicare Parts A, B, and D, who received androgen deprivation therapy. We limited to those who subsequently received a CRPC-defining treatment (CDT). We identified patients with evidence of bone metastasis using claims. Our primary outcome was receipt of a BMA (zoledronic acid or denosumab) within 180 days of initiating CDT.

RESULTS

Among 1292 included patients, 1034 (80%) had bone metastasis. BMA use within 180 days of initiating CDT was higher among patients with bone metastases than those without (705/1034 [68%] vs 56/258 [22%]). Among patients without bone metastasis, those with high osteoporotic fracture risk were more likely than those without to receive a BMA (OR = 2.48, 95% CI: 1.17, 5.29); however, only 26% of patients with high fracture risk received a BMA. Among patients who received BMAs, most (62%) first initiated them >90 days before initiating CDT.

CONCLUSIONS

Two-thirds of patients with mCRPC and bone metastases received BMAs within 180 days after initiating CDT. A greater proportion of patients without bone metastasis may warrant BMA therapy for osteoporotic fracture prevention. Some patients with bone metastasis may be able to delay BMA initiation until CRPC.

Improving Bone Health in Patients with Metastatic Prostate Cancer with the Use of Algorithm-Based Clinical Practice Tool

Background: The bone health of patients with locally advanced and metastatic prostate cancer is at risk from treatment-related bone density loss and skeletal-related events from metastatic disease in bones. Evidence-based guidelines recommend using denosumab or zoledronic acid at bone metastasis-indicated dosages in the setting of castration-resistant prostate cancer with bone metastases and at the osteoporosis-indicated dosages in the hormone-sensitive setting in patients with a significant risk of fragility fracture. For the concerns of jaw osteonecrosis, a dental evaluation is recommended before starting bone-modifying agents. The literature review suggests a limited evidence-based practice for bone health with prostate cancer in the real world. Both under-treatment and inappropriate dosing of bone remodeling therapies place additional risks to bone health. An incomplete dental work up before starting bone-modifying agents increases the risk of jaw osteonecrosis. Methods: We created an algorithm-based clinical practice tool to minimize the deviation from evidence-based guidelines at our center and provide appropriate bone health care to our patients by ensuring indication-appropriate dosing and dental screening rates. This order set was incorporated into the electronic medical record system for ordering a bone remodeling agent for prostate cancer. The tool prompts the clinicians to follow the appropriate algorithm in a stepwise manner to ensure a pretreatment dental evaluation and use of the correct dosage of drugs. Results: We analyzed the data from Sept 2019 to April 2022 following the incorporation of this tool. 0/35 (0%) patients were placed on inappropriate bone modifying agent dosing, and dental health was addressed in every patient before initiating treatment. We compared the change in the practice of prescribing and noted a significant difference in the clinician’s practice while prescribing denosumab/zoledronic acid before and after implementation of this tool [incorrect dosing: 24/41 vs. 0/35 (p < 0.00001)]; and an improvement in pretreatment dental checkup before and after implementation of the tool was noted to be [missed dental evaluation:12/41 vs. 0/35 (p < 0.00001)]. Conclusion: We found that incorporating an evidence-based algorithm in the order set while prescribing bone remodeling agents significantly improved our institutional clinical practice of indication-appropriate dosing and dental screening rates, and facilitated high-quality, evidence-based care to our patients with prostate cancer.

Cancer treatment and survivorship statistics, 2022

The number of cancer survivors continues to increase in the United States due to the growth and aging of the population as well as advances in early detection and treatment. To assist the public health community in better serving these individuals, the American Cancer Society and the National Cancer Institute collaborate triennially to estimate cancer prevalence in the United States using incidence and survival data from the Surveillance, Epidemiology, and End Results cancer registries, vital statistics from the Centers for Disease Control and Prevention's National Center for Health Statistics, and population projections from the US Census Bureau. Current treatment patterns based on information in the National Cancer Database are presented for the most prevalent cancer types by race, and cancer-related and treatment-related side-effects are also briefly described. More than 18 million Americans (8.3 million males and 9.7 million females) with a history of cancer were alive on January 1, 2022. The 3 most prevalent cancers are prostate (3,523,230), melanoma of the skin (760,640), and colon and rectum (726,450) among males and breast (4,055,770), uterine corpus (891,560), and thyroid (823,800) among females. More than one-half (53%) of survivors were diagnosed within the past 10 years, and two-thirds (67%) were aged 65 years or older. One of the largest racial disparities in treatment is for rectal cancer, for which 41% of Black patients with stage I disease receive proctectomy or proctocolectomy compared to 66% of White patients. Surgical receipt is also substantially lower among Black patients with non-small cell lung cancer, 49% for stages I-II and 16% for stage III versus 55% and 22% for White patients, respectively. These treatment disparities are exacerbated by the fact that Black patients continue to be less likely to be diagnosed with stage I disease than White patients for most cancers, with some of the largest disparities for female breast (53% vs 68%) and endometrial (59% vs 73%). Although there are a growing number of tools that can assist patients, caregivers, and clinicians in navigating the various phases of cancer survivorship, further evidence-based strategies and equitable access to available resources are needed to mitigate disparities for communities of color and optimize care for people with a history of cancer. CA Cancer J Clin. 2022;72:409-436.