Treatment dynamics of bone-targeting agents among men with bone metastases from prostate cancer in the United States

Bone-targeting agents in major solid tumour metastases: a multinational cohort study

OBJECTIVE

To describe the epidemiology, clinical characteristics and utilisation patterns of bone-targeting agents (BTAs) in patients with bone metastases from breast, prostate and lung cancer.

METHODS

This is a multinational retrospective cohort study including patients with three major solid tumours (breast, prostate and lung cancer) and newly initiated on BTAs (ie, denosumab, zoledronic acid and pamidronate). Records were retrieved from nationwide health databases from Hong Kong and Taiwan (HK and TW: 2013-2017) and Korea (KR: 2012-2016). Descriptive analyses included the annual incidence rates of bone metastases and the cumulative incidence curves of BTA initiation. We used Sankey diagrams to visualise the dynamic BTA utilisation patterns.

RESULTS

The annual incidence rate of bone metastases ranged from 3.5% to 4.5% in TW, from 9.6% to 10.3% in HK and from 2.9% to 3.8% in KR. We identified 14.1% (5127), 9.3% (883) and 9.4% (4800) of patients with bone metastases newly initiated on BTAs in TW, HK and KR, respectively. The most frequently used BTA in TW (67.1%) and HK (51.9%) was denosumab, while in KR (84.8%) it was zoledronic acid. Sankey diagrams indicated the proportion of patients remaining on denosumab was highest in TW and HK, while it was zoledronic acid in KR. Specifically, in TW, patients who were on bisphosphonates or had discontinued treatment frequently switched to or reinitiated denosumab.

CONCLUSIONS

We found the rate of BTA utilisation remained low across all sites and tumour types in recent years. The dynamic utilisation patterns of BTAs provide better understanding of the treatment landscape for future evaluation of associated outcomes of patients.

Assessment of bone-targeting agents use in patients with bone metastasis from breast, lung or prostate cancer using structured and unstructured electronic health records from a regional UK-based hospital

ObjectiveTo assess use of bone-targeting agents (BTA) in patients with confirmed bone metastases (BM) from breast cancer (BC), non-small cell lung cancer (NSCLC) or prostate cancer (PC).

DESIGN

Retrospective cohort study.

SETTING

Regional hospital-based oncology database of approximately 2 million patients in England.

PARTICIPANTS

Patients aged ≥18 years with a diagnosis of BC, NSCLC or PC as well as BM between 1 January 2007 and 31 December 2018, with follow-up to 30 June 2020 or death; BM diagnosis ascertained from recorded medical codes and unstructured data using natural language processing (NLP).

MAIN OUTCOMES MEASURES

Initiation or non-initiation of BTA following BM diagnosis, time from BM diagnosis to BTA initiation, time from first to last BTA, time from last BTA to death.

RESULTS

This study included 559 BC, 894 NSCLC and 1013 PC with BM; median age (Q1-Q3) was 65 (52-76), 69 (62-77) and 75 (62-77) years, respectively. NLP identified BM diagnosis from unstructured data for 92% patients with BC, 92% patients with NSCLC and 95% patients with PC. Among patients with BC, NSCLC and PC with BM, 47%, 87% and 88% did not receive a BTA, and 53%, 13% and 12% received at least one BTA, starting a median 65 (27-167), 60 (28-162) and 610 (295-980) days after BM, respectively. Median (Q1-Q3) duration of BTA treatment was 481 (188-816), 89 (49-195) and 115 (53-193) days for patients with BC, NSCLC and PC. For those with a death record, median time from last BTA to death was 54 (26-109) for BC, 38 (17-98) for NSCLC and 112 (44-218) days for PC.

CONCLUSION

In this study identifying BM diagnosis from both structured and unstructured data, a high proportion of patients did not receive a BTA. Unstructured data provide new insights on the real-world use of BTA.

Initiation of bone-targeted agents in patients with bone metastases and breast or castrate-resistant prostate cancer actively treated in routine clinical practice in Europe

BACKGROUND

Guidelines recommend starting bone-targeted agents (BTA), such as zoledronic acid and denosumab, as soon as bone metastases (BMs) are definitively diagnosed in all patients with breast cancer (BC) or castration-resistant prostate cancer (CRPC) whether they are symptomatic or not.

METHODS

Data were analyzed from 1364 patients with BC and 1161 patients with CRPC who had BMs and were receiving anti-cancer therapy in hospitals across six European countries (Belgium, France, Germany, Italy, Spain and the UK). The 731 physicians (medical oncologists or urologists) provided insights in the decision-making factors driving their management of bone health for these patients, and the patient medical records indicated how these decisions were reflected in routine clinical practice.

RESULTS

Within three months of a BM diagnosis, 74% of BC and 51% of CRPC patients had initiated treatment with a BTA. Around 12% of BC and 23% of CRPC patients did not receive a BTA following BM diagnosis. Irrespective of the tumour type (BC or CRPC), most physicians prescribed either denosumab or zoledronic acid as first BTA therapy. Physicians reported bone pain as a major decision-making factor to initiate a BTA. The presence of bone complications at BM diagnosis and bone pain at BM diagnosis were found to be significant predictive factors for a BTA initiation, irrespective of tumour type.

CONCLUSIONS

Despite European Society for Medical Oncology (ESMO) guidance on bone protection irrespective of symptomatic disease, not all patients with BMs received a BTA following a BM diagnosis. This suggests that clinical judgements and patients' communication of their pain to their physicians contributed to the decision to prescribe bone protection therapy in cancer patients.

Medication adherence with denosumab in patients with bone metastases from solid tumors treated in routine clinical settings: a retrospective study

PURPOSE

To describe (non)adherence with denosumab among patients with solid tumors and bone metastases.

METHODS

This retrospective, observational study pooled data from two completed prospective, multicenter cohort studies (X-TREME; Study 240) in adult patients with bone metastases from primary breast, prostate, lung, kidney, or other solid cancer types and administered denosumab 120 mg in routine clinical practice in Germany and Central and Eastern Europe. The studies were conducted between May 2012 and May 2017; pooled analysis was completed in August 2021. Medication adherence was described according to a three-component consensus taxonomy: initiation (first-ever administration ≤ 90 days from bone metastasis diagnosis), implementation (actual vs prescribed dosing; optimal implementation = regular/consistent dosing), and persistence (≤ 60-day gap between administrations at 3, 6, 9, and 12 months). Descriptive analyses were conducted for each cancer type.

RESULTS

The analysis included 1748 patients with solid tumors and bone metastases. Adherence with denosumab was generally high across the initiation, implementation, and persistence phases. Most patients experienced timely initiation (from 64.4% [kidney cancer] to 81.2% [breast cancer]) and optimal implementation (from 62.4% [lung cancer] to 72.5% [breast cancer]). The proportion of patients who were persistent with treatment at 6 months ranged from 41.4% (lung cancer) to 77.8% (prostate cancer).

CONCLUSIONS

This study revealed variations by cancer type in the initiation, implementation, and persistence of denosumab in patients with solid tumors and bone metastases in routine clinical practice. Further cancer-specific studies are warranted to examine the determinants of (non)adherence with denosumab, and potential ways to improve medication adherence.

Assessment of Bone Health Education in US Multiple Myeloma and Solid Tumor Patients at Risk for Skeletal-Related Events

Purpose

Cancer patients with bone metastasis (BM) from solid tumors or multiple myeloma (MM) have an increased risk of painful skeletal-related events (SREs), which can decrease quality of life and increase mortality. Bone targeting agents (BTAs) can help delay or prevent SREs; however, a significant portion of eligible patients are not receiving BTA therapy. This study was conducted to understand patient awareness of cancer-related bone health and to identify opportunities to improve bone health education in cancer patients at risk of SREs.

Methods

The online BonE heAlth eduCatiOn Needs assessment (BEACON) survey included questions about patient demographics, cancer diagnosis and treatments (including BTA usage), and extent and satisfaction with bone health education received. Direct-to-patient outreach was used to recruit patients. Eligible patients were US adults with a diagnosis of self-reported MM or BM from a solid tumor (breast, lung, or prostate cancer) within the past three years.

Results

Of 125 patients, 71% were diagnosed with solid tumors with BM and 29% with MM. At least one prior SRE was experienced by 57% of patients (38% radiation to bone, 32% bone fracture, 22% spinal cord compression, and 19% surgery to bone), and 74% were currently receiving BTA therapy. Awareness of cancer bone health, protection strategies, and screening tests was low to moderate; patients were least informed of the impact of lifestyle changes (38%) and specific cancer treatments (≤35%) on bone health. Sixty-two percent of patients were not completely satisfied with the bone health education received. Patients generally wanted more information (58%) and to receive information by more than one mode of communication.

Conclusion

Notable gaps in bone health education were observed in cancer patients at risk for SREs indicating an important need for improved communication and education strategies to promote better health outcomes.

Androgen receptor expression reduces stemness characteristics of prostate cancer cells (PC3) by repression of CD44 and SOX2

Studies have shown that a subgroup of tumor cells possess stemness characteristics having self-renewal capacity and the ability to form new tumors. We sought to identify the plausible stemness factor that determines the "molecular signature" of prostate cancer (PCa) cells derived from different metastases (PC3, PCa2b, LNCaP, and DU145) and whether androgen receptor (AR) influences the maintenance of stemness features. Here we show sex-determining region Y (SRY)-box 2 (SOX2) as a putative stem cell marker in PC3 PCa cells and not in DU145, PCa2b, or LNCaP cells. PCa2b and PC3 cells were derived from bone metastases. PCa2b cells which are positive for the AR failed to demonstrate the expression of either cluster of differentiation 44 (CD44) or SOX2. Knockdown (KD) of AR in these cells did not affect the expression of either CD44 or SOX2. Conversely, PC3 cells, which are negative for AR, expressed both CD44 and SOX2. However, the expression of AR downregulated the expression of both CD44 and SOX2 in PC3 cells. CD44 regulates SOX2 expression as KD of CD44 and reduces SOX2 levels considerably. SOX2 KD attenuated not only the expression of SNAIL and SLUG but also the migration and tumorsphere formation in PC3 cells. Collectively, our findings underscore a novel role of CD44 signaling in the maintenance of stemness and progression of cancer through SOX2 in AR-independent PC3 cells. SOX2 has a role in the regulation of expression of SNAIL and SLUG. SOX2 could be a potential therapeutic target to thwart the progression of SOX2-positive cancer cells or recurrence of androgen-independent PCa.

Use of bone-modifying agents among breast cancer patients with bone metastasis: evidence from oncology practices in the US

Purpose

Bone-modifying agents (BMAs) are recommended for women with bone metastasis from breast cancer to prevent skeletal-related events. We examined the usage patterns and identified the factors associated with the use of BMAs (denosumab and intravenous bisphosphonates) among women in the US.

Patients and methods

Electronic health records from oncology clinics were used to identify women diagnosed with bone metastasis from breast cancer between 2013 and 2014. Patients were excluded if they had recently used a BMA or had concurrent cancer at an additional primary site. The incidence of BMA initiation, interruption, and reinitiation were estimated using competing risk regression models. A generalized linear model was used to estimate risk factors for treatment initiation and interruption.

Results

There were 589 women diagnosed with bone metastasis from breast cancer. By 1 year, 68% of these patients (95% CI: 64%, 71%) had initiated treatment with a BMA. Denosumab and zoledronic acid were the most commonly used agents, whereas pamidronate was used infrequently. Young women were more likely to initiate a BMA than older women (adjusted risk difference: 6.4 [95% CI: 1.5, 10.9]). Of the 412 patients who initiated a BMA, 46% (95% CI: 41%, 51%) experienced an interruption within 1 year. Seventy-four percent (95% CI: 68%, 79%) of patients who interrupted their treatment had reinitiated therapy within 1 year of interruption.

Conclusion

The majority of women diagnosed with bone metastasis from breast cancer initiate a BMA within 1 year of diagnosis, but a large proportion, particularly among the elderly, do not use these therapies.