Risk of skeletal-related events in patients with advanced prostate cancer treated with pamidronate or zoledronic acid

Bone mineral density changes of lumbar spine and femur in osteoporotic patient treated with bisphosphonates and beta-hydroxy-beta-methylbutyrate (HMB): Case report

RATIONALE

Currently available approaches to osteoporosis treatment include application of antiresorptive and anabolic agents influencing bone tissue metabolism. The aim of the study was to present bone mineral density (BMD) changes of lumbar spine in osteoporotic patient treated with bisphosphonates such as ibandronic acid and pamidronic acid, and beta-hydroxy-beta-methylbutyrate (HMB).

PATIENT CONCERNS

BMD and volumetric BMD (vBMD) of lumbar spine were measured during the 6 year observation period with the use of dual-energy X-ray absorptiometry (DEXA) and quantitative computed tomography (QCT).

DIAGNOSES

The described case report of osteoporotic patient with family history of severe osteoporosis has shown site-dependent response of bone tissue to antiosteoporotic treatment with bisphosphonates.

INTERVENTIONS AND OUTCOMES

Twenty-five-month treatment with ibandronic acid improved proximal femur BMD with relatively poor effects on lumbar spine BMD. Over 15-month therapy with pamidronic acid was effective to improve lumbar spine BMD, while in the proximal femur the treatment was not effective. A total of 61-week long oral administration with calcium salt of HMB improved vBMD of lumbar spine in the trabecular and cortical bone compartments when monitored by QCT. Positive effects of nearly 2.5 year HMB treatment on BMD of lumbar spine and femur in the patient were also confirmed using DEXA method.

LESSONS

The results obtained indicate that HMB may be applied for the effective treatment of osteoporosis in humans. Further studies on wider human population are recommended to evaluate mechanisms influencing bone tissue metabolism by HMB.

Measurement of skeletal related events in SEER-Medicare: a comparison of claims-based methods

Background

Skeletal related events (SREs) are common in men with metastatic prostate cancer (mPC). Various methods have been used to identify SREs from claims data. The objective of this study was to provide a framework for measuring SREs from claims and compare SRE prevalence and cumulative incidence estimates based on alternative approaches in men with mPC.

Methods

Several claims-based approaches for identifying SREs were developed and applied to data for men aged [greater than or equal to] 66 years newly diagnosed with mPC between 2000 and 2009 in the SEER-Medicare datasets and followed through 2010 or until censoring. Post-diagnosis SREs were identified using claims that indicated spinal cord compression (SCC), pathologic fracture (PF), surgery to bone (BS), or radiation (suggestive of bone palliative radiation, RAD). To measure SRE prevalence, two SRE definitions were created: ‘base case’ (most commonly used in the literature) and ‘alternative’ in which different claims were used to identify each type of SRE. To measure cumulative incidence, we used the ‘base case’ definition and applied three periods in which claims were clustered to episodes: 14-, 21-, and 28-day windows.

Results

Among 8997 mPC patients, 46 % experienced an SRE according to the ‘base case’ definition and 43 % patients experienced an SRE according to the ‘alternative’ definition. Varying the code definition from ‘base case’ to ‘alternative’ resulted in an 8 % increase in the overall SRE prevalence. Using the 21-day window, a total of 12,930 SRE episodes were observed during follow up. Varying the window length from 21 to 28 days resulted in an 8 % decrease in SRE cumulative incidence (RAD: 10 %, PF: 8 %, SCC: 6 %, BS: 0.2 %).

Conclusions

SRE prevalence was affected by the codes used, with PF being most impacted. The overall SRE cumulative incidence was affected by the window length used, with RAD being most affected. These results underscore the importance of the baseline definitions used to study claims data when attempting to understand relevant clinical events such as SREs in the real world setting.

Clinical and economic burden of bone metastasis and skeletal-related events in prostate cancer

PURPOSE OF REVIEW

We review the clinical trials and observational studies literature regarding the clinical and economic burden of bone metastasis and skeletal-related events (SREs) in prostate cancer, and discuss current gaps in understanding the impact of bone metastasis in this disease.

RECENT FINDINGS

Trial data indicate that SREs occur in half of prostate cancer patients with bone metastasis in the absence of treatment, and 30-45% among those who receive bone-modifying agents. In the United States, the cost of SRE ranged from $7553 per radiation episode to $88 838 per bone surgery episode. Prevalence of SRE, time to SRE occurrence, and cost of SRE varied across studies because of differences in study populations, follow-up period, and the algorithm used to measure SRE. There is limited evidence on the clinical and economic impact by SRE subtype. Information regarding patient-reported outcomes and costs from the patient's perspective is lacking.

SUMMARY

Bone metastasis and SREs in prostate cancer patients are associated with considerable morbidity, reduced survival, and substantial economic burden. Consistent study methodology, particularly the measurement of SREs, is necessary to allow comparison of estimates across studies. The inclusion of patient-centered clinical and economic outcomes in future research will provide pertinent information regarding the burden of bone metastasis and SREs.

Future of bisphosphonates and denosumab for men with advanced prostate cancer

Prostate cancer is the most common cancer occurring in American men of all races. It is also the second leading cause of cancer death among men in the USA. Bone metastasis is a frequent occurrence in men with advanced prostate cancer, with skeletal-related events being a common complication and having negative consequences, leading to severe pain, increased health care costs, increased risk of death, and decreased quality of life for patients. Bone loss can also result from antiandrogen therapy, which can further contribute to skeletal-related events. Treatment with antiresorptive agents bisphosphonates, and the newly approved denosumab, a receptor activator of nuclear factor kappa-B ligand (RANK-L) inhibitor, has been shown to reduce the risk of skeletal-related complications and prevent treatment-induced bone loss in patients with advanced prostate cancer. This review discusses the role of antiresorptive agents bisphosphonates and RANK-L inhibitor in the current treatment of advanced prostate cancer by examining the primary literature and also focuses on the likely role of the bisphosphonates in the treatment of advanced prostate cancer in the future.

Evaluation of the clinical benefit of long-term (beyond 2 years) treatment of skeletal-related events in advanced cancers with zoledronic acid

BACKGROUND

Skeletal complications of malignant bone disease are common among patients with both solid tumors and multiple myeloma (MM). Zoledronic acid (ZOL; Zometa*) is an intravenous bisphosphonate with proven efficacy in reducing the incidence of skeletal complications and delaying the time to a first skeletal complication. This study was designed to assess the continued benefit of ZOL treatment over a prolonged period.

METHODS

This was a retrospective claims analysis study using information gathered from two national US managed-care plan databases. Patients ≥18 years of age with a single type of solid tumor or MM who were diagnosed with bone lesions and experienced at least one skeletal complication (before or after receiving ZOL) were included.

RESULTS

Of the 28,385 patients, those with lung and breast cancer composed the largest group. Greater percentages of MM and breast cancer patients were treated with ZOL. On average, those with renal cell carcinoma and lung cancer had a longer time between bone metastasis diagnosis and start of therapy with ZOL. Compared with an untreated cohort, patients treated with ZOL had a 24% reduction in incidence of fracture, a 45% reduction in incidence of spinal cord compression, and a 56% reduction in risk of mortality. Patients with persistence with ZOL over 180 days had a reduced incidence of fracture before controlling for other factors.

CONCLUSIONS

Patients treated with ZOL had reduced risks of fracture, spinal cord compression, and mortality compared with patients in the no-treatment cohort. Longer persistence with ZOL was associated with better outcomes. Greatest benefits were observed for patients treated on a regular basis with ZOL for a period beyond 18 months.