Strategies for management of prostate cancer-related bone pain

Comparison of 18F-NaF Imaging, 99mTc-MDP Scintigraphy, and 18F-FDG for Detecting Bone Metastases

Bone is a common metastasis site in several malignancies, most importantly prostate and breast cancers. Given the significance of the early and accurate diagnosis of bone metastases for preliminary staging, treatment planning and monitoring, restaging, and survival prediction in patients with malignancy, it is critical to compare and contrast the strengths and weaknesses of imaging modalities. Although technetium-99m-labeled diphosphonates [99mTc-MDP] scintigraphy has been used for assessing skeletal involvement, there is a renewed interest in fluorine-18-labeled sodium fluoride [18F-NaF] bone imaging with positron emission tomography or positron emission tomography/computed tomography, since this approach provides essential advantages in bone metastases evaluation. This review study aimed to discuss the basic and technical aspects of 18F-NaF imaging and its mechanism of action, and compare this modality with the 99mTc-MDP bone scan and 18F-fluorodeoxyglucose using current evidence from the pertinent literature and case examples of the center in the study.

Personal Medicine and Bone Metastases: Biomarkers, Micro-RNAs and Bone Metastases

Bone metastasis is a major cause of morbidity within solid tumours of the breast, prostate, lung and kidney. Metastasis to the skeleton is associated with a wide range of complications including bone fractures, spinal cord compression, hypercalcaemia and increased bone pain. Improved treatments for bone metastasis, such as the use of anti-bone resorptive bisphosphonate agents, within post-menopausal women have improved disease-free survival; however, these treatments are not without side effects. There is thus a need for biomarkers, which will predict the risk of developing the spread to bone within these cancers. The application of molecular profiling techniques, together with animal model systems and engineered cell-lines has enabled the identification of a series of potential bone-metastasis biomarker molecules predictive of bone metastasis risk. Some of these biomarker candidates have been validated within patient-derived samples providing a step towards clinical utility. Recent developments in multiplex biomarker quantification now enable the simultaneous measurement of up to 96 micro-RNA/protein molecules in a spatially defined manner with single-cell resolution, thus enabling the characterisation of the key molecules active at the sites of pre-metastatic niche formation as well as tumour-stroma signalling. These technologies have considerable potential to inform biomarker discovery. Additionally, a potential future extension of these discoveries could also be the identification of novel drug targets within cancer spread to bone. This chapter summarises recent findings in biomarker discovery within the key bone metastatic cancers (breast, prostate, lung and renal cell carcinoma). Tissue-based and circulating blood-based biomarkers are discussed from the fields of genomics, epigenetic regulation (micro-RNAs) and protein/cell-signalling together with a discussion of the potential future development of these markers towards clinical development.

Metastatic Bone Disease in the Era of Bone-Targeted Therapy: Clinical Impact

Advances in the diagnosis and treatment of tumors by surgery, chemotherapy, biotherapy, radiotherapy and other modalities have increased the survival of cancer patients over the last 20 years. As a consequence, bone now represents the third most common site of metastatic involvement after the lung and liver. Approximately 20–25% of patients with neoplastic disease develop clinically evident bone metastases (BMs) during the natural course of their illness, with a further 50% of such lesions being identified during autopsy. BMs are the major cause of morbidity in cancer patients because of their epidemiological and clinical impact. Pain is the most frequent symptom in about 75% of patients but other serious complications can also occur, such as pathological fractures, spinal cord compression, hypercalcemia and bone marrow suppression. These complications worsen the patient's general condition and reduce patients’ mobility, facilitating the development of lung infections, skin ulcers, deep vein thrombosis, etc., and ultimately reducing prognosis and quality of life. The frequency of serious complications depends on the site and type of lesions and the treatment administered. Over the last 10 years, the introduction of bisphosphonates for the treatment of patients with BMs has led to a marked decrease in the frequency of complications, thus improving quality of life and clinical outcome. Furthermore, progress in understanding the pathophysiology of bone metastases has resulted in the development of new bone-targeted molecules such as denosumab. We therefore felt it would be useful to report on the epidemiological, clinical and economic impact of bone disease in a cancer setting.

A Retrospective Analysis of the First 41 mCRPC Patients with Bone Pain Treated with Radium-223 at the National Institute of Oncology in Hungary

Radium-223 dichloride is an alpha-emitting radiopharmaceutical which significantly prolongs overall survival in patients with castration-resistant prostate cancer (CRPC) and symptomatic bone metastases. This was a retrospective analysis of the efficacy and safety of Radium-223 in the first 41 patients treated at a single center in Hungary. Radium-223 was given at a dose of 50 kBq/kg intravenously every 4 weeks for up to 6 cycles. Between 23rd July 2014 and 23rd February 2016, 41 patients were treated. Patient demographics, laboratory values, treatment outcomes and adverse events were collected from medical records. The mean age was 72.2 years (SD: 7.1). 24 patients received Radium-223 as first-line treatment (58%), 7 patients as second (17%), 3 as third (7.3%), 6 as (14.6%), and 1 as fifth-line therapy (2.4%). The mean number of cycles administered was 5.5 (SD: 1.1). The most common side effects were anemia (32% grade 1-3), nausea (28%, grade 1), diarrhea (4%, grade 2), thrombocytopenia (4%, grade 3). The mean baseline PSA level was 307.2 ng/ml (SD: 525.7), which increased to a mean value of 728.5 ng/ml (SD: 1277) by the end of treatment. The baseline mean ALP of 521.1 U/L (SD: 728) decreased to 245.1 U/L (SD: 283.5). The majority of patients experienced a decrease (37%) or complete cessation (43%) of bone pain intensity. In our symptomatic prostate cancer patient population, Radium-223 proved to be efficient in terms of pain relief, with moderate side effects. No PSA response was detected, while alkaline phosphatase levels significantly decreased.

PET Imaging of Skeletal Metastases and Its Role in Personalizing Further Management

In oncology, the skeleton is one of the most frequently encountered sites for metastatic disease and thus early detection not only has an impact on an individual patient's management but also on the overall outcome. Multiparametric and multimodal hybrid PET/computed tomography and PET/MR imaging have revolutionized imaging for bone metastases, but irrespective of tumor biology or morphology of the bone lesion it remains unclear which imaging modality is the most clinically relevant to guide individualized cancer care. In this review, we highlight the current clinical challenges of PET imaging in evaluation and quantification of skeletal tumor burden and its impact on personalized cancer management.

Radiotherapy for oligometastases and oligo-recurrence of bone in prostate cancer

Purpose. To retrospectively evaluate the clinical significance of radiotherapy for oligometastases of bone in prostate cancer (PCa). Methods and Materials. Between 2003 and 2008, 35 PCa patients with oligometastases of bone were treated with radiotherapy. Results. The median radiotherapy dose was 40 Gy. The 3-year overall survival rates for all patients, for patients that received a radiotherapy dose of ≥40 Gy (n = 21) and for those that received <40 Gy (n = 14), were 77.2%, 90.5%, and 50.0%, respectively. Fourteen out of 16 patients (87.5%) who had pain were improved 1 month after radiotherapy. The median duration of pain relief was 12 months. Pathological fracture and spinal cord compression (SCC) were not seen at the treated sites but developed at nonirradiated sites in three patients (8.6%) and in one patient (2.8%), respectively. Although the high-dose group (≥40 Gy) achieved better survival than the low-dose group (<40 Gy), it was not independent prognostic factor in multivariable analysis. Conclusions. Radiotherapy of bone oligometastases in PCa was effective for long-term pain relief. Pathological fracture and SCC were not seen at the treated sites. A larger clinical trial is warranted to study the actual benefit following radiotherapy for oligometastases of bone in PCa.

Preventive or late administration of anti-NGF therapy attenuates tumor-induced nerve sprouting, neuroma formation, and cancer pain

Early, preemptive blockade of nerve growth factor (NGF)/tropomyosin receptor kinase A (TrkA) attenuates tumor-induced nerve sprouting and bone cancer pain. A critical unanswered question is whether late blockade of NGF/TrkA can attenuate cancer pain once NGF-induced nerve sprouting and neuroma formation has occurred. By means of a mouse model of prostate cancer-induced bone pain, anti-NGF was either administered preemptively at day 14 after tumor injection when nerve sprouting had yet to occur, or late at day 35, when extensive nerve sprouting had occurred. Animals were humanely killed at day 70 when, in vehicle-treated animals, significant nerve sprouting and neuroma formation was present in the tumor-bearing bone. Although preemptive and sustained administration (days 14-70) of anti-NGF more rapidly attenuated bone cancer nociceptive behaviors than late and sustained administration (days 35-70), by day 70 after tumor injection, both preemptive and late administration of anti-NGF significantly reduced nociceptive behaviors, sensory and sympathetic nerve sprouting, and neuroma formation. In this model, as in most cancers, the individual cancer cell colonies have a limited half-life because they are constantly proliferating, metastasizing, and undergoing necrosis as the parent cancer cell colony outgrows its blood supply. Similarly, the sensory and sympathetic nerve fibers that innervate the tumor undergo sprouting at the viable/leading edge of the parent tumor, degenerate as the parent cancer cell colony becomes necrotic, and resprout in the viable, newly formed daughter cell colonies. These results suggest that preemptive or late-stage blockade of NGF/TrkA can attenuate nerve sprouting and cancer pain.

Pathologic fractures correlate with reduced survival in patients with malignant bone disease

BACKGROUND

Data from randomized, controlled trials of zoledronic acid were retrospectively analyzed to assess the effect of pathologic fractures on survival in patients with malignant bone disease.

METHODS

A Cox regression model was used to estimate the effect of fractures (time-dependent variable) on survival in patients with stage III multiple myeloma or bone metastases from solid tumors enrolled in 3 large trials. Patients were randomized to receive zoledronic acid, pamidronate, or placebo every 3-4 weeks for up to 24 months (prostate cancer, breast cancer, and multiple myeloma) or up to 21 months (lung and other solid tumors).

RESULTS

A total of 3049 patients with multiple myeloma (n = 513), breast (n = 1130), prostate (n = 640), or lung cancer or other solid tumors (n = 766) were included in this analysis. Patients with multiple myeloma had the highest fracture incidence (43%), followed by breast (35%), prostate (19%), and lung cancer (17%). In all tumor types except lung, pathologic fracture was associated with a significant increase in risk of death, and breast cancer patients had the greatest increased risk. After adjustment for baseline characteristics, including performance status and prior skeletal complications, breast cancer patients who developed a pathologic fracture on study had a significant 32% increased risk of death relative to patients without a fracture (hazard ratio = 1.32; P < .01); patients with multiple myeloma or prostate cancer had a >20% increased risk of death.

CONCLUSIONS

These results suggest that fractures are associated with increased risk of death in patients with malignant bone disease. Therefore, preventing fractures is an important goal of therapy.

Effects of skeletal morbidities on longitudinal patient-reported outcomes and survival in patients with metastatic prostate cancer

GOALS OF WORK

Patients with prostate cancer metastasized to bone frequently experience skeletal morbidities as a result of their disease. We sought to quantify the longitudinal effects on patient-reported outcomes of skeletal-related events (SREs) and to ascertain the declines in health-related quality of life (HRQOL) and pain experienced by patients who experienced SREs.

MATERIALS AND METHODS

Data are from a clinical trial for the treatment of SREs associated with advanced prostate cancer metastatic to bone. Outcome measures included the Functional Assessment of Cancer Therapy-General (FACT-G) and the Brief Pain Inventory. Among patients who survived 6 months after randomization, patients with no SREs in the initial 6 months after randomization were matched via propensity scores with those experiencing one or more SREs. Similarly, patients with one SRE were matched with a subset of patients with two or more SREs.

MAIN RESULTS

Patients with SREs in the initial period had significantly worse survival and HRQOL than those with no SREs. Significant differences were found between the pain differences, FACT-G total scores, and FACT-G physical, emotional, and functional subscales. Comparisons of patients with single vs multiple SREs showed similar patterns.

CONCLUSIONS

The presence of SREs is significantly associated with worse survival and poorer HRQOL in this patient population. Increasing SRE intensity shows a pattern of increasingly decreased survival and poorer HRQOL.

The significance of skeletal-related events for the health-related quality of life of patients with metastatic prostate cancer

BACKGROUND

We examined the clinical relevance of skeletal-related events (SREs) for health state preferences, pain and health-related quality of life in patients with advanced prostate cancer and a history of bone metastases.

PATIENTS AND METHODS

Data were from a clinical trial of zoledronic acid versus placebo in the treatment of SREs associated with advanced prostate cancer metastatic to bone. Patients (n=248) were included if they experienced an SRE during the study. Outcome measures were assessed at fixed intervals. We used mixed-effects models to estimate changes in outcomes after each patient's first SRE.

RESULTS

There were clinically meaningful and statistically significant declines in physical well-being after: radiation and pathologic fractures; functional well-being after radiation; and emotional well-being after radiation and pathologic fractures. There also were meaningful and significant declines in preference and utility scores after radiation and fracture. Pain intensity declined after radiation, but not after other SREs; no other pain measure changed substantively.

CONCLUSIONS

SREs have important and significant effects on measures of health-related quality of life in men with prostate cancer. Treatments that prevent SREs may not demonstrate corresponding effects on outcomes if the effects of SREs occur between scheduled outcome assessments. Implications for trial design are discussed.

Bone turnover markers as predictors of skeletal complications in prostate cancer, lung cancer, and other solid tumors

BACKGROUND

Whether bone markers have prognostic value in patients with bone metastases is unknown. We investigated this question in patients with bone metastases secondary to prostate cancer and to non-small-cell lung cancer (NSCLC) and other solid tumors assigned to the placebo arms of two phase III trials of zoledronic acid.

METHODS

Levels of the urinary bone resorption marker N-telopeptide and the serum bone formation marker bone-specific alkaline phosphatase were assessed every 3 months for patients with prostate cancer (n = 203) or NSCLC or other solid tumors (n = 238) and were categorized as low or high. Patients were monitored for skeletal-related events, bone disease progression, and death. The relative risks (RRs) and 95% confidence intervals (CIs) for these outcomes were estimated for patients with high versus low levels of each marker using intensity-based multiple event and Cox regression models. All statistical tests were two-sided.

RESULTS

In each disease group and overall, high levels of each marker at the beginning of the study were statistically significantly associated with an increased risk of negative outcomes. Use of recent marker assessments as time-dependent covariates gave even greater prognostic significance. High N-telopeptide levels were a stronger prognostic indicator of negative outcomes than bone-specific alkaline phosphatase levels. In recent assessments, patients with high N-telopeptide levels had an increased relative risk of skeletal-related events (prostate cancer, RR = 3.25, 95% CI = 2.26 to 4.68, P<.001; NSCLC and other solid tumors, RR = 1.79, 95% CI = 1.15 to 2.79, P = .010), disease progression (prostate cancer, RR = 2.02, 95% CI = 1.48 to 2.74, P<.001; NSCLC and other solid tumors, RR = 1.91, 95% CI = 1.16 to 3.15, P = .011), and death (prostate cancer, RR = 4.59, 95% CI = 2.82 to 7.46, P<.001; NSCLC and other solid tumors, RR = 2.67, 95% CI = 1.85 to 3.85, P<.001) compared with patients with low N-telopeptide levels.

CONCLUSIONS

Baseline and recent bone marker levels were predictive of negative clinical outcomes in patients with bone metastases secondary to prostate cancer and to NSCLC and other solid tumors. N-telopeptide levels were more consistent prognostic indicators than bone-specific alkaline phosphatase for all tumor types, reflecting the key role of osteolysis in the development of skeletal complications.

Severe hypophosphatemic osteomalacia in hormone-refractory prostate cancer metastatic to the skeleton: natural history and pitfalls in management

We report the case of a severe symptomatic hypophosphatemic osteomalacia in a 66-year-old patient with hormone-refractory prostate cancer metastatic to the skeleton. A follow-up of 2 years from diagnosis to development of hormone refractoriness and death allowed us to study the natural history of this uncommon disturbance of mineral homeostasis in this common malignancy. Relevant to the difficult management of the late stages of prostate cancer is the failure of hypophosphatemia to respond to conventional therapeutic approaches and the favorable outcome of antitumor therapy suggesting that this group of patients, although having a poor prognosis, could still benefit from aggressive second line therapy. In this malignancy in which metastases have a predilection for bone, failure to recognize osteomalacia can only result in significantly increasing the burden of skeletal complications.

Zoledronic Acid Significantly Reduces Pathologic Fractures in Patients with Advanced-Stage Prostate Cancer Metastatic to Bone

The skeletal complications of metastatic bone disease secondary to advanced prostate cancer result in significant morbidity. In particular, pathologic fractures often require clinical intervention and are independent predictors of mortality in men with advanced prostate cancer. Before the introduction of zoledronic acid, bisphosphonates had been shown to provide pain palliation in patients with prostate cancer and bone metastases but were not efficacious in preventing skeletal complications. Zoledronic acid is the first bisphosphonate to show efficacy in reducing skeletal complications associated with the predominantly osteoblastic bone lesions characteristic of prostate cancer. In a large phase III randomized trial, zoledronic acid 4 mg every 3 weeks for 15 months significantly reduced the percentage of men who experienced a skeletal complication and reduced the incidence of pathologic fractures. Additionally, zoledronic acid 4 mg significantly decreased the annual incidence of skeletal complications, including fractures, and provided better control of bone pain compared with placebo. Adverse events with zoledronic acid were primarily limited to the flu-like, acute-phase symptoms previously reported with intravenous bisphosphonates, namely fever, myalgia, nausea, and anemia. These adverse events were mild to moderate and easily managed with supportive care. Zoledronic acid is the first and only bisphosphonate shown to reduce skeletal morbidity, including fractures, in patients with advanced prostate cancer and bone metastases.

Bisphosphonates: their evolving role in the management of prostate cancer-related bone disease

PURPOSE OF REVIEW

The use of androgen deprivation therapy has increased because of its use as part of multimodality therapy for high-risk early stage disease and in recurrent nonmetastatic disease. Hormonal therapy is associated with secondary osteoporosis and increased skeletal morbidity. Furthermore, in patients with established bone metastases, osseous complications are a significant problem. Bisphosphonates have been investigated in the prevention of bone density loss and skeletal morbidity. Results of these studies are now becoming available.

RECENT FINDINGS

Data are emerging that demonstrate that bisphosphonates can prevent skeletal morbidity, such as pathologic fractures and spinal cord compression in men with hormone-refractory prostate cancer. The early use of bisphosphonates has also been shown to prevent bone loss due to androgen deprivation therapy. Current third-generation bisphosphonates are several hundred times more potent than their predecessors. Evidence is emerging that these drugs not only inhibit bone resorption but also are cytotoxic to prostate cancer cells.

SUMMARY

Bisphosphonates are assuming a prominent ancillary role in prostate cancer therapy through their ability to prevent skeletal morbidity. Their potential to interfere with the formation of osseous tumor deposits has lead to investigations into the capacity of these drugs to prevent bone metastasis.