Emerging strategies and therapies for treatment of Paget's disease of bone

Paget's disease of bone (PDB) is a progressive monostotic or polyostotic metabolic bone disease characterized by focal abnormal bone remodeling, with increased bone resorption and excessive, disorganized, new bone formation. PDB rarely occurs before middle age, and it is the second most frequent metabolic bone disorder after osteoporosis, affecting up to 3% of adults over 55 years of age. One of the most striking and intriguing clinical features is the focal nature of the disorder, in that once the disease is established within a bone, there is only local spread within that bone and no systemic dissemination. Despite many years of intense research, the etiology of PDB has still to be conclusively determined. Based on a detailed review of genetic and viral factors incriminated in PDB, we propose a unifying hypothesis from which we can suggest emerging strategies and therapies. PDB results in weakened bone strength and abnormal bone architecture, leading to pain, deformity or, depending on the bone involved, fracture in the affected bone. The diagnostic assessment includes serum total alkaline phosphatase, total body bone scintigraphy, skull and enlarged view pelvis x-rays, and if needed, additional x-rays. The ideal therapeutic option would eliminate bone pain, normalize serum total alkaline phosphatase with prolonged remission, heal radiographic osteolytic lesions, restore normal lamellar bone, and prevent recurrence and complications. With the development of increasingly potent bisphosphonates, culminating in the introduction of a single intravenous infusion of zoledronic acid 5 mg, these goals of treatment are close to being achieved, together with long-term remission in almost all patients. Based on the recent pathophysiological findings, emerging strategies and therapies are reviewed: ie, pulse treatment with zoledronic acid; denosumab, a fully human monoclonal antibody directed against RANK ligand; tocilizumab, an interleukin-6 receptor inhibitor; odanacatib, a cathepsin K inhibitor; and proteasome and Dickkopf-1 inhibitors.

Juvenile Paget's disease

Juvenile Pagets disease (JPD), a rare genetic disorder characterized by markedly accelerated bone turnover, presents in early childhood. We report a child with typical features of JPD who remained undiagnosed till 15 years of age. Rarity of this disease in Indian literature and need for early diagnosis to prevent progression of disease prompted us to report this case.

Paget's disease 2: exploring diagnosis, management and support strategies

This is the second of a two-part unit on Paget's disease. Part 1 outlined the epidemiology, pathophysiology, causes and clinical features of the condition. This part outlines advice on diagnosis, drug therapy, surgery, other management options and emotional support.

Paget disease of bone

Despite significant advances in management, Paget disease remains an enigmatic disorder. There are no animal models, and while its end result --a focal disorder of accelerated bone turnover--is easily recognized, the causes and evolution of the disorder remain uncertain. Recent evidence strongly implicates both genetic and environmental factors in its etiology. The authors consider some of the unresolved questions surrounding Paget disease, including the attenuating prevalence and severity of the disease; how these observations might be reconciled with an apparently highly penetrant genetic susceptibility; what the putative environmental triggers of Paget disease might be; and what relapse after treatment tells us. Most observations seem to fit best with the idea that Paget disease behaves as a multifocal benign neoplasm.

Treatment of Paget's disease of bone: a survey of clinical practice in Australia

Consensus guidelines for the treatment of Paget's disease of bone have been published, but it is not known how closely these reflect clinical practice. We conducted a multi-centre, stratified, retrospective review of case notes of 531 subjects treated for Paget's disease of bone between 2000 and 2005 in 29 Australian centres. The subjects received 1072 courses of bisphosphonate treatment (pamidronate 363, alendronate 324, risedronate 208, tiludronate 103, zoledronic acid 69, and etidronate 5). The most recent treatment received was oral therapy in 57% of patients (alendronate 29%, risedronate 24%, and tiludronate 4%) and intravenous in 43% (pamidronate 33%, and zoledronic acid 10%). For oral bisphosphonates, the percentages of courses which were at the recommended dosage and duration were: alendronate 33%, risedronate 60% and tiludronate 29%. Pamidronate was administered in a wide range of dosing schedules, most commonly 60 mg every 3 months (18%), 6 months (17%) or annually (12%), whereas zoledronic acid was mainly given as a 4 mg infusion (98%) as a single dose (52%) or annually (19%). Most clinicians reported taking into account symptoms, plasma alkaline phosphatase activity and anatomical location of disease in determining the need for treatment. Patient preference, intolerance of oral therapy and compliance were ranked highest in determining the choice between oral and intravenous therapy. We conclude that oral and intravenous bisphosphonate dosing regimens are both commonly used to treat Paget's disease of bone in Australia. Only a minority of courses of oral bisphosphonate treatment are at the recommended dosage and duration, and there is a lack of consensus on regimens for intravenous treatment.

[Paget's disease of bone]

Paget's disease of bone (PDB) is a chronic disorder of bone metabolism characterized by abnormalities of osteoclast function possibly based on the genetic background and slow viral infection. The symptoms of PDB are usually pain and deformity in involved bones and a subsequent increasing risk of pathological fractures, neurological complications and secondary malignant tumor development. The diagnosis of PDB is based on the clinical manifestations carefully examined, laboratory data such as measurement of serum alkaline phosphatase and characteristic findings of radiology including bone scintigraphy. The pathological examination also utilized for diagnosis of PDB in order to exclude bone metastases. Recently, the guidelines for diagnosis and management of PDB in Japan is proposed. According to these guidelines, etidronate and calcitonin are approved by government for treating PDB and surgical treatment are suggested to apply for orthopaedic problems in PDB. Also, rehabilitation is important for preventing the onset and worsening of de-conditioning secondary due to the complications of PDB.

Paget disease of bone

Paget disease of bone, also known as osteitis deformans, is a nonmalignant disease of bone that causes accelerated and abnormal bone remodeling. It is the second most common bone disorder, osteoporosis being first. It is a localized disorder, meaning it affects just 1 or several bones in the body. Paget disease of bone is characterized by enlarged and deformed bones and occurs mainly in the axial skeleton. The cause of the disease is still not known entirely, but genetics are certain to be involved, and viral factors also are suspected.

Sarcomas arising in Paget disease of bone: a clinicopathologic analysis of 70 cases

CONTEXT

Sarcomatous transformation is a rare complication of Paget disease of bone. Prognosis in patients with other types of sarcomas arising in bone has improved in the last several decades because of therapeutic advances. However, because of the rarity of Paget sarcoma, outcome studies in these patients are limited.

OBJECTIVE

To determine whether prognosis for Paget sarcoma has improved.

DESIGN

Seventy cases of sarcomas arising in the setting of Paget disease were collected, and the histologic and clinical findings were reviewed. Clinical follow-up was obtained in 67 cases.

RESULTS

Sarcoma arising in Paget disease tended to arise in older men (46 men, 24 women; age range, 31-88 years; mean age, 66 years) and predominated in the axial skeleton (n = 37), especially in the pelvis. Thirty-three patients had a clinical history of Paget disease ranging in duration from 16 months to 30 years (mean, 15 years). No significant difference in incidence between monostotic (n = 33) and polyostotic (n = 36) disease was noted. Most tumors were osteosarcomas (88%). All tumors were high grade. Follow-up information was obtained in 67 of 70 cases (range of follow-up, 1-252 months). Survival ranged from 1 month to 20 years, with a 5-year survival rate of 10%.

CONCLUSIONS

Prognosis remains poor in patients with Paget sarcoma. There is no significant correlation between the number of bones involved with Paget disease or the duration of disease and development of Paget sarcoma. Poor prognosis in Paget sarcoma is unrelated to site or stage at presentation.

[Italian guidelines for the diagnosis and treatment of Paget's disease of bone]

Paget's disease of bone is a chronic focal abnormality of bone turnover that remains totally asymptomatic over a very long period of time but that eventually ensue in bone pain and skeletal deformities. Although, in the last decade new insights have been obtained on its etiology, this remains largely obscure. Effective medical treatment (based on the use of bisphosphonates) has become available and the diagnostic procedures are now well defined. However, there remains considerable controversy regarding the hierarchy of diagnostic procedures and the medical treatment threshold. In the last few years different institution have published national guidelines, reflecting local national health systems and the available medical treatment. In this review, a working group derived from members of the SIOMMMS has examined the information available regarding the diagnosis and treatment of Paget's disease in order to develop guidelines to assist in the management of this condition. The first draft was then extensively reviewed by experts derived from the most representative scientific societies of rheumatology, internal medicine, and orthopaedic surgery. The document provides the most updated recommendations based primarily on the "evidence-based- medicine" but also on the Italian regulation for the diagnostic procedures and on the available medical treatments.

Epidemiology, impact, management, and cost of Paget's disease of bone in France

OBJECTIVES

To evaluate the epidemiology, quality-of-life (QoL) impact, management, and cost of Paget's disease of bone.

METHODS

Retrospective and prospective data were collected in a representative cross-section of office-based and hospital-based rheumatologists in France, in early 2005. Each rheumatologist included consecutive outpatients with Paget's disease seen over a 2-month period. For each patient, a medical questionnaire and the 36-item Short-Form self-questionnaire (SF-36) evaluating health-related quality of life were completed. A descriptive analysis of the patient population was conducted. Medical costs over the last 12 months were estimated.

RESULTS

Four hundred and forty-six medical questionnaires and 387 SF-36 questionnaires were available. Mean age was 74 years, and 58.3% of patients were male. The diagnosis was fortuitous (usually radiological) in 39.2% of cases. Complications occurred in 40% of cases; 97.8% of complications involved the joints. Bisphosphonate therapy was used in nearly 84% of patients. The SF-36 scores were significantly decreased compared to the general population, in both males and females. Total cost of management was less than one-third the cost of managing type 2 diabetes mellitus.

CONCLUSION

The results confirm the well-established characteristics of Paget's disease. Bisphosphonate therapy was widely used. Quality of life was significantly altered. The cost of management was moderate.

Paget's disease of bone

Paget's disease of bone is a focal disorder of bone remodeling accompanied initially by an increase in bone resorption, followed by a disorganized and excessive formation of bone, leading to pain, fractures and deformities. It exhibits a marked geographical variation in its prevalence. In Brazil it predominantly affects persons of European descent. The majority of the reported cases of the disease in Brazil are from Recife, owing to its peculiar mixed European colonization over approximately four centuries. The etiology is complex and involves both genetic and environmental factors. The disease is often asymptomatic and diagnosis is usually based on biochemical markers of bone turnover, radionuclide bone scan and radiological examination. Bisphosphonates, in particular zoledronic acid, are regarded as the treatment of choice for Paget's disease of bone.

Paget sarcoma of the spine: Scottish Bone Tumor Registry experience

STUDY DESIGN

Retrospective case study of 13 cases of Paget sarcoma of the spine accrued from a prospectively collected Tumor Registry database.

OBJECTIVES

To analyze the clinical, radiologic, and histologic features of Paget sarcoma of the spine and to determine the factors influencing the prognosis.

SUMMARY OF BACKGROUND DATA

Paget disease of bone is a common disorder with the spine being involved in over 50% of patients. However, sarcomatous degeneration in the vertebral column is an extremely rare complication. There is very little in the literature with regard to clinical presentation and prognosis of patients with Paget sarcoma affecting the vertebral column.

METHODS

Between January 1944 and December 2003, 89 patients were registered with a diagnosis of Paget sarcoma in the Scottish Bone Tumor Registry. Thirteen patients with Paget sarcoma of the spine were analyzed with regard to their clinical, radiologic, and histopathologic features along with the prognostic predictors.

RESULTS

The mean age was 66.9 years (range: 56-79 years). There were 10 males and three females. There were seven cases involving the sacral spine (63.6%), three cases involving lumbar vertebrae, two affecting the dorsal spine, and one with diffuse dorsolumbar involvement (D11-L3). The mode of presentation was progressively increasing low back pain (in all 13), unilateral sciatica (six; left-sided, five; right-sided, one), bilateral sciatica (two), lower limb weakness (eight), and autonomic dysfunction (four). Ten of 13 cases (76.9%) were osteosarcoma. The rest were chondrosarcoma (n = 1), fibrosarcoma (n = 1), and malignant fibrous histiocytoma (n = 1). Decompression laminectomy was performed in three patients with progressive neurologic deficit. Eight patients had received radiotherapy. The mean survival was 4.22 months.

CONCLUSIONS

This series confirmed that Paget sarcoma of the spine has a very poor prognosis. We found a constellation of symptomatology in patients with sarcomatous Paget spine resulting from radiculomedullary compression, primarily lumbosacral involvement and predominantly osteosarcomatous histology. There was no significant difference observed on the overall prognosis of the patients with Paget sarcoma of the spine in the last 6 decades.

Medical care costs of Paget's disease of bone in a privately insured population

INTRODUCTION

Medical care costs are difficult to calculate in diseases such as Paget's disease because they have low detection rates and a wide range of clinical manifestations that commonly occur in aging patient populations.

MATERIALS AND METHODS

Using 2001-2002 MarketScan Research databases, this study linked medical claims, prescription records, and encounter data on 2.8 million active and retired employees to create a longitudinal panel with 24 months of observation. Patients with Paget's disease were identified by ICD-9 code 731.0. Matched controls (MC) were identified through an exact match procedure using gender, age, and predicted Medicare costs estimated with a risk adjuster. Diagnostic and expenditure records were extracted for the sample and prevalence rates calculated for 20 conditions with well-documented associations to Paget's disease. Comorbidities and health care costs of Paget's disease patients were compared to those of the MCs, and the differences tested using Chi-square and t tests.

RESULTS

Our study identified 244 matched pairs. The average age was 72.7 years; 50.8% were female. Significantly higher comorbidities (P < 0.05) were detected in Paget's disease patients relative to MCs for: pathological fractures (4.9% vs. 0.4%), heart murmurs (3.3% vs. 0.4%), low back pain (19.7% vs. 8.6%), spinal stenosis (16.4% vs. 9.8%), and hearing loss (13.5% vs. 5.7%), respectively. Biannual per patient outpatient costs were significantly higher in Paget's disease patients (Paget's disease $9301 vs. MC $6339, P < 0.05), especially for services associated with physician visits and diagnostic tests. Prescription costs for antiresportive agents and analgesics were also higher (Paget's disease $1115 vs. MC $507, P < 0.05). Inpatient costs (Paget's disease $16,144 vs. MC $21,480) were comparable.

CONCLUSION

This study is the first to describe the excessive costs of Paget's disease, based on known patterns of disease expression, evaluation, and treatment.

Scapulo-humeral Paget's sarcoma: Scottish Bone Tumour Registry experience

This study aimed to analyse the clinical, radiological and histological features of 16 scapulo-humeral Paget's sarcoma cases accrued from Scottish Bone Tumour Registry between January 1950 and December 2000. The mean age was 61.5 (range, 44-77) years with 12 men and 4 women. There were three scapular cases and 13 humeral (1 whole length, 5 upper humeral, 5 lower humeral and 2 mid-humeral). These patients presented with progressively increasing pain in the shoulder, arm or elbow (n = 5), a painful mass associated with a pathological fracture (n = 4), a pathological fracture with progressively worsening pain (n = 3), a painful mass (n = 3) and a painless mass associated with wrist drop (n = 1). Histology showed predominantly osteosarcoma (n = 12), followed by pleomorphic sarcoma (n = 2), malignant fibrous histiocytoma (n = 1) and fibrosarcoma (n = 1). Overall, the median survival period was 4.5 months. In summary, Paget's sarcoma of the scapulo-humeral area presents with progressively worsening pain, a painful mass with or without a pathological fracture, predominantly lytic in humeral and purely sclerotic in scapular lesions, osteosarcoma-dominant histology, primarily treated with an early limb ablative surgery and associated with a poor 1-year survival (12.5%) and 5-year survival (6.2%) rate.

Guidelines for diagnosis and management of Paget's disease of bone in Japan

We here propose guidelines for the diagnosis and management of Paget's disease of bone (PDB) in Japan. These guidelines provide basic information on the epidemiology, pathophysiology, clinical signs and symptoms, diagnosis, indications for treatment, and available therapy, including orthopedic surgery. PDB is a chronic disorder characterized by focal abnormalities of bone turnover. The characteristic feature of PDB is excessive osteoclastic bone resorption coupled to increased and disorganized bone formation. The most common symptom of PDB is pain in involved bones. The most serious complication of PDB is malignant bone or soft-tissue tumor. PDB is uncommon in Japan; our survey in 2003 found 169 patients with PDB. The prevalence of PDB in Japan is 0.15/100 000; in patients aged 55 years or more, the proportion reaches 0.41/100 000. A careful medical history and physical examination are essential for the diagnosis. The diagnosis of PDB is based on finding the typical features on radiographs. Bone scintigraphy and measurement of serum alkaline phosphatase are sensitive means of screening for PDB. Since PDB is a rare disease in Japan, bone biopsy is quite often used to exclude bone metastases. The only evidence-based indication for treatment of PDB is pain in involved bones. In Japan, etidronate and calcitonin are approved by the Ministry of Health, Labour and Welfare for treating PDB, but currently risedronate is also under development for treating PDB in Japan. Indications for surgical intervention in PDB include unstable fractures, osteoarthritis, malignant soft-tissue tumor, osteosarcoma, and bone deformity.

Paget's sarcoma: a historical and outcome review

Paget's sarcoma is a rare entity that principally occurs in elderly people with extensive Paget's disease. The primary sites of occurrence are the pelvis, proximal femur, proximal humerus, and calvarium. The lesions are highly malignant and the patients frequently are found to have metastases at the time of discovery. The survival rate reported in the literature generally is very poor. We were able to locate 16 patients with Paget's sarcoma in the Dr. Henry L. Jaffe Pathology Collection treated from 1942 to 1967. These were added to 27 patients treated for the disease by the Harvard Orthopaedic Oncology Group from 1972 to 2001. Three were giant cell tumors, which are occasionally found in patients with florid Paget's disease but are not malignant. Of the remaining 40 patients, outcome data were available on 35 patients. The rate of Musculoskeletal Tumor Society Stage III tumors was very high (35%) and the rate of survival was 14% at approximately 2.5 years, without differences between the two series. In view of the remarkable concordance in the poor survival figures for patients treated between 1946 and 1967 and those treated between 1972 and 2001 it appears that little progress has occurred in the treatment of Paget's sarcoma over the years, which is in sharp contrast with the current statistics for standard osteosarcoma.

LEVEL OF EVIDENCE

Prognostic study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Radiologic case study. The case: Lytic phase of Paget disease

When confronted with a radiographic osteolytic lesion where the diagnosis of Paget disease is considered, preservation of fatty marrow signal intensity on MRI excludes more ominous diagnostic considerations.

Paget's disease: a case in point

Paget's disease (PD) is the second most common bone disease in older adults, yet many clinicians are unfamiliar with it and may not consider it a diagnostic possibility. This article uses a case study to introduce the topic of Paget's disease. The definition, incidence, and etiology of PD is addressed. Normal bone physiology is defined in contrast to the pathophysiology of PD. Patient history, laboratory tests, and imaging studies are summarized with regard to the diagnosis of PD. Treatment options are discussed including pharmacologic management and prognosis. The article concludes with implications for nursing care of the patient with PD.

Monostotic Paget?s disease of the tibia in Korea

The incidence of Paget's disease has been estimated to be about 3%, but it is extremely rare in Asia, especially in Korea. In addition, monostotic involvement seems to be far less frequent. In this report, we describe a case of monostotic Paget's disease localized in the right tibia.