The epidemiology of Paget's disease in Britain: is the prevalence decreasing?

The Decline of Paget's Disease of Bone and Domestic Coal Use-A Hypothesis

The cause of Paget's disease of bone (PDB) is unknown. It emerged as a distinct entity in Britain in the late nineteenth century when it was prevalent, and florid presentation not uncommon. Epidemiological surveys in the 1970s showed that Britain had a substantially higher prevalence of PDB than any other country. Studies in the late twentieth and early twenty-first centuries have documented an unexplained change in presentation, with a greatly reduced prevalence and less severe disease than formerly. The emergence of PDB in Britain coincided with rapid industrialization which, in turn, was driven by the use of coal for energy. In the home, bituminous coal was customarily burnt on an open hearth for heating. Using data on coal production, population size, and estimates of domestic use, the estimated exposure to domestic coal burning rose threefold in Britain during the nineteenth century and began to fall after 1900. This pattern fits well with the decline in PDB documented from death certification and prevalence surveys. Colonists moving from Britain to North America, Australia and New Zealand established coal mines and also used coal for domestic heating. PDB was found in these settler populations, but was largely absent from people indigenous to these lands. In all parts of the world PDB prevalence has fallen as the burning of coal in open hearths for domestic heating has reduced. The nature of the putative factor in coal that could initiate PDB is unknown, but possible candidates include both organic and inorganic constituents of bituminous coal.

Long-term effectiveness of zoledronic acid in patients with Paget's disease of bone - a retrospective cohort study

PURPOSE

The aims of the current study were to describe clinical and biochemical features of patients with Paget disease of bone (PDB) followed at our medical center, and to examine the long-term effectiveness of zoledronate.

METHODS

Retrospective cohort study included consecutive patients≥18 years with a diagnosis of PDB, followed in the Rabin Medical Center (RMC) Institute of Endocrinology from 1973 to 2023. The cohort comprised two groups: patients treated/not treated with zoledronic acid (ZOL/NZOL). The primary outcome was the percentage of patients who achieved a biochemical therapeutic response.

RESULTS

Overall, 101 patients with PDB were included, 68 in the ZOL group and 33 in the NZOL group. The mean age was 65.2 ± 10.0 years, and 47% were female. Notably, 77% exhibited monostotic involvement, and only 3% had experienced fractures attributed to PDB. Mean ALP level at diagnosis was 160 ± 70.6 U/L. The median follow-up duration was 17 years since PDB diagnosis, comparable between the groups. Primary outcome was more prevalent in the ZOL compared to the NZOL group [42 patients (88%) VS 11 patients (52%) respectively, P = 0.004]. At the end of follow-up, mean ALP levels in the NZOL group were significantly higher than the levels in the ZOL group irrespective of the number of infusions received.

CONCLUSION

The majority of patients with PDB experience a mild disease course, marked by monostotic involvement and a low prevalence of fractures. Zoledronic acid effectively manages PDB, providing sustained biochemical response. The necessity for multiple zoledronic acid injections remains questionable, often implemented due to osteoporosis.

Prevalence and incidence of Paget's disease of bone: Temporal trend over 20 years in the province of Quebec, Canada

BACKGROUND

Paget's disease of bone (PDB) is a focal bone disorder characterized by an increased bone remodeling and an anarchic bone structure. A decline of prevalence and incidence of PDB has been observed in some countries. No epidemiological data are available on PDB in Canada.

AIMS

We aimed at examining the evolution of the prevalence and incidence of PDB in Quebec (Canada) by analyzing health administrative databases.

METHODS

PDB case definition relied on one or more hospitalizations, or one or more physician-billing claims with a diagnosis code of PDB. To identify incident cases, a 'run-in' period of four years (1996-1999) was used to exclude prevalent cases. For each fiscal year from 2000 to 2001 to 2019-2020 (population size 2,914,480), crude age and sex-specific prevalence and incidence rates of PDB among individuals aged ≥55 years were determined, and sex-specific rates were also standardized to the 2011 age structure of the Quebec population. Generalized linear regressions were used to test for linear changes in standardized prevalence and incidence rates.

RESULTS

Over the study period, standardized prevalence of PDB has remained stable in Quebec, from 0.44 % in 2000/2001 to 0.43 % in 2019/2020 (mean change -0.002, p-value = 0.0935). For the 2019-2020 fiscal year, 13,165 men and women had been diagnosed with PDB and prevalence of PDB increased with age. Standardized incidence of PDB has decreased over time from 0.77/1000 in 2000/2001 to 0.28/1000 in 2019-2020 (mean change -0.228/year, p-value<0.0001), the incidence decreasing from 0.82/1000 to 0.37/1000 in men and from 0.76/1000 to 0.22/1000 in women, respectively. This decrease was observed in all age categories.

CONCLUSION

With the exception of a slight increase in PDB prevalence up to 0.55 % in years 2005 to 2007, the prevalence of PDB has remained stable in Quebec over the past 20 years, 13,160 men and women being currently diagnosed with PDB. The incidence has decreased over time. Our results support the epidemiological changes of PDB reported in other countries.

Decline in clinical severity of Paget's disease of bone: Comparison between a contemporary cohort and a historical cohort

BACKGROUND

European and Australian studies have reported a decrease in the prevalence, incidence and clinical severity of Paget's disease of bone (PDB). There are no studies on the current clinical characteristics of PDB in Quebec, Canada.

AIMS

The purpose of this study was to describe the characteristics of unrelated patients with PDB diagnosed after the year 2000 in our region and to compare them to a historical cohort diagnosed before 2000.

METHODS

In this retrospective descriptive cohort study, socio-demographic data and clinical characteristics for the contemporary cohort were collected from electronic medical records of patients with PDB followed at our university hospital. For the historical cohort, the same data were collected from the research files of PDB participants in our research program. Inclusion criteria were: age > 18 years, having PDB diagnosed by a rheumatologist, and being followed in our hospital. Exclusion criteria were: having a relative with PDB participating in this study. Variables were reported as mean, standard deviation, frequency and percentage. Chi-square tests were used to compare categorical variables. Continuous values were compared with Wilcoxon-Mann-Whitney tests. Unadjusted p-values and adjusted p-values with the Bonferroni correction method were calculated. A p-value <0.05 was considered statistically significant.

RESULTS

Among the 195 patients with PDB in the contemporary cohort, 53.3 % were men, 60.5 % had monostotic involvement, 14.2 % were symptomatic at diagnosis. In comparison to the historical cohort of 173 patients, patients in the contemporary cohort were older at diagnosis (68.7  10.7 vs. 58.5  10.1; p < 0.0001) and had less family history of PDB (13.8 % vs. 33.6 %; p = 0.0024). They also had lower total alkaline phosphatase levels at diagnosis (118.0 (85.0-184.0)) vs. 184.0 (115.0-312.0)); p = 0.0006), a lower pagetic bone number (1.0 (1.0-3.0) vs. 2.0 (1.0-5.0); p < 0.0001), lower pagetic bone fractures (6.7 % vs. 36.7 %; p = 0.0078) and lower bone deformities (13.0 % vs. 54.0 %; p < 0.0001). There was no significant difference for pagetic bone pain (52.0 % vs. 52.6 %; p = 1.0000), percentage of patients who had orthopedic surgery related to PDB complications (8.8 % vs. 28.6 %; p = 1.0000), secondary osteoarthritis (43.0 % vs. 51.6 %; p = 1.0000), and hearing impairment (51.9 % vs. 61.1 %; p = 0.1000).

CONCLUSION

The contemporary cohort is characterized by an older age at diagnosis, a majority of monostotic disease and fewer complications of PDB. This decline in clinical severity of PDB in Quebec is consistent with studies reported in other countries.

Paget’s disease of bone: the first case reported in Iraqi Kurdish

Background

Paget’s disease of bone (PDB) is a chronic bone disorder which insidiously evolves parallel with the aging process. The affected bone has a distinct imaging appearance, and the clinical manifestations are variable. This disease is ubiquitous among people of Anglo-Saxonian origin. However, it is rarely reported among Asian descents.

Case presentation

Here, the first diagnosed case of Paget’s disease of bone in an Iraqi Kurdish patient, a gentleman in his seventh decade of life underwent sectional imaging for evaluation of spine hopefully to find a potential musculoskeletal or neurological culprit behind his back discomfort. Biochemical confirmation tests were demanded based on the state of the art of the typical radiological judgment, perhaps negating pathological tissue affirmation. Marked geographical variation of the disease occurrence made it seldom to encounter such entity in the Middle East, particularly in Iraq. To the author’s knowledge, scarce cases have been described in Iraq, none in the Kurdish population.

Conclusion

This case report elicits an extremely rare metabolic osseous disease that was radiologically diagnosed at venture when bone window computed tomography (CT) is performed for an unrelated indication.

Update on the pathogenesis and genetics of Paget’s disease of bone

Studies over the past two decades have led to major advances in the pathogenesis of Paget’s disease of bone (PDB) and particularly on the role of genetic factors. Germline mutations of different genes have been identified, as a possible cause of this disorder, and most of the underlying pathways are implicated in the regulation of osteoclast differentiation and function, whereas other are involved in cell autophagy mechanisms. In particular, about 30 different germline mutations of the Sequestosome 1 gene (SQSTM1) have been described in a significant proportion of familial and sporadic PDB cases. The majority of SQSTM1 mutations affect the ubiquitin-binding domain of the protein and are associated to a more severe clinical expression of the disease. Also, germline mutations in the ZNF687 and PFN1 genes have been associated to severe, early onset, polyostotic PDB with increased susceptibly to neoplastic degeneration, particularly giant cell tumor. Mutations in the VCP (Valosin Containing Protein) gene cause the autosomal dominant syndrome “Inclusion Body Myopathy, PDB, Fronto-temporal Dementia,” characterized by pagetic manifestations, associated with myopathy, amyotrophic lateral sclerosis and fronto-temporal dementia. Moreover, germline mutations in the TNFRSF11A gene, which encodes for RANK, were associated with rare syndromes showing some histopathological, radiological, and clinical overlap with PDB and in two cases of early onset PDB-like disease. Likewise, genome wide association studies performed in unrelated PDB cases identified other potential predisposition genes and/or susceptibility loci. Thus, it is likely that polygenic factors are involved in the PDB pathogenesis in many individuals and that modifying genes may contribute in refining the clinical phenotype. Moreover, the contribution of somatic mutations of SQSTM1 gene and/or epigenetic mechanisms in the pathogenesis of skeletal pagetic abnormalities and eventually neoplastic degeneration, cannot be excluded. Indeed, clinical and experimental observations indicate that genetic susceptibility might not be a sufficient condition for the clinical development of PDB without the concomitant intervention of viral infection, in primis paramixoviruses, and/or other environmental factors (e.g., pesticides, heavy metals or tobacco exposure), at least in a subset of cases. This review summarizes the most important advances that have been made in the field of cellular and molecular biology PDB over the past decades.

Clinical Characteristics and Pathogenic Gene Identification in Chinese Patients With Paget's Disease of Bone

OBJECTIVE

To evaluate the clinical features of sporadic Paget's disease of bone (PDB) in China and further explore the underlying genetic abnormalities of the disease.

METHODS

Clinical characteristics, biochemical indices, bone turnover markers and radiographic examinations of the patients were collected. Genomic DNA was extracted from peripheral blood and whole-exome sequencing was carried out to identify the potential pathogenic genes. The pathogenicity of the variants was thereafter investigated by bioinformatics analysis.

RESULTS

A total of 50 patients (57.20 ± 15.52 years, male/female: 1.63: 1) with PDB were included and the mean onset age was 48.34 years (48.34 ± 17.24 years). 94.0% of the patients exhibited symptomatic patterns described as bone pain (86.0%), elevated skin temperature at the lesion site (26.0%), bone deformity (22.0%) and local swelling (18.0%). The most frequently involved lesion sites were pelvis (52.0%), femur (42.0%), tibia (28.0%), skull (28.0%) and spine (18.0%), respectively. Additionally, 40.0% of them accompanied with osteoarthritis, 14.0% with pathological fractures, and the misdiagnosis rate of PDB was as high as 36.0%. Serum level of alkaline phosphatase was significantly increased, with the mean value of 284.00 U/L (quartiles, 177.00-595.00 U/L). Two heterozygous missense mutations of SQSTM1 gene (c.1211T>C, M404T) and one novel heterozygous missense mutation in HNRNPA2B1 gene (c.989C>T, p. P330L) were identified in our study. Moreover, several potential disease-causing genes were detected and markedly enriched in the pathways of neurodegeneration (including WNT16, RYR3 and RYR1 genes) and amyotrophic lateral sclerosis (ALS, including NUP205, CAPN2, and NUP214 genes).

CONCLUSION

In contrast to Western patients, Chinese patients have an earlier onset age, more severe symptoms, and lower frequency of SQSTM1 gene mutation (4.0%). Moreover, a novel heterozygous missense mutation in HNRNPA2B1 gene was identified in one male patient with isolated bone phenotype. As for other genetic factors, it was indicated that WNT16, RYR3, RYR1, NUP205, CAPN2 and NUP214 genes may be potential pathogenic genes, pathways of neurodegeneration and ALS may play a vital role in the pathogenesis of PDB.

Decreasing severity of Paget's disease of bone in northern Italy over the last two decades: results of a monocentric study on 391 patients

Patients with Paget's disease of bone recruited over the last 20 years by a single centre were evaluated to find possible clinical changes. All markers of severity showed consistent downward trends. A reduced disease incidence could seemingly refer to lower sensitivity of the diagnostic tools owing to lower severity.

INTRODUCTION

This study aimed to evaluate if the severity of Paget's disease of bone (PDB) is decreasing and whether a milder phenotype can have affected the results of studies on disease prevalence.

METHODS

From August 2007 to August 2019, 167 patients with PDB were referred to our centre. Demographic and clinical characteristics were collected and compared with those of a sample of 224 patients enrolled in the same setting between January 2000 and July 2007. Multivariate analyses on 391 patients as a whole were performed assuming the year of presentation as explanatory variable.

RESULTS

Patients of newer sample were diagnosed at a significantly older age (64.0 ± 11.3 vs 61.1 ± 11.6; p = 0.01). By comparing clinical features acknowledged as markers of disease severity, the mean number of involved bones, the proportion of skeletal involvement, and pre-treatment serum alkaline phosphatase (SAP) values all showed significant decreases (p < 0.001) in the more recent sample. Multivariate analyses confirmed these results for the latter two indices. Further markers of disease severity such as the prevalence of monostotic disease and normal SAP at diagnosis showed the same trend. The sensitivity of tools allowing incidental diagnosis in asymptomatic patients showed a reduced sensitivity: -11% for radiological assessments and -33% for SAP.

CONCLUSIONS

Allowing for referral differences, our study provides information on reduced severity of PDB over the last two decades. A milder phenotype affects the age at onset and impairs the sensitivity of the diagnostic tools contributing to reduce the prevalence of PDB patients incidentally discovered.

An update on imaging of Paget's sarcoma

Paget's sarcoma is a rare and particularly aggressive tumour arising within pagetic bone, affecting approximately 1% of patients with Paget's disease during the course of their disease. Most of these tumours are osteosarcomas, but the age profile, skeletal distribution and clinical outcomes differ considerably from conventional osteosarcoma. In this review, we outline the clinical, radiographic/CT, scintigraphic and magnetic resonance imaging features of Paget's sarcoma. We also review the neoplastic and non-neoplastic mimics of Paget's sarcoma that should be considered in the differential diagnosis when encountering an aggressive lesion within pagetic bone.

Paget's Disease of the Bone: Patterns of Referral to Secondary Care Following Diagnosis on X-rays

Paget's disease of bone (PDB) is the second commonest metabolic bone disorder in the UK after osteoporosis and is both underdiagnosed and undertreated. PDB is often found incidentally on plain X-rays. There is effective treatment so identification of affected individuals is important. The aim was to conduct an audit to determine what proportion of individuals with X-ray evidence of PDB were referred to secondary care. A retrospective audit of X-rays reports in men and women over 55 years of age was undertaken over 18 months searching for the key word "Paget's." The images of possible cases were reviewed and the presence of PDB confirmed. The proportion already known to secondary care was determined and those that had had isotope bone scans and treatment. Data recorded included site of lesion, age, gender, level of total alkaline phosphatase (ALP) and complications. A total of 68,873 X-rays were screened and 43 cases found. Pelvic images had the highest proportion of positive findings at 0.2% and 65% of the cases. 74% had not been referred to secondary care. The mean age was 86.7 years (range 65-95) and the ALP was elevated in 65% with a mean of 189u/L (range 47-804u/L). In 33 individuals, PDB had been recorded in the reports of previous X-rays. The rate of referral for specialist care remains low. The prevalence of the condition appears to be falling.

Incidence of Paget's Disease of Bone in the UK: Evidence of a Continuing Decline

OBJECTIVES

To characterise the incidence of clinically diagnosed Paget's disease of bone in the UK during 1999-2015 and to determine variation in incidence of disease by age, sex, geography and level of deprivation.

METHODS

Incident cases of Paget's disease occurring between 1999-2015 were identified from primary care records. Overall crude incidence and incidence stratified by age and sex was calculated each year from 1999-2015. Direct age- and sex-standardised incidence was also calculated. We used Poisson regression to look at variation in incidence by deprivation and UK region.

RESULTS

3,592 incident cases of Paget's disease were identified between 1999-2015. Incidence increased with age and at all ages was greater in men than women. In women and men, respectively, crude incidence increased from 0.037 and 0.074 per 10 000 population per year among those aged 45-49 years to 3.7 and 6.3 per 10 000 population per year among those 85 years and older. Overall standardised incidence reduced from 0.75/10 000 person-years in 1999-0.20/10 000 person-years in 2015. After adjustment for age and sex, incidence was >30% higher in the most, compared with least deprived quintile of deprivation. There was evidence of geographic variation, with highest incidence in the North West of England, which persisted after adjustment for age, sex, and level of deprivation.

CONCLUSION

The incidence of clinically diagnosed Paget's disease has continued to decrease since 1999. The reason for the decline in incidence remains unknown though the rapidity of change points to an alteration in one or more environmental determinants.

Pattern of SQSTM1 Gene Variants in a Hungarian Cohort of Paget's Disease of Bone

Paget's disease of bone (PDB) is characterized by focal or multifocal increase in bone turnover. One of the most well-established candidate genes for susceptibility to PDB is Sequestosome 1 (SQSTM1). Mutations in SQSTM1 have been documented among Western-European, British and American patients with PDB. However, there is no information on SQSTM1 mutation status in PDB patients from the Central- and Eastern-European regions. In this study, we conducted a mutation screening for SQSTM1 gene variants in 82 PDB patients and 100 control participants in Hungary. Mutations of SQSTM1 were detected in 18 PDB patients (21.95%); associations between genotype and clinical characteristics were also analyzed. Altogether, six different exonic alterations, including two types of UTR variants in the SQSTM1 gene, were observed in our PDB patients. Similarly, to previous genetic studies on Paget's disease, our most commonly detected variant was the c.1175C > T (p.Pro392Leu) in nine cases (four in monostotic and five in polyostotic form). We have surveyed the germline SQSTM1 variant distribution among Hungarian patients with PDB. We also highlighted that the pattern of the analyzed disease-associated pathophysiological parameters could partially discriminate PDB patients with normal or mutant SQSTM1 genotype. However, our findings also underline and strengthen that not solely SQSTM1 stands in the background of the complex PDB etiology.

Recent advances in understanding and managing Paget's disease

Paget’s disease is a condition which continues to challenge and surprise. The dramatic fall in its incidence over the last three decades has been an enormous surprise, as is the capacity of a single infusion of the potent bisphosphonate, zoledronate, to produce biochemical remission in 90% of patients, remissions which usually persist for many years and raise the possibility of a cure in some patients. However, challenges in its management remain. The trials carried out in Paget’s disease have almost always had biochemical indices as their primary endpoints. From these studies, we also know that bone pain is relieved, quality of life improved, bone histology normalised, and radiological lesions healed. Thus, disease progression is halted. Studies have not been powered to assess whether clinically important endpoints such as fracture and the need for joint replacement surgery are diminished, although these complications are well established as part of the natural history of the condition. Since disease progression is prevented by potent bisphosphonates, it is likely that disease complications will also be prevented. Zoledronate also reduces the frequency of follow-up needed and therefore provides a very cost-effective intervention in those who have symptomatic disease or are at risk of complications.

Paget's Disease of Bone

Paget's disease of bone (PDB) is a chronic and focal bone disorder, characterized by increased osteoclast-mediated bone resorption and a subsequent compensatory increase in bone formation, resulting in a disorganized mosaic of woven and lamellar bone at one or more affected skeletal sites. As a result, bone pain, noticeable deformities, arthritis at adjacent joints, and fractures can occur. In a small proportion of cases neoplastic degeneration in osteosarcoma, or, less frequently, giant cell tumor has been also described at PDB sites. While recent epidemiological evidences clearly indicate a decrease in the prevalence and the severity of PDB, over the past 2 decades there have been consistent advances on the genetic mechanisms of disease. It is now clear that PDB is a genetically heterogeneous disorder, with mutations in at least two different genes (SQSTM1, ZNF687) and more common predisposing variants. As a counterpart to the genetic hypothesis, the focal nature of lesions, the decline in prevalence rates, and the incomplete penetrance of the disease among family members suggest that one or more environmental triggers may play a role in the pathophysiology of PDB. The exact nature of these triggers and how they might interact with the genetic factors are less understood, but recent experimental data from mice models suggest the implication of paramixoviral infections. The clinical management of PDB has also evolved considerably, with the development of potent aminobisphosphonates such as zoledronic acid which, given as a single intravenous infusion, now allows a long-term disease remission in the majority of patients.

Diagnosis and Management of Paget's Disease of Bone in Adults: A Clinical Guideline

An evidence-based clinical guideline for the diagnosis and management of Paget's disease of bone (PDB) was developed using GRADE methodology, by a Guideline Development Group (GDG) led by the Paget's Association (UK). A systematic review of diagnostic tests and pharmacological and nonpharmacological treatment options was conducted that sought to address several key questions of clinical relevance. Twelve recommendations and five conditional recommendations were made, but there was insufficient evidence to address eight of the questions posed. The following recommendations were identified as the most important: 1) Radionuclide bone scans, in addition to targeted radiographs, are recommended as a means of fully and accurately defining the extent of metabolically active disease in patients with PDB. 2) Serum total alkaline phosphatase (ALP) is recommended as a first-line biochemical screening test in combination with liver function tests in screening for the presence of metabolically active PDB. 3) Bisphosphonates are recommended for the treatment of bone pain associated with PDB. Zoledronic acid is recommended as the bisphosphonate most likely to give a favorable pain response. 4) Treatment aimed at improving symptoms is recommended over a treat-to-target strategy aimed at normalizing total ALP in PDB. 5) Total hip or knee replacements are recommended for patients with PDB who develop osteoarthritis in whom medical treatment is inadequate. There is insufficient information to recommend one type of surgical approach over another. The guideline was endorsed by the European Calcified Tissues Society, the International Osteoporosis Foundation, the American Society of Bone and Mineral Research, the Bone Research Society (UK), and the British Geriatric Society. The GDG noted that there had been a lack of research on patient-focused clinical outcomes in PDB and identified several areas where further research was needed. © 2019 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Genetic regulatory mechanisms in human osteoclasts suggest a role for the STMP1 and DCSTAMP genes in Paget's disease of bone

Paget’s disease of bone (PDB) is characterised by focal abnormalities of bone remodelling, with increased osteoclastic resorption the primary feature of the disease. Genetic factors have been shown to play an important role in PDB, and genome-wide association studies (GWAS) have identified 7 genetic loci as associated with PDB at the genome-wide level. Expression quantitative trait locus (eQTL) studies using cell types that are directly relevant to the disease of interest are increasingly being used to identify putative effector genes for GWAS loci. We have recently constructed a unique osteoclast-specific eQTL resource using cells differentiated in vitro from 158 subjects for study of the genetics of bone disease. Considering the major role osteoclasts have in PDB, we used this resource to investigate potential genetic regulatory effects for the 7 PDB genome-wide significant loci on genes located within 500 kb of each locus. After correction for multiple testing, we observed statistically significant associations for rs4294134 with expression of the gene STMP1, and rs2458413 with expression of the genes DPYS and DCSTAMP. The eQTL associations observed for rs4294134 with STMP1, and rs2458413 with DCSTAMP were further supported by eQTL data from other tissue types. The product of the STMP1 gene has not been extensively studied, however the DCSTAMP gene has an established role in osteoclast differentiation and the associations seen between rs2458413 and PDB are likely mediated through regulatory effects on this gene. This study highlights the value of eQTL data in determining which genes are relevant to GWAS loci.

Paget's Disease of Bone: An Entity Still Exists in India

BACKGROUND

Paget's disease of bone (PDB) is uncommonly reported from India. We attempted to study the clinical and imaging features and management of participants who presented with PDB.

MATERIALS AND METHODS

In this retrospective study, clinical and imaging profile, biochemistry, and treatment outcomes of participants with PDB (n = 48) were obtained.

RESULTS

The mean age was 60 ± 11.3 years and 35% were women. Twenty percent were asymptomatic. Many (87%) had polyostotic involvement. Sixty percent (n = 29) underwent treatment with zoledronic acid and rest with oral bisphosphonates, and all achieved remission.

CONCLUSION

Most of the pagetic participants had polyostotic disease and one-fifth were asymptomatic. All participants had disease remission following treatment.

Paget's disease of bone

Paget's disease is a chronic focal high turnover bone disorder that is primarily present in middle-aged or older adults. It seems to be restricted to humans and has no clear parallels with other diseases. Although much has been learnt about its pathology and epidemiology, and treatment is now highly effective we still lack a complete understanding of its etiology and biology. This review focusses on the natural history of the disorder, in particular its changing epidemiology, recent discoveries about its genetic basis and current approaches to diagnosis and treatment. While there is strong evidence for genetic predisposition to Paget's disease, there is also compelling evidence that it is becoming less prevalent, the age of patients at presentation is increasing and that the extent of skeletal involvement is diminishing, implying that there is an important, but as yet unidentified, environmental factor in its etiology. Contemporary patients are typically elderly and have few bones involved. Treatment with potent intravenous bisphosphonates provides prolonged remission and many will require only once in a lifetime treatment.

Paget's Disease of Bone: Approach to Its Historical Origins

Paget's disease of bone is the second most common bone disease after osteoporosis. It is characterized by focal regions of highly exaggerated bone remodeling, with abnormalities in all phases of the remodeling process. This study aims to investigate the hypothesis of a possible British origin of Paget's disease of bone by studying the worldwide geographic distribution of cases identified in ancient skeletons excavated from archaeological sites. The methodology consists in reviewing cases of Paget's disease of bone described in the literature.

Paget Disease of Bone

The current understanding of Paget disease of bone (PDB) has vastly changed since Paget described the first case in 1877. Medical management of this condition remains the mainstay of treatment. Surgical intervention is usually only used in fractures through pagetic bone, need for realignment to correct deformity in major long bones, prophylactic treatment of impending fractures, joint arthroplasty in severe arthritis, or spinal decompression in cases of bony compression of neural elements. Advances in surgical technique have allowed early return to function and mobilization. Despite medical and surgical intervention, a small subset of patients with PDB develops Paget sarcoma.

Diagnosis and management of Paget's disease of bone

OBJECTIVE

To conduct a literature review on the diagnosis and management of Paget's disease of bone.

MATERIALS AND METHODS

This scientific statement was generated by a request from the Brazilian Medical Association (AMB) to the Brazilian Society of Endocrinology and Metabolism (SBEM) as part of its Clinical Practice Guidelines program. Articles were identified by searching in PubMed and Cochrane databases as well as abstracts presented at the Endocrine Society, Brazilian Society for Endocrinology Annual Meetings and the American Society for Bone and Mineral Research Annual Meeting during the last 5 years. Grading quality of evidence and strength of recommendation were adapted from the first report of the Oxford Centre for Evidence-based Medicine. All grades of recommendation, including "D", are based on scientific evidence. The differences between A, B, C and D, are due exclusively to the methods employed in generating evidence.

CONCLUSION

We present a scientific statement on Paget's disease of bone providing the level of evidence and the degree of recommendation regarding causes, clinical presentation as well as surgical and medical treatment.

Paget's Disease of Bone among Various Ethnic Groups

Paget's disease of bone (PDB) is a relatively benign disease common among many European populations, including those in the UK, Italy and Spain. However, it appears to be rare among Scandinavians and non-European immigrants living in Europe. The prevalence among Asian populations may be underestimated because a large number of reported cases were discovered incidentally. There is a need for surveys addressing the prevalence rate and consequences of PDB to be carried out in various parts of the world, particularly Asia.

Monostotic Paget's disease of the femur: a diagnostic challenge and an overlooked risk

BACKGROUND

Although radiological diagnosis of Paget's disease of bone (PD) is usually straightforward, monostotic cases may potentially raise specific problems which lead to performing invasive procedures. Therefore, the purpose of this study is to ascertain whether or not monostotic femoral Paget's disease (MFPD) presentation poses particular diagnostic difficulties which prompt excessive use of excisional biopsies.

METHODS

We retrospectively reviewed the medical records of 24 MFPD patients identified from a series of 412 patients; their clinical features were compared with those of the remaining 164 monostotic cases and the radiological images were systematically assessed.

RESULTS

When compared with the remaining monostotic cases, MFPD patients were more prone to having normal alkaline phosphatase levels (31.8% vs. 16.4%; 0.08) and a significantly higher percentage of patients have PD symptoms (75% vs. 51%; 0.02) and complain of bone pain (73.9% vs. 40.8%; 0.003). Six (25%) MFPD patients evidenced a fracture over the pagetic lesion. This incidence is higher than that of the monostotic cases of other locations (8.4%; p=0.02). The existence of PD lesion was not recognised initially in 10 cases and an excisional bone biopsy was performed in 7 (29%). One patient subsequently experienced a fracture through the biopsy site and another two experienced worsening of their previous bone pain.

CONCLUSION

The femur is a relatively common monostotic PD location which often causes diagnostic confusion, prompting a bone biopsy in many cases. Careful assessment of this lesion by X-ray examination may help attain an early appropriate diagnosis and avoidance of unnecessary surgical morbidity.

New insights into the role of sequestosome 1/p62 mutant proteins in the pathogenesis of Paget's disease of bone

Paget's disease of bone (PDB) is characterized by focal areas of aberrant and excessive bone turnover, specifically increased bone resorption and disorganized bone formation. Germline mutations in the sequestosome 1/p62 (SQSTM1/p62) gene are common in PDB patients, with most mutations affecting the ubiquitin-associated domain of the protein. In vitro, osteoclast precursor cells expressing PDB-mutant SQSTM1/p62 protein are associated with increases in nuclear factor κB activation, osteoclast differentiation, and bone resorption. Although the precise mechanisms by which SQSTM1/p62 mutations contribute to disease pathogenesis and progression are not well defined, it is apparent that as well as affecting nuclear factor κB signaling, SQSTM1/p62 is a master regulator of ubiquitinated protein turnover via autophagy and the ubiquitin-proteasome system. Additional roles for SQSTM1/p62 in the oxidative stress-induced Keap1/Nrf2 pathway and in caspase-mediated apoptosis that were recently reported are potentially relevant to the pathogenesis of PDB. Thus, SQSTM1/p62 may serve as a molecular link or switch between autophagy, apoptosis, and cell survival signaling. The purpose of this review is to outline recent advances in understanding of the multiple pathophysiological roles of SQSTM1/p62 protein, with particular emphasis on their relationship to PDB, including challenges associated with translating SQSTM1/p62 research into clinical diagnosis and treatment.

Epidemiology of Paget's disease of bone: a systematic review and meta-analysis of secular changes

CONTEXT

Several studies have suggested that the prevalence and severity of PDB have fallen in recent years. The magnitude of this trend and its globalization have not been well established.

OBJECTIVE

The objective of this study is to estimate the pooled magnitude of the changes in the prevalence of PDB and as a secondary objective, to make up a world atlas of PDB prevalence.

METHODS

A systematic review of English and non-English articles using MEDLINE (1946 to 2013) and EMBASE (1980 to 2013) was the method used. Search terms included epidemiology, incidence, prevalence, cohort studies, osteitis deformans or Paget's disease of bone. Studies with incidence and/or prevalence rate for PDB were included. Two authors independently extracted the data using predefined data fields and quality assessment. A pooled analysis based on random-effects models was carried out for secular trends.

RESULTS

Twenty-eight articles documented the prevalence of PDB; four articles the incidence and two articles the rate of new referrals. The prevalence of PDB varied greatly between the different countries, from 0.00028% in Japan to 5.4% in the UK. There were available data on changes in prevalence from two different surveys over two different time frames in Europe and New Zealand. In all but one city (Turin), a drop in the prevalence of PDB was recorded (pooled OR 0.64; 95% CI 0.45-0.91).

CONCLUSION

The incidence and prevalence rates of PDB vary widely between populations but both have decreased in most regions over recent years. The changes are heterogeneous however and within countries, the largest changes have been in areas that previously had a high prevalence. The reasons for these changes remain unclear at present but are likely to be due to an interaction between genetic factors and environmental triggers which may differ in different regions.

Mutations in SQSTM1 encoding p62 in amyotrophic lateral sclerosis: genetics and neuropathology

Mutations in SQSTM1 encoding the sequestosome 1/p62 protein have recently been identified in familial and sporadic cases of amyotrophic lateral sclerosis (ALS). p62 is a component of the ubiquitin inclusions detected in degenerating neurons in ALS patients. We sequenced SQSTM1 in 90 French patients with familial ALS (FALS) and 74 autopsied ALS cases with sporadic ALS (SALS). We identified, at the heterozygote state, one missense c.1175C>T, p.Pro392Leu (exon 8) in one of our FALS and one substitution in intron 7 (the c.1165+1G>A, previously called IVS7+1 G-A, A390X) affecting the exon 7 splicing site in one SALS. These mutations that are located in the ubiquitin-associated domain (UBA domain) of the p62 protein have already been described in Paget's disease and ALS patients carrying these mutations had both concomitant Paget's disease. However, we also identified two novel missense mutations in two SALS: the c.259A>G, p.Met87Val in exon 2 and the c.304A>G, p.Lys102Glu in exon 3. These mutations that were not detected in 360 control subjects are possibly pathogenic. Neuropathology analysis of three patients carrying SQSTM1 variants revealed the presence of large round p62 inclusions in motor neurons, and immunoblot analysis showed an increased p62 and TDP-43 protein levels in the spinal cord. Our results confirm that SQSTM1 gene mutations could be the cause or genetic susceptibility factor of ALS in some patients.

Secular changes in Paget's disease: contrasting changes in the number of new referrals and in disease severity in two neighboring regions of Spain

SUMMARY

We studied the changes in the number of new referrals with Paget's disease of bone (PDB) and severity of PDB in a high prevalence focus and its neighboring region. Referral of patients changed only in the high prevalence focus. The severity of PDB decreased in both regions. These results could suggest the effects of an environmental influence on disease activity.

INTRODUCTION

The prevalence and severity of PDB have decreased in several countries over recent years. We previously reported a high radiological prevalence of PDB in Vitigudino. Here we sought to determine if secular changes in the number of new referrals and severity of PDB had occurred over recent years.

METHODS

We studied 280 patients with clinically diagnosed PDB who were evaluated at a regional referral center for metabolic bone disease between 1986 and 2009. Changes in the number of new referrals were calculated by relating these data to the number of subjects at risk as determined by population registers. Trends in disease severity were analyzed with alkaline phosphatase (ALP) activity and disease extent on scan.

RESULTS

Referrals from the Vitigudino region increased substantially between 1986 and 2003 but fell markedly between 2004 and 2009, although by this time there had been depopulation of the region due to emigration. No significant changes in the rates of referral occurred in the remainder of Salamanca. ALP activity and disease extent decreased in Salamanca, but only ALP activity decreased in Vitigudino. Referrals rate and severity of PDB in Vitigudino were greater than in the remainder of Salamanca.

CONCLUSIONS

Referral of patients with clinically diagnosed PDB has remained stable for most of Salamanca during the past 24 years, but substantial changes have been observed in Vitigudino. In agreement with other reports, the severity of PDB has decreased in both regions consistent with the effects of an environmental influence on disease activity.

Implications of a new radiological approach for the assessment of Paget disease

In the present study, we quantified the proportion of skeletal involvement of Paget disease of bone (PDB) not captured by an abdominal X-ray. We also analyzed extension and severity over time and tested the hypothesis that X-rays from selected areas could replace bone scans for mapping PBD. We examined whole skeletal (99m)TC-MDP bone scans from 208 consecutive untreated patients. Pagetic bones included in an abdominal X-ray were delimited; disease extension and activity were calculated using Coutris's index as well as Renier's index and serum alkaline phosphatase (AP) values, respectively. The study period (1965-2007) was divided into quartiles according to the date of the diagnosis. The percentage of patients with PDB captured by an abdominal X-ray was 79 % (95 % CI 74-85 %). In the last quartile vs. the first quartile, PDB was diagnosed at a more advanced age (67 ± 11 vs. 57 ± 9 years, respectively), with a lower median extension (4 vs. 7) and similar median activity (32 vs. 35) but less activity through median AP values (183 vs. 485 UI/L). The skeletal locations to X-ray in order to capture up to 93 % of PDB extension were the abdomen, skull with facial bones, and both tibias. In conclusion, one-fifth of patients are underdiagnosed when assessing prevalence of PDB by an X-ray of the abdomen, and there is a secular trend to presentation in older patients with a decreasing extension of the disease. A set of X-rays that includes abdomen, skull with facial bones, and both tibias provides a reliable alternative to bone scans.

Paget's Disease of Bone: A Review of Epidemiology, Pathophysiology and Management

Paget's disease of bone is a common disorder which may affect one or many bones. Although many patients are asymptomatic, a variety of symptoms and complications may occur. Fortunately, effective pharmacologic therapy, primarily with potent bisphosphonates, is now available to treat patients with complications or symptoms. This review of Paget's disease of bone will include epidemiology and pathophysiology, complications and clinical findings, indications for treatment, and the drugs currently available to treat this condition.

Effect of Paget's disease of bone (osteitis deformans) on the progression of prostate cancer bone metastasis

Background:

Patients with prostate cancer tend to die from bone metastases. Until now, no evidence has shown that Paget’s disease of bone (PDB) affects the progression of bone metastasis or overall survival of patients with prostate cancer.

Methods:

We searched our patient database for men who had presented with prostate cancer and PDB between June 1993 and March 2009, and identified best-matched control patients according to stage, grade, age, date of diagnosis, treatment, and race.

Results:

Among 1346 consecutive patients with prostate cancer diagnosed before 2008, 15 were confirmed to have comorbid PDB. Twenty-six more were identified from the institutional billing search. Including the 41 best-matched controls, our total study population was 82 patients. In the Kaplan–Meier analysis, we estimated median times from diagnosis of prostate cancer to bone metastasis to be 21.5 years for those with PDB and 9.4 years for those without PDB (P=0.044). Median overall survival times were 11.8 and 9.2 years for the two groups, respectively (P=0.008).

Conclusion:

For the first time, we have obtained evidence that patients with prostate cancer and PDB have delayed time to bone metastases and improved overall survival than do patients with prostate cancer alone.

Asymptomatic Paget's bone disease in ethnic Thais: a series of four case reports and a review of the literature

Paget's bone disease is quite common in some parts of Europe and countries inhabited by European emigrants, but it is rare in Asia. There have been only 13 reported cases in Southeast Asia, including one reported case from Thailand. Half of the previously reported cases had bone symptoms and the other half were asymptomatic, but were incidentally discovered when patients were being investigated for other medical problems. Here are reported cases of four asymptomatic patients who presented elevation of serum alkaline phosphatase during routine annual medical checkups. All patients were of Chinese descent and all cases were proven by biopsy. Based on this experience, we are of the opinion that a substantial number of unrecognized cases of Paget's disease exist among ethnic Thais. We feel that they would be revealed if clinicians were alerted of its presence and if they included it as a possible diagnosis together with metastasis and osteoporosis when examining bone lesions or when results for elevated serum alkaline phosphatase are detected during routine checkups. We also anticipate that a higher prevalence of this disease may occur in future Thai generations due to the addition of offspring from Asian-European intermarriages to offspring of Chinese descent in the ethnic Thai population.

Familial Paget disease and SQSTM1 mutations in New Zealand

Genetic factors play an important role in the pathogenesis of Paget disease of bone (PDB). SQSTM1 is the most important disease-associated gene identified to date. We investigated the relationship of family history, phenotype, and SQSTM1 mutation status in New Zealand (a country with a high prevalence of PDB) in patients with a family history and/or a severe phenotype. We studied 61 unrelated subjects with familial PDB. Family history was subclassified into three groups according to the closeness of the relationship. We also studied a fourth group of 19 unrelated patients defined by early onset and/or severe disease but no family history. The PDB phenotype was defined according to age, alkaline phosphatase activity, and disease extent on scintiscan at the time of diagnosis. Mutations in exon 8 of SQSTM1 were detected by screening of genomic DNA. Four different mutations were identified; the ubiquitous P392L mutation and the truncating mutation E396X accounted for 89% of cases. Overall 26% of patients with familial PBD in New Zealand had disease-associated mutations in the SQSTM1 gene. Mutations were most prevalent (60%) in those with a parent or sibling and at least one other relative affected (P < 0.002). The severity of the phenotype was significantly related to SQSTM1 mutation status but not the strength of the family history (P < 0.005). SQSTM1 mutations were found in 10.5% of patients with early onset and/or severe disease but no family history.

Indications for a genetic association of a VCP polymorphism with the pathogenesis of sporadic Paget's disease of bone, but not for TNFSF11 (RANKL) and IL-6 polymorphisms

Paget's disease of bone (PDB) is, after osteoporosis, the second most common metabolic bone disorder in the elderly Caucasian population. Mutations in the sequestosome 1 gene (SQSTM1) are responsible for the etiology of PDB in a subset of patients, but the disease pathogenesis in the remaining PDB patients is still unknown. Therefore association studies investigating the relationship between genetic polymorphisms and sporadic PDB have been performed in order to find the susceptibility polymorphisms. In this paper, we sought to determine whether polymorphisms in 3 functional candidate genes play a role in the development of sporadic PDB: TNFSF11 (receptor activator of nuclear factor κB ligand, RANKL), VCP (valosin-containing protein) and IL-6 (interleukin 6). Analyzing 9 tag SNPs and 2 multi-marker tests (MMTs) in TNFSF11, 3 tag SNPs and 1 MMT in VCP and 8 tag SNPs in IL-6 in a population of 196 Belgian patients with sporadic PDB and 212 Belgian control individuals revealed that one VCP SNP (rs565070) turned out to be associated with PDB in this Belgian study population (p=5.5×10(-3)). None of the tag SNPs or MMTs selected for TNFSF11 or IL-6 was associated with PDB. Still, replication of our findings in the VCP gene in other populations is important to confirm our results. However, when combining data of VCP with those from other susceptible gene regions from previous association studies (i.e. TNFRSF11A, CSF1, OPTN and TM7SF4), independent effect of each gene region was found and the cumulative population attributable risk is 72.7%.

Imaging of Paget disease of bone and its musculoskeletal complications: self-assessment module

The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her skills in diagnostic radiology with regard to imaging of Paget disease of bone and its musculoskeletal complications.

Genome-wide association identifies three new susceptibility loci for Paget's disease of bone

Paget's disease of bone (PDB) is a common disorder characterized by focal abnormalities of bone remodeling. We previously identified variants at the CSF1, OPTN and TNFRSF11A loci as risk factors for PDB by genome-wide association study. Here we extended this study, identified three new loci and confirmed their association with PDB in 2,215 affected individuals (cases) and 4,370 controls from seven independent populations. The new associations were with rs5742915 within PML on 15q24 (odds ratio (OR) = 1.34, P = 1.6 × 10(-14)), rs10498635 within RIN3 on 14q32 (OR = 1.44, P = 2.55 × 10(-11)) and rs4294134 within NUP205 on 7q33 (OR = 1.45, P = 8.45 × 10(-10)). Our data also confirmed the association of TM7SF4 (rs2458413, OR = 1.40, P = 7.38 × 10(-17)) with PDB. These seven loci explained ∼13% of the familial risk of PDB. These studies provide new insights into the genetic architecture and pathophysiology of PDB.