A multidisciplinary care pathway improves quality of life and reduces pain in patients with fibrous dysplasia/McCune-Albright syndrome: a multicenter prospective observational study

Developing a Standardised Dataset for Natural History Studies in Fibrous Dysplasia/McCune-Albright Syndrome

Fibrous dysplasia/McCune-Albright syndrome (FD/MAS) is a rare and complex condition caused by somatic variants in the GNAS gene that lead to a wide clinical spectrum. The diagnostic process and therapeutic pathway vary per centre and therefore international harmonisation of data collection should be pursued. To understand the diagnostic pathways and clinical outcomes of patients with FD/MAS reported on an electronic-reporting tool (e-REC) across European centres to guide the develop a condition-specific module within the European Registries for Rare Endocrine and Bone conditions. Centres that reported new cases on e-REC between October 2019 and May 2021 were approached to complete a survey in May 2021. Fifty-eight cases were included. Median age at presentation was 20 years (range, 0, 72). Of the 58 included cases, the presentation type was isolated craniofacial FD in 19 (33%), monostotic FD in 15 (26%), polyostotic FD in 10 (17%), and MAS in 13 (13%). Standardised questionnaires to assess pain and quality of life were used routinely in 21/58 patients (36%). The majority of patients had more than one healthcare provider, with great diversity in the specialty of the coordinating physician. A standardised dataset module for FD/MAS was developed through collaboration with the FD/MAS study group, incorporating expert consensus and clinical insights. Key variables were identified to capture essential diagnostic, clinical, and patient-reported outcomes. The diagnostic path for patients with FD/MAS across European expert centres is variable. The outcomes of this study allowed the building of the first international FD/MAS-specific data collection.

A Qualitative Approach to Quality of Life in Fibrous Bone Dysplasia /McCune Albright Syndrome: Looking Beyond Quantitative Analysis

This study explores FD/MAS patient's perceptions about their disease and its impact on their quality of life. We have evaluated quality of life (QoL) in French Fibrous Dysplasia/MacCune-Albright Syndrome (FD/MAS) patients using a qualitative approach with focus groups to explore perceptions, symptoms and limitations associated with FD/MAS and a quantitative method with the Short Form-36 (SF36) to quantify QoL. Focus groups revealed the heterogeneity of FD forms and allowed for understanding the reasons of reduced QoL. Patients identified pain as the dominant symptom. The impact on mental health was explained by diagnostic uncertainty, disease chronicity and rarity and the inconsistent effectiveness of therapies. Patients talked about disability but also of coping strategies. They expressed their need for comprehensive and multi-disciplinary care from medical and paramedical professionals familiar with their pathology. The quantitative questionnaire SF36 confirmed reduced QoL in these patients compared with the French general population in all sub-domains: physical function (72.1 versus 84.4, p = 0.0001), physical role (60.5 versus 81.1, p = 0.0004), body pain (58.7 versus 72.4, p = 0.0004), general health (50.08 versus 67.6, p < 0.0001), energy (44.58 versus 57.2, p < 0.0001), social function (61.34 versus 80.5, p < 0.0001), emotional role (57.98 versus 81.3, p = 0.0002) and emotional well-being (57.98 versus 81.3, p = 0.0097). Polyostotic patients had poorer QoL compared with monostotic patients. A better understanding of the disease experience and expectations of FD patients will enable practitioners to provide care better adapted to patients' needs, and pave the way for optimizing DF care.

Pediatric Fibrous Dysplasia of the Skull Base: Update on Management and Treatment

BACKGROUND

Fibrous dysplasia (FD) is often difficult for skull base surgeons to address. FD arises due to the abnormal proliferation of fibroblasts, ultimately resulting in immature osseous tissue replacing normal cancellous bone. When the skull base is involved, it can result in cranial nerve compression. FD affecting the optic canal and optic nerve is the most concerning as new onset of vision loss is considered a surgical emergency. The prevalence of FD is approximately 3.6 per 1,000,000. The most severe implications of this disease are neurological deficits due to cranial nerve compression, cosmetic appearance, and high recurrence rates even in the setting of surgical and medical therapy interventions.

METHODS

A PubMed search of "pediatric fibrous dysplasia management" using MESH Terms was conducted. Articles were excluded for non-English languages, inaccessibility, and events/erratum/letters to the editor. Included articles were in English, as well as encompassed pediatric FD case reports or comprehensive reviews of FD that discussed pediatric presentations.

RESULTS

A total of 109 articles were reviewed, and 44 were included in the final review. Most articles were case reports. There is a clear need for guidelines regarding surgical intervention, especially in the pediatric population, where hormonal fluctuation can influence rates of recurrence and bony deformity. Overall, most surgeons recommend close observation with biomarkers and radiographic imaging for asymptomatic patients until at least the age of 16 years old. Conservative methods, such as RANK-L inhibitors, can be utilized to decrease growth with some success, especially in older adolescents.

CONCLUSION

This review is an update on this disease and its presentations, imaging findings, and treatment options. The current literature lacks clear guidance on management, especially in regard to surgical intervention or recurrence monitoring algorithms.

Incidence and Prevalence of Fibrous Dysplasia/McCune-Albright Syndrome: A Nationwide Registry-Based Study in Denmark

CONTEXT

Fibrous dysplasia/McCune-Albright syndrome (FD/MAS) is a rare genetic disorder. Incidence and prevalence are not well-studied. Epidemiological research is complicated by the rarity of FD/MAS, absence of registries, heterogeneous presentation, and possibly asymptomatic phenotype. FD/MAS may present with FGF23-mediated hypophosphatemia, of which the epidemiology is also unclear.

OBJECTIVE

Evaluate incidence and prevalence of FD/MAS and FD/MAS-related hypophosphatemia.

METHODS

This cohort study based on the nationwide Danish National Patient Registry from 1995-2018, included patients identified by ICD-10 codes M85.0 (monostotic FD [MFD]) and Q78.1 (polyostotic FD [PFD]/MAS). Incidence rates and prevalence were calculated and stratified by sex, age, calendar period, and diagnosis code. Cases were screened for FD-associated hypophosphatemia by diagnosis code E.83 (disorder of mineral metabolism) and dispatched vitamin D analogues.

RESULTS

A total of 408 patients were identified, 269 with MFD (66%), 139 with PFD/MAS (34%), comparable between sexes. Incidence of FD/MAS demonstrated increasing secular trend with a rate of 3.6 per 1 000 000 person-years (95% CI: 2.9, 4.5) in 2015-2018. Incidence peaked between age 11 and 20. Prevalence of FD/MAS increased over time to 61.0 (95% CI: 54.6, 67.4) per 1 000 000 persons in 2018. The incidence rate of MFD was 1.5-fold that of PFD/MAS in the first decade, rising to 2.5-fold in the last decade. No FD/MAS cases were registered with diagnosis code or treatment for hypophosphatemia.

CONCLUSION

FD/MAS is rare, diagnosis peaks during adolescence without sex predominance, and MFD is most prevalent. Hypophosphatemia may be underdiagnosed and undertreated, or it may be underregistered, comparing this study to literature.

Craniofacial disorders and dysplasias: Molecular, clinical, and management perspectives

There is a wide spectrum of craniofacial bone disorders and dysplasias because embryological development of the craniofacial region is complex. Classification of craniofacial bone disorders and dysplasias is also complex because they exhibit complex clinical, pathological, and molecular heterogeneity. Most craniofacial disorders and dysplasias are rare but they present an array of phenotypes that functionally impact the orofacial complex. Management of craniofacial disorders is a multidisciplinary approach that involves the collaborative efforts of multiple professionals. This review provides an overview of the complexity of craniofacial disorders and dysplasias from molecular, clinical, and management perspectives.

A Rare Skeletal Disorder, Fibrous Dysplasia: A Review of Its Pathogenesis and Therapeutic Prospects

Fibrous dysplasia (FD) is a rare, non-hereditary skeletal disorder characterized by its chronic course of non-neoplastic fibrous tissue buildup in place of healthy bone. A myriad of factors have been associated with its onset and progression. Perturbation of cell-cell signaling networks and response outputs leading to disrupted building blocks, incoherent multi-level organization, and loss of rigid structural motifs in mineralized tissues are factors that have been identified to participate in FD induction. In more recent years, novel insights into the unique biology of FD are transforming our understandings of its pathology, natural discourse of the disease, and treatment prospects. Herein, we built upon existing knowledge with recent findings to review clinical, etiologic, and histological features of FD and discussed known and potential mechanisms underlying FD manifestations. Subsequently, we ended on a note of optimism by highlighting emerging therapeutic approaches aimed at either halting or ameliorating disease progression.