Premature Epiphyseal Closure of the Lower Extremities Contributing to Short Stature after cis-Retinoic Acid Therapy in Medulloblastoma: A Case Report

Exploring height outcomes with adjuvant aromatase inhibition in growth hormone-deficient male survivors of childhood cancer

BACKGROUND

Aromatase inhibitors (AI) may improve height in short stature conditions; however, the effect in childhood cancer survivors (CCS) is unknown. We assessed final adult height (FAH) in CCS treated with AI and GH compared with those treated with GH alone.

METHODS

Retrospective cohort study of GH-deficient male CCS treated between 2007 and 2023. FAH was noted as the height at the fusion of growth plates or 18 years of age. Multivariable linear regression was used to examine treatment association with FAH, adjusting for other risk factors.

RESULTS

Ninety-two patients were included; 70 were treated with GH and 22 with combination AI/GH. The mean age at GH initiation did not differ between groups. The mean age at AI initiation was 13.7 ± 1.9 years. A greater proportion of patients in the AI/GH group were treated with stem cell transplantation, abdominal radiation, total body irradiation, and cis-retinoic acid (p < .01). Multivariable linear regression demonstrated no significant treatment association with FAH Z-score (β = 0.04, 95% CI: -0.9 to 0.9). History of spinal radiation (β = -0.93, 95% CI: -1.7 to -0.2), lower starting height Z-score (β = -0.8, 95% CI: -1.2 to -0.4), and greater difference between bone age and chronological age (β = -0.3, 95% CI: -0.5 to -0.07) were associated with lower FAH Z-score.

CONCLUSIONS

Adjuvant AI was not associated with increased FAH in male CCS compared with GH monotherapy. Future work is needed to determine the optimal adjunctive treatment to maximize FAH for this population.

Reduction of New Heterotopic Ossification (HO) in the Open-Label, Phase 3 MOVE Trial of Palovarotene for Fibrodysplasia Ossificans Progressiva (FOP)

Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare, severely disabling genetic disorder of progressive heterotopic ossification (HO). The single-arm, open-label, phase 3 MOVE trial (NCT03312634) assessed efficacy and safety of palovarotene, a selective retinoic acid receptor gamma agonist, in patients with FOP. Findings were compared with FOP natural history study (NHS; NCT02322255) participants untreated beyond standard of care. Patients aged ≥4 years received palovarotene once daily (chronic: 5 mg; flare-up: 20 mg for 4 weeks, then 10 mg for ≥8 weeks; weight-adjusted if skeletally immature). The primary endpoint was annualized change in new HO volume versus NHS participants (by low-dose whole-body computed tomography [WBCT]), analyzed using a Bayesian compound Poisson model (BcPM) with square-root transformation. Twelve-month interim analyses met futility criteria; dosing was paused. An independent Data Monitoring Committee recommended trial continuation. Post hoc 18-month interim analyses utilized BcPM with square-root transformation and HO data collapsed to equalize MOVE and NHS visit schedules, BcPM without transformation, and weighted linear mixed-effects (wLME) models, alongside prespecified analysis. Safety was assessed throughout. Eighteen-month interim analyses included 97 MOVE and 101 NHS individuals with post-baseline WBCT. BcPM analyses without transformation showed 99.4% probability of any reduction in new HO with palovarotene versus NHS participants (with transformation: 65.4%). Mean annualized new HO volume was 60% lower in MOVE versus the NHS. wLME results were similar (54% reduction fitted; nominal p = 0.039). All palovarotene-treated patients reported ≥1 adverse event (AE); 97.0% reported ≥1 retinoid-associated AE; 29.3% reported ≥1 serious AE, including premature physeal closure (PPC)/epiphyseal disorder in 21/57 (36.8%) patients aged <14 years. Post hoc computational analyses using WBCT showed decreased vertebral bone mineral density, content, and strength, and increased vertebral fracture risk in palovarotene-treated patients. Thus, post hoc analyses showed evidence for efficacy of palovarotene in reducing new HO in FOP, but high risk of PPC in skeletally immature patients. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Therapy of psoriasis during pregnancy and breast-feeding

There have been multiple systemic drugs approved for the therapy of psoriasis vulgaris and psoriasis arthritis (PsA) in the last decade. However, treatment decisions are difficult to make in women planning a pregnancy and in pregnant and lactating women due to the paucity of data for such cases. The strongest evidence for psoriasis therapy during pregnancy exists for topical corticosteroids. Medically controlled use of UVB-therapy is also considered safe. The best evidence regarding systemic therapy during pregnancy and lactation is available for the group of TNF-alpha inhibitors, which is also reflected in the respective medical product information. This is especially important in cases of psoriatic arthritis. Among traditional systemic therapeutics, the largest clinical experience exists for ciclosporin, which, if medically necessary, may be continued during gestation. However, TNF-alpha inhibitors, especially the pegylated form, should be preferred in case of pregnancy. Furthermore, an elective pregnancy termination is not necessary due to systemic therapy of psoriasis with many further substances during the first pregnancy weeks. The current work provides a comprehensive review of the scientific literature on treatment of psoriasis during pregnancy and lactation. Based on the available scientific information, severity of psoriasis and patient's comorbidities, the best possible therapeutic approach can be found in consensus with the patient.

Physeal Abnormalities in Children With High-risk Neuroblastoma Intensively Treated With/Without 13-Cis-Retinoic Acid

BACKGROUND

This study aimed to investigate the presence of physeal abnormality and its effect on growth in children with high-risk neuroblastoma treated by intensive multimodal treatment with/without 13-cis-retinoic acid (13-CRA).

METHODS

Fifteen patients diagnosed with high-risk neuroblastomas at the age of 1 to 10 years, who received treatment such as high-dose chemotherapy and autologous stem cell transplantation with/without 13-CRA, and with complete data during their >2-year follow-up were retrospectively reviewed. The physeal abnormalities were investigated by whole-body magnetic resonance imaging, serially performed every 3 to 6 months. The patients' height growth was also investigated and compared with that of age-and-sex-matched patients with brain tumors who also underwent high-dose chemotherapy and autologous stem cell transplantation.

RESULTS

Six of 15 patients presented multifocal physeal abnormalities during follow-up, and all lesions occurred in patients with 13-CRA use. The lesions in 3 patients completely resolved spontaneously without any adverse effect on growth, but some lesions in the other 3 patients progressed to disturb the bony growth. Height growth of matched patients with brain tumors were not significantly different, and none of the matched controls showed definite bony deformity during the follow-up.

CONCLUSIONS

Some children who were treated for high-risk neuroblastomas experienced multifocal physeal insults, probably due to the use of 13-CRA. Most lesions resolved spontaneously, but some led to bony deformity. If the lesions are not followed by premature physeal closure, there seems to be no further adverse effect of 13-CRA on leg length growth. Routine periodic screening for physeal status is needed for the patients with high-risk neuroblastomas using 13-CRA.

LEVEL OF EVIDENCE

Level IV-prognostic study.

Genu varum deformity due to premature epiphyseal closure after treatment with isotretinoin for neuroblastoma: A case report

Isotretinoin, a vitamin A derivative, is known to induce premature epiphyseal closure. We report the case of a 9-year-old boy with neuroblastoma who demonstrated premature epiphyseal closure after 1 year of isotretinoin treatment (72.3 mg/m²/day). A bone bridge developed on the bilateral proximal tibial growth plate resulting in genu varum. We performed hemiepiphysiodesis on the bilateral proximal tibia in anticipation of the spontaneous resolution of the bone bridge. Genu varum on the left side was corrected with the resolution of bone bridge. For the remaining bone bridge on the right side, arthroscopy-assisted physeal bar resection was performed, and genu varum on the right lower extremity was also corrected. A regular review of the alignment of the upper and lower limbs is necessary to provide timely intervention in patients using isotretinoin, considering the possibility of premature epiphyseal closure.

Premature epiphyseal growth plate arrest after isotretinoin therapy for high-risk neuroblastoma: A case series and review of the literature

BACKGROUND

Vitamin A-derived retinoids have been reported to cause skeletal abnormalities ranging from hypercalcemia to premature epiphyseal closure. Isotretinoin is a retinoid used as standard therapy for high-risk neuroblastoma and has been reported to cause premature epiphyseal growth plate arrest.

PROCEDURE

We identified patients from the Children's Hospital Los Angeles (CHLA) database with high-risk neuroblastoma diagnosed from 1991 to 2018 who experienced premature epiphyseal growth plate arrest and compared their characteristics to other patients with high-risk neuroblastoma. We then performed a literature review of this complication. Data collection included diagnosis age of neuroblastoma, presentation age, agent of exposure, dose, exposure range, and skeletal deformity.

RESULTS

Among 216 patients, high-risk neuroblastoma was diagnosed before age of five years (n = 165), between ages of 5 and 10 years (n = 41), and after 10 years of age (n = 13). Three out of 216 patients developed premature epiphyseal growth arrest after isotretinoin exposure (overall incidence = 1.38%). The incidence of bony abnormalities was significantly higher in patients diagnosed in 5- to 10-year age group than in other two groups (P = 0.014). Literature review identified eight additional patients with neuroblastoma who presented with retinoid associated skeletal abnormalities. The median range of isotretinoin exposure for these 11 patients was between 6.5 and 7.625 years (range, 2-14) with no cases of isotretinoin therapy completion before age 5 years.

CONCLUSION

Bone toxicity associated with isotretinoin exposure is a concern. Growth plate arrest is a serious adverse effect that is attributable to isotretinoin therapy. Our findings suggest the prepubescent growth plate may be most at risk, and we recommend special attention to this population.

Evaluating growth failure with diffusion tensor imaging in pediatric survivors of high-risk neuroblastoma treated with high-dose cis-retinoic acid

BACKGROUND

The survival of patients with high-risk neuroblastoma has increased with multimodal therapy, but most survivors demonstrate growth failure.

OBJECTIVE

To assess physeal abnormalities in children with high-risk neuroblastoma in comparison to normal controls by using diffusion tensor imaging (DTI) of the distal femoral physis and adjacent metaphysis.

MATERIALS AND METHODS

We prospectively obtained physeal DTI at 3.0 T in 20 subjects (mean age: 12.4 years, 7 females) with high-risk neuroblastoma treated with high-dose cis-retinoic acid, and 20 age- and gender-matched controls. We compared fractional anisotropy (FA), normalized tract volume (cm³/cm²) and tract concentration (tracts/cm²) between the groups, in relation to height Z-score and response to growth hormone therapy. Tractography images were evaluated qualitatively.

RESULTS

DTI parameters were significantly lower in high-risk neuroblastoma survivors compared to controls (P<0.01), particularly if the patients were exposed to both cis-retinoic acid and total body irradiation (P<0.05). For survivors and controls, DTI values were respectively [mean ± standard deviation]: tract concentration (tracts/cm²), 23.2±14.7 and 36.7±10.5; normalized tract volume (cm³/cm²), 0.44±0.27 and 0.70±0.21, and FA, 0.22±0.05 and 0.26±0.02. High-risk neuroblastoma survivors responding to growth hormone compared to non-responders had higher FA (0.25±0.04 and 0.18±0.03, respectively, P=0.02), and tract concentration (tracts/cm²) (31.4±13.7 and 14.8±7.9, respectively, P<0.05). FA, normalized tract volume and tract concentration were linearly related to height Z-score (R²>0.31; P<0.001). Qualitatively, tracts were nearly absent in all non-responders to growth hormone and abundant in all responders (P=0.02).

CONCLUSION

DTI shows physeal abnormalities that correlate with short stature in high-risk neuroblastoma survivors and demonstrates response to growth hormone treatment.

The safety of isotretinoin treatment in patients with bone fractures

Isotretinoin is widely applicable in dermatology, although it may develop severe side effects in the skeletal system. An intention of this review was to establish the safety of oral isotretinoin in patients with bone fractures. Both MEDLINE/Pubmed and SCOPUS databases were searched to investigate the influence of isotretinoin on the skeletal system. The drug shows a strong osteoporotic activity in rats whereas this effect is milder in humans. Biochemical markers of bone turnover remain unchanged except for serum calcium in patients receiving a high dose of isotretinoin. An excessive intake of vitamin A may impair functioning of vitamin D especially in people with a vitamin D deficiency, therefore a similar side effect may also occur in patients on isotretinoin treatment. We suggest reducing the use of isotretinoin after bone injury or continuing the treatment at low dosing with a concomitant correction of vitamin D and calcium status.

Exogenous Vitamin D signaling alters skeletal patterning, differentiation, and tissue integration during limb regeneration in the axolotl

Urodele amphibians such as the axolotl regenerate complete limbs as adults, and understanding how the "blueprint", or pattern, of the regenerate is established and manipulated are areas of intense interest. Nutrient signaling plays an important role in pattern formation during regeneration. Retinoic acid signaling is the most characterized pathway during this process. Exogenous retinoic acid (RA) reprograms the pattern information in regenerating cells to a more posterior, ventral, and proximal identity. Vitamin D signaling shares several molecular similarities with RA and has been shown to alter pattern formation during zebrafish pectoral fin regeneration. To determine if exogenous Vitamin D signaling is capable of reprograming pattern in the axolotl limb blastema, we treated regenerating limbs with a potent Vitamin D agonist. Under the studied conditions, exogenous Vitamin D did not act in a manner similar to RA and failed to proximalize the pattern of the resulting regenerates. The Vitamin D treatment did result in several skeletal defects during regeneration, including carpal fusions along the A/P axis; failure to integrate the newly regenerated tissue with the existing tissue, formation of ectopic nodules of cartilage at the site of amputation, and altered bone morphology in uninjured skeletal tissue.

Palovarotene reduces heterotopic ossification in juvenile FOP mice but exhibits pronounced skeletal toxicity

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder characterized by debilitating heterotopic ossification (HO). The retinoic acid receptor gamma agonist, palovarotene, and antibody-mediated activin A blockade have entered human clinical trials, but how these therapeutic modalities affect the behavior of pathogenic fibro/adipogenic progenitors (FAPs) is unclear. Using live-animal luminescence imaging, we show that transplanted pathogenic FAPs undergo rapid initial expansion, with peak number strongly correlating with HO severity. Palovarotene significantly reduced expansion of pathogenic FAPs, but was less effective than activin A inhibition, which restored wild-type population growth dynamics to FAPs. Palovarotene pretreatment did not reduce FAPs’ skeletogenic potential, indicating that efficacy requires chronic administration. Although palovarotene inhibited chondrogenic differentiation in vitro and reduced HO in juvenile FOP mice, daily dosing resulted in aggressive synovial joint overgrowth and long bone growth plate ablation. These results highlight the challenge of inhibiting pathological bone formation prior to skeletal maturation.

Diagnosis of GH Deficiency as a Late Effect of Radiotherapy in Survivors of Childhood Cancers

BACKGROUND

Limited guidance exists for selecting a laboratory method for diagnosing GH deficiency (GHD) when it occurs as a late effect of radiotherapy in childhood cancer survivors (CCSs).

METHODS

We searched Medline, Embase, Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, and Scopus for studies evaluating GHD that used IGF-1 or IGF-binding protein 3 (IGFBP-3) measurements compared with GH dynamic testing.

RESULTS

We included 15 studies [IGF-1 (8 studies) and IGFBP-3 (7 studies)] enrolling 477 patients. Comparator tests varied widely. Overall, both IGF-1 and IGFBP-3 had suboptimal diagnostic accuracy but were strongly correlated. The use of both tests simultaneously in the same cohort did not improve the diagnostic accuracy. Despite high variability in the testing protocols, dynamic tests remained the most accurate for appropriately identifying patients with GHD. The insulin tolerance test (ITT) appears to be the most accepted reference test when used alone or in combination with arginine; however, standardized testing strategies among practice groups are absent. GHRH and arginine stimulation performed almost similarly to the ITT; however, in one study GHRH with arginine stimulation had 66% sensitivity and 88% specificity compared with the ITT. Insufficient data were available to assess the accuracy of serial GH testing (nocturnal or over 24 hours).

CONCLUSION

The diagnostic accuracy of various dynamic tests for GHD in CCSs appears to follow the same patterns as those in non-CCSs. Interpreting GHRH stimulation is a challenge given the primarily hypothalamic dysfunction in CCSs. IGF-1 and IGFBP-3 perform poorly in this population.

MANAGEMENT OF ENDOCRINE DISEASE: Diagnostic and therapeutic approach of tall stature

Tall stature is defined as a height of more than 2 standard deviations (s.d.) above average for same sex and age. Tall individuals are usually referred to endocrinologists so that hormonal disorders leading to abnormal growth are excluded. However, the majority of these patients have familial tall stature or constitutional advance of growth (generally associated with obesity), both of which are diagnoses of exclusion. It is necessary to have familiarity with a large number of rarer overgrowth syndromes, especially because some of them may have severe complications such as aortic aneurysm, thromboembolism and tumor predisposition and demand-specific follow-up approaches. Additionally, endocrine disorders associated with tall stature have specific treatments and for this reason their recognition is mandatory. With this review, we intend to provide an up-to-date summary of the genetic conditions associated with overgrowth to emphasize a practical diagnostic approach of patients with tall stature and to discuss the limitations of current growth interruption treatment options.

Accelerated Skeletal Maturation in Disorders of Retinoic Acid Metabolism: A Case Report and Focused Review of the Literature

Nutritional excess of vitamin A, a precursor for retinoic acid (RA), causes premature epiphyseal fusion, craniosynostosis, and light-dependent retinopathy. Similarly, homozygous loss-of-function mutations in CYP26B1, one of the major RA-metabolizing enzymes, cause advanced bone age, premature epiphyseal fusion, and craniosynostosis. In this paper, a patient with markedly accelerated skeletal and dental development, retinal scarring, and autism-spectrum disease is presented and the role of retinoic acid in longitudinal bone growth and skeletal maturation is reviewed. Genetic studies were carried out using SNP array and exome sequencing. RA isomers were measured in the patient, family members, and in 18 age-matched healthy children using high-performance liquid chromatography coupled to tandem mass spectrometry. A genomic SNP array identified a novel 8.3 megabase microdeletion on chromosome 10q23.2-23.33. The 79 deleted genes included CYP26A1 and C1, both major RA-metabolizing enzymes. Exome sequencing did not detect any variants that were predicted to be deleterious in the remaining alleles of these genes or other known retinoic acid-metabolizing enzymes. The patient exhibited elevated plasma total RA (16.5 vs. 12.6±1.5 nM, mean±SD, subject vs. controls) and 13-cisRA (10.7 nM vs. 6.1±1.1). The findings support the hypothesis that elevated RA concentrations accelerate bone and dental maturation in humans. CYP26A1 and C1 haploinsufficiency may contribute to the elevated retinoic acid concentrations and clinical findings of the patient, although this phenotype has not been reported in other patients with similar deletions, suggesting that other unknown genetic or environmental factors may also contribute.