Low bone mineral density in adolescents with leukemia after hematopoietic stem cell transplantation: prolonged steroid therapy for GvHD and endocrinopathy after hematopoietic stem cell transplantation might be major concerns?

Bone Mineral Density in Survivors of Childhood Cancer: A Meta-Analysis

CONTEXT

There is an increasing population of childhood cancer survivors (CCS) at risk for treatment-related toxicities, including skeletal morbidities. Bone mineral density (BMD) is a proxy for bone health and reductions are associated with osteoporosis and fractures.

OBJECTIVE

To investigate bone health in CCS by conducting a systematic review and meta-analysis of BMD after completed treatments.

DATA SOURCES

We searched Medline, Embase, Cochrane, and Web of Science in May 2019 and updated in May 2023.

STUDY SELECTION

Studies reporting BMD Z-scores measured with dual-energy x-ray absorptiometry in CCS after treatment completion.

DATA EXTRACTION

We performed a pooled analysis of studies reporting BMD Z-scores and thereafter we analyzed studies comparing BMD in survivors and healthy controls. All analyses were performed based on the site of BMD measurement.

RESULTS

Of 4243 studies, 84 were included (N = 8106). The mean time off-treatment across the studies ranged from 2 months to 24 years. The overall pooled mean Z-score was -0.57 (95% confidence interval [CI] -0.59 to -0.55) in the whole-body, -0.84 (95% CI -0.86 to -0.83) in the lumbar spine, -0.79 (95% CI -0.81 to -0.77) in the femoral neck and -0.14 (95% CI -0.18 to -0.11) in the total hip. When comparing survivors with controls, BMD was significantly lower in survivors at all sites.

LIMITATIONS

English publications, study-level meta-analysis.

CONCLUSIONS

We showed a significant reduction of BMD Z-scores in CCS. Given the increased fracture risk already within -1 SD, these results emphasize the need for BMD surveillance and secondary prevention in CCS.

Identification of leukemia stem cell expression signatures through Monte Carlo feature selection strategy and support vector machine

Acute myeloid leukemia (AML) is a type of blood cancer characterized by the rapid growth of immature white blood cells from the bone marrow. Therapy resistance resulting from the persistence of leukemia stem cells (LSCs) are found in numerous patients. Comparative transcriptome studies have been previously conducted to analyze differentially expressed genes between LSC⁺ and LSC^- cells. However, these studies mainly focused on a limited number of genes with the most obvious expression differences between the two cell types. We developed a computational approach incorporating several machine learning algorithms, including Monte Carlo feature selection (MCFS), incremental feature selection (IFS), support vector machine (SVM), Repeated Incremental Pruning to Produce Error Reduction (RIPPER), to identify gene expression features specific to LSCs. One thousand 0ne hudred fifty-nine features (genes) were first identified, which can be used to build the optimal SVM classifier for distinguishing LSC⁺ and LSC^- cells. Among these 1159 genes, the top 17 genes were identified as LSC-specific biomarkers. In addition, six classification rules were produced by RIPPER algorithm. The subsequent literature review on these features/genes and the classification rules and functional enrichment analyses of the 1159 features/genes confirmed the relevance of extracted genes and rules to the characteristics of LSCs.

Mandibular radiomorphometric assessment of bone mineral density in survivors of pediatric hematopoietic stem-cell transplantation

OBJECTIVE

Hematopoietic stem-cell transplantation (HSCT) childhood survivors of hematologic malignancies are prone to develop late osteopenia and osteoporosis. The purpose of this retrospective study was to quantitatively and qualitatively assess bone mineral density (BMD) in HSCT childhood survivors and to compare the effectiveness of both qualitative and quantitative assessment methods.

METHODS

DESIGN BMD assessment using panoramic radiographs of childhood HSCT survivors aged 3.69-18.88 years using two radiomorphometric indexes. Case-control double-blinded comparison of panoramic radiographic images from childhood HSCT survivors and age- and sex-matched healthy controls. Quantitative assessment was performed by measuring the cortical bone width bilaterally at the mental foramen level. Qualitative assessment was performed using the mandibular cortical index bilaterally on all panoramic images.

RESULTS

Radiographs were taken 6.59-83.95 months after bone marrow transplantation [median±SD=25.92±24.9 months]. Fifty-two panoramic radiographic images were analyzed: 21 from HSCT survivors and 31 from healthy controls aged 3.69-25.1 years [mean±SD=11.89±5.28 years]. The mandibular cortical bone width was 17% smaller in childhood HSCT survivors than in healthy controls (case group: 2.420, control group: 3.307; p=0.00617). Qualitative analysis revealed an increased frequency of severe mandibular cortical erosion in childhood HSCT survivors, although no significant difference was observed (case group: 1.540, control group: 1.490; p=0.32). The interobserver agreement was 85% (Kappa index).

CONCLUSIONS

HSCT childhood survivors exhibit quantitative and qualitative mandibular bone impairments. Further studies are needed to establish an association between mandibular cortical bone impairment and osteoporosis.

Thyroid dysfunction in children with leukemia over the first year after hematopoietic stem cell transplantation

Background Thyroid function in children with leukemia during the first year after hematopoietic stem cell transplantation (HSCT) was investigated. Methods The medical records of 186 subjects [111 boys and 75 girls; lymphoid=75, myeloid=111; median age at HSCT was 10.7 (0.8-21.8) years old] were reviewed retrospectively. Results In children with leukemia, T3 decreased at 1 month (p<0.001) and recovered 9 months to the levels before HSCT. TSH decreased at 1 month (p<0.001), recovered at 3 months and increased at 12 months (p<0.001) to the levels before HSCT. The incidence of euthyroid sick syndrome (ESS, 23.2%, 15.5%, 5.9%, 5.2%, 3.9%, p for trend <0.001) decreased and subclinical hypothyroidism (SH, 0%, 3.9%, 14.8%, 22.1%, 21.3%, p for trend <0.001) increased at 1, 3, 6, 9 and 12 months after HSCT. Out of 55 patients developing ESS during 3 months after HSCT, 54 recovered to normal thyroid function within 5 months without medication. Among the total 186 subjects, 21 patients have been treated with levothyroxine. Both height and weight standard deviation scores continued to decrease over 1 year after HSCT. Conclusions In children with leukemia, one-quarter had ESS at 1 month and one-fifth had SH at 12 months and continued growth impairments were observed during 1 year after HSCT. Most of the ESS patients recovered to normal within 5 months without medication. More long-term follow-up of thyroid function and growth in children with leukemia after HSCT is crucial.