Genomic studies of pediatric acute lymphoblastic leukemia (ALL) have shown remarkable heterogeneity in initial diagnosis, with multiple (sub)clones harboring lesions in relapse-associated genes.... Show moreGenomic studies of pediatric acute lymphoblastic leukemia (ALL) have shown remarkable heterogeneity in initial diagnosis, with multiple (sub)clones harboring lesions in relapse-associated genes. However, the clinical relevance of these subclonal alterations remains unclear. We assessed the clinical relevance and prognostic value of subclonal alterations in the relapse-associated genes IKZF1, CREBBP, KRAS, NRAS, PTPN11, TP53, NT5C2, and WHSC1 in 503 ALL cases. Using molecular inversion probe sequencing and breakpoint-spanning polymerase chain reaction analysis we reliably detected alterations with an allele frequency below 1%. We identified 660 genomic alterations in 285 diagnostic samples of which 495 (75%) were subclonal. RAS pathway mutations were common, particularly in minor subclones, and comparisons between RAS hotspot mutations revealed differences in their capacity to drive clonal expansion in ALL. We did not find an association of subclonal alterations with unfavorable outcome. Particularly for IKZF1, an established prognostic marker in ALL, all clonal but none of the subclonal alterations were preserved at relapse. We conclude that, for the genes tested, there is no basis to consider subclonal alterations detected at diagnosis for risk group stratification of ALL treatment. Show less
Genomic alterations in relapsed B-cell precursor acute lymphoblastic leukemia (BCP-ALL) may provide insight into the role of specific genomic events in relapse development. Along this line,... Show moreGenomic alterations in relapsed B-cell precursor acute lymphoblastic leukemia (BCP-ALL) may provide insight into the role of specific genomic events in relapse development. Along this line, comparisons between the spectrum of alterations in relapses that arise in different upfront treatment protocols may provide valuable information on the association between the tumor genome, protocol components and outcome. Here, we performed a comprehensive characterization of relapsed BCP-ALL cases that developed in the context of 3 completed Dutch upfront studies, ALL8, ALL9, and ALL10. In total, 123 pediatric BCP-ALL relapses and 77 paired samples from primary diagnosis were analyzed for alterations in 22 recurrently affected genes. We found pronounced differences in relapse alterations between the 3 studies. Specifically, CREBBP mutations were observed predominantly in relapses after treatment with ALL8 and ALL10 which, in the latter group, were all detected in medium risk-treated patients. IKZF1 alterations were enriched 2.2-fold (p = 0.01) and 2.9-fold (p < 0.001) in ALL8 and ALL9 relapses compared to diagnosis, respectively, whereas no significant enrichment was found for relapses that were observed after treatment with ALL10. Furthermore, IKZF1 deletions were more frequently preserved from a major clone at diagnosis in relapses after ALL9 compared to relapses after ALL8 and ALL10 (p = 0.03). These data are in line with previous studies showing that the prognostic value of IKZF1 deletions differs between upfront protocols and is particularly strong in the ALL9 regimen. In conclusion, our data reveal a correlation between upfront treatment and the genetic composition of relapsed BCP-ALL. Show less
Background. This study aimed to compare the health related quality of life (HRQoL) of children and adolescents after malignant bone tumor surgery of the leg with healthy controls. Procedure.... Show moreBackground. This study aimed to compare the health related quality of life (HRQoL) of children and adolescents after malignant bone tumor surgery of the leg with healthy controls. Procedure. Patients between 8 and 25 years old were cross-sectional recruited. Patients under 16 years of age received the TNO (Netherlands Organization for Applied Scientific Research) and AZL (Leiden University Medical Center) Children's Quality of Life Questionnaire (TACQOL), patients aged 16 years and older received the TNO-AZL Questionnaire for Adult's Quality of Life (TAAQOL) and the Short Form-36 (SF-36). Three age- and sex-matched normative random samples, drawn from large, nationwide studies, were used for the comparison with healthy controls. Patients were interviewed regarding their most important problems related to the disease and its treatment. Results. Eighty-one patients with a mean age of 16.9 years (SD 4.2) were included (41 female). Limb sparing surgery was executed in 38 patients, ablative surgery in 43 patients. In comparison with healthy controls, patients had significantly poorer HROoL within the domains autonomy and motor function of the TACQOL, gross motor function, cognitive functioning, daily functioning and sexuality of the TAAQOL, and physical functioning, role physical, general health, and the physical and mental component summary scales of the SF-36. Patients reported limitations in physical activities, participation in sports, and cosmetic aspects as the most detrimental consequences of their disease and its treatment. Conclusion. In children and adolescents who underwent surgery for a malignant tumor of the leg physical, functioning was significantly impaired as compared to healthy controls. Pediatr Blood Cancer 2010;54:738-745. (c) 2010 Wiley-Liss, Inc. Show less
