Bone mineral density in childhood survivors of acute lymphoblastic leukemia treated without cranial irradiation.

Adult survivors of childhood acute lymphoblastic leukemia (ALL) whose treatment included cranial irradiation (XRT) have reduced bone mineral density (BMD). Fifty-three survivors of ALL (aged 6-17 yr; 22 males and 31 females), who had completed their treatment without XRT, at least 1 yr previously, and 187 (5-19 yr; 86 males and 101 females) healthy controls were examined with dual energy x-ray absorptiometry of the total body and L1-L4 vertebrae and peripheral quantitative computer tomography at the distal and midradial sites. The total body and lumbar spine BMDs did not differ between the ALL survivors and controls. Distal radial trabecular BMD (difference, -0.080 mg/cm(3); 95% confidence interval, -0.139 to -0.020; P = 0.009), but not total BMD (difference, -0.006 mg/cm(3); confidence interval, -0.051 to 0.039; P = 0.80), was lower in ALL survivors compared with controls. At the midradial site, both endosteal (11% larger; P = 0.0001) and periosteal (4% larger; P = 0.001) circumferences were greater, and cortical thickness was thinner by 6% (P = 0.006) in the ALL subjects, leading to an increase in the axial moment of inertia in the ALL subjects (difference, 13%; P = 0.008). In conclusion, BMD, except at the radius, is normal in childhood survivors of ALL treated without XRT. At the midradial site, we speculate that ALL or its treatment resulted in endosteal bone loss and cortical bone thinning, but the axial moment of inertia and, hence, strength was maintained as a result of bone gain at the periosteal surface.

Rhabdomyosarcoma in Nijmegen breakage syndrome: strong association with perianal primary site.

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive disorder resulting from mutations in the NBS1 gene, which encodes for the DNA double strand break repair protein nibrin. NBS is clinically characterized by microcephaly, dysmorphic features, immunodeficiency, and increased susceptibility to malignancy, mainly of lymphoid origin. Here, we describe a 7-year-old girl with NBS who is homozygous for the NBS1 698del4 mutation. She had been diagnosed with perianal rhabdomyosarcoma (RMS) and experienced severe toxicity from chemotherapy. RMS arising perianally is extremely uncommon but has been previously described in two cases with NBS. The strong association of perianal RMS with NBS should, therefore, be considered when confronted with a perianal RMS, as this carries important clinical implications in terms of potential need for therapy modification and follow up investigations. In addition, it suggests a role for the NBS1 gene and the nibrin dependent pathway in the pathogenesis of RMS, especially those arising perianally.

Puberty in children with cancer.

Cancer may impinge on puberty either directly through a mass lesion effect on the reproductive axis or indirectly through hormones secreted by tumours, for example human chorionic gonadotrophin, or weight loss, or the actual presence of a chronic disease process per se. The more frequent pubertal problems faced by children with cancer are due to the impact of treatment either on the central nervous system, the hypothalamic-pituitary axis or the gonad; in this review, we concentrate on these complications and their potential management.