Endocrine Abstracts

In this workshop, we would like to discuss several clinical cases in the context of our recently published/collected data on bone health after childhood cancer therapy (below). Although risk factors for reduced BMD in childhood cancer survivors (CCS) had been identified, it remained unknown which survivors were at highest absolute risk of reduced BMD and might benefit from BMD assessment by DXA. In collaboration with the American SJLIFE cohort (n=2, 032), we developed prediction models for low and very low BMD in adult CCS, and externally validated these models on a single-center Dutch cohort (n=403). The models included male sex, lower weight, shorter height, younger attained age, smoking, and cranial and abdominal irradiation and correctly identified BMD status in most white adult survivors. In addition, we and others developed an evidence-based international guideline for BMD surveillance in CCS. In short, BMD surveillance is now recommended for survivors treated with cranial/craniospinal or total body irradiation using DXA at entry into long-term follow-up (2-5 years after completion of therapy), and if normal (Z-score >-1), again at 25 years of age. Several of the gaps in knowledge that had been identified in the guideline could be addressed in our subsequent study in a national cohort of adult Dutch CCS (n=2, 003). We observed that CCS have a 3.5 times (males) or 5.4 times (females) increased risk of any fracture, and also the frequency of vertebral fractures seems to be increased in this group (13.3%). For the first time, it was shown in a multivariable model that reduced BMD (especially very low lumbar spine BMD) is indeed significantly associated with a history of fractures in CCS, which highlights the importance of BMD surveillance. Several novel associations between previous cancer treatment, endocrine disorders, and vitamin deficiencies and reduced BMD and fractures were observed.