The rising incidence of atraumatic fractures in patients either with Ewing's sarcoma or osteosarcoma years after chemotherapy revealed a growing population of childhood cancer survivors with a decreased bone mineral density (BMD) possibly due to a long-term effect of the chemotherapy. Therefore we started to screen our patients below 50y of age who were treated for bone malignancies between 1994 and 2009.

The first series of measurements included 15 patients – eight Ewing's sarcoma, three female and five male, with a mean age of 18y (±13SD), and seven osteosarcoma, two female and five male, with a mean age of 19y(±9SD). We screened the patients for deficits in their bone status using DEXA (dual-energy-x-ray-absorptiometry) to gain the T-and Z-Scores of the proximal femur and the lumbal spine. Additionally we took blood samples for endocrinological analysis and utilised a questionnaire to scan the patient's liefestyle. The mean time between diagnosis and investigation was 95months (±79SD) in Ewing's sarcoma and 105months (±54 SD) in osteosarcoma.

The results of the age and gender matched lumbal measurement (Z-Score) of the Ewing's sarcoma patients showed a reduction of the BMD in six cases (6/8), including three times osteopenia (3/8) and two times osteoporosis (2/8). The osteosarcoma patients presented a BMD-decline in four cases (4/7) with two times osteopenia (2/7) and one osteoporosis (1/7).

In the proximal femur six Ewing's sarcoma (6/8) and six osteosarcoma patients (6/7) showed a BMD-decrease including three osteopenic (3/8) and one osteoporotic (1/8) Ewing's sarcoma and four osteopenic osteosarcoma (4/7). We found two cases of pathologic fractures (2/15), one Ewing's sarcoma 29 months after diagnosis with a fracture of the distal femur and the proximal Tibia (1/8) and one osteosarcoma with a fractured distal femur after 72 months (1/7).

As presented in our case series osteoporosis after chemotherapy is an underestimated long-term effect of the chemotherapeutic treatment. In our series BMD-reduction seems to be independent of tumour-type and chemotherapeutic agent like MTX.

High-dose methothrexate, a standard agent in the therapy protocols for osteosarcoma, has long been suspected to have a negative long-term effect on bone metabolism and bone mineral density, especially in children and young adults. Recent literature questioned this association as also the BMD of Ewing‘s sarcoma patients treated without methothrexate is known to be decreased. We therefore wanted to screen our patients treated for Ewing‘s sarcoma and osteosarcoma for osteopenia/osteoporosis-associated fractures.

Between 1994 and 2008 107 patients below 50y of age were treated for bone malignancies including 51 Ewing’s sarcomas – 31 male and 20 female – with a mean age at diagnosis of 17y(±11SD) and 56 osteosarcomas – 36 male and 20 female – with a mean age of 23y(±12SD). We screened the patients‘ files for fractures after chemotherapy.

We found five patients with not trauma-associated fractures – one Ewing‘s sarcoma(1/51;2%) and four osteosarcoma patients(4/56;7%). They presented one fracture of the proximal femur 107 months after tumour diagnosis, three fractures of the distal femur after 29, 51, and 72 months and two fractures of the proximal tibia after 29 and 32 months (one patient suffered from fractures affecting both – the distal femur and the proximal tibia).

As presented in our case series fractures due to an osteoporotic process after chemotherapy for bone sarcomas are well known late effects. Although described in several studies therapeutic recommendations for pro-phylaxis are sparse. Furthermore the fact that fractures occurred in both types of sarcoma casts MTX as the main cause of chemotherapy-induced osteoporosis into doubt. Additionally we estimate a high number of unreported cases of premature osteoporosis because sarcoma patients are usually not tested for their BMD-levels. Therefore further studies using DEXA (dual-energy-x-ray-absorptiometry) to measure the patients BMDs after chemotherapy are needed.