High prevalence of late adverse events in malignant bone tumour survivors diagnosed at adult age.

BACKGROUND: Late treatment-related adverse events are particularly prevalent in survivors of childhood bone cancer because of the combination of cytotoxic drugs, major surgery and radiotherapy. Existing studies for late toxicity in survivors of Ewing's sarcoma (ES) and osteosarcoma (OS) diagnosed at adult age have focused on specific sequelae. We investigated a broad spectrum of potential late effects in these patients. METHODS: Relapse-free OS and ES patients aged ≥ 16 at diagnosis and treated at the Radboud University Medical Centre (1982-2007) were invited for systematic late toxicity screening. This included history taking, physical examination, echocardiogram, bone densitometry, audiogram, and serum and urine screening for renal toxicity and infertility. Adverse events were graded according to the Common Terminology Criteria for Adverse Events version 3.0. RESULTS: In 24 survivors (63% male, mean age at screening 45.7 years, mean follow-up 10.9 years, 70% OS) we found a median of eight adverse events. Frequent findings included abnormal gait, osteoporosis, pain, left ventricular systolic dysfunction, obesity and nephropathy. The maximum grade of any adverse event was mild in four (17%), moderate in 11 (46%), severe in six (25%), and disabling in three cases (13%). There was a trend towards more events in patients diagnosed at an older age. CONCLUSION: The incidence of late adverse events in this study of survivors of bone tumours diagnosed at adult age is higher than in any previously published childhood cancer survivorship study. Older patients seem to be particularly at risk. Our findings underscore the need for systematic screening of late effects in bone cancer survivors of adult age at diagnosis.

Prognostic and therapeutic relevance of the IGF pathway in Ewing's sarcoma patients.

The optimal target and timing of drugs interfering with the insulin-like growth factor (IGF) signaling system in Ewing's sarcoma (ES) remain undetermined. We examined the expression of IGF signaling proteins in ES samples taken before and after chemotherapy, and speculate about the optimal way of treating ES patients in the future. Tumor material (36 initial biopsies and 24 resection specimens after neoadjuvant chemotherapy) and follow-up data of 41 patients treated for ES at the Radboud University Nijmegen Medical Centre were analyzed. Immunohistochemical staining was done for IGF1, IGF2, IGFBP3, IGF-1R, phosphorylated AKT (pAKT), phosphorylated mTOR (pmTOR), and phosphorylated ERK (pERK), and staining intensity was scored semiquantitatively. Change of protein expression during treatment, correlations of effector cascade signaling, and influence on progression-free (PFS) and overall survival (OS) were tested. All potential targets were widely expressed at both time points. After chemotherapy, pmTOR expression decreased significantly (p = 0.021) while IGFBP3 increased (p = 0.005). Correlations exist between IGF-1R and pERK (ρ = 0.286, p = 0.031), IGF-1R and pAKT (ρ = 0.269, p = 0.045), pAKT and pERK (ρ = 0.460, p = 0.000), and pERK and pmTOR (ρ = 0.273, p = 0.038). In therapy-naive samples, combined expression of pAKT, pmTOR, and pERK predicted worse PFS (median, 11 vs. 32 months; p = 0.039) and OS (median, 18 vs. 83 months; p = 0.023). We identify an unfavorable prognostic group of ES patients with widely activated IGF-effector cascades, demonstrate cooperation between the different downstream pathways, and show how expression of IGF-related proteins may change after exposure to chemotherapy. These findings should be taken into account when designing future trials with IGF-targeting agents. We suggest the prospective exploration of chemotherapy and multi-target tyrosine kinase inhibitors in the first-line setting.

Targeted therapy for Ewing's sarcoma: significance of heterogeneity.

BACKGROUND: Survival in Ewing's sarcoma (ES) is limited. Experience with insulin-like growth factor targeting drugs, which require specific molecular tumour alterations, herald a major breakthrough. We screened for tumour heterogeneity within patients by DNA quantification. MATERIALS AND METHODS: DNA image cytometry (IC) was performed on 41 samples from 21 patients, evaluating if ploidy state remained constant over time and between different lesions within patients and the prognostic value of ploidy was assessed. RESULTS: DNA content varied over time and different ploidy states were found to coexist at a single timepoint. Non-diploid DNA content was associated with shorter overall survival (median, 19 vs. 84 months, p=0.047). CONCLUSION: We encountered a change and heterogeneity of ploidy state. This implies that screening for targets on a single tumour sample is insufficient and may lead to under- or overtreatment. The fact that non-diploid DNA content was associated with an adverse outcome confirms that this technique discriminates biologically different tumour clones.

Promises and challenges of positron emission tomography for assessment of sarcoma in daily clinical practice.

A correct histological diagnosis, careful staging and detection of tumour response to treatment are all crucial in the management of sarcomas. Imaging is important in all of these stages. Sarcomas have distinct biological and treatment-related features posing challenges for imaging. For example, size measurements may not adequately reflect response rates. Techniques which can measure tissue function rather than generate merely anatomical data such as positron emission tomography (PET) are rapidly gaining interest. We discuss the importance of imaging in different stages of patient management, emphasising the unique characteristics of sarcoma. Furthermore, we discuss the potential of PET for the various indications, focussing on therapy evaluation.