Metabolic Profile And Neoadjuvant Chemotherapy Sensitivity In High-Grade Bone Sarcoma.

e22506 Background: Neoadjuvant chemotherapy with intercalated surgery is the standard of care for resectable high-grade bone sarcoma (BS) but identification of biomarkers for chemosensitivity prediction is still needed. Methods: We recruited 121 pts with new primary localized or metastatic BS, measured fasting blood glucose and insulin, body mass index (BMI). The HOMA-IR (Homeostasis Model Assessment) score ((Glucose (mmol/l) x Insulin) / 22.5), which has been proven to reliably detect insulin resistance was calculated, and patients with HOMA-IR > 2.6 were considered as insulin resistant (IR). We collected characteristics usually associated with insulin resistance (IR): age, obesity, diabetes, dyslipidemia and hypertension. Results: Out of 121 pts, 48 (40%) were IR: HOMA-IR > 2.6. Thirty IR patients (62%) had no cardiovascular risk factor. In univariate analysis, IR was associated with obesity (BMI > 30 kg/m2)(23% vs 3%, p = 0.0013), but not with age (median 38.4 vs 43.3 years, p = 0.15). IR was more prevalent in Ewing sarcoma (12/21; 57%) and chondrosarcoma (7/13; 54%) followed by osteosarcoma (25/61; 41%) and other rare bone sarcomas (4/26; 15.3%)(p = 0.037). After preoperative chemotherapy and surgery of Ewing tumor and osteosarcoma, pathologic tumor necrosis was higher in IR pts (85.8 vs 69.3%, p = 0.012). Using multivariate linear regression models, IR was independently associated with pathologic tumor necrosis (p = 0.042) but not with obesity (p = 0.55). Conclusions: Our results suggest that tumor-induced metabolic profile may help to discriminate best candidates for preoperative chemotherapy in high-grade bone sarcomas. Further studies are needed to confirm and explain these results.