Even when retrospective statistical identification for a biomarker has been achieved, the ultimate proof of its usefulness in the clinic still requires prospective evidence. Our prospective study aims to validate the prognosis value of the CINSARC signature in a prospective way. Moreover, the neoadjuvant setting is an ideal one to identify molecular predictive factors of sensitivity to chemotherapy by correlating tumor response with genetic profile of STS. Moreover, molecular profiling of treatment-refractory tumor cells may reveal alterations that are associated with drug resistance, metastatic recurrence and disease progression. The identifications of such factors in the neoadjuvant setting may help to improve the management of STS patients in the adjuvant and metastatic settings