Unlike epithelial cancers that are both more homogeneous and easily categorized by their respective tissues of origin (e. g. , breast or lung cancer), sarcomas represent a diverse class of molecularly distinct bone and soft-tissue mesenchymal neoplasms of more than 50 subtypes. This diversity, as well as the relative rarity of sarcomas as a whole, has presented challenges in conducting prospective randomized clinical trials to assess the value of neoadjuvant chemotherapy for any given subtype. Most clinical trials and meta-analyses have neglected the phenotypic and molecular heterogeneity differentiating one sarcoma subtype from another in favor of a simplified grouping that ensures timely trial completion. As the success of treating gastrointestinal stromal tumors (GISTs) with imatinib demonstrates, a decision to provide neoadjuvant chemotherapy must take into consideration both the subtype being treated and the effect such treatment would be expected to exert upon that subtype. VSports手机版.