Immunotherapy provides an additional treatment option for this "metastasis-loving" tumor

Both sarcoma and cancer are classified as malignant tumors, with the primary distinction arising from their different origins and nomenclatures. Malignant tumors originating from epithelial tissue are termed "cancer". For instance, those originating from the skin, nasopharynx, esophagus, and lungs and bronchi are designated as XXX cancer. Conversely, malignant tumors arising from mesenchymal tissue such as bone, fibrous tissue, or lymphatic tissue are referred to as sarcoma. Common examples include osteosarcoma, chondrosarcoma, and fibrosarcoma. The difference between sarcoma and cancer also manifests in prognosis, with the incidence rate of sarcoma significantly lower than that of cancer. Most sarcomas are more difficult to detect and address early on. Additionally, as malignant tumors, sarcomas are less thoroughly studied due to the limited sample size, and treatment options are relatively fewer compared to many common cancers.

Cancer primarily originates from epithelial tissue and is prone to metastasize through the underlying lymphatic vessels; whereas osteosarcoma originates from bone tissue with abundant blood supply, making it more likely to metastasize via the bloodstream, with the most common metastatic site being the lungs, as the lungs collect most of the blood from the body for gas exchange. Sarcomas that metastasize via the bloodstream tend to be more prone to further metastasis.