This is a multicenter, randomized, open label phase lll trial to assess whether preoperative chemotherapy, as an adjunct to curative-intent surgery, improves the prognosis of high risk DDLPS (dedifferentiated Liposarcoma) and LMS (Leiomyosarcoma) patients as measured by disease free survival.

After confirmation of eligibility criteria, patients will be randomized to either the standard arm or experimental arm.

This single arm study is designed to demonstrate the feasibility of a radically different approach for an exceptionally high-risk subset of MES with widely metastatic disease (WMES). We incorporate the use of evolutionary principles that apply to species and population dynamics as related to adaptation and extinction to populations of cancer cells that similarly adapt and that we are attempting to make extinct, resulting in a cure for the patient. Such principles include an initial intense first strike to deplete the bulk of the cancer cells, followed by a series of sequential second strikes towards eliminating residual, resistant populations, followed by a prolonged period of maintenance chemotherapy to eliminate any remnant cells, using agents generally regarded to be active against newly diagnosed ES.