This randomized phase II/III trial studies how well pazopanib hydrochloride, combination
chemotherapy, and radiation therapy work and compares it to radiation therapy alone or in
combination with pazopanib hydrochloride or combination chemotherapy in treating patients
with newly diagnosed non-rhabdomyosarcoma soft tissue sarcomas that can be removed by
surgery. Radiation therapy uses high energy x-rays to kill tumor cells. Drugs used in
chemotherapy, such as ifosfamide and doxorubicin hydrochloride, work in different ways to
stop the growth of tumor cells, either by killing the cells, by stopping them from dividing,
or by stopping them from spreading. Pazopanib hydrochloride may stop the growth of tumor
cells by blocking some of the enzymes needed for cell growth. It is not yet known whether
radiation therapy works better when given with or without combination chemotherapy and/or
pazopanib hydrochloride in treating patients with non-rhabdomyosarcoma soft tissue sarcomas.