Navtemadlin and Radiation Therapy in Treating Patients With Soft Tissue Sarcoma

Inclusion Criteria: * PRIOR TO STEP 1 REGISTRATION INCLUSION CRITERIA * Patients with pathologically proven diagnosis of grade 2-3 (intermediate or high grade) soft tissue sarcoma with size \>= 5 cm are eligible to enroll if the intention to treat is curative. They must have sufficient tissue to submit to central laboratory for review as well as for NGS sequencing (see submission requirement). Biopsy should be obtained within 180 days prior to registration. Availability of tumor tissue is mandatory for study eligibility. The patient must have consented to provide archived formalin-fixed paraffin-embedded tumor tissue for future central pathology review, NGS sequencing and/or translational research * Appropriate stage for study entry based on the following diagnostic workup: * History/physical examination within 30 days prior to registration; * Imaging of the primary tumor by MRI and/or computed tomography (CT) with or without contrast and/or positron emission tomography (PET)/CT within 30 days prior to registration; * Staging workup evaluated by chest CT and/or PET/CT showing no distant metastasis within 30 days prior to registration * There is a planned definitive surgical resection of the primary tumor * Eastern Cooperative Oncology Group (ECOG) or Zubrod performance status of 0-1 within 30 days prior to registration * Absolute neutrophil count \>= 1500/uL (within 30 days prior to registration) * Platelet count \>= 100,000/uL (within 30 days prior to registration) *…