What is your approach to adjuvant therapy for a fully resected, isolated retroperitoneal high grade sarcoma?

Middle aged woman s/p remote hysterectomy for benign indications >20 years ago, isolated retroperitoneal 10 cm mass, fully excised, high grade leiomyosarcoma. Does it change your recommendations if the tumor was morcellated in a bag and removed laparoscopically, with negative biopsies of resection bed?