You can participate in this study if

• Histologically proven primary high risk leiomyosarcoma (LMS) or Liposarcoma (LPS) of retroperitoneal space or infra-peritoneal spaces of pelvis.
• LMS
• LPS
• Representative formalin fixed, paraffin embedded tumor blocks or unstained tissue slides must be available at baseline for histological central review.
• Unifocal tumor
• Absence of extension through the sciatic notch or across the diaphragm
• Resectable tumor: resectability is based on pre-operative imaging (CT-abdomen, potentially also with MRI) and has to be defined by the local treating sarcoma team.
• Tumor not previously treated (no previous surgery (excluding diagnostic biopsy), radiotherapy or systemic therapy)
• Patient must have radiologically measurable disease (RECIST 1.1), as confirmed by imaging within the 28 days prior to randomization. CT thorax abdomen pelvis with IV contrast is the preferred imaging modality. In case of any contra-indications (medical or regulatory), it is allowed to perform a non-contrast CT thorax + MRI abdomen & pelvis.
• WHO (World Health Organization) performance status ≤ 2
• Adequate haematological and organ function
• American Society of Anesthesiologist (ASA) score < 3
• Women of child bearing potential (WOCBP) must have a negative serum pregnancy test within 7 days prior to the first dose of study treatment or surgery.
• Patients of childbearing / reproductive potential should use highly effective birth control measures, as defined by the investigator, during the study treatment period and for at least 6 months after the last dose of treatment or date of surgery. A highly effective method of birth control is defined as a method which results in a low failure rate (i.e. less than 1% per year) when used consistently and correctly.
• Female subjects who are breast feeding should discontinue nursing prior to the first day of study treatment and until 6 months after the last study treatment.
• Before patient registration/randomization, written informed consent must be given according to ICH/GCP, and national/local regulations.

You cannot participate in this study if

• Sarcoma originated from bone structure, abdominal or gynecological viscera
• Metastatic disease
• Tumors with extension through the sciatic notch or across the diaphragm
• Hypersensitivity to doxorubicin, ifosfamide, dacarbazine or to any of their metabolites or to any of their excipients
• Persistent myelosuppression
• Myocardial infarction within the last 6 months
• Uncontrolled cardiac arrhythmia
• Previous treatment with maximum cumulative doses (450mg/m² Doxorubicin or equivalent 900mg/m² EpiADM) of doxorubicin, daunorubicin, epirubicin, idarubicin, and/or other anthracyclines and anthracenediones
• Active and uncontrolled infections
• Vaccination with live vaccines within 30 days prior to study entry
• Inflammation of the urinary bladder (interstitial cystitis) and/or obstructions of the urine flow.
• Other invasive malignancy within 5 years, with the exception of adequately treated non-melanoma skin cancer, localized cervical cancer, localized and presumably cured prostate cancer.
• Uncontrolled severe illness, infection,medical condition (including, uncontrolled diabetes or hypertension), other than the Primary LPS or LMS of the retroperitoneum.
• Female patients who are pregnant or breastfeeding or female and male patients of reproductive potential who are not willing to employ effective birth control method.