Doxorubicin vs. Trabectedin Plus Doxorubicin in Non Operable and/or Metastatic STS

Inclusion Criteria:

* The patient must sign voluntarily the informed consent from before any study test is conducted that is not part of routine patient care, with the knowledge that he/she can abandon the study at any time without this affecting his/her previous care.
* Aged between 18 and 70.
* Pathological diagnosis of non operable and/or metastatic soft tissue sarcoma.
* The following histological subtypes can be included:

  * Undifferentiated pleomorphic sarcoma (previously,malignant fibrous istiocytoma)
  * Leiomyosarcoma
  * Angiosarcoma
  * Liposarcoma
  * Synovial sarcoma
  * Fibrosarcoma
  * Hemangiopericytoma
  * Neurofibrosarcoma
  * Mixofibrosarcoma
  * Unclassified sarcoma
* Measurable disease, according to RECIST criteria
* Performance status 0-2 Eastern Cooperative Oncology Group(ECOG).
* Adequate bone marrow function (hemoglobin \> 10 g/dL, leukocytes ≥ 3.000/mm3, neutrophils ≥1.500/mm3, platelets ≥ 100.000/mm3). Patients with plasma creatinine ≤ 1,6 mg/dL, transaminases ≤2.5 times the upper limit of normal (ULN), total bilirubin ≤ upper limit of normal (ULN), CPK ≤ 2.5 times upper limit of normal (ULN), alkaline phosphatase ≤ 2.5 times the upper limit of normal (ULN) are acceptable. If the increase of alkaline phosphatase is \> 2.5 times the upper limit of normal (ULN), then the alkaline phosphatase liver fraction and/or 5' nucleotidase and/or GGT must be ≤ upper limit of normal (ULN).
* Men or women of child bearing potential should be using an effective method of contraception before entry into the study and throughout the same and for 6 months after ending the study. Women of childbearing potential must have a negative urine pregnancy test before study entry.
* Normal cardiac function with a Left ventricular ejection fraction (LVEF) ≥ 50% by echocardiogram or Multiple Uptake Gated Acquisition Scan (MUGA).

Exclusion Criteria:

* Previous chemotherapy treatment.
* Previous radiotherapy involving the only localization(s) of measurable tumoral disease.
* Performance status\> 2 Eastern Cooperative Oncology Group(ECOG).
* Central Nervous System (CNS) metastases.
* Plasma bilirubin \> upper limit of normal(ULN).
* Creatinine \> 1.6 mg/dL.
* History of other neoplastic disease with the exception of basalioma or in situ cervical cancer adequately treated.
* Significant cardiovascular disease (for example, dyspnea \> 2 NYHA)
* Significant systemic diseases grade 3 or higher on the NCI-CTC version 3.0 scale, that limit patient availability, or according to investigator judgment may contribute significantly to treatment toxicity.
* Uncontrolled bacterial, mycotic or viral infections.
* Women who are pregnant or breast-feeding
* Psychological, familial, social or geographic circumstances that limit the patient's ability to comply with the protocol or informed consent.
* Patients participating in another clinical trial or receiving any other investigational product.
* Patients who had participated in another clinical trial and/or had received any other investigational product in the last 30 days prior to inclusion.
* The following histologic subtypes are excluded:

  * Rhabdomyosarcoma
  * Ewing's family of tumors
  * Desmoplastic small round cell tumor
  * Clear cell sarcoma
  * Alveolar sarcoma