Retroperitoneal and pelvic sarcoma

"Scientific evidence shows that the quality of surgery can reduce the recurrence rate by up to 44%."


What is retroperitoneal and pelvic sarcoma?

Retroperitoneal and pelvic sarcomas are a rare group of soft tissue tumors, originating in the posterior part of the abdominal cavity and pelvis, which require an interdisciplinary team for their correct medical approach. 

When these sarcomas are localized, surgery is the axis around which the whole treatment revolves. The quality of the first surgical intervention performed after diagnosis will determine the evolution and the best possible survival rates, as well as the reduction of recurrences.

It is therefore essential to have an interdisciplinary team - made up of general and digestive surgeons, urologists, medical oncologists, radiation oncologists, vascular surgeons, anatomopathologists, traumatologists, interventional radiologists, nuclear medicine specialists, radiologists and nurses - with the experience to carry out each intervention correctly. Multidisciplinarity is the basis of the work of the professionals at the Clínica Universidad de Navarra, who know how to put the patient at the center of their activity. 


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What are the symptoms of sarcoma
located in the retroperitoneum or pelvis?

This type of sarcoma can be difficult to diagnose in its initial stages due to its location and the absence of specific symptoms, despite its large size. Many times, its discovery is an incidental finding. 

Patients may experience general symptoms such as abdominal or lower back pain, which are often mistakenly attributed to more common causes. As the sarcoma grows, it may cause a palpable mass in the abdomen and more obvious symptoms, such as unexplained weight loss, fatigue and fever. In advanced cases, it can affect adjacent organs, leading to additional symptoms.

The most common symptoms are:

  • Large palpable mass.
  • Abdominal or lumbar pain.
  • Tiredness.
  • Weight loss.

Do you have any of these symptoms?

May have a retroperitoneal or pelvic sarcoma

What are the causes of these sarcomas?

The exact causes of retroperitoneal and pelvic sarcomas are largely unknown, but several risk factors and circumstances have been identified that may contribute to their development.

Some sarcomas are associated with inherited genetic syndromes. For example, Li-Fraumeni disease, Werner syndrome, and neurofibromatosis type 1 (NF1) have been linked to an increased risk of developing sarcomas.

Types of retroperitoneal and pelvic sarcomas

The most frequent retroperitoneal sarcomas are liposarcomas which, depending on their histological diagnosis, can be differentiated or dedifferentiated.

The second most common type are rhabdomyosarcomas. They are known for their tendency to recur.

Scientific evidence shows that the quality of surgery can reduce the recurrence rate by up to 44%.

How is retroperitoneal and pelvic sarcoma diagnosed?

Accurate diagnosis of these sarcomas is crucial and is made by a combination of imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), and sometimes biopsy.

Preoperative radiological assessment by expert radiologists, using CT, MRI and sometimes PET, is essential to determine the surgical strategy. Preoperative biopsies by interventional radiologists are also a priority, as they help to determine the histology and the molecular and genetic characteristics of each tumor. The surgical approach for each patient will depend on the biology of each tumor. 

How is retroperitoneal and pelvic sarcoma treated?

Sarcomas in the retroperitoneum or pelvis should be treated in specialized units to achieve the best chance of success.

When these sarcomas are localized, surgery is the mainstay of treatment. The quality of the first surgical intervention performed after diagnosis will determine the evolution and the best possible survival rates, as well as the reduction of recurrences.

Because of their location (close to vital structures such as the aorta and vena cava), their size (sometimes more than 20 centimeters) and the need to obtain tumor-free margins, surgery for retroperitoneal sarcomas is usually complex. In many cases it is necessary to remove affected organs, such as the kidney, colon, psoas muscle, peritoneum, spleen, pancreas....

Some retroperitoneal sarcomas also benefit from preoperative radiotherapy to reduce recurrence. In addition, in the approach to this complex pathology, resources are offered to perform intraoperative radiotherapy that can improve the results.

The role of neoadjuvant chemotherapy prior to surgery is currently being investigated to facilitate surgery and improve cure rates.  

In those cases where the disease is not localized in the abdominal cavity, or where despite previous surgical treatment there is a recurrence of the disease, the role of chemotherapy could be important. In-depth knowledge of each histological subtype and its behavior is key to the choice of the best treatment.

In addition, in cases where the usual treatment options are not effective, having a Clinical Trials Unit with a wide variety of clinical trials could help to find other therapeutic options.

Proton therapy for cancer

Proton therapy is the most precise external radiotherapy modality, providing better distribution of radiation dose and therefore less irradiation of healthy tissues.

The Proton Therapy Unit of the Cancer Center Clínica Universidad de Navarra in its Madrid headquarters is the most advanced in Europe and the first in a Cancer Center, with all its healthcare, academic and research support.

Where do we treat it?


The Sarcomas Area of the
Cancer Center Clínica Universidad de Navarra

The Sarcomas Area is one of the most prestigious centers in the world in this field. Its team of professionals is internationally recognized in this field of medicine.

In our center, all diagnostic tests (including biopsy) can be performed, usually in less than 24 hours. We also have teams of highly trained professionals in intra-arterial chemotherapy, brachytherapy, isolated limb perfusion, etc.

Imagen de la fachada de consultas de la sede en Pamplona de la Clínica Universidad de Navarra

Why at the Clinica?

  • Integral evaluation of the patient.
  • Cutting edge technology.
  • Expert professionals who are an international reference.

Our team of professionals