Madrid, 11 December 2023. - Retroperitoneal sarcoma is a type of cancer that originates in the soft tissue of the retroperitoneal area, the space located at the bottom of the abdomen, between the rear of the abdominal organs and the spinal column. These soft tissues can include muscles, nerves, fat or blood vessels. Retroperitoneal sarcoma is a rare form of cancer and the tumours that develop in this area can be difficult to treat due to both their location and behaviour. The average annual incidence of soft tissue sarcomas is between 3-4 cases per 100,000 population. 15% occur in the retroperitoneum1.
Because they are often diagnosed at an advanced stage and surgical intervention can be complicated, retroperitoneal sarcomas generally require treatment in a specialist unit with highly qualified medical personnel. For this reason, MD Anderson Cancer Center Madrid has recently opened its Multidisciplinary Retroperitoneal Sarcoma Unit Sarcoma Retroperitoneal, making it one of the few centres in Spain able to offer this specialist care. Leading the unit are Dr. Ricardo Cubedo, Head of Sarcomas and Hereditary Cancer at the Medical Oncology Department, and Dr. Irene López Rojo, MD Anderson Madrid surgical oncologist and member of the Spanish Association of Surgeons (AEC).where she acts as spokesperson for the Mesenchymal Tumours and Sarcomas Section. Dr. López Rojo reiterates that, “retroperitoneal sarcoma is a rare and difficult to treat tumour that requires a multidisciplinary approach”.
The survival rates after five years for retroperitoneal sarcoma vary widely, but, in general, are around 50% to 70% according to scientific studies. The prognosis for retroperitoneal sarcoma may differ significantly from one patient to another and depends on various factors such as histological type, the extension and spread of the tumour and the possibility of performing a complete surgical excision. “Retroperitoneal sarcoma is a diverse disease, and each case is unique and should be treated in an individual manner,” explained Cubedo. As such, the doctor warned that that the diagnosis for this type of tumour generally involves a series of steps which include clinical assessment, image testing and, in the majority of cases, a biopsy to obtain a sample of the tumour to identify its histological subtype. “The latter help us to understand what type of tumour we are dealing with before operating and help us plan the surgery required on the patient in a more personalised manner directed at their particular tumour type”, clarified López Rojo, co-director of the new Unit.
Non-specific symptoms and late diagnosis
Sometimes the symptoms of retroperitoneal sarcoma are not evident in the early stages, which can result in the tumour only being diagnosed when it has grown sufficiently to cause discomfort or press against the surrounding organs. “We often encounter patients of between 30-60 years of age with a relatively late diagnosis. These are patients with an increased abdominal girth that may be interpreted as obesity or a hernia, given that there are no clear symptoms”, insisted the specialist, who went on to clarify that often the diagnosis arrives when it is already evident and discovered with imaging tests.
The patient may experience abdominal or lower back pain or inflammation and occasionally swelling in a limb, but the most common sign, he stressed, is an increase in abdominal girth. “We have even seen tumours of 10-20 kilos. These cancers, as can occur with other types of tumour, consume so much that patients can sometimes suffer inexplicable weight loss. In such cases in may be clear that the patients are losing weight around the arms, legs and face, yet continue to show an increased volume around the abdominal region. This is a clear symptom”, added Doctor Cubedo.
The initial surgery will be a determining factor in the prognosis for the patient
The treatment of retroperitoneal sarcoma involves a multidisciplinary approach that may include surgery, radiotherapy and chemotherapy. One of the most influential factors in the prognosis and survival of the patient is ensuring that the initial surgery is performed accurately, excising the visible tumour with adequate oncological security margins. However, in some tumour types this treatment will require additional chemotherapy or radiotherapy to optimise the results. To both facilitate surgery and minimise the possibility of residual tumour, it may be advisable to administer preoperative chemotherapy and radiotherapy.
Due to the rarity of retroperitoneal sarcoma and the complexity associated with its treatment, doctors recommend that patients seek the attention of a specialist medical team for these tumours in order to receive comprehensive and personalised care. “This is a technically complex surgery as these tumours are often surrounded by vital structures such as the aorta, the pancreas, the kidneys, the vena cava etc. This is why it is important to attend a centre with experience in sarcomas, given that the initial surgery may determine the prognosis for the patient”, indicated López Rojo.
The challenges with retroperitoneal sarcoma
The treatment of retroperitoneal sarcoma presents a number of challenges due to the anatomical location of the tumour, the diversity of subtypes and the potential difficulty in achieving a complete surgical excision.
“In addition to the surgical complexity and obtaining adequate margins, the challenge consists in preventing the recurrence of the tumour. In the event that it reappears, the aim is to diagnose it quickly so that the surgeons can act and proceed to remove it again. We face these problems every day. The initial surgery is key to the prognosis of the patient, given that both chemotherapy and radiotherapy are frequently ineffective in these cases”, concluded Doctor Irene López Rojo.