Retroperitoneal sarcoma is a relatively rare type of cancer, accounting for just 15 percent of all soft tissue sarcomas and less than 1 percent of diagnosed cancers. This type of cancer grows in cells called mesenchymal cells in several types of tissue. There are several treatments available for retroperitoneal sarcoma, but the success of these treatments is variable because of the wide range of histologic cancer types that exist. This type of cancer can grow in multiple cell types, including fat, muscle, connective tissue and nerve tissue, and each type responds differently to treatment.
The overall rarity of this disease means that each subtype is even more rare. For this reason, there is little current data regarding symptoms, prognosis and treatment of this type of cancer. Most studies that exist have combined data encompassing several decades of treatment of patients with different cancer subtypes, and the results of such studies are highly variable.
Just one symptom presents as a common feature of retroperitoneal sarcoma. This is the presence of a mass in the abdomen. This sometimes is accompanied by other symptoms, but the mass often is the only symptom. When other symptoms do manifest, these can include gastrointestinal bleeding, gastrointestinal obstruction and pain or swelling in the lower abdomen.
Diagnosis of this cancer typically is made on the basis of diagnostic imaging tests as well as blood tests and other examinations. After cancer has been identified, a biopsy must be carried out to determine the cancer’s histologic type. This term refers to the type of cell that has become malignant, as well as the new cancer-associated proteins that the newly malignant cells produce or express on their surfaces. The histologic subtype of the cancer often influences treatment decisions and prognosis.
The three main treatments for retroperitoneal sarcoma are surgery, chemotherapy and radiation therapy. When the cancer is noninvasive and not recurrent, the treatment of choice generally is surgery. During the procedure, the surgeon removes as much of the tumor mass as possible. Surgery is then followed up with chemotherapy or radiation therapy to kill any cancer cells that remain. For some sarcoma types, this additional post-surgery treatment can improve the outcome of treatment and improve the patient's prognosis.
Successful treatment for this type of cancer is uncommon, largely because the disease often is diagnosed late in its progression. If there is a recurrence after initial treatment, it most likely will happen within five years. Metastasis, or spread of the cancer, most often occurs in the liver or lungs. When the disease is recurrent or metastatic, the chances of successful surgery greatly diminish.