Retroperitoneal cancer is a group of rare tumors that occur in the retroperitoneum, a location in the back of the abdomen, next to the kidneys. Retroperitoneal sarcomas grow slowly and can eventually reach the size of 20 to 30 centimeters.
Types of Retroperitonial Cancer
The two most common types of retroperitoneal cancer are liposarcoma (originating in fat) and leiomyosarcoma (originating in smooth muscle). Other less common types of retroperitoneal cancer are solitary fibrous tumor, pleomorphic sarcoma, malignant nerve sheath tumor, synovial sarcoma and Ewing’s sarcoma.
Liposarcoma is most common in middle-aged men between the ages of 50 and 65. Patients with liposarcoma can have slow growing tumors that don’t spread, or tumors that grow rapidly and aggressively spread and infiltrate other organs. The five subtypes of liposarcoma are well differentiated, dedifferentiated, myxoid, round cell and pleomorphic.
Leiomyosarcoma is a form of soft tissue sarcoma, a cancer with about 15,000 new cases diagnosed each year in the US. Soft tissue sarcoma can occur in both men and women and is more common in adults, than in children or adolescents. Leiomyosarcoma accounts for about seven to 11 percent of all cases of soft tissue sarcoma.
Cause and Risk Factors
At this time, the cause of liposarcoma is unclear. Liposarcoma forms when a fat cell mutates and begins to rapidly multiply and live when other healthy cells would die.
Risk factors of liposarcoma may include prior radiation, damage to the lymph system, family history of cancer, and long term exposure to certain toxic chemicals such as vinyl chloride.
The exact cause of leiomyosarcoma is currently unknown. Research suggests that abnormalities in DNA can lead to abnormal genetic changes and the growth of cancerous cells.
Risk factors of sarcoma include:
- Inherited syndromes such as hereditary retinoblastoma, Li-Fraumeni syndrome, familial adenomatous polyposis, neurofibromatosis, tuberous sclerosis and Werner syndrome.
- Chemical exposure to herbicides, arsenic and dioxin.
- Radiation exposure from previous radiation treatment.
Symptoms
Symptoms of liposarcoma include:
- Abdominal swelling
- Abdominal pain
- Feeling full sooner when eating
- Constipation
- Blood in stool
The symptoms of leiomyosarcoma will vary depending on the location, size and spread of the tumor. The early stages of this cancer may be asymptomatic.
Symptoms of leiomyosarcoma include:
- A noticeable lump or swelling
- Pain
- Weight loss
- Nausea
- Vomiting
Leiomyosarcoma tumors may cause bleeding in the gastrointestinal tract and lead to black, tarry, foul-smelling stools (melena), abdominal discomfort and even vomiting of blood (hematemesis).
Patients who notice any of these signs should immediately schedule an appointment with their doctor and request a CT scan, MRI, histopathology and or a blood test to screen for retroperitoneal cancer.
Treatment
At this time, surgery is the main treatment option for patients with retroperitoneal cancer. Because of how large the tumor is, it may touch, compress, displace or invade major organs and blood vessels. Surgery typically requires the efforts of multiple teams to carefully remove the tumors, multiple organs and even major blood vessels. As a result, surgery can last for eight hours or more and demand significant physical and mental energy.
Patients may also undergo radiation and or chemotherapy, but there is currently insufficient evidence to determine if these nonsurgical treatments are effective.
It is highly likely that the cancer will return and require additional surgery — usually more complex and with greater risk than the previous surgery.
