Palliative Treatment Options Scare for Retroperitoneal Sarcomas

Patients with retroperitoneal sarcomas who are unable to obtain complete resection after initial resection are left with few treatment options for palliative therapy, according to the results of a study published recently in Annals of Oncology.

Within retroperitoneal sarcomas, advanced disease includes unresectable locoregional disease, abdominal sarcomatosis, and distant metastasis. Although a second surgical resection is an option for patients, the likelihood of a complete resection decreases with relapses, according to the researchers led by Maud Toulmonde, MD, of the Institut Bergonié, France.

“The two major drugs used in advanced soft-tissue sarcomas are doxorubicin and ifosfamide. Trabectedin has also shown activity, especially in liposarcomas and leiomyosarcomas,” Toulmonde and colleagues wrote. “However, apart from these drugs, options are limited and inclusion in a clinical trial is the best choice. Until recently, very few phase II clinical trials for new drugs in advanced soft-tissue sarcomas have focused on specific histological subtypes and retrospective studies on this topic are rare and small.”

To further understand the patterns of palliative therapy within retroperitoneal sarcomas, the researchers conducted a retrospective analysis of 10 years of data on adult patients with the disease. The study included 586 patients, of whom 51% received palliative chemotherapy (176 with metastatic disease and 123 with locoregional evolution) and 8.5% underwent palliative surgery.

Of the 299 patients undergoing palliative chemotherapy, half had treatment with a single chemotherapy, most often an anthracycline (75%). Thirty patients underwent additional maintenance chemotherapy after their first-line treatment.

“Response rate with anthracyclines was only 15% for liposarcomas, and only one response was observed for dedifferentiated liposarcoma without anthracyclines,” the researchers wrote. “These results are concordant with two smaller studies, which evaluated chemotherapy for advanced well-differentiated/dedifferentiated liposarcoma, and support the poor sensitivity of liposarcoma to conventional chemotherapy.”

The researchers assessed response in 255 (85%) patients and found that 27% had progressive disease, 57% had stable disease, 14.5% had partial disease, and 1.5% had a complete response. Patients had a median of 5.9 months from initiation of palliative treatment until disease progression and a median overall survival of 15.8 months.

“We did not find any benefit in survival for palliative surgery,” the researchers wrote. “However, we cannot exclude that this treatment may have a symptomatic role and therefore an impact on quality of life, notwithstanding its potential morbidity.”

Currently, based on the modest benefit of palliative surgery and chemotherapy, best supportive care should be considered in patients with a poor performance status, the researchers said.