GENETIC POLYMORPHISM OF RETROPERITONEAL MYXOID LIPOSARCOMA

[Active surgical approach for retroperitoneal liposarcoma]

OBJECTIVE

To assess the influence of active surgical approach on the long-term postoperative outcomes in patients with retroperitoneal liposarcoma.

MATERIAL AND METHODS

A retrospective study included 190 patients with retroperitoneal liposarcoma. The effect of malignancy grade, adjuvant chemotherapy, number of separate tumor nodes in primary neoplasm and the first relapse, as well as the number of previous total resections on survival rate was analyzed.

RESULTS

Overall and relapse-free survival is significantly worse in patients with high-grade retroperitoneal liposarcoma (G2-3) compared to low-grade (G1) tumor (p_log-rank=0.000). Multifocal growth of primary tumor (p=0.869; p_log-rank=0.607) and multiple (>1) separately located nodes in abdominal cavity and retroperitoneal space at the first relapse (p_log-rank=0.158 to 0.985) did not significantly impair prognosis after total resection of all types of retroperitoneal liposarcoma regardless malignancy grade. Adjuvant chemotherapy does not significantly improve relapse-free survival. Overall survival was significantly higher in patients who underwent ≥4 previous total resections compared to 1 surgical treatment for all types of retroperitoneal liposarcoma regardless malignancy grade (p=0.000; p_log-rank=0.001).

CONCLUSION

The only potentially radical treatment for patients with retroperitoneal liposarcoma is surgery. We reported the advantages of active surgical approach for improvement of long-term outcomes in patients with retroperitoneal liposarcoma.

[Differentiated surgical approach for retroperitoneal non-organ liposarcoma]

OBJECTIVE

To determine the indications for combined and organ-sparing surgery depending on malignancy grade of retroperitoneal liposarcoma.

MATERIAL AND METHODS

A retrospective study included 190 patients with retroperitoneal liposarcoma. Influence of malignancy grade, lesion of adjacent organs and resection/excision of adjacent organs on the overall and recurrence-free survival was studied. Moreover, we analyzed the issue of kidney-sparing surgery and nephrectomy.

RESULTS

Overall and recurrence-free survival were significantly worse in high grade (G2-3) compared to low-grade tumors (G1) (p=0.0001; log-rank test). Visceral invasion was revealed in 23% of patients with low-grade (G1) tumors and 53% of patients with high-grade (G2-3) neoplasms. Visceral invasion significantly impairs overall and recurrence-free survival in both low grade (G1) and high-grade (G2-3) tumors (p=0.0001; log-rank test). In case of low grade (G1) retroperitoneal liposarcoma, overall and recurrence-free survival was similar after combined surgery without histologically confirmed visceral invasion of liposarcoma and organ-sparing surgery (p=0.006; p=0.053; log-rank test). On the contrary, high grade (G2-3) tumor was followed by significantly better overall and recurrence-free survival after combined surgery without histologically confirmed visceral invasion compared to organ-sparing surgery (p=0.006; p=0.053; log-rank test). Recurrence-free survival was similar after kidney-sparing surgery and nephrectomy among patients with low-grade (G1) tumor (p=0.456; log-rank test). In case of high-grade retroperitoneal liposarcoma (G2-3), recurrence-free survival was significantly worse after kidney-sparing surgery compared to nephrectomy (p=0.039; log-rank test).

CONCLUSION

Surgery is the only potentially radical treatment of patients with retroperitoneal liposarcoma. Organ-sparing including kidney-sparing surgery is advisable for low-grade liposarcoma (G1). On the contrary, organ-sparing surgery impairs long-term results and prognosis in patients with high-grade tumors (G2-3). Combined operations including nephrectomy are justified for high-grade retroperitoneal liposarcoma (G2-3).