Long-term results of surgical treatment of patients with retroperitoneal leiomyosarcoma

Relevance. Leiomyosarcomas is highly aggressive tumors with poor prognosis. Surgical resection is a standard treatment approach. However, data of long-term results of surgical treatment are lacking due to rarity of retroperitoneal form of leiomyosarcoma. Prognostic significance of tumor size, grade and recurrence type remains unclear as well.

Aim. To analyze results of surgical treatment of patients with retroperitoneal leiomyosarcoma and to define prognostic factors which are associated with disease-free and overall survival.

Materials and methods. The study included patients with primary retroperitoneal leiomyosarcomas who have received surgical or combined treatment between January 2003 and April 2019 at Blokhin National Medical Research Centre of Oncology. Short- and long-term clinical outcomes of surgical and combined treatment as well as recurrence rate, pattern of recurrence and morphological features were analyzed in order to define prognostic factors of disease-free and overall survival.

Results. The study included 64 patients with primary retroperitoneal leiomyosarcomas – 12 men (18%) and 52 women (82%). Median tumor size was 10.5±5.0 cm. Most of the operations (93.3%) were done by open approach. Combined resections were performed in 62.5% of cases (n=40), vascular resections – in 17.2% cases (n=11). Radical (R0) resections were performed in 54 cases (85.9%). Postoperative morbidity and mortality rate were 39% and 0% respectively. Adjuvant chemotherapy or radiotherapy received 21 (35%) patients and 1 (1.7%) patient respectively. 46 (71.9%) patients had a disease recurrence. Recurrence type (local recurrence/distant metastases) did not influence overall survival (р=0.655). Median disease-free survival was 27 months (95% CI 10–43.9). 3-year and 5-year disease-free survival was 43% and 21% respectively. Median overall survival was 79 months (95% CI 49–108.9). 3-year and 5-year overall survival was 73% and 59% respectively. Among patients grade 2 and grade 3 tumors median disease-free survival was 49 vs. 18 months (р=0.271), median overall survival – 146 vs. 58 months (р=0.018). There were no statistically significant differences in rate of radical resections among patients with different tumor location (р=0.804) or its size (р=0,520). Patients, who have undergone radical (R0) resection, had better overall (р=0.028) and disease-free survival (р<0.001). Adjuvant chemotherapy was not associated lower risk of disease recurrence (p=0.976), type of recurrence (р=0.981) and lower overall survival (р=0.284).

Conclusion. Tumor grade and radical resection are the most important prognostic factors in patients with retroperitoneal leiomyosarcoma. In our study, tumor size was not correlated with long-term results and possibility of radical resection.