LAUSR

INTRODUCTION AND OBJECTIVE: Liposarcoma is one of the most common subtypes of soft tissue sarcoma. The tumor often develops in the lower extremities and the retroperitoneal or paratesticular region. The standard treatment for localized liposarcoma is surgical resection with negative margins. However, there are no guidelines for paratesticular liposarcoma due to its rarity. The effects of high inguinal orchiectomy and adjuvant radiation therapy (RT) have not yet been quantitatively evaluated. METHODS: A systematic Medline and Google search was performed to identify articles describing localized paratesticular liposarcoma published between 1979 and 2018 in English. The final cohort included 261 patients in 173 articles. The starting point was the time of surgical treatment, and the endpoint was the time of recurrence, local recurrence or distant metastasis. RESULTS: The average age was 59.9 years (range 15-89), and the average tumor size was 11.0 cm (range 0.4-55). One hundred and seventy-three patients underwent high inguinal orchiectomy, and 28 underwent only tumor resection. Based on the Kaplan-Meier curves, recurrence-free survival rates were significantly higher in those who underwent high inguinal orchiectomy than in those who underwent tumorectomy (p<0.001) (Figure 1a). Moreover, those with microscopic positive margins had a higher risk of recurrence than those with negative margins (p<0.001). In contrast, adjuvant RT after resection had no significant effect on recurrence-free survival, even in subgroup analysis of patients with positive margins. Regarding the pathological subtypes, dedifferentiated, pleomorphic and round cell liposarcoma had a higher risk of recurrence than well-differentiated or myxoid liposarcoma (Figure 1b). In the multivariate analysis, high inguinal orchiectomy greatly affected recurrence-free survival (hazard ratio 0.04, p<0.001). Furthermore, the tumor size (hazard ratio 1.11, p[0.04), and dedifferentiated and round cell subtypes (hazard ratio 30.8, p[0.002 and hazard ratio 29.7, p[0.02, respectively) are independent risk factors for recurrence. CONCLUSIONS: Our study revealed complete resection with high inguinal orchiectomy to be a satisfactory surgical approach for paratesticular liposarcoma. However, the effects of adjuvant RT remain unclear. Source of Funding: None