Optimal surgical treatment for paratesticular leiomyosarcoma: retrospective analysis of 217 reported cases

Background Paratesticular leiomyosarcoma (LMS) is a rare tumor. Conventionally, tumor resection by high inguinal orchiectomy is performed as the preferred treatment approach for paratesticular sarcoma. On the other hand, testis-sparing surgery has recently attracted attention as a less-invasive treatment option for paratesticular sarcoma. However, the prognostic predictors and optimal treatment strategy for paratesticular LMS remain unclear because of its rarity. In this study, we systematically reviewed previously reported cases of paratesticular LMS to evaluate the prognostic factors and establish the optimal treatment strategy. Methods A systematic search of Medline, Web of Science, Embase, and Google was performed to find articles describing localized paratesticular LMS published between 1971 and 2020 in English. The final cohort included 217 patients in 167 articles. The starting point of this study was the time of definitive surgical treatment, and the end point was the time of local recurrence (LR), distant metastasis (DM), and disease-specific mortality. Results Patients with cutaneous LMS had a slightly better LR-free survival, DM-free survival, and disease-specific survival than those with subcutaneous LMS (p = 0.745, p = 0.033, and p = 0.126, respectively). Patients with higher grade tumors had a significantly higher risk of DM and disease-specific mortality (Grade 3 vs Grade 1 p < 0.001, and Grade 3 vs Grade 1 p < 0.001, respectively). In addition, those with a microscopic positive margin had a significantly higher risk of LR and DM than those with a negative margin (p < 0.001, and p = 0.018, respectively). Patients who underwent simple tumorectomy had a slightly higher risk of LR than those who underwent high inguinal orchiectomy (p = 0.067). Subgroup analysis of cutaneous LMS demonstrated that the difference in LR between simple tumorectomy and high inguinal orchiectomy was limited (p = 0.212). On the other hand, subgroup analysis of subcutaneous LMS revealed a significant difference in LR (p = 0.039). Conclusions Our study demonstrated that subcutaneous LMS and high-grade tumors are prognostic factors for paratesticular LMS. For subcutaneous LMS, tumorectomy with high inguinal orchiectomy should be the optimal treatment strategy to achieve a negative surgical margin.