Primary renal leiomyosarcoma in adult patients: a systematic review and individual patient data analysis

The optimal management of primary renal leiomyosarcomas is unknown owing to its rarity and minimal available information about their primary, adjuvant treatment and clinical outcomes. This study systematically reviews treatment evidence and effects in terms of survival for leiomyosarcomas arising primarily from kidney, renal pelvis and renal vessels. PubMed and Embase databases were searched from inception to March 2023, with manual searches of reference lists. Two investigators independently reviewed the studies reporting management and survival outcomes of renal leiomyosarcomas. A total of 85 publications met inclusion criteria, reporting on 188 cases. The median age was 55.5 years, predominantly female [52.7%]. Pain was the most common presenting symptom [41.5%], and most tumors were high grade [45.8%]. Complete surgical resection with negative margins forms definitive treatment. The median disease-free survival and overall survival (OS) for all reviewed patients were 24 months [95%CI 4.1–43.9] and 42 months [95%CI 32.5–51.4], respectively. The OS of 1 year, 2 year, 3 year and 5 year was 78.8%, 64.4%, 53.8% and 38.9%, respectively. On univariate analysis, favorable factors for OS included tumor size ≤ 5 cm, low-grade histology, tumors of renal vascular origin and non-metastatic disease at presentation. Neoadjuvant or adjuvant treatment with either radiotherapy or chemotherapy has been shown to improve OS (NR vs. 36 months, p < 0.001), especially for high-grade tumors > 5 cm in size. Radical nephrectomy with en bloc tumor resection with negative margins forms the mainstay of treatment for renal leiomyosarcomas. Adjuvant radiotherapy or chemotherapy appears to improve OS. To validate this treatment strategy, prospective multicentric efforts are required to acquire reliable data from randomized trials.