LAUSR

increase the detection of incidental (asymptomatic and/or small-sized) tumors. Related to this, we previously reported that the presence of symptoms at diagnosis was associated with a poor prognosis in patients with retroperitoneal liposarcoma. Given that increasingly more incidental cases might be diagnosed in the current clinical practice, the presence of symptoms at diagnosis could be an easily accessible, useful prognostic factor in patients with retroperitoneal liposarcoma. As mentioned in the present study, there is currently no other effective treatment than surgery for retroperitoneal sarcomas. Notably, the tyrosine kinase inhibitor, pazopanib, has been approved for soft tissue sarcomas worldwide. However, the current guideline does not recommend its use for liposarcoma, which is the most common (30–50%) histological subtype of retroperitoneal sarcoma, because it is less effective than other subtypes. Therefore, the development of effective treatment options for retroperitoneal sarcomas, especially for retroperitoneal liposarcoma, is urgently warranted. Finally, the limitations of the present study included its retrospective design and small number of patients, as the authors mentioned, although its sample size (167) was relatively large for the area in which the study was carried out. Additional studies with larger sample sizes and, if possible, a prospective study design are required to confirm the present results and accumulate clinical evidence of retroperitoneal tumors. Satoru Taguchi M.D. Department of Urology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan [email protected]