[Retroperitoneal soft tissue sarcoma: role of radiotherapy].

Background: Retroperitoneal soft tissue sarcomas (RPS) include tumors of mesenchymal origin with overall well-defined histological subtypes and heterogenic prognosis. For the first time with the publication of the STRASS study, which investigated the value of neoadjuvant radiotherapy in primary RPS, there is phase III evidence for the use of radiotherapy.

Objective: The primary objective of the present article is to present the role of neoadjuvant radiotherapy in RPS since the publication of the STRASS study.

Material and methods: We performed a non-systematic literature search. The results of retrospective and observational studies were compared to those of the STRASS study.

Results: In the two of the largest analyses, the surveillance, epidemiology, and end results program (SEER) and the American National Cancer Database (NCDB), an improvement in overall survival due to radiotherapy in RPS could be shown. In contrast to these results, there was no significant improvement in 3‑year abdominal recurrence-free survival in the STRASS study. There was solely a trend to improved abdominal recurrence-free survival in initially unplanned subgroup analyses for patients with liposarcoma as well as low-grade sarcoma but not for leiomyosarcoma or high-grade sarcoma.

Conclusion: Thanks to international collaboration an academic randomized trial was even feasible in such a rare disease as RPS. The results of the STRASS study have relativized the potential benefit of radiotherapy in RPS. A longer follow-up especially regarding the role of radiotherapy in liposarcomas is desirable.